Latest / Daniel and Kelly’s Extraordinary Universe / How Many Babies Should You Have? (featuring Katie Goldin)

Transcript

How Many Babies Should You Have? (featuring Katie Goldin) · Daniel and Kelly’s Extraordinary Universe

0:05
Speaker 1: Daniel, did you want to ask an alien related question?
0:08
Speaker 1: Or are you good?
0:11
Speaker 2: Oh my gosh. The answer to that is always yes.
0:15
Speaker 3: Green is the answer green?
0:20
Speaker 2: Yeah, Katie. My question is what color are alien nipples?
0:23
Speaker 4: M you know what, I've always imagined them as lavender.
0:27
Speaker 4: Isn't that funny?
0:31
Speaker 2: Maybe they also taste like lavender?
0:32
Speaker 3: You hey, you know what.
0:34
Speaker 4: We're getting into some real strange territory here, right.
0:38
Speaker 2: That's a little taste of the conversation we have on
0:40
Speaker 2: today's episode. It's not about aliens, mostly though it is
0:44
Speaker 2: a little bit, And it's not about nipples mostly again,
0:47
Speaker 2: though it is a little bit. It's about babies. How
0:50
Speaker 2: many babies should you have? Some critters have lots of
0:53
Speaker 2: babies and hope a few survive. Others have just a
0:56
Speaker 2: few babies and take extra special care of them. What's
0:59
Speaker 2: the best strategy evolutionarily? Why do some critics choose one
1:03
Speaker 2: or the other? Does biology make any sense at all?
1:06
Speaker 2: Or does it just depend We'll dig into that on
1:09
Speaker 2: today's episode of Daniel and Kelly's Extraordinary Reproductive Universe.
1:13
Speaker 1: So on today's show, we're talking about the birds and
1:16
Speaker 1: the bees. So decide ahead of time if you think
1:19
Speaker 1: that's an appropriate topic for your children. Thanks for listening.
1:36
Speaker 2: Hi. I'm Daniel. I'm a particle physicist, and I have
1:39
Speaker 2: two kids so that neither of them have to be
1:41
Speaker 2: the middle child.
1:42
Speaker 1: Yeah. Hi, I'm Kelly wider Smith. I am a parasitologist.
1:47
Speaker 1: I have two kids because that's all I could handle.
1:52
Speaker 4: I'm Katie Golden. I host a podcast called Creature Feature.
1:56
Speaker 4: I have a dog so that she doesn't have to
1:58
Speaker 4: be a middle child.
2:04
Speaker 1: Katie, it's so great to have you on the show.
2:06
Speaker 3: Yeah, I'm so excited to be here.
2:07
Speaker 4: I too love parasites, by the way, so we've got
2:11
Speaker 4: that in common.
2:12
Speaker 1: I mean, that's the most important thing to have in common,
2:14
Speaker 1: I think.
2:14
Speaker 4: Yeah, that was what got me so into biology. Is
2:17
Speaker 4: a class I took. The official title of the class
2:20
Speaker 4: was like about mimicry, but the professor who ran the
2:25
Speaker 4: class was like so interested in parasites.
2:27
Speaker 3: That was basically all we talked about.
2:29
Speaker 4: And it's like he made the right call because that
2:32
Speaker 4: was super interesting, and it's like I love hearing about
2:35
Speaker 4: all these weird little freaks, and I gotta know more.
2:37
Speaker 2: What if it was a parasite that affected the host
2:40
Speaker 2: and made them interested in studying parasites.
2:43
Speaker 3: I'm probably chock full of that.
2:48
Speaker 1: Carl Zimmer's book Parasite Rex like changed my life. Yeah,
2:51
Speaker 1: it was going to be a parasitologist after reading.
2:53
Speaker 4: That, seeing the little isopod that's the parasite for fish,
2:57
Speaker 4: just like peeking out from a fishmouth, going like, hey
3:00
Speaker 4: U that altered my brain chemistry forever.
3:02
Speaker 1: It's pretty awesome. So I was talking to my friend
3:04
Speaker 1: Stacy Farina the other day and so the story with
3:06
Speaker 1: that isopod goes that it like eats the fish's tongue
3:09
Speaker 1: and replaces the tongue, and she studies fish like skeletal stuff,
3:14
Speaker 1: and she was like, you know, I've looked at a
3:16
Speaker 1: bunch of them and the tongue is still there. Guys, Yeah,
3:18
Speaker 1: what So I think they're actually just like clinging to
3:21
Speaker 1: the tongue and they're eating stuff, but they haven't really
3:24
Speaker 1: eaten the tongue, which I think is part of like
3:26
Speaker 1: what the pop side.
3:27
Speaker 4: Well, it's yeah, it's like the idea that they're now
3:30
Speaker 4: acting as the tongue. I thought they fed off of
3:33
Speaker 4: the blood supply, so they may cause some atrophying of
3:36
Speaker 4: the tongue, but it's not so much that they eat
3:37
Speaker 4: the whole tongue and then replace it. It's that they're
3:40
Speaker 4: stealing nutrients from the fish, and then when they leave
3:44
Speaker 4: the fish, usually the fish doesn't survive because it's basically
3:49
Speaker 4: mangled its tongue to the point where it can't use
3:51
Speaker 4: it as much anymore. That's my understanding. But also I
3:54
Speaker 4: think we have a fairly poor understanding of them because
3:57
Speaker 4: it's not every day that you find these little guy
4:00
Speaker 4: because you'd have to just like open up a bunch
4:02
Speaker 4: of fish mouths of like, let me see inside your
4:04
Speaker 4: mouth what you got in there?
4:06
Speaker 1: You know all the best stories, Katie, I look in
4:09
Speaker 1: a lot of fish mouths.
4:11
Speaker 2: And that's why we invited Katie on the podcast today
4:13
Speaker 2: to talk to us about babies.
4:16
Speaker 4: Yes, which hard to segue from fish mouths to babies.
4:23
Speaker 2: It's really hard to keep you guys on track. But
4:25
Speaker 2: I'm doing my best here.
4:29
Speaker 1: Well, I mean, what if we get the chance to
4:31
Speaker 1: talk about parasites, we will, But pulling back. So the
4:33
Speaker 1: reason we're talking about babies today is because we had
4:36
Speaker 1: a question from a listener, Nathan Ryan. He wanted to
4:39
Speaker 1: know about the benefits of having lots of babies relative
4:42
Speaker 1: to the benefits of just having a few, and so
4:44
Speaker 1: he was like, why would you ever have just a
4:46
Speaker 1: few when you could just flood the environment with babies?
4:50
Speaker 1: And ecological theory has a lot of ideas about that,
4:54
Speaker 1: and so I thought today we would talk about how
4:56
Speaker 1: many babies should you have?
4:58
Speaker 2: Thank you, Kelly for taking us back on on track
5:00
Speaker 2: and away from parasites, as difficult as that is for you.
5:03
Speaker 2: I love this question because in his email he specifically
5:06
Speaker 2: mentions the two kinds of strategies are strategy and case strategy,
5:11
Speaker 2: which describe having lots or few babies. That's really cool
5:14
Speaker 2: because I'm excited whenever I see a theory in biology.
5:18
Speaker 2: What it's not just descriptive like naming the parts of
5:21
Speaker 2: the flower, but building a mathematical model to understand the
5:24
Speaker 2: dynamics and how it all works. See, even underneath biology
5:28
Speaker 2: there has to be math. So we're going to dig
5:30
Speaker 2: into this question by walking through a bunch of examples
5:32
Speaker 2: of extremes lots of babies, few babies, and then thinking
5:36
Speaker 2: about whether the current theory about our in case strategists
5:39
Speaker 2: is actually working or not.
5:41
Speaker 4: This is such a good question in both personal lives
5:45
Speaker 4: and in olationary biology.
5:47
Speaker 2: Do you think Nathan is considering whether to have like
5:49
Speaker 2: two or like fifty kids.
5:53
Speaker 1: You better be considering whether he wants two or fifty wives.
5:56
Speaker 1: If he's going to have that many kids. That's a
5:58
Speaker 1: complicated question.
5:59
Speaker 2: Well he could be you never know, right.
6:01
Speaker 1: Right, Yeah, No, that's a good point.
6:03
Speaker 2: What do you think is the maximum number of kids
6:05
Speaker 2: any individual human has ever had?
6:07
Speaker 3: Mm?
6:08
Speaker 2: Genghis Khan.
6:09
Speaker 4: You know, I wouldn't be surprised if some of those
6:11
Speaker 4: warlords just like did get around enough to have like
6:15
Speaker 4: one hundred kids, not by one person.
6:18
Speaker 3: That would be not possible, right, We all have limits,
6:22
Speaker 3: you know.
6:22
Speaker 4: I think a lot of that though, is probably them
6:24
Speaker 4: thinking they have one hundred kids, or it's like those
6:27
Speaker 4: are my kids too? And got news for you, buddy,
6:30
Speaker 4: Probably not.
6:31
Speaker 1: You don't always know. That's one of the benefits of
6:33
Speaker 1: being the woman.
6:34
Speaker 3: You can be sure usually in most circumstances.
6:38
Speaker 2: Yes, I remember reading that there was a woman in
6:41
Speaker 2: the seventeen hundreds who gave birth to sixty nine children.
6:44
Speaker 3: How would that even work?
6:46
Speaker 2: Because it's sixteen pairs of twins, seven sets of triplets,
6:49
Speaker 2: and four sets of.
6:50
Speaker 3: Quadruplets and she lived through all of it.
6:53
Speaker 2: Yeah, And sixty seven of the sixty nine survived. But
6:57
Speaker 2: this is from the seventeen hundreds, and it's sort of
6:59
Speaker 2: like story and not like, yeah, well documented.
7:02
Speaker 1: Yeah, that would be intense.
