Episode 315: Dogs and Cats

02/13/23 • 9 min

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Thanks to Fabiana and Hazel for their suggestions this week, where we learn more about dogs and cats! Further reading: Gene mutation that makes dogs small existed in ancient wolves Feline genetics help pinpoint first-ever domestication of cats Cats Learn Names of Their Feline Friends A cat (Dracula, specifically, with Dracula the toy): A dog, in case you've never seen a dog before: Show transcript: Welcome to Strange Animals Podcast. I’m your host, Kate Shaw. This week we’re going to revisit two great topics suggested by two great listeners, Fabiana and Hazel. They suggested dogs and cats, respectively. We’ve covered both before, but there’s always more to learn about any animal. Let’s look specifically at two recent studies that can add to our knowledge. We’ll start with Fabiana’s suggestion of dogs. Results of a study published in January of 2022 examined the genetics of wolves and dogs to see how small dog breeds developed. We’re not completely sure how domestic dogs are related to wolf species alive today, since dogs have been domesticated for tens of thousands of years, and were probably domesticated at different times in different places by different groups of people, and potentially domesticated from different species of wolf, and since wolves and dogs can interbreed and produce fertile offspring. It’s very complicated, to say the least. Wolves are roughly the same size throughout the world, depending on species and environment. The gray wolf, which is native to the northern parts of North America and most of Eurasia, stands about 2 and a half feet tall at the shoulder, or about 85 cm, and weighs around 88 lbs, or 40 kg, on average, although wolves who live in warmer areas tend to be smaller. There are certainly dog breeds bigger than this, but there are lots of dog breeds that are much, much smaller. I mean, the Chihuahua only grows around 9 inches tall, or 23 cm, and usually barely weighs 6 lbs, or 2.7 kg. The prevailing belief is that small dog breeds came about because people bred the smallest dogs together and chose the smallest puppies from that pairing to breed to other small dogs. That’s true, but the genetic capacity for small size had to be there to start with in order to breed a 6-lb Chihuahua from an 88-lb wolf, no matter how many generations of dogs were in between. Researchers knew the genetic code for this size difference had to be somewhere, but it took a decade of study before they found it. Once they found the growth hormone mutation that could allow for very small size when expressed, they searched for it in over 200 dog breeds to see if it was there in all dogs. Sure enough, it was. The scientists hypothesized that the genetic mutation showed up after dogs were domesticated, somewhere around 20,000 years ago. To test this, they looked for the mutation in the genetic profiles of both living and extinct canid species. To their surprise, the mutation was present in all of them, including the genetic profile of a Siberian wolf that lived 54,000 years ago. Without this mutation, we wouldn’t have Chihuahuas or Yorkshire terriers or other small dog breeds that so many people love. That means the mutation was beneficial for domesticated dogs, but at the same time it was mostly non-beneficial for wild canids. When dogs were domesticated around 20,000 years ago, and possibly well before that, the world was in the middle of a glacial maximum. The climate throughout the entire Earth was considerably colder than it is today. Ocean levels were lower because so much water was frozen, with ice sheets covering northern Europe and North America to a depth of about 2 1/2 miles, or 4 km. Northern Asia had fewer ice sheets but was much dryer than it is today. In fact, the world was a lot dryer overall, so places that weren’t covered in ice were more likely to be deserts, leading to massive dust storms and just a general dustiness throughout the world.

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Episode 314: Animals Discovered in 2022

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Let's learn about some of the animals discovered in 2022! There are lots, so let's go! Further Reading: In Japanese waters, a newly described anemone lives on the back of a hermit crab Rare ‘fossil’ clam discovered alive Marine Biologists Discover New Giant Isopod Mysterious ‘blue goo’ at the bottom of the sea stumps scientists New Species of Mossy Frog Discovered in Vietnam A Wildlife YouTuber Discovered This New Species of Tarantula in Thailand Meet Nepenthes pudica, Carnivorous Plant that Produces Underground Traps Scientists discover shark graveyard at the bottom of the ocean Further Watching: JoCho Sippawat's YouTube channel A newly discovered sea anemone (photo by Akihiro Yoshikawa): A mysterious blue blob seen by a deep-sea rover: A newly discovered frog: A newly discovered tarantula (photo by JoCho Sippawat): Show transcript: Welcome to Strange Animals Podcast. I’m your host, Kate Shaw. It’s the 2022 discoveries episode, where we learn about some of the animals discovered in 2022! Most of the time these animals were actually discovered by scientists before 2022, but the description was published in that year so that’s when we first learned about them. And, of course, a lot of these animals were already known to the local people but had never been studied by scientists before. There are lots of animals in the world but not that many scientists. The great thing is, so many animals get discovered in any given year that I have to pick and choose the ones I think listeners will find most interesting, which in a stunning coincidence turns out to be the ones that I personally find most interesting. Funny how that works out. We’ll start in the ocean, which is full of weird animals that no human has ever seen before. It’s about a hermit crab who carries a friend around. The hermit crab was already known to science, but until a team of scientists observed it in its natural habitat, the deep sea off the Pacific coast of Japan, no one realized it had an anemone friend. The sea anemone is related to jellyfish and is a common animal throughout the world’s oceans. Some species float around, some anchor themselves to a hard surface. Many species have developed a symbiotic relationship with other animals, such as the clownfish, which is sometimes called the anemonefish because it relies on the anemone to survive. Anemones sting the way jellyfish do, but it doesn’t sting the clownfish. Researchers aren’t sure why not, but it may have something to do with the clownfish’s mucus coating. Specifically, the mucus may have a particular taste that the anemone recognizes as belonging to a friend. If the anemone does accidentally sting the clownfish, it’s still okay because the fish is generally immune to the anemone’s toxins. The clownfish lives among the anemone’s tentacles, which protects it from predators, and in return its movements bring more oxygen to the anemone by circulating water through its tentacles, its droppings provide minerals to the anemone, and because the clownfish is small and brightly colored, it might even attract predators that the anemone can catch and eat. Anemones also develop mutualistic relationships with other organisms, including a single-celled algae that lives in its body and photosynthesizes light into energy. The algae has a safe place to live while the anemone receives some of the energy from the algae’s photosynthesis. But some species of anemone have a relationship with crabs, including this newly discovered anemone. The anemone anchors itself to the shell that the hermit crab lives in. The crab gains protection from predators, who would have to go through the stinging tentacles and the shell to get to the crab, while the anemone gets carried to new places where it can find more food. It also gathers up pieces of food that the crab scatters while eating, because crabs are messy eaters. The problem is that hermit crabs have to move into bigger shells...

