Speaker 1: Quick of technical notes. So I'm on the road, so
Speaker 1: my audio quality is not as good as it typically
Speaker 1: is when I'm in the studio. That should be back
Speaker 1: to normal once I return in just about a week.
Speaker 1: Please hang with me when I have sort of a
Speaker 1: little bit more of a janky audio situation, but I
Speaker 1: will do my best to make it sound soothing and
Speaker 1: beautiful on your ears. Welcome to Creature Future production of iHeartRadio.
Speaker 1: I'm your host so many parasites, Katie Golden. I studied
Speaker 1: psychology and evolutionary biology, and today on the show, it's
Speaker 1: another listener Questions episode. I answer your questions to the
Speaker 1: best of my ability. You can write to me at
Speaker 1: creaturefeuturepod at gmail dot com with any questions you have
Speaker 1: about animals evolutionary biology. Can send me pictures of your pets,
Speaker 1: and I love to answer these questions. They often send
Speaker 1: me on very interesting sort of study sessions trying to
Speaker 1: find out about your questions. And let's just get right
Speaker 1: into it. First listener question, Folks say things like crocodiles
Speaker 1: have been around for x million years, relatively unchanged, and
Speaker 1: obviously evolution is an ongoing process. But speaking to classifying animals,
Speaker 1: what's the oldest and what's the newest animal? When and
Speaker 1: how do new classifications of species happens. This is from
Speaker 1: Blake our Hi Blake. This is a really interesting question,
Speaker 1: very good question. It is a bit of a touchy
Speaker 1: topic in evolutionary biology because the broad answer is that
Speaker 1: definition of species and distinctions between species can be a
Speaker 1: bit of a gray area. So there are different schools
Speaker 1: of thought when it comes to defining species. One is
Speaker 1: the biological species cheese concept. It defines a species as
Speaker 1: a group that can produce viable fertile offspring. So while
Speaker 1: a horse can technically have offspring with a zebra making
Speaker 1: a zores, the resulting hybrid is infertile, so the horse
Speaker 1: and the cibra are considered separate species. But this concept
Speaker 1: has some issues. It's not something that can easily be
Speaker 1: applied to fossil species, so we may not know whether
Speaker 1: they can produce viable fertile offspring or not. It also
Speaker 1: doesn't take into account speciation by geographical barrier. So perhaps
Speaker 1: two species that got separated are and are on different
Speaker 1: continents could reproduce viable fertile hybrid offspring. But does it
Speaker 1: really mean that these species that have been living apart
Speaker 1: for millions of years are the same species. There are
Speaker 1: also species of animals that reproduce asexually, and so the
Speaker 1: biological species concept doesn't really apply to them typically. I mean,
Speaker 1: usually when you have asexuality and species, they do go
Speaker 1: through phases of sexual reproduction, but still it adds a
Speaker 1: layer of complexity. There are also species that are quite
Speaker 1: clearly anatomically distinct, such as polar bears and grizzly bears,
Speaker 1: who can freely hybridize and produce viable, fertile hybrids. So
Speaker 1: pizleies and grollar bears are actually fertile and they can
Speaker 1: have offspring. Neanderthals and humans are considered different species. I
Speaker 1: mean we have different evolutionary lineages or more cousins than
Speaker 1: We didn't evolve from Neanderthals. We are cousins to Neanderthals,
Speaker 1: but we still have a lot of Neanderthal DNA floating
Speaker 1: around in our current human populations because of how we
Speaker 1: interbred successfully with the Neanderthals. In fact, one of the theories
Speaker 1: of Neanderthals disappearing is that, sure, we probably killed a
Speaker 1: lot of them off or out competed them, but a
Speaker 1: lot just simply kind of like integrated into human society,
Speaker 1: like we have Neanderthal DNA. There was a lot of
Speaker 1: interbreeding and so yeah, it just kind of Neanderthals became
Speaker 1: subsumed by humans. So basically defining what a new species
Speaker 1: is can get kind of messy, and there are some
Speaker 1: rough ways to do it, such as seeing if they
Speaker 1: can interbreed, looking at geographical location, looking at phenotypical differences