7:04
Speaker 4: I have a hard time believing that, maybe just because
7:06
Speaker 4: I simply don't want to believe it like that.
7:12
Speaker 1: It boggles the mind, it does. Yeah, yeah, I don't
7:15
Speaker 1: think I want to believe it either. But let's jump
7:17
Speaker 1: into the main episode then. So we thought that first,
7:20
Speaker 1: if you're thinking about how many babies you should have,
7:23
Speaker 1: then you should think about how much energy it's going
7:26
Speaker 1: to take for each one of those babies from you.
7:28
Speaker 1: So how much energy is it going to take to
7:30
Speaker 1: protect and provision the young? And actually, we're not really
7:34
Speaker 1: talking about humans at all today. We're talking about non
7:36
Speaker 1: human animals. And so let's take a little walk through
7:40
Speaker 1: who does the care in different animals And so I'll
7:42
Speaker 1: start with fish. Actually, and fish, the males do a
7:46
Speaker 1: lot of the care. And you know, this is possible
7:48
Speaker 1: because most of the time eggs are put out into
7:51
Speaker 1: the environment and fertilization happens externally, and so you know,
7:54
Speaker 1: either one of them could be the one who splits.
7:57
Speaker 1: But for whatever reason, it's been the males who tend
7:59
Speaker 1: to so, for example small mouth bass and large mouth bass.
8:03
Speaker 1: The males will sort of use their fins to clear
8:05
Speaker 1: out an area, like a little depression where a nest
8:08
Speaker 1: will be, and then a female comes by, and if
8:10
Speaker 1: she decides the male sexy enough, she'll deposit some eggs,
8:13
Speaker 1: and then the male will deposit his sperm, and then
8:16
Speaker 1: it's his job to stay there and use his fins
8:19
Speaker 1: to aerate the eggs and make sure there's fresh water
8:22
Speaker 1: passing over them that through diffusion can like get into
8:25
Speaker 1: the eggs to keep those guys alive, and then also
8:27
Speaker 1: make sure that no predators eat those eggs, because they're
8:30
Speaker 1: amazing little balls of energy that would be great for
8:33
Speaker 1: like little minnows or crayfish. And so he's got to
8:36
Speaker 1: like defend the nest.
8:37
Speaker 2: Tasty little omelet of babies right there.
8:40
Speaker 1: That's right, that's right, pre made, and so I think
8:43
Speaker 1: it's pretty energetically expensive. They don't tend to eat, well,
8:46
Speaker 1: this is happening, and it's sort of not clear why,
8:48
Speaker 1: but maybe it's because they can't control themselves and they
8:51
Speaker 1: might eat the eggs. So anyway, they tend to not eat.
8:54
Speaker 1: It's a lot of work, but the males are doing
8:55
Speaker 1: most of the care, and so the eggs hatch, they
8:57
Speaker 1: swim up, and when they swim away, the male's job
8:59
Speaker 1: for the most part is done. He stays with them
9:01
Speaker 1: for a little while, but then they go off on
9:03
Speaker 1: their own. That's quite different than what happens with birds,
9:06
Speaker 1: right Katie.
9:07
Speaker 4: Yeah, I mean birds have a lot of different strategies.
9:09
Speaker 4: You have a lot of bird species where it's the
9:13
Speaker 4: female taking care of the offspring because she lays the eggs,
9:16
Speaker 4: and she of course has to keep the eggs warm
9:19
Speaker 4: under her body, so she stays with the nest. But
9:20
Speaker 4: you also have a lot of species of birds who
9:23
Speaker 4: work together, so you have a pair of parents, particularly
9:27
Speaker 4: in harsher environments, so sea birds in particular penguins obviously
9:32
Speaker 4: in their very harsh Antarctic environments. There are other species
9:37
Speaker 4: of penguins that live in warmer environments, but an amazing
9:41
Speaker 4: example is great hornbills. So they are a species of
9:45
Speaker 4: bird that go to extreme lengths to protect their eggs.
9:48
Speaker 4: The males actually will seal the females into a hollow
9:52
Speaker 4: inside a tree using his own feces, in her feces
9:56
Speaker 4: in a bit of mud to create sort of a
9:58
Speaker 4: plaster beautiful oh biology. Yeah, and then they leave a
10:02
Speaker 4: tiny hole and the male will go out and very
10:06
Speaker 4: devotedly bring back food for the female and then for
10:10
Speaker 4: the chicks once they hatch. And the reason that there's
10:14
Speaker 4: so much care in these situations of both parents working
10:17
Speaker 4: together is environmental stressors. So for the hornbills, it's in
10:22
Speaker 4: the places that they live in Southeast Asia. In these forests,
10:25
Speaker 4: there's a ton of predatory snakes who eat eggs, eat chicks,
10:29
Speaker 4: so so many arboreal snakes that creating sort of a
10:33
Speaker 4: sealed off, you know, bunker for the female and the
10:38
Speaker 4: eggs is really important. For seabirds, the there's a lot
10:41
Speaker 4: of kleptive parasites. Those are other birds that want to
10:44
Speaker 4: steal resources, including eggs, including eating chicks. It's just a
10:48
Speaker 4: very very harsh environment, particularly the ones that live in
10:51
Speaker 4: cold environments. So and also finding food is difficult. They
10:55
Speaker 4: have to leave the colony, go out to sea, go fishing,
10:57
Speaker 4: and so both parents need to kind of like switch
11:00
Speaker 4: off and alternate in terms of like taking care of.
11:03
Speaker 3: The egg, taking care of the chicks. If they didn't.
11:05
Speaker 4: Both put all of their effort into it, most likely
11:08
Speaker 4: their chicks wouldn't survive. And also just an interesting note.
11:12
Speaker 4: In species of birds where they're both working together as
11:15
Speaker 4: a pair, usually there's not as much sexual dimorphism, meaning
11:19
Speaker 4: like both of the male and the female look very similar. Also,
11:25
Speaker 4: when they're mating, both of them will often do some
11:28
Speaker 4: kind of mating display and try to impress the other
11:32
Speaker 4: mate equally because they're both putting in so much effort
11:35
Speaker 4: into the offspring, they're both equally trying to assess whether
11:40
Speaker 4: their mate is going to be good wears. In a
11:41
Speaker 4: lot of other species, where the female is the one
11:44
Speaker 4: doing most of the child rearing, it's the male that's
11:47
Speaker 4: trying to impress her because she's the one putting all
11:51
Speaker 4: of this investment into the offspring, Whereas the male is
11:54
Speaker 4: just kind of like going around sewing as wild out,
11:57
Speaker 4: so for him, he doesn't need to be as cheesy,
11:59
Speaker 4: where as the female needs to be really cheesy.
12:01
Speaker 2: So in this scenario where the female gets sealed in
12:04
Speaker 2: with the eggs and cares for them, do you think
12:06
Speaker 2: she's like into that or is she like tracked in
12:09
Speaker 2: like a slave in his like weird poo palace that
12:12
Speaker 2: he builds for her.
12:13
Speaker 3: She's into it.
12:14
Speaker 4: She can actually kind of kool aid man break out
12:16
Speaker 4: anytime she wants, but she's in there, and as long
12:20
Speaker 4: as the male comes and like feeds her, she will
12:22
Speaker 4: stay there with the eggs take care of them. If
12:25
Speaker 4: the male stops feeding her, I think she will break
12:28
Speaker 4: out and leave the eggs. And so there's a mutually
12:32
Speaker 4: bit official investment there, like the male coming back to
12:35
Speaker 4: feed her. Usually the male would only not come back
12:38
Speaker 4: if he came to some devastating ends. So the female
12:42
Speaker 4: completely cooperates and that she actually helps build the wall
12:45
Speaker 4: as well. So it's not like not a casko of
12:48
Speaker 4: a mantiato, but with porn bills.
12:52
Speaker 2: How would you have felt, Kelly, if you've been sealed
12:54
Speaker 2: into a room with your babies by your husband's poop.
12:57
Speaker 1: I mean, our house is pretty messy when we first
13:00
Speaker 1: had our kids. I don't know how different that was,
13:04
Speaker 1: and the diapers were piling up. I guess it wasn't
13:06
Speaker 1: zac species, It's right. I think I would have left,
13:10
Speaker 1: even with young people in the houses.
13:12
Speaker 4: But he's getting you uber eats like all the time,
13:15
Speaker 4: so that's an important aspect of it.
13:18
Speaker 2: But so the big picture here is that we're seeing
13:20
Speaker 2: lots of different kinds of scenarios, different strategies in different scenarios,
13:24
Speaker 2: and so the idea is that they're responding to the
13:26
Speaker 2: different situations they're in by developing these different strategies.
13:30
Speaker 3: That's right.
13:31
Speaker 4: Also when you have major differences among different types of animals,
13:36
Speaker 4: so like, for instance, mammals, usually it's the female doing
13:40
Speaker 4: most of the caring for young and a big reason
13:44
Speaker 4: for that is lactation. So like mammals, mammary glands, mammals
13:49
Speaker 4: have this ability to lactate and feed their offspring and
13:53
Speaker 4: this is how they care for very young babies and
13:56
Speaker 4: so usually not always, this means that the female is
13:59
Speaker 4: the one doing the primary caregiving for the offspring. You
14:03
Speaker 4: do see this, of course in other types of animals,
14:06
Speaker 4: so like there's a type of limbless worm like amphibian
14:09
Speaker 4: called the sicilian, which actually has something akin to malk
14:14
Speaker 4: Some species have this like viscous fluid that it produces
14:17
Speaker 4: from its kloeca that the offspring feed from. Like some
14:21
Speaker 4: species they actually allow their offspring to sort of chew
14:24
Speaker 4: on some like thick nutritional skin that they have a
14:27
Speaker 4: little excess mom jerky. And in these situations, the mom
14:31
Speaker 4: actually offers parental care to the offspring. But also in mammals,
14:37
Speaker 4: another exception is that there's a lot of very social
14:40
Speaker 4: species of animals where there's both male and female parenting.