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Episode 316: The Blobfish and a Round Bunny

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This week we learn more about the blobfish thanks to Matilde's suggestion, and we'll also learn about a primitive rabbit. Further reading: In Defense of the Blobfish: Why the 'World's Ugliest Animal' Isn't as Ugly as You Think It Is A rare rabbit plays an important ecological role by spreading seeds The Amami Rabbit: A Living Fossil in the Wilds of Amami Ōshima [amazing photos in this article!] The blobfish as we usually see it: The blobfish as it looks when it's in its deep-sea home: The Amami rabbit is so so so round: Show transcript: Welcome to Strange Animals Podcast. I’m your host, Kate Shaw. This week we’re going to learn a little more about the blobfish, which is Matilde’s suggestion, and we’ll also talk about an unusual primitive rabbit that’s still alive today. We talked about the blobfish briefly in episode 231. The blobfish lives on the sea floor in deep water near Australia and New Zealand. It grows about a foot long at most, or 30 cm, and has weak muscles and a weak skeleton, but it doesn’t need to be any stronger since the intense pressure of the water presses in around the fish all the time. Its gelatinous flesh is slightly less dense than the water around it, which means it can float just above the sea floor without much effort, just drifting along, giving its tail and broad fins a little flap every so often. It eats whatever detritus floats down from far above, although it also really likes to eat small crustaceans that live on the sea floor. But wait, you may be thinking, I’ve seen pictures of the blobfish and it looks like a pinkish blob with a cartoony frown and a droopy nose. Is that blobfish a different one from the one I just described? No! The trouble is that the blobfish lives in really deep water, up to 4,000 feet below the surface, or 1200 meters. That means that there’s up to 4,000 feet of water above the fish, and if you’ve ever had to carry a bucket of water more than a few steps, you’ll know that water is really heavy. So the blobfish has 4,000 feet of water pressing on it from all directions. This is naturally called water pressure, and at the depths where the blobfish lives, it’s 120 times higher than water pressure in, for instance, your bathtub. At that water pressure, you could not survive for even one second. You would be instantly crushed into a messy blob if you were suddenly transported into water that deep, because your body is adapted to live on the earth’s surface. But the opposite is true for the blobfish. If it was suddenly transported to the earth’s surface, or at least the water’s surface, without all that comfortable pressure keeping its body in place like a really big exoskeleton you can swim through, the blobfish would expand. And that’s exactly what happens when a fishing net catches a blobfish and pulls it to the surface. It just goes BLOB all over the place. The blobfish was voted the world’s ugliest animal in 2013, which doesn’t seem fair since no one looks good when they’ve exploded into a blob. When the blobfish is alive in its deep-sea home, it’s silvery or grayish with little spikes all over its body. It’s a member of the family Psychrolutidae, sometimes called toadfish, and it has little black eyes near the top of its head sort of like a toad. Its head is large and wide, while its body tapers to a thin little flat tail. We know almost nothing so far about the blobfish, but we do know a bit about some of its close relatives like the blob sculpin. The blob sculpin lives in the North Pacific Ocean in even deeper water than the blobfish, up to 9200 feet deep, or 2800 meters. That’s about a mile and three-quarters deep, or almost 3 kilometers. Deep-sea animals are mostly solitary, but the blob sculpin gathers in large numbers to spawn. The females choose a nesting area and they all lay their eggs in the same place. Then the males release sperm into the water that fertilizes the eggs.