Speaker 1: so that's like what they look like, what is on
Speaker 1: the outside, and even examining genetic lineages and differences. So generally,
Speaker 1: if you have a species evolving into another species, it
Speaker 1: will either be anatomically, locationally or genetically distinct enough that
Speaker 1: scientists think it deserves its own category. In terms of
Speaker 1: Blake's question about oldest in newest species, things like sponges
Speaker 1: and comb jellies are probably the oldest animal species. These
Speaker 1: are oceanic species like sea sponges comb jellies that are
Speaker 1: these very simple looking interesting like almost transparent orbs or
Speaker 1: like tiny blimps. These probably came about over seven hundred
Speaker 1: million years ago. For comparison, crocodiles are only two hundred
Speaker 1: million years old, and the first flowering plant popped up
Speaker 1: only around one hundred and thirty million years ago. In
Speaker 1: terms of the newest animal. That's a little bit trickier
Speaker 1: given that evolution is a fluid process. It's happening all
Speaker 1: around us, and we simply don't have researchers looking at
Speaker 1: every single animal species on the planet being able to
Speaker 1: detect exactly when speciation happens. But an example of one
Speaker 1: of the newer species on Earth is a finch on
Speaker 1: the Galapagos Islands. Those same finches that Darwin noted had
Speaker 1: differently shaped beaks for the different types of seeds and
Speaker 1: food found on the different islands are still going through evolution.
Speaker 1: So in the nineteen nineties and early two thousands, researchers
Speaker 1: noted that a cactus finch had migrated over to a
Speaker 1: Galapagos island that it's not native to, the Daphne Major Island.
Speaker 1: Then researchers noticed a hybrid species come from this invader
Speaker 1: cactus finch and a native medium ground finch. The new
Speaker 1: hybrid species is actually fertile and has to breed only
Speaker 1: with other hybrids because they have such a different beak
Speaker 1: shape and different song to track females, it can really
Speaker 1: only breed with other hybrids, so of course there's a
Speaker 1: lot of inbreeding, but they managed to continue to function
Speaker 1: and grow to be a population of around twenty three
Speaker 1: into vials and eight bonded pairs. So I think researchers
Speaker 1: considered this a new species. So this just happened basically
Speaker 1: in the early two thousands, so that's pretty recent. I mean,
Speaker 1: this is by no means does this mean this is
Speaker 1: the absolute newest species. We just this is a relatively
Speaker 1: recent one that where we sort of notice the speciation.
Speaker 1: But yeah, this is probably happening too many species over
Speaker 1: the around the Earth, but we just simply don't know.
Speaker 1: And you can like track sort of the genetic changes
Speaker 1: and be able to see like when these kinds of
Speaker 1: speciations have occurred. But yeah, it can be quite recently,
Speaker 1: just within the last couple of decades. So we're going
Speaker 1: to take a quick break and then answer more listener questions.
Speaker 1: Here is another listener question. I thought maybe one idea
Speaker 1: for an episode could be unusual ways animals evolved to
Speaker 1: be aware of enemy or prey in their environment or
Speaker 1: have you done something like this already? I mean heads
Speaker 1: that spin around, weird eye placements for three hundred and
Speaker 1: sixty degree views supernatural senses only sleeping with half of
Speaker 1: your brain at a time, you probably know better ones.
Speaker 1: So this is from pekin In who sent me a
Speaker 1: really cute video of a kingfisher who has really amazing
Speaker 1: rotation of the head so it can turn its head
Speaker 1: much like an owl and look all scan all around
Speaker 1: rather than moving its eyes. I may indeed use this
Speaker 1: idea for a full episode, but in the meantime this
Speaker 1: suggestion actually made me think of weird eyes. And one
Speaker 1: of the weirdest eyes I can think of is this
Speaker 1: third eye that a lot of animals have called the
Speaker 1: parietal eye. So this is present in amphibians, lizards, salamanders,
Speaker 1: to ataras, which is a lizard like reptile. It's also
Speaker 1: found in lampreeze, which are these sort of eel like fish.