14:43
Speaker 4: I mean humans is an example. There's also alloparenting, which
14:47
Speaker 4: is when either loosely related or non related individuals take
14:51
Speaker 4: care of the offspring that is not directly theirs. That's
14:56
Speaker 4: like common in a lot of different mammalian species, and
15:00
Speaker 4: that culminates into a version of mammals that actually becomes
15:04
Speaker 4: somewhat more insect like like naked mole rats who have
15:07
Speaker 4: a use social system where they have a queen who reproduces,
15:12
Speaker 4: and everyone else is basically facilitating the queen's reproduction. So
15:16
Speaker 4: that's like an extreme example of mammals going more towards
15:20
Speaker 4: like a b ant colony type model.
15:22
Speaker 2: I've heard this story. I think it may be apocryphal,
15:25
Speaker 2: and I want to ask you that in humans, it's possible,
15:28
Speaker 2: though difficult, for males to lactate given the right circumstances.
15:33
Speaker 2: Is that true or not?
15:34
Speaker 3: It's true.
15:35
Speaker 4: It's basically like hormones will determine lactation, So if some
15:40
Speaker 4: men naturally will produce, some hormones that may actually cause
15:45
Speaker 4: them to do a little bit of lactation. And actually,
15:47
Speaker 4: if someone takes hormones, you can induce lactation, and so
15:53
Speaker 4: you know, yeah, I mean honestly, like the differences between say,
15:57
Speaker 4: like male and female phenotypes in humans is so guided
16:01
Speaker 4: by hormones that when those are either you know, you
16:06
Speaker 4: have atypical levels of them, or you introduce synthetic hormones,
16:10
Speaker 4: so you can completely alter the phenotypic representation that includes
16:14
Speaker 4: functions like lactation.
16:16
Speaker 2: Does that mean that males have mammary glands they're just.
16:19
Speaker 4: Not active, yes, yes, essentially, yeah, mind blown.
16:23
Speaker 3: Yeah, you've got nipples.
16:25
Speaker 2: You've got I was aware of the nipples. Thank you.
16:30
Speaker 3: Just making sure.
16:31
Speaker 2: Let's give Daniel a tour here.
16:35
Speaker 3: Of these things.
16:36
Speaker 4: Just call them my chest buttons. Yeah, the memory glands
16:39
Speaker 4: and then are very underdeveloped. But there are like cases
16:43
Speaker 4: with like genetic differences where some men will have larger
16:47
Speaker 4: breasts and larger memory glands and some men can lactate,
16:51
Speaker 4: and yeah, that can totally happen, but you know it's
16:54
Speaker 4: not necessarily going to be enough maybe to feed a baby.
16:58
Speaker 4: But hey, you know what, get whatever help you can
17:01
Speaker 4: is what I say, every drop probably counts.
17:04
Speaker 2: No, try, gentlemen out there. She's not the only one
17:06
Speaker 2: who has to wake up in the middle of the
17:08
Speaker 2: night to feed the baby.
17:11
Speaker 1: Yes, that's right. Humping is a great technology. Yes, so
17:15
Speaker 1: when birds they make that like crop milk, do the
17:18
Speaker 1: males do that? Tours, that's something that just the females do.
17:20
Speaker 4: Males can also make crop milk. I think it depends
17:23
Speaker 4: on the species, but yes, you do have a mutual
17:25
Speaker 4: ability a lot of species to make crop milk that
17:28
Speaker 4: is not necessarily tied to you know, just the females,
17:31
Speaker 4: but some animals do, like the sicilian that I mentioned,
17:36
Speaker 4: like that can be just the female. And probably the
17:39
Speaker 4: explanation for that is in a lot of species, basically,
17:44
Speaker 4: unless you're an asexually producing animal, it's the female who's
17:48
Speaker 4: going to be giving birth to the offspring. Or unless
17:51
Speaker 4: you are a sea horse, in which case there's like
17:54
Speaker 4: basically two birds right where the female lays the eggs
17:58
Speaker 4: and does develop inside the males and then he gives
18:01
Speaker 4: birth to the live offspring. So the reason that you
18:05
Speaker 4: will often have cases where once an animal develops sort
18:08
Speaker 4: of a tool for offering nutritional aid to their offspring
18:13
Speaker 4: that it will be female is because usually it's the
18:16
Speaker 4: female who gives birth to the offspring.
18:19
Speaker 1: Now, insects are heroes of mine because they don't do
18:21
Speaker 1: a lot of parental care. Now, Katy, can you tell
18:24
Speaker 1: us about those?
18:25
Speaker 4: So later we're going to talk a little bit about
18:28
Speaker 4: R and K selection and just very briefly, our selection
18:31
Speaker 4: being you have a ton of offspring, you know, a
18:35
Speaker 4: bunch of cheaply made offspring, and K selection being you
18:38
Speaker 4: have maybe one or two really high quality offspring. It's
18:43
Speaker 4: very much an over generalization, but we'll get into the
18:46
Speaker 4: details later, but insects are sort of like the absolute
18:50
Speaker 4: champions of our selection, popping out enormous numbers of babies
18:55
Speaker 4: and just highly expendable babies.
18:59
Speaker 2: Either love them or you have lots of them, right,
19:01
Speaker 2: these are the two options.
19:03
Speaker 4: Well, essentially, it's a little more complicated than that, but yes,
19:07
Speaker 4: that is like sort of the basic idea behind it,
19:11
Speaker 4: and parental care is really rare in both insects and arthropods.
19:15
Speaker 4: So there are some notable exceptions such as like, usually
19:21
Speaker 4: it's the female again for the reason that I said,
19:23
Speaker 4: which is the female that lays eggs or gives birth
19:26
Speaker 4: to offspring, so scorpions will carry their young on their back.
19:30
Speaker 4: Centipedes will kind of curl up in this cute little
19:33
Speaker 4: nest like cradle for her offspring, which it's very adorable.
19:37
Speaker 4: There are even types of spiders like the desert spider
19:40
Speaker 4: who basically once she lays her eggs, she starts to
19:45
Speaker 4: digest her own insides and then will regurgitate her own
19:50
Speaker 4: juices for her offspring to feed on. And she does
19:53
Speaker 4: not survive this process. She turns herself into like a
19:56
Speaker 4: mom smoothie and then.
19:58
Speaker 3: Allows her offspring to eat her.
20:00
Speaker 4: It's called matrophagi eating one's mother, and the babies will
20:04
Speaker 4: eat like ninety five percent of her biomouse.
20:06
Speaker 1: You know, it's not cool. There's no petrophage or why
20:09
Speaker 1: are there no dad's getting.
20:10
Speaker 4: Eat there's probably some dads getting eaten, but yeah. The
20:14
Speaker 4: reason that it's usually matrophagi is because of the fact
20:18
Speaker 4: that usually it's the mother that gives birth or lays
20:21
Speaker 4: the eggs.
20:22
Speaker 3: But there are some very rare.
20:24
Speaker 4: Examples of both the mother and the father and insects
20:28
Speaker 4: taking care of their offspring. The only example I can
20:30
Speaker 4: think of there may be more, but this one is
20:33
Speaker 4: also really cool is burying beetles. So these are beetles
20:36
Speaker 4: that will find the carcass of some small animal and
20:39
Speaker 4: then we'll bury it. And the reason they do this
20:43
Speaker 4: is so that they can lay their eggs on a
20:46
Speaker 4: source of food, so they bury it to keep it
20:49
Speaker 4: away from other competitors, and then they lay their offspring
20:52
Speaker 4: in this sort of like little den of rotting meat.
20:57
Speaker 4: And then they actually will stay. Both the mother and
20:59
Speaker 4: the father bearing beetle will stay and protect their offspring,
21:03
Speaker 4: so they'll maintain the larder, make sure they have plenty
21:05
Speaker 4: to eat, and then they'll fight off competition and predators
21:09
Speaker 4: until the larva pupate into their more adult forms.
21:13
Speaker 3: So that's super rare.
21:15
Speaker 4: It just doesn't happen very frequently in insects or in
21:18
Speaker 4: arthropods because their usual techniques just have a huge amount
21:21
Speaker 4: of offspring, and statistically a lot of them are gonna
21:25
Speaker 4: make it.
21:26
Speaker 1: So I think any of the moms or dads out
21:27
Speaker 1: there are probably feeling a little bit better about what
21:30
Speaker 1: we went through when our kids were young right now
21:32
Speaker 1: after hearing about the insect examples. But let's go ahead
21:35
Speaker 1: and take a break, and when we get back we'll
21:37
Speaker 1: talk a bit more. About the costs associated with having babies,
21:56
Speaker 1: and we're back. So we've gone through and we've talked
21:58
Speaker 1: about the different in ways that the responsibility of taking
22:02
Speaker 1: care of the kids tends to be divided up in
22:04
Speaker 1: the animal kingdom. So now we're going to dig into
22:06
Speaker 1: some examples of it being costly to have offspring. And
22:09
Speaker 1: I think for most of us who have had kids
22:10
Speaker 1: were like, yes, of course it's costly to have offspring.
22:13
Speaker 1: Like a bunch of us moms lost weight while we
22:16
Speaker 1: were breastfeeding because it's calorically expensive and you're not sleeping,
22:19
Speaker 1: and you know it's obviously costly. But that's true for animals,
22:23
Speaker 1: not just humans. And there are some really nice examples
22:26
Speaker 1: of this. So, for example, David Lack did this long
22:29
Speaker 1: term study of these birds called great tits Paris major
22:33
Speaker 1: and confession, I didn't realize this was a bird species
22:36
Speaker 1: the first time I heard about these and a person
22:39
Speaker 1: who ended up being my PhD advisor started talking to
22:42
Speaker 1: me about great tits and I just had a like
22:44
Speaker 1: deer in the headlights moment, and it took me a second.
22:46
Speaker 1: He said something about eggs and I was like, ah,
22:49
Speaker 1: I think we're talking about birds or fish. And eventually.
22:54
Speaker 4: The first time I heard about great tits was when
22:56
Speaker 4: I was on a bird watching expedition with the bunch
23:00
Speaker 4: of senior citizens when I was in high school, and
23:03
Speaker 4: this sweet little old lady leaned over to me and says,
23:06
Speaker 4: now you have younger ears, so see if you can
23:08
Speaker 4: hear some great tits.
23:12
Speaker 1: That doesn't make any sense to.
23:13
Speaker 2: Place sound life, Yeah.
23:15
Speaker 4: Yeah, keep your eyes peeled for great tits. Just coming
23:18
Speaker 4: from this octagenarian. It was a wonderful moment.
23:22
Speaker 2: She's probably seen a lot, she knows right, it's.
23:24
Speaker 3: Nothing you ain't seen before.
23:27
Speaker 1: Maybe we should put a little warning at the top
23:29
Speaker 1: of this episode.
23:31
Speaker 2: But more broadly, like, we're hearing these examples about like
23:34
Speaker 2: different strategies, males taking care of the babies, females taking
23:37
Speaker 2: care of the babies. What do we learn sort of
23:40
Speaker 2: broadly from these examples, Like are there obvious trends here
23:43
Speaker 2: where people respond in certain ways to certain circumstances or
23:46
Speaker 2: is it just like a scattering of examples And the
23:48
Speaker 2: answer is it all depends.
23:50
Speaker 4: There are patterns, for sure. There have been attempts to
23:53
Speaker 4: kind of put the patterns into much more simple mathematical equations,
23:58
Speaker 4: which sometimes work but then sometimes they fail. But in
24:02
Speaker 4: general there are patterns. But because there are so many
24:06
Speaker 4: essentially factors that are a component in these evolutionary quote
24:12
Speaker 4: unquote choices, it can be difficult to see the pattern
24:16
Speaker 4: from the noise, but they do exist, and there have
24:18
Speaker 4: been some like observable patterns that have been found that
24:22
Speaker 4: can kind of help sway the decision in terms of
24:24
Speaker 4: like what type of offspring strategy species end up falling into, right, Kelly.
24:32
Speaker 1: Yeah, so we are essentially making the argument that it
24:35
Speaker 1: depends today, which Daniel will not be surprised to hear.
24:38
Speaker 1: So I found this quote from a textbook that I
24:40
Speaker 1: used in grad school, and it's the evolution of care
24:42
Speaker 1: behavior is complex, and we are still far from fully
24:45
Speaker 1: understanding which factors really influence the evolution of care in
24:48
Speaker 1: both males and females. Models are arguments like the ones
24:52
Speaker 1: presented above in this textbook may also prove too simple
24:55
Speaker 1: because they generally consider just a few factors at a time.
24:58
Speaker 1: So we're talking today some of the different solutions that
25:01
Speaker 1: evolution has landed on and some of the different factors
25:05
Speaker 1: that influence the decisions that end up getting made over
25:07
Speaker 1: evolutionary time. But it really does depend Life.
25:11
Speaker 2: Is messy and lots of factors must come into play,
25:13
Speaker 2: predation and environment and variability and all sorts of crazy stuff.
25:18
Speaker 2: It'd be amazing if you could boil it down to
25:20
Speaker 2: just a few variables like you can in physics. I
25:22
Speaker 2: don't know why physics ever works, frankly.
25:25
Speaker 1: So yeah, we're going to talk about a lot of variability,
25:29
Speaker 1: and then we're going to narrow down a little bit
25:31
Speaker 1: on one attempt to sort of summarize what we see
25:34
Speaker 1: and why we see it. And then we're going to
25:36
Speaker 1: talk about how that sort of way of summarizing things
25:39
Speaker 1: fell apart, and how now we're back to trying to
25:41
Speaker 1: find more complicated models that include more variable.
25:43
Speaker 2: All right, now I'm ready to talk about great tits.
25:47
Speaker 1: That's great.
25:48
Speaker 4: It's always good to get into the math before we
25:50
Speaker 4: start talking about great that's right.
25:52
Speaker 1: That's right. That's how most of these conversations work out.
25:55
Speaker 1: So there's this researcher in England. Great tits are these
25:58
Speaker 1: tiny little birds, and there's this population that's been monitored
26:01
Speaker 1: for decades and all of the birds, or as many
26:04
Speaker 1: as possible, are caught every year they're banded. And then
26:06
Speaker 1: you look to see who's coming back year after year.
26:09
Speaker 1: These birds tend to lay one set at one clutch
26:12
Speaker 1: of eggs once a year, and the army of graduate
26:16
Speaker 1: students who were working on this for decades would go
26:18
Speaker 1: out and they would count how many eggs. They would
26:20
Speaker 1: weigh the birds soon after they hatched, and then they'd
26:23
Speaker 1: measure survival by determining who came back. And they were
26:27
Speaker 1: looking at a large enough area that I think they
26:29
Speaker 1: decided that, you know, the birds who flew to join
26:31
Speaker 1: a different population. That was a negligible number of birds,
26:34
Speaker 1: so they pretty much were keeping track of everybody. And
26:37
Speaker 1: they noticed that these birds usually lay eight or nine eggs,
26:41
Speaker 1: and that the more eggs there were in a nest,
26:44
Speaker 1: the smaller the offspring would be. And you could test
26:48
Speaker 1: this by moving eggs between nests and looking to see
26:51
Speaker 1: if you like, make the parents feed more offspring, What
26:54
Speaker 1: does that do to the size of the birds and
26:57
Speaker 1: the parents are out from like dusk to dawn, gone
27:00
Speaker 1: to dusk, that would be it from done to dusk.
27:02
Speaker 3: Trying depending on how you look at it.
27:04
Speaker 2: Yeah, they depends whether drinking, yeah.
27:08
Speaker 1: Right, drinking caterpillar juice or something yummy. And they found
27:15
Speaker 1: that the more birds they had to feed, the smaller
27:17
Speaker 1: the birds were, and then if you look at those
27:19
Speaker 1: small birds, they're less likely to survive and show up
27:22
Speaker 1: again in the population as adults. So if you have
27:25
Speaker 1: too many babies, those babies don't seem to make it,
27:27
Speaker 1: and you've expended all of that energy for nothing. But
27:31
Speaker 1: they did some like mathematical modeling and moving some eggs around,
27:34
Speaker 1: and they ended up deciding like, okay, but it looks
27:37
Speaker 1: like the birds are producing fewer eggs than we think
27:40
Speaker 1: that they could be producing optimally every year that they
27:42
Speaker 1: could feed enough and enough of them could come back
27:45
Speaker 1: in the future. Why aren't they making more eggs? And
27:48
Speaker 1: the idea here was that you're not just trying to
27:50
Speaker 1: maximize the number of eggs that you're producing in one year.
27:53
Speaker 1: You're thinking about your lifetime reproductive success. So if you
27:56
Speaker 1: go all out and you raise as many eggs this
27:58
Speaker 1: year as you can, probably gonna exhaust yourself and not
28:01
Speaker 1: be able to survive until the next year so that
28:03
Speaker 1: you can have more offspring. And to be honest, because
28:06
Speaker 1: ecology is complicated, as far as I know, they didn't
28:09
Speaker 1: find good evidence for that in this system, but they
28:12
Speaker 1: have found evidence for that in other systems, so like
28:15
Speaker 1: in European kestrels, so these are birds that are predators
28:18
Speaker 1: and they pick off little mammals. They found that if
28:21
Speaker 1: you put extra eggs in a nest and like those
28:24
Speaker 1: adults had to feed more babies, the babies were less
28:27
Speaker 1: likely to survive to adults, and the adults who had
28:30
Speaker 1: more babies in their nest were less likely to show
28:32
Speaker 1: up the next year, so they were less likely to
28:34
Speaker 1: survive the winter.
28:35
Speaker 4: It just sounds though, like they instead of like showing up.
28:38
Speaker 4: I know what you mean is their survival rates, but
28:40
Speaker 4: it does kind of sound like when you gave them
28:42
Speaker 4: too many kids.
28:42
Speaker 3: They're like, that's it. I'm out, I'm leaving done.
28:45
Speaker 1: That's right, I'm gonna go become a dancer. I'm done.
28:48
Speaker 1: But you know this is ecology, right, So the answer
28:51
Speaker 1: has to be it depends. And even though you feel
28:53
Speaker 1: like you have a nice model, nice theory for understanding
28:56
Speaker 1: how this stuff works, if you look in a different system,
28:58
Speaker 1: you don't always find support. So David Resnick studies guppies.
29:01
Speaker 1: These are these tiny little fish that you find in Trinidad,
29:04
Speaker 1: and he took them into I think this was a
29:06
Speaker 1: lab study, and he compared the females who were paired
29:10
Speaker 1: with a male and could mate to females who didn't
29:12
Speaker 1: have a male. And the idea was supposed to be
29:14
Speaker 1: that the females who had to produce young would end
29:18
Speaker 1: up weighing less because it's energetically expensive than the females
29:21
Speaker 1: who didn't have to produce young. But they didn't find
29:24
Speaker 1: that the females who had to produce babies just ate more.
29:27
Speaker 1: That's what I did for sure, and so they ended
29:31
Speaker 1: up being in just as good shape. And so you know,
29:34
Speaker 1: this kind of stuff can depend on like how many
29:36
Speaker 1: resources are available in the environment. Like if you're feeding
29:39
Speaker 1: baby chicks, but it's a year where there's just loads
29:42
Speaker 1: of insects, maybe it's one of those years where the
29:44
Speaker 1: cicadas come out of the ground and there's just food everywhere,
29:48
Speaker 1: then you know you don't have as many trade offs.