Speaker 1: They're found in some species of fish and in sharks.
Speaker 1: So the third eye is not like a wide open,
Speaker 1: regular eyeball, but you can often see a small bump
Speaker 1: or ridge on top of the animal's head, or in
Speaker 1: species that have interesting coloration, sometimes you see like a
Speaker 1: band of coloration around the eye. So it usually presents
Speaker 1: as this tiny gray oval and As the animal matures,
Speaker 1: it usually gets covered in a layer of skin. So
Speaker 1: the eye is not like the other two eyes. It
Speaker 1: does not have the rod and cone photoreceptors that we
Speaker 1: have in say, like our eyeballs, but it is more
Speaker 1: like a photosensitive mass that is connected to the pineal gland.
Speaker 1: So the pineal gland has roles in hormone production and
Speaker 1: regulating circadian rhythm and thermal regulation. So it's thought that
Speaker 1: this parietal eye also helps in these processes. So one
Speaker 1: theory is that it acts as a docimitter, which is
Speaker 1: a device that measures ionizing radiation. So the idea is
Speaker 1: that this is basically a biological docimter. So the parietal
Speaker 1: eye could potentially help regulate hormone production and thermal regulation
Speaker 1: based on the intensity of the sun's radiation. So which
Speaker 1: you know, seems to make sense, like you need to
Speaker 1: know like how to regulate your body's temperature if it's
Speaker 1: hotter outside, or how to regulate say, melatonin production based
Speaker 1: on the sun's position in the sky in terms of
Speaker 1: regulating sleep wake cycles. So when researchers remove the third eye,
Speaker 1: this parietal eye, from lizards, it seems to mess up
Speaker 1: their basking behavior and activity schedule, which shows it basically
Speaker 1: functions like a sun's sensitive watch for lizards, helping them
Speaker 1: know when they should be most active, when they should rest,
Speaker 1: and when they should either bask in the sun or
Speaker 1: or find refuge in the shade. It also seems to
Speaker 1: help lizards with navigation, using the sun as a marker
Speaker 1: and knowing how to navigate by memory. So in an experiment,
Speaker 1: lizards were trained that there's an invisible ledge in this
Speaker 1: pool of water, and they were basically they learned how
Speaker 1: to use the sun to navigate to this ledge, but
Speaker 1: when their parietal eyes were either covered or just surgically removed,
Speaker 1: they would swim in these random directions and fail to
Speaker 1: be able to find this ledge. It seems like it's
Speaker 1: also functioning as an internal compass by using the radiation
Speaker 1: as a sun as sort of a marker, and then
Speaker 1: being able to track like the lizard's relative position to
Speaker 1: the sun to determine location, which is really cool. I
Speaker 1: wish I had a third eye. I'm really bad at navigation.
Speaker 1: I very easily get turned around, so I could use
Speaker 1: all the help I can get and it would look
Speaker 1: really cool. We're going to take a quick break and
Speaker 1: answer another listener question when we get back. Next listener question,
Speaker 1: I have a question for your Listener Questions podcast. Why
Speaker 1: are gorillas so big and strong? Animals usually only invest
Speaker 1: that much energy into muscle if there's some evolutionary advantage,
Speaker 1: But what do gorillas get out of being so strong,
Speaker 1: especially compared to other primates? Thanks Gary, Hi, Gary, So
Speaker 1: this is a really interesting question because gorillas are herbivores.
Speaker 1: I mean, sometimes they will eat termites and ants, but
Speaker 1: either way, these food sources don't necessarily require a lot
Speaker 1: of strength to eat. In fact, there are many herbivores
Speaker 1: that are quite strong, like hippos. So it's very interesting
Speaker 1: when you see, like, you know, actually carnivores certainly do
Speaker 1: not have the monopoly on being strong, and some of
Speaker 1: the strongest animals are herbivore and they get all of
Speaker 1: their sort of muscle mass from vegetation, which is really interesting.