29:50
Speaker 2: So if you can just sit on the couch and
29:51
Speaker 2: eat Ben and Jerry's, then you should have lots of kids.
29:54
Speaker 1: And so they quote from earlier is about how there's
29:57
Speaker 1: lots of other factors to consider.
30:00
Speaker 2: Flavors of Ben and Jerry's are available. This kind of stuff.
30:03
Speaker 4: People often ask like can I feed, say, wild birds,
30:07
Speaker 4: and the answers It depends again because one of the
30:11
Speaker 4: problems if you feed wild birds too much, you actually
30:14
Speaker 4: give them a false sense of security in terms of like, oh,
30:17
Speaker 4: there's a lot of plenty, I can have a lot
30:19
Speaker 4: of babies, and then they end up having more babies earlier,
30:24
Speaker 4: and then they might miss key points in terms of
30:27
Speaker 4: like some species maybe time their offspring to the emergence
30:32
Speaker 4: of certain insects, right, like they follow the breeding cycle
30:35
Speaker 4: of caterpillars or other insects, and then they may if
30:39
Speaker 4: you give them too many resources artificially, they may actually
30:42
Speaker 4: have more offspring earlier, and then when they migrate, right,
30:45
Speaker 4: they don't stay in your backyard forever. Then they migrate,
30:48
Speaker 4: and then they don't actually have the resources that they
30:52
Speaker 4: kind of were led to believe they would have. It
30:54
Speaker 4: can actually cause a population crash. So like there's a
30:57
Speaker 4: lot of like weird unexpected consequences is where a lot
31:01
Speaker 4: of species have this kind of like timing system, and
31:03
Speaker 4: they can also kind of they can change their breeding
31:06
Speaker 4: behavior based on the stress and the resources that they
31:11
Speaker 4: have available to them.
31:12
Speaker 2: What if you feed wild birds, but you do it consistently.
31:15
Speaker 2: You don't just like yanke it away from them.
31:17
Speaker 4: Well, it depends, like if they migrate, then you'd have
31:21
Speaker 4: to follow them. It's like, all right, where are you going?
31:23
Speaker 3: Get on a plane?
31:25
Speaker 1: You tag them and migrate with them.
31:27
Speaker 4: And if you're just feeding birds consistently and they stay
31:30
Speaker 4: in your backyard, that's how we got chickens.
31:34
Speaker 2: That's not so bad, that's delicious.
31:38
Speaker 1: You can also transmit diseases at feeders, Yeah, that's true.
31:43
Speaker 1: It had been like fifteen minutes since we had talked
31:45
Speaker 1: about parasites, so I had to pull that back.
31:47
Speaker 4: When you have a really crowded public feeder, you've got
31:49
Speaker 4: a lot of birds, you know, rubbing up against each other,
31:52
Speaker 4: so then they can transfer diseases. So like, especially when
31:54
Speaker 4: there's like avian flu going around, it's probably not a
31:57
Speaker 4: good time to take in those feeders.
31:59
Speaker 2: We had a bird feeder our backyard and there was
32:01
Speaker 2: a blue jay in the neighborhood and who really liked
32:03
Speaker 2: like the bigger seeds. I think it was the some
32:05
Speaker 2: flower seeds. He was also a bully, so he would
32:07
Speaker 2: like chase away all the other birds and then he
32:09
Speaker 2: would sift through and just like throwing seeds left and
32:12
Speaker 2: right to get to the some flower seeds and gobble
32:14
Speaker 2: them up, but making a mess everywhere, and all the
32:17
Speaker 2: other birds were scared. We had to like try to
32:19
Speaker 2: chase this guy away.
32:20
Speaker 1: Yeah, we have a family member like that. We stopped
32:22
Speaker 1: inviting them to say. So, we've talked about a variety
32:28
Speaker 1: of different ways that nature has sort of solved the
32:30
Speaker 1: problem of who takes care of the offspring? How many
32:33
Speaker 1: offspring do you have? But sometimes it's complicated, So let's
32:36
Speaker 1: move on to this idea of R and K strategists.
32:40
Speaker 1: So this idea was meant to sort of come up
32:42
Speaker 1: with a theory that would explain why sometimes you get
32:46
Speaker 1: organisms species that make loads of offspring and then other
32:49
Speaker 1: times you get species that just make a few offspring.
32:52
Speaker 1: So what kind of conditions would promote doing something crazy
32:56
Speaker 1: like having thousands of offspring? So the idea here is
32:59
Speaker 1: that maybe you have some environments that are just changing
33:03
Speaker 1: all the time. They're unpredictable. Maybe like periodically fires come
33:08
Speaker 1: through and they just sort of devastate the environment. And
33:11
Speaker 1: so it's not necessarily that like resources are limited. It's
33:14
Speaker 1: just every once in a while something catastrophic happens and
33:17
Speaker 1: in that case, as the theory went, the idea is
33:20
Speaker 1: that you should produce loads of offspring, and you should
33:23
Speaker 1: start producing these offspring as young as you can, so
33:26
Speaker 1: that you can get as many chances at making offspring
33:29
Speaker 1: as possible, and that you can fill any new niche
33:33
Speaker 1: that opens up by having all of these new offspring. Whereas,
33:36
Speaker 1: if you're in an environment where there's a set number
33:40
Speaker 1: of resources, that environment is pretty stable, it's pretty predictable,
33:43
Speaker 1: then you should invest in making a few number of
33:46
Speaker 1: offspring that are in really great shape and they're really
33:49
Speaker 1: good competitors because there's going to be a lot of
33:51
Speaker 1: competition for those resources since everybody's sort of at the
33:55
Speaker 1: limits of what the environment can handle in terms of
33:58
Speaker 1: the amount of resources that are available there for everybody.
34:01
Speaker 2: Does that make sense to you? I mean, I try
34:02
Speaker 2: to imagine myself as a parent in this circumstance, and
34:05
Speaker 2: like it seems like that makes sense under the assumption
34:08
Speaker 2: that you can do nothing to help your kids survive, Right,
34:11
Speaker 2: you should just have lots of them because it's all random.
34:14
Speaker 2: But I'm imagining, like if I have kids in suburban
34:16
Speaker 2: southern California where things are pretty stable, versus I have
34:19
Speaker 2: kids in like post apocalyptic Mad Max scenario, Like, am
34:23
Speaker 2: I going to pump out one hundred kids and then
34:25
Speaker 2: just like let them run crazy free and hope they survive?
34:29
Speaker 2: It feels to me like I'd still be better off
34:31
Speaker 2: having few kids and trying to like navigate them through
34:34
Speaker 2: the chaos.
34:35
Speaker 1: Well, evolution has selected our species over time to be
34:39
Speaker 1: really good at making a small number of offspring, and
34:41
Speaker 1: you can use our intelligence to sort of help them
34:44
Speaker 1: survive in this complicated environment. I would say that we
34:47
Speaker 1: don't necessarily have the ability at this point to make
34:52
Speaker 1: as many offspring as it would take. To think of
34:54
Speaker 1: yourself as an R strategist, what's your take on this, Katie.
34:57
Speaker 4: Yeah, I mean I think it's kind of comes down
35:00
Speaker 4: to probably very complicated statistical probabilities that I have no
35:04
Speaker 4: way of kind of conceptualizing. But you know, it's sort
35:07
Speaker 4: of like a I'm going to make a stock market comparison,
35:10
Speaker 4: but I want to make it clear I don't know
35:12
Speaker 4: anything about investment. But if you have like a really
35:16
Speaker 4: risky market, right, like you diversify your portfolio in general, right,
35:21
Speaker 4: Whereas maybe if you have it more stable market, It's like, man,
35:23
Speaker 4: I know that everybody loves apple juice, so I'll keep
35:29
Speaker 4: investing in apple juice. I don't mess around with the
35:31
Speaker 4: stock market because I truly don't understand it.
35:34
Speaker 2: I don't think apple juice is a growth industry. Katie's
35:36
Speaker 2: not an investment. Don't take advice from Katie, folks.
35:39
Speaker 4: If I drink enough, it's a growth industry for me.
35:41
Speaker 4: But like, one thing is that you can think of
35:45
Speaker 4: it in terms of like an individual's success, right, Like
35:48
Speaker 4: I'm a parent, I can like make sure my child
35:51
Speaker 4: reaches adulthood. But you can also look at it in
35:53
Speaker 4: terms of just like the spread of a bunch of genes.
35:57
Speaker 3: And there have been.
35:58
Speaker 4: Some sort of like back and forth arguments about like
36:02
Speaker 4: what matters more genes or phenotype, right, but in general,
36:06
Speaker 4: like sometimes you may have a situation in which having
36:11
Speaker 4: a ton of offspring and not taking care of them
36:14
Speaker 4: but just leaving it up to chance is the best strategy,
36:18
Speaker 4: even if, like you say, take care of your offspring,
36:21
Speaker 4: because say there's a disease that comes around, Like, no
36:24
Speaker 4: matter how good you take care of your offspring, a
36:27
Speaker 4: disease that comes hit you, there's nothing you can do
36:30
Speaker 4: about that.
36:30
Speaker 3: But if you have fifty.
36:32
Speaker 4: Thousand offspring and one or two of them have a
36:34
Speaker 4: genetic mutation where they manage to avoid this like devastating disease.
36:39
Speaker 4: Then your genes get passed on and it doesn't matter
36:42
Speaker 4: that you were a terrible parent hypothetically, But of course
36:47
Speaker 4: obviously we do have all kinds of parenting right in nature,
36:53
Speaker 4: and so it does mean that there have been stable
36:56
Speaker 4: patterns of both our and case strategists being.
37:00
Speaker 3: Able to survive.
37:02
Speaker 4: But it's just that there isn't one single strategy that
37:05
Speaker 4: always wins. The species that we see alive today have
37:08
Speaker 4: not been raining the earth for the past, you know,
37:11
Speaker 4: millions of years, Like, so many species have gone extinct
37:16
Speaker 4: or have turned into a different species that survived to today.