Speaker 1: So gorillas, unlike certain species like hippos, are actually not
Speaker 1: that aggressive. They don't typically use their body mass to
Speaker 1: just like you know, mow down other species. They're one
Speaker 1: of the more gentle primate species, especially with conspecifics. So
Speaker 1: conspecifics means a member of your own species, and gorillas
Speaker 1: tend to try to avoid conflict with each other, but
Speaker 1: the males will get territorial. They have a harem system
Speaker 1: where there is a dominant silverback gorilla who controls a
Speaker 1: troop of gorillas. Usually it ranges too up to like
Speaker 1: thirty individuals, including females and juveniles and babies, and the
Speaker 1: dominant male has the exclusive mating rites with the females
Speaker 1: unless being sneaky, and so he will attack any other
Speaker 1: males who tries to basically take over his territory, which
Speaker 1: comes with those mating rights to those females, And often
Speaker 1: there will be these aggressive displays, you know, chest thudding
Speaker 1: that that kind of like trope is. It's true. They
Speaker 1: will try to seem like like, look I am big,
Speaker 1: I am scary and strong. You don't want to take
Speaker 1: me on as a challenger, so that they you know,
Speaker 1: they would prefer to settle things relatively peacefully so they
Speaker 1: don't have to risk being injured. But they will fight,
Speaker 1: and sometimes they will fight to the death, especially when
Speaker 1: you have two troops of gorilla coming together. You have
Speaker 1: two dominant silver backs and they are trying to fight
Speaker 1: over territory. They can sometimes kill each other. They are
Speaker 1: also highly defensive of their families, both females and males,
Speaker 1: and they will definitely turn you into a body part
Speaker 1: salad if you come off as a threat to them
Speaker 1: or their family. But when you compare them to something
Speaker 1: like chimpanzees, they are a little bit less aggressive. Chimpanzees
Speaker 1: are a bit more I guess, ornery of a species.
Speaker 1: So why they're so strong, I mean, one thing you
Speaker 1: look at is the difference between males and females. So
Speaker 1: for the Western Lowland gorilla, which is found in the
Speaker 1: Congo basin, males weigh around three hundred to five hundred pounds,
Speaker 1: which is around one thirty to two hundred thirty kilograms,
Speaker 1: whereas females range from about one hundred and fifty to
Speaker 1: two hundred pounds, which is about one hundred and fourteen kilograms.
Speaker 1: So females are quite a bit smaller than the males,
Speaker 1: and this is a hint for what the strength is
Speaker 1: typically used for. The relatively greater strength of the males
Speaker 1: is likely a great benefit to them so that they
Speaker 1: can defend territory and access to females. So evolutionary pressures
Speaker 1: would greatly reward these stronger, bigger males, and with enough
Speaker 1: access to vegetation to feed their bulk, they are able
Speaker 1: to get very large. Now, unlike humans who have to
Speaker 1: like work out, go to the gym, do reps get
Speaker 1: swollen to maintain muscle mass, Girls' metabolism will automatically convert
Speaker 1: vegetation and cellulose into muscle mass. And they spend a
Speaker 1: lot of time on the ground rather than in the trees,
Speaker 1: so they're walking on their arms and a lot of
Speaker 1: like upper body strength used to move around, and they
Speaker 1: kind of have traded off the nimbleness of say like
Speaker 1: a chimpanzee who can spend more time in the trees
Speaker 1: for just being more of a tank. So the large
Speaker 1: silver backed dominant males can lead these troops around, you know,
Speaker 1: thirty individuals, like I said, and you know, even when
Speaker 1: he is threatened, he tries to kind of just put
Speaker 1: on this display. So they really are more docile then
Speaker 1: a lot of species. That doesn't mean you should try
Speaker 1: to approach one and like give him a fist bump
Speaker 1: or something, because he will ruin your entire body if
Speaker 1: he thinks you are a threat, like and you know
Speaker 1: you're a strange a stranger basically coming up to his family.