37:19
Speaker 4: So like there's a lot of strategies that were tried
37:22
Speaker 4: and then then failed, and then a little different strategy
37:25
Speaker 4: was tried and failed. So it's really just about cannas.
37:28
Speaker 4: Species find an amount of stability for a certain chunk
37:33
Speaker 4: of time, and then that lasts for some amount of time,
37:36
Speaker 4: and there's no guarantee that any of the current survivors
37:38
Speaker 4: now are going to last the next million years.
37:41
Speaker 2: I think it's interesting that you talk about like good
37:43
Speaker 2: parenting and bad parenting. It's funny to put these sort
37:46
Speaker 2: of like moral labels on it, and we joke a
37:48
Speaker 2: little bit, but you know, it makes me wonder if
37:51
Speaker 2: you're the parent in a species where you just sort
37:53
Speaker 2: of like make a lot of them and spraym into
37:55
Speaker 2: the environment and ignore them, do you still love your
37:58
Speaker 2: babies or is it just like not a bigger part
38:00
Speaker 2: of your life.
38:00
Speaker 3: Sometimes you eat them, sometimes you eat them, sometimes you
38:03
Speaker 3: eat them.
38:04
Speaker 2: You love them for dinner.
38:06
Speaker 4: There are a lot of like amphibians and fish that
38:09
Speaker 4: will sometimes eat some of their offspring just like it's
38:12
Speaker 4: fine if I nibble on a few of them, right,
38:15
Speaker 4: But again, it's not because they're cruel. It's because of
38:17
Speaker 4: the trade off between your own personal survival and health
38:22
Speaker 4: and being able to bear future offspring and your offspring
38:26
Speaker 4: surviving in fact, like there are some species of animals
38:29
Speaker 4: that will like fight to the death to protect their offspring,
38:32
Speaker 4: Like I've seen elk try to stomp the dickens out
38:35
Speaker 4: of a mountain lion to save her offspring. Whereas some
38:39
Speaker 4: animals who have a higher fecundity, like they see a
38:43
Speaker 4: predator and they're like, all right, I'm out because I
38:45
Speaker 4: can have babies in the future.
38:47
Speaker 1: Well, we have hit optimum dKu episode here because we've
38:51
Speaker 1: talked about poop and cannibalism. But we're still going to
38:55
Speaker 1: go ahead and do one more session even though we've
38:57
Speaker 1: hit all the high points. So let's go ahead and
38:59
Speaker 1: take a break, and when we come back we will
39:02
Speaker 1: talk more about babies. Before the last break, Katie was
39:21
Speaker 1: talking about variability and parental care, how some animals are
39:25
Speaker 1: willing to risk their lives and some just aren't willing
39:28
Speaker 1: to risk their lives for their babies. One of the
39:30
Speaker 1: things that got me really excited about behavioral ecology was
39:32
Speaker 1: that even within species, there's a lot of variability, and
39:35
Speaker 1: trying to understand why some animals are great parents and
39:39
Speaker 1: some are kind of miserable is just fascinating to me.
39:42
Speaker 1: Like I studied small mouth bass for a while, and
39:44
Speaker 1: after the ice would melt off the lakes in Wisconsin,
39:48
Speaker 1: it was still absolutely frigid. We would jump in and
39:51
Speaker 1: we would try to find every nest in this northern
39:54
Speaker 1: Wisconsin lake and some of the males you would approach
39:57
Speaker 1: their nest and you could see just like the sh
40:00
Speaker 1: sho of them as they ran off and the minnows
40:02
Speaker 1: would come in and they'd try to eat their eggs
40:04
Speaker 1: and you just would never see that mail again. And
40:07
Speaker 1: then there were other males who you'd be like trying
40:09
Speaker 1: to figure out where the nest is, you haven't even
40:11
Speaker 1: located it yet, and they would literally like torpedo you
40:15
Speaker 1: in the face and knock your mask off and like,
40:17
Speaker 1: you know, knock your snorkel out of your mouth, and
40:19
Speaker 1: they would just keep like ramming into you. So even
40:22
Speaker 1: within species, there's loads of differences, and I don't think
40:25
Speaker 1: we understand very well what those differences are. Sometimes it
40:28
Speaker 1: has to do with how big the males are. So like,
40:31
Speaker 1: if a male is huge and all of the predators
40:33
Speaker 1: in the lake have little mouths, then he can be
40:36
Speaker 1: pretty sure nothing's going to be able to eat him,
40:38
Speaker 1: so he might as well attack. Whereas if you're the
40:40
Speaker 1: little guy, maybe you don't get gutsy until you grow
40:44
Speaker 1: for a few more years, until you're big enough that
40:46
Speaker 1: probably nothing can eat you. But there's loads of variability
40:49
Speaker 1: even within species, which I think is just totally fascinating
40:52
Speaker 1: and adorable.
40:53
Speaker 4: I mean that reminds me of like sort of different
40:54
Speaker 4: mating strategies where you have sort of sneaky males versus
40:58
Speaker 4: large sort of job males, like in salmon and coho salmon,
41:03
Speaker 4: like there's the jacks, which are the little guys, and
41:06
Speaker 4: then the hook noses, i think based on the shape
41:09
Speaker 4: of their face, which are the bigger ones. And the
41:11
Speaker 4: little guys actually do a really good job of sneakily
41:14
Speaker 4: mating with females, whereas the big guys they may have
41:17
Speaker 4: a more like secure position in terms of not being
41:21
Speaker 4: preyed upon, but they're less agile, and actually the jacks
41:26
Speaker 4: tend to be more numerous because what happens is the
41:28
Speaker 4: female will depositor eggs and the jack kind of like
41:32
Speaker 4: zoom out there and puts the sperm on the eggs
41:35
Speaker 4: and then zooms away right like an.
41:37
Speaker 3: Egg assass and just like boop, like fertilized.
41:40
Speaker 4: But yeah, it's also like even a single individual can
41:43
Speaker 4: change their strategy based on say, environmental stressors like kangaroos
41:49
Speaker 4: and wallabies can basically control when they have offspring. It's
41:54
Speaker 4: called embryonic diapause. So it's like when they freeze the
41:58
Speaker 4: development of their embryo when they feel like stressed or
42:01
Speaker 4: like the conditions aren't right, so they're controlling their fecundity.
42:05
Speaker 4: There's also what we mentioned earlier about cannibalism, like eating
42:08
Speaker 4: your eggs, eating your offspring when resources seem limited or
42:13
Speaker 4: when you're stressed out, like bears will sometimes do that,
42:16
Speaker 4: Like bears will eat their newly born offspring like black bears,
42:19
Speaker 4: and it's like, well, why would they do that, Well,
42:21
Speaker 4: if it's a weaker offspring, or if they're stressed out
42:23
Speaker 4: and they feel like resources aren't good at that time,
42:25
Speaker 4: they actually control whether or not they want to invest
42:28
Speaker 4: in an offspring at that point.
42:30
Speaker 1: Tough decisions. Our kids don't know how lucky they are
42:33
Speaker 1: to have made it as far as they did that
42:35
Speaker 1: we never snacked them right, even when things were scary.
42:39
Speaker 4: They think it's terrible when parents eat their chocolate bunnies,
42:42
Speaker 4: and they don't know it could be so much.
42:44
Speaker 1: Worse, so much worse. I'm gonna have to tell my
42:46
Speaker 1: kids that around here. Yeah, it'll be good. I'm a
42:49
Speaker 1: great parent. So to get back to RNK strategists, so
42:53
Speaker 1: we have kind of given some examples of different rn
42:56
Speaker 1: K strategists over the course of this chat, Haiti mentioned
43:00
Speaker 1: that insects are the classic R strategists and just like
43:04
Speaker 1: a funny aside. I could never remember if the rs
43:06
Speaker 1: and the k's, which one was the fast and lots
43:08
Speaker 1: of babies and which one was the slow and just
43:10
Speaker 1: a few babies. And this morning, my really embarrassing way
43:14
Speaker 1: of remembering was Kelly starts with K and I only
43:17
Speaker 1: had a few babies. And so anyway, anyone needs to
43:20
Speaker 1: remember that in the future, just think about Kelly only
43:22
Speaker 1: had two babies. But anyway, that was also my way
43:24
Speaker 1: of remembering if I was going to Slovakia or Slovenia
43:28
Speaker 1: to give a talk, Slovakia has a K in it
43:30
Speaker 1: and Kelly's going.
43:31
Speaker 4: I remember it with a rapid fire for our and
43:34
Speaker 4: quality with K because I'm good at spelling.
43:38
Speaker 3: I love it.
43:39
Speaker 1: Okay, so you and our notes have a really great
43:43
Speaker 1: explanation of whale parental care. Do you want to chat
43:47
Speaker 1: about them as like ideal K specialists?
43:50
Speaker 3: Yeah? Absolutely so.
43:51
Speaker 4: Whales are, especially the largest whales. Blue whales are an
43:55
Speaker 4: excellent example of K strategists, right like they fit into
43:59
Speaker 4: the classical. They're big, they live a long time, they're intelligent,
44:04
Speaker 4: and they have a very long gestation period of about
44:08
Speaker 4: a year, and they only have an offspring every presidential
44:14
Speaker 4: term essentially like every four years or so. So they
44:18
Speaker 4: are very slow in terms of producing a lot of offspring,
44:22
Speaker 4: but they pour a huge amount of resources into the offspring.
44:26
Speaker 4: They produce about fifty gallons of milk per day.
44:29
Speaker 2: That's incredible.
44:30
Speaker 4: Yeah, it's also really high quality milk. It's very very
44:34
Speaker 4: fat dense.
44:36
Speaker 2: Is it delicious?
44:37
Speaker 3: You know?
44:37
Speaker 4: I would love to try some hot fresh whale milk.