Speaker 1: He's not gonna assume you're there for good purposes. Another
Speaker 1: thing that they can use their strength for is to
Speaker 1: rip in tear branches to get up vegetation. And young
Speaker 1: gorillas will easily scale trees, but the adults really don't
Speaker 1: spend too much time in the trees. They can climb trees, though,
Speaker 1: and they will if they want to get a snack
Speaker 1: up there. So in terms of the question why why
Speaker 1: gorillas are so big compared to chimpanzees, I mean, one
Speaker 1: thing is that you kind of have this this thing
Speaker 1: that happens in evolution where it doesn't you don't always
Speaker 1: have to arrive to the same evolutionary design in order
Speaker 1: to be a successful species. So it's whatever evolutionary path
Speaker 1: that takes you towards something. So you have probably the
Speaker 1: selection for larger males because that makes it easier for
Speaker 1: them to compete for females in their environment. And then
Speaker 1: you have this kind of run a voye selection where
Speaker 1: like they get bigger and bigger, and as the males
Speaker 1: get bigger, the females also have to get bigger. I mean,
Speaker 1: you can't really have like a Chihuahua sized female and
Speaker 1: a you know, like girlicized male, So the females also
Speaker 1: will get larger in size even if there is this
Speaker 1: sexual dimorphism. Availability of vegetation is important, so if they
Speaker 1: live in a habitat where they really do have a
Speaker 1: lot of access to the food they need to nourish
Speaker 1: their bodies, that will allow for a larger size. Oh,
Speaker 1: an extinct primate called Gigantopithecus is it's like it looks
Speaker 1: like this, like huge a tan. It went extinct because
Speaker 1: of climate change, and they were so specialized in eating
Speaker 1: very specific vegetation. Once that was reduced by the change
Speaker 1: in climate, they were not able to generalize their eating
Speaker 1: behavior enough and they would they just died out due
Speaker 1: to lack of nutrition to maintain such a huge body.
Speaker 1: So being big is great, but it comes with this
Speaker 1: trade off, right, Like it means that if there are
Speaker 1: fewer resources, you are in a lot of trouble. So
Speaker 1: that's that's why, like not all species just like go
Speaker 1: towards being as big as possible. There are other ways.
Speaker 1: There are other ways to be successful as an animal.
Speaker 1: So while you might think that gorillas face no threats
Speaker 1: other than humans, given how giant they are, they're young,
Speaker 1: are actually quite vulnerable. So there was this case when
Speaker 1: seven gorillas were attacked by twenty seven chimpanzees for over
Speaker 1: an hour, during which time the chimpanzees were able to
Speaker 1: separate one of the babies from its mother, They kidnapped it,
Speaker 1: they killed it, and ate it. Nature is really brutal
Speaker 1: sometimes so, but you can see that even with all
Speaker 1: their strength, gorillas can be victims of attacks by huge
Speaker 1: mobs of chimpanzee. So the fact that they're really physically
Speaker 1: strong doesn't necessarily always give them an advantage to protect
Speaker 1: their young against chimpanzees who are able to just kind
Speaker 1: of a mass an army and be quick and nimble
Speaker 1: and then like steal away some of their young. So
Speaker 1: that large size does come with some downsides, which is agility,
Speaker 1: being able to quickly you know, hide, and so you know,
Speaker 1: I think that you and also what I mentioned earlier
Speaker 1: in terms of like getting enough vegetation, it might increase
Speaker 1: competition because each individual needs more food. So it's a
Speaker 1: trade off and it's not going to be the path
Speaker 1: at Some species take getting that big, but yeah, some
Speaker 1: species like it. It has worked out for the grills
Speaker 1: pretty much until you know, humans came into the picture
Speaker 1: and we've really been messing with them in terms of
Speaker 1: their habitat, and that's the main threat to them. Chimpanzees
Speaker 1: are not like the biggest threat. It's it's humans as usual.
Speaker 1: We are the most dangerous primate. So onto the Mystery
Speaker 1: animal sound game. Every week I play a mystery animal
Speaker 1: sound and you try to guess who is making that sound.
Speaker 1: So last week I actually did a rerun episode. I've
Speaker 1: been actually visiting the US, so I live abroad, but
Speaker 1: I came back to the US to visit family, visit friends,
Speaker 1: go to a few weddings. So last week I played
Speaker 1: a rerun. I might do the same next week. We'll see.
Speaker 1: I'll try to fit in another recording, but if I can't,
Speaker 1: I will pick out one of my favorite episodes for
Speaker 1: you to listen to. First, let us go over what
Speaker 1: was in the rerun episode, because there was a mystery
Speaker 1: animal sound and the hint given was this Its name
Speaker 1: sounds like a collaboration between a biologist, a heavy metal band,
Speaker 1: and a hairdresser. So congratulations to Amanda and Boyd and
Speaker 1: middle school grade seven for guessing correctly. The screaming Harry armadillo.
Speaker 1: So the screaming Harry armadillo is exactly as it sounds.
Speaker 1: It's a very hairy armadillo and it screams when it
Speaker 1: is handled. So they are found in Central and South
Speaker 1: American desert environments and they do not like to be
Speaker 1: picked up. And when a human picks them up, usually
Speaker 1: in a zoo or wildlife rescue organization, they will make
Speaker 1: this horrible man drake shriek. So onto the next mystery
Speaker 1: animal sound from the episode missing parts from two weeks ago.
Speaker 1: The hint this hairy animal doesn't want his picnic on
Speaker 1: a rainy day. So congratulations to Auntie Bee, Emily M
Speaker 1: and David D and David D's son Xavier, who all
Speaker 1: geessed correctly. The sun bear. So. Sun bears are the
Speaker 1: smallest bear species, weighing only around fifty to one hundred
Speaker 1: and forty pounds around twenty five to sixty five kilogrounds.
Speaker 1: They are found in rainforests in Southeast Asia. They have
Speaker 1: a patch of yellowish fur on their chests and are
Speaker 1: otherwise black with these tan muscles. They are very cute.
Speaker 1: They're pigeon toed with feet facing inwards and have large
Speaker 1: hooklike claws, allowing them to easily climb trees to get
Speaker 1: both protection and food sources such as honey bee's fruit.
Speaker 1: They'll rip open hollow trees just to get at the
Speaker 1: bees and honey inside. They eat also vegetation, termites, even
Speaker 1: small vertebrates when the chance arises, basically anything tasty that
Speaker 1: they can get their cute little Freddy Krueger claws on.
Speaker 1: In addition to threats from humans, young sunbears must contend
Speaker 1: with predation by pythons and leopards. Otherwise, they live in
Speaker 1: pretty hospitable environments, and they have enough nutrition to be
Speaker 1: active year round, and they do not hybridate onto This
Speaker 1: week's mister animal sound, the hint squeakers here doesn't like
Speaker 1: being handled. In fact, his own hands have turned into
Speaker 1: something very different through evolution. So do not adjust your podcast.
Speaker 1: That is an animal noise and not just the audio
Speaker 1: going crazy. Uh if you think you know who is squawking,
Speaker 1: each right to me at Creature Futurepod at gmail dot com.
Speaker 1: All right to me with your questions. I do these
Speaker 1: listener questions episode relatively regularly, so I try to get
Speaker 1: to every question in my inbox. And if I don't
Speaker 1: answer it on the show. I do try to respond
Speaker 1: to those emails, even if I am slow like a sloth.
Speaker 1: I will get there eventually. So thank you guys so
Speaker 1: much for writing into me. And thank you to the
Speaker 1: Space Classics for their super awesome song XO. Lumina Creature
Speaker 1: features a production of iHeartRadio. For more podcasts like the
Speaker 1: one you just heard, visit the iHeartRadio app, Apple Podcasts,
Speaker 1: or Hi Guess what. Maybe I listen to your favorite shows. Look,
Speaker 1: I will not rat you out to the podcast police.
Speaker 1: Don't worry. See you next Wednesday.