44:41
Speaker 4: That sounds very good, especially because we know what their
44:43
Speaker 4: diet is, Like a ton of krill that's got to
44:46
Speaker 4: have a nice fishy aftertaste.
44:49
Speaker 2: Wait, how big is a blue whale nipple? I mean,
44:51
Speaker 2: could a human even actually like get it fresh from
44:54
Speaker 2: the whale?
44:55
Speaker 4: You know, I've actually never seen a blue whale nipple,
44:58
Speaker 4: so I don't know. I'm gonna assume it's pretty big.
45:02
Speaker 2: If I google that, am I going to get on
45:03
Speaker 2: some terrorists watch list? Right now? You know?
45:05
Speaker 4: I did once google elephant breasts, and I'm sure I'm
45:09
Speaker 4: on a list. Oh no, But I meant literally elephant
45:14
Speaker 4: breast because I was curious about breastfeeding and elephants.
45:18
Speaker 3: And I can't explain everything.
45:20
Speaker 2: Since we're on the topic of Katie's weird history, what
45:22
Speaker 2: is the most interesting animal whose milk you have had?
45:25
Speaker 3: Oh? I mean, I think just goat milk.
45:27
Speaker 4: I'm not very exciting. I haven't done anything too adventurous.
45:31
Speaker 4: I wish I could say, like I've suckled on a
45:33
Speaker 4: sicilian or something, but no, I really haven't.
45:36
Speaker 3: Oh, goat milk. I guess human milk though.
45:39
Speaker 2: Right, milk is pretty weird.
45:41
Speaker 3: Human milk's pretty weird, but we all drink it as babies.
45:43
Speaker 2: I lived in a small village in France where the
45:45
Speaker 2: grocery store had pony milk available, Yes, little bottles of
45:50
Speaker 2: pony milk.
45:51
Speaker 3: Like from specifically ponies. Like, okay, why not?
45:56
Speaker 2: I was.
46:00
Speaker 3: Really it wasn't very good.
46:02
Speaker 2: It was too horsy for me.
46:03
Speaker 3: Yeah, okay.
46:04
Speaker 2: You know how a milk sort of reminds you of
46:06
Speaker 2: the odor of an animal, like goats, so it tastes
46:08
Speaker 2: like the way goats smells a little bit. Not a
46:10
Speaker 2: fan of the way horses smell.
46:12
Speaker 4: I feel that I definitely can only handle a certain
46:14
Speaker 4: amount of goat cheese before I'm like, I feel like
46:17
Speaker 4: I'm eating the smell of the.
46:18
Speaker 2: Goat exactly, like I'm licking a sweaty gat or something.
46:22
Speaker 1: Yeah, it smells and tastes like hay to me, and
46:24
Speaker 1: I love it. But anyway, let's get back.
46:25
Speaker 4: To blue whales all right, So blue whale milk probably
46:27
Speaker 4: tastes like blue whale, and the calves actually gain hundreds
46:32
Speaker 4: of pounds of weigh every few days.
46:35
Speaker 2: Incredible.
46:35
Speaker 4: They grow at an incredible way. They go from being
46:38
Speaker 4: about the sights of like a shipping container to like
46:44
Speaker 4: nearly a football field, right, So it's wild. It's a
46:47
Speaker 4: wild amount of growth. So this also highlights sort of
46:50
Speaker 4: the interesting trade off between somatic growth, meaning growing yourself
46:55
Speaker 4: and growing your offspring. Whales spend their first parts of
46:59
Speaker 4: their lives just grow, growing themselves to enormous sizes by
47:02
Speaker 4: drinking a huge amount of their mother's milk, and then
47:05
Speaker 4: when they're old enough, they start to filter feed on krill.
47:08
Speaker 4: They're balen whales. They have those bristle structures in their mouths.
47:12
Speaker 4: They take in huge amounts of sea water and then
47:15
Speaker 4: expel it all out, and then krill, which are hugely
47:19
Speaker 4: inbundant of a huge source of biomass, get caught in
47:22
Speaker 4: their bileen and then they can swallow that and just
47:26
Speaker 4: they eat. They're like vacuums that are able to exploit
47:30
Speaker 4: a massive amount of biomass in the ocean. It'd be
47:34
Speaker 4: like a cow on land that's just giant and had
47:36
Speaker 4: like a giant sort of like lawn mower mouth that
47:39
Speaker 4: could go and like mow an entire field and like
47:43
Speaker 4: a few hours.
47:44
Speaker 1: Why hasn't evolution come up with that yet?
47:47
Speaker 3: It's coming.
47:48
Speaker 4: Giant, terrifying cows are coming, I'm sure, and they'll be
47:50
Speaker 4: shaped like crabs based on other patterns in nature.
47:55
Speaker 1: But we just had an interview with the woman who
47:57
Speaker 1: wrote the review paper and how grumpy she is about
48:00
Speaker 1: how it's been interpreted. But anyway, crab episode coming soon.
48:03
Speaker 4: I stand firmly behind my crab carsonization of cow's theory.
48:10
Speaker 1: Excellent.
48:11
Speaker 4: But yeah, so after this period of growing the self
48:14
Speaker 4: to these enormous sizes, then they can enter into the
48:16
Speaker 4: reproductive period and then spend a lot of resources developing
48:20
Speaker 4: the offspring, taking a year to develop the embryo to
48:24
Speaker 4: becoming the live born offspring, and then just feeding it
48:28
Speaker 4: huge amounts. Basically, they inhabit this evolutionary niche where they
48:32
Speaker 4: invest their resources into being really big, and then when
48:36
Speaker 4: you give birth, your offspring has taken a whole year
48:40
Speaker 4: to develop inside your massive body. So there's very few
48:43
Speaker 4: predators who could actually target your offspring, and honestly, they
48:47
Speaker 4: had very little in terms of competitors and predators until
48:52
Speaker 4: humans figured out how to fashion a harpoon. And that
48:56
Speaker 4: we liked whale juices for a lot of disgusting use.
49:00
Speaker 2: Is that sounds like a title for a great book,
49:02
Speaker 2: Whale Juices for Disgusting uses.
49:07
Speaker 4: Whale Jesus for Disgusting uses a very highly unethical guide
49:11
Speaker 4: to using whale Ambergriss.
49:14
Speaker 1: Yeah, Okay, So we've talked about insects being amazing r strategists.
49:18
Speaker 1: We've now talked about blue whales being amazing case strategists.
49:22
Speaker 1: And now that you feel like maybe you've got this
49:24
Speaker 1: strategy in your mind, I'm going to go ahead and
49:26
Speaker 1: tell you that this probably does not represent reality because
49:30
Speaker 1: it's more of a spectrum when you look into these things,
49:32
Speaker 1: and it's, you know, not surprising that things don't fit
49:35
Speaker 1: into little categories because probably the only thing in an
49:39
Speaker 1: environment that matters isn't like how often a fire passes through.
49:42
Speaker 1: And so usually when you find species, you find some
49:46
Speaker 1: like combination of these different kinds of traits. So a
49:48
Speaker 1: classic example is an elm tree. So an elm tree
49:52
Speaker 1: is kind of like a case strategist in that it
49:55
Speaker 1: lives for a really, really really long time and it
49:58
Speaker 1: gets huge. And why it to get huge is because
50:01
Speaker 1: it is competing with the other trees in the canopy.
50:03
Speaker 1: And if you can't get to the top of the canopy,
50:05
Speaker 1: you don't get light and you don't get to survive.
50:07
Speaker 1: And Daniel, this sort of addresses your question earlier about like, well,
50:12
Speaker 1: why wouldn't you always just have a few offspring that
50:14
Speaker 1: you invest a lot in? So for these seeds, they
50:17
Speaker 1: make loads of seeds. I think they can make up
50:19
Speaker 1: to a million seeds in their lifetime. And these seeds
50:20
Speaker 1: are tiny, and the only way any of those seeds
50:23
Speaker 1: get to survive is if they happen to end up
50:26
Speaker 1: in a spot on the floor where they get really lucky,
50:30
Speaker 1: Like maybe a super old tree that's one hundred years
50:32
Speaker 1: old has finally fallen over and died, and now there's
50:35
Speaker 1: a little bit of light coming through the canopy making
50:37
Speaker 1: it to the forest floor, and your offspring just don't
50:40
Speaker 1: have any chance to survive unless they end up randomly
50:44
Speaker 1: in one of those spots.
50:45
Speaker 2: It's like waiting for a physics professor to retire and
50:47
Speaker 2: open up a professorship.
50:49
Speaker 1: Finally, right, or answer your emails.
50:51
Speaker 3: Yeah, it's completely random, Yes.
50:54
Speaker 1: Completely random, and so like if you had made five
50:57
Speaker 1: of the greatest acorns in the warld Oh, thank.
51:01
Speaker 2: You, My acorns are wonderful.
51:03
Speaker 3: Yes, okay, a lot of squirrel energy over here. I
51:06
Speaker 3: don't know why.
51:08
Speaker 1: Yeah, that's right.
51:10
Speaker 2: I'm just trying to imagine what is it like to
51:12
Speaker 2: be a good elm parent, Like you know, you're really
51:15
Speaker 2: craft these acorns, or dold you just care deeply about them,
51:17
Speaker 2: or you're like weirdly irrationally proud of your acorns. I
51:20
Speaker 2: don't know. I was trying to do it.
51:22
Speaker 1: And the promorphizing trees. I never could say that word
51:25
Speaker 1: without first stumbling and overthinking it. But also, if you
51:28
Speaker 1: make like giant seeds, they're gonna get eaten by squirrels,
51:31
Speaker 1: and so just for a variety of reasons, the best
51:33
Speaker 1: strategy is to make lots of them every year and
51:36
Speaker 1: scatter them as far as you can and not care
51:39
Speaker 1: and not care. It seems like there's really no better
51:41
Speaker 1: strategy than that, and the environment is selecting for that.
51:43
Speaker 4: An animal equivalent to the elm tree are actually a sunfish.
51:48
Speaker 4: They're huge, huge fish, like the size of a kiddie pool,
51:52
Speaker 4: and they're those weird guys that are kind of like
51:54
Speaker 4: flat and they've got the big eyeballs and they're really funny.
51:58
Speaker 4: But you would think, like, okay, there huge so that
52:00
Speaker 4: they can have large offspring that like nobody messes with.
52:04
Speaker 4: But actually their offspring are teeny teeny tiny. They're only
52:07
Speaker 4: a couple millimeters big. They're nearly like planktonic, and they
52:11
Speaker 4: have huge amounts of them. The females can lay like
52:13
Speaker 4: millions of eggs in her lifetime, and so it's kind
52:17
Speaker 4: of like the elm situation where they're just doing like
52:20
Speaker 4: I'm just gonna scatter a bunch of them. It's a
52:22
Speaker 4: little less clear why they do this versus the elm right,
52:25
Speaker 4: because it's not the same situation where the elm seeds
52:28
Speaker 4: need to find that perfect location where they don't have
52:31
Speaker 4: to compete with other trees to get sunlight through the canopy.
52:34
Speaker 4: But in the ocean you have a lot of evolutionary
52:38
Speaker 4: pressures where it's hard not to get eaten and the
52:41
Speaker 4: ocean and it also takes a lot of resources right
52:44
Speaker 4: to create a large offspring. So for these sunfish, even
52:50
Speaker 4: though it seems like they're going towards the blue whale
52:52
Speaker 4: strategy of like, hey they're big, right, so maybe it's
52:55
Speaker 4: so that they can just invest a lot in one offspring.
52:58
Speaker 4: No complete opposite, just a bunch of tiny babies that
53:01
Speaker 4: get eaten up like little popcorn and then like some
53:04
Speaker 4: of them though, happen to keep growing and growing and
53:07
Speaker 4: growing until they're just enormous.
53:09
Speaker 2: So, Kelly, if we think that the R strategy in
53:12
Speaker 2: case strategy is a little too simplistic, how we like
53:14
Speaker 2: upgraded our model to understand this in terms of like
53:18
Speaker 2: more variables, and it's sort of a higher dimensional evolutionary space.
53:21
Speaker 1: Yeah, so now we talk about life history strategies, and
53:25
Speaker 1: the decisions that animals make are things like when do
53:27
Speaker 1: you start breeding, how many times in your life will
53:30
Speaker 1: you breed, how many offspring do you make each of
53:32
Speaker 1: those breeding attempts, and how much do you care for them?
53:35
Speaker 1: And evolution has happened upon a lot of different answers
53:39
Speaker 1: to all of those questions, and it depends on lots
53:42
Speaker 1: of stuff like how competitive the environment is, how much
53:45
Speaker 1: food is available, how many other individuals are in the population,
53:49
Speaker 1: how stable is your environment, et cetera, et cetera. There's
53:52
Speaker 1: a lot of different factors that sort of go into
53:55
Speaker 1: these decisions, and so the way we think about it
53:57
Speaker 1: right now involves a lot more variable and it's quite
54:00
Speaker 1: a bit more complicated.
54:02
Speaker 3: Yeah, it's complicated.
54:03
Speaker 4: It's just like the Facebook message, you know, Like that's
54:06
Speaker 4: basically like all these mathematicians, all these evolutionary biologists trying
54:11
Speaker 4: to get it down to some nice, beautiful formulas, and
54:14
Speaker 4: the best we can come up with is it's complicated.
54:18
Speaker 2: In my mind, there's sort of two possible scenarios, or
54:21
Speaker 2: maybe a spectrum of them, one in which, like, it's
54:23
Speaker 2: complicated and it depends on lots of factors, but if
54:26
Speaker 2: you knew all those factors, you could understand it, and
54:29
Speaker 2: you know, everybody is responding to those factors in a
54:32
Speaker 2: way that makes sense to us. And the other is
54:34
Speaker 2: that it's just kind of random, like does everything have
54:37
Speaker 2: to have a reason, Like, you know, you might ask
54:40
Speaker 2: why are there so many different kind of eye colors
54:42
Speaker 2: in humans? Is there a reason why that is? Or
54:44
Speaker 2: just sort of like, hey, these are the group that
54:46
Speaker 2: survived and a lot of it is just random. How
54:49
Speaker 2: much of it does need to be explained. How much
54:52
Speaker 2: of it can we just say, hey, this is sort
54:53
Speaker 2: of just what happened.
54:55
Speaker 1: Yeah, so that's a great question. I mean, I think
54:56
Speaker 1: we are, over time having a better understan standing of
55:00
Speaker 1: what factors you need to think about ahead of time.
55:02
Speaker 1: If you were to predict, like if somebody plopped a
55:05
Speaker 1: brand new species in front of you, we could ask
55:07
Speaker 1: a certain set of questions and have a pretty good
55:11
Speaker 1: guess for what that animal should do. And it depends
55:13
Speaker 1: a little bit on like evolutionary trajectory. If it's a mammal,
55:16
Speaker 1: then probably female's going to be the one who's doing
55:18
Speaker 1: a lot of investing. So you'd predict that the males
55:20
Speaker 1: would try to mate with as many females as they
55:23
Speaker 1: could to maximize numbers, and then the females are going
55:25
Speaker 1: to have to invest a lot more heavily in the
55:27
Speaker 1: offscoing that they have, and so it is becoming more
55:31
Speaker 1: of a predictive science. But it's taken a lot of work.
55:35
Speaker 4: Let's say you, Katie, evolution is really interesting because you
55:38
Speaker 4: always have an element of randomness, right, Genetic mutation is random,
55:43
Speaker 4: although geologists would disagree, right, an earthquake is quasi random,
55:48
Speaker 4: right when it comes to animals, Like an animal certainly
55:50
Speaker 4: can't predict when an earthquake happens or some like dramatic
55:52
Speaker 4: environmental change happens. You know, sort of like whether or
55:56
Speaker 4: not you're just in the right place at the wrong
55:59
Speaker 4: time or the wrong place at the right time. All
56:01
Speaker 4: of those things are these random things. But when you
56:04
Speaker 4: have a system over long, long, long periods of time,
56:07
Speaker 4: that's when randomness starts to get shaped into something that
56:11
Speaker 4: seems more intentional, seems more like, oh, this feels like
56:15
Speaker 4: this is becoming more and more efficient. But the truth
56:18
Speaker 4: is that the species that we see today, we are
56:20
Speaker 4: just sort of lucky enough to have this glimpse of
56:23
Speaker 4: the earth at this period of time where we have
56:26
Speaker 4: all these species, and they are not like ideal optimized
56:31
Speaker 4: creatures in every sense, right, Like a lot of the
56:35
Speaker 4: evolutionary traits that they have, like some of them have
56:37
Speaker 4: been selected for, and some of them have been either
56:41
Speaker 4: initially selected for and then evolution switched up on them, right,
56:45
Speaker 4: like where their environment switched up and the strategy has
56:48
Speaker 4: to switch. But they never got rid of it, right
56:50
Speaker 4: because it either wasn't harming them or they just never
56:53
Speaker 4: lucked into the gene that helped them get rid of it. Right,
56:56
Speaker 4: So evolution doesn't create perfectly optimized, streamlined animals, but it
57:02
Speaker 4: does create animals that, generally speaking, are good at survival.
57:06
Speaker 4: And so there's like some potential randomness right where it's like,
57:11
Speaker 4: just happened to be.
57:11
Speaker 3: That this basically worked.
57:13
Speaker 4: It's like an old car that's like, yeah, it's got
57:17
Speaker 4: pretty bad mileage and the carburetor makes a weird noise,
57:20
Speaker 4: but it's still going. And there are species like that
57:23
Speaker 4: where it's like it's not perfect, but it's still going.
57:26
Speaker 3: Some of it can be a little bit random and
57:29
Speaker 3: certainly not perfect.
57:30
Speaker 1: Yes, I feel not perfectly suited to my environment much
57:33
Speaker 1: of the time. And on that note, Daniel, did you
57:37
Speaker 1: want to ask an alien related question? Or are you good?
57:42
Speaker 2: Oh my gosh, The answer to that is always yes.
57:45
Speaker 1: All right, we can pull back. Do you want to
57:46
Speaker 1: ask your alien question?
57:47
Speaker 3: Green is the answer, green, Miakati?
57:54
Speaker 2: My question is what color are alien nipples?
57:57
Speaker 3: You know what?
57:58
Speaker 4: I've always imagined them as lavender, not funny.
58:04
Speaker 2: Maybe they also taste like lavender.
58:05
Speaker 4: Yuh hey, you know what, We're getting into some real
58:08
Speaker 4: strange territory here.
58:10
Speaker 2: Right.
58:11
Speaker 3: Thanks for being on the show, Katie, Yeah, absolutely, thanks
58:13
Speaker 3: for having me.
58:21
Speaker 1: Daniel and Kelly's Extraordinary Universe is produced by iHeartRadio. We
58:25
Speaker 1: would love to hear from you, We really would.
58:28
Speaker 2: We want to know what questions you have about this
58:31
Speaker 2: Extraordinary Universe.
58:32
Speaker 1: Want to know your thoughts on recent shows, suggestions for
58:35
Speaker 1: future shows. If you contact us, we will get back
58:39
Speaker 1: to you.
58:39
Speaker 2: We really mean it. We answer every message. Email us
58:42
Speaker 2: at questions at danieland Kelly dot org, or.
58:46
Speaker 1: You can find us on social media. We have accounts
58:48
Speaker 1: on x, Instagram, Blue Sky and on all of those platforms.
58:52
Speaker 1: You can find us at D and K Universe.
58:55
Speaker 2: Don't be shy right to us.