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8 Times Very Different Animals Evolved Very Similar Traits

Koalas and humans (specifically, Australian Prime Minister Tony Abbott and U.S. President Barack Obama). Image credit: Andrew Taylor/G20 Australia via Getty Images

Ever show up at a party dressed to the nines only to find that someone else was wearing the same outfit as you? Awkward! But don’t be too embarrassed. Something like this happens in nature all the time. Different creatures sometimes face very similar problems and environmental pressures, like getting from point A to point B or protecting themselves from predators that hunt a certain way. Faced with the same challenges, two (or more) groups of organisms may arrive at the same solution independently and develop adaptations that are similar in form or function but weren’t found in their last common ancestor.

This phenomenon is called convergent evolution (say that to your next dress twin), and you can see it all over. Here are just a few examples.

1. HUMANS HAVE FINGERPRINTS … AND SO DO KOALAS.

While the pattern of dermal ridges on your fingertips is unique to you, the ridges in general are not. Some of our primate relatives like chimpanzees and gorillas have them, too. We all got them from a common ancestor, but another animal developed them all on its own: the koala. Koalas have dermal ridges that form whorls, loops and arches just like ours, and the researchers that first noted them say that they’re very similar in form to those of humans— similar enough that even under a microscope, koala and human fingerprints are hard to tell apart. Moreover, just like human fingerprints, koala fingerprints seem to be unique to individuals. (Note to koalas: You had better not find yourself in a crime scene.)

The scientists think that koalas’ ridges developed fairly recently in their evolutionary history, as most of their close relatives don’t have them, and suggested they might be an adaptation for grasping and manipulating the koala’s favorite food, eucalyptus leaves. Though to be fair, scientists are still trying to figure out why we have fingerprints, even though they don’t appear to improve our grip.

2. BATS, BIRDS, AND FLYING BUGS: THREE DIFFERENT SOLUTIONS FOR WINGS

A barn owl at British Wildlife Centre, Surrey, England. Image credit: Peter Trimming via Wikimedia Commons // CC BY 2.0

One of the clearest examples of convergence is flight in birds and bats. The two groups aren’t closely related; they descend from non-flying ancestors and developed the ability to fly independently. In both cases, their forelimbs morphed over time into wings, but in different ways. Bats took to the air using a membrane (called the patagium) attached to their body, arms, and elongated fingers, while birds’ wings consist of feathers extending all along a forelimb whose finger bones fused together to create a different shape. Flying insects, meanwhile, developed their wings in a whole other way. With no internal skeleton to tweak like birds and bats, their wings came from modifications to their exoskeletons.

3. BATS AND WHALES: REAL-LIFE DAREDEVILS

Bats share another adaptation with a different, much larger animal. Both bats and the toothed whales echolocate, meaning that they emit high-pitched sounds and listen for the echoes in order to navigate and hunt. Bats produce their echolocation calls with their larynx and emit them through their mouth or nose, while whales pass air through their nasal passage to push vibrations out from a fatty tissue called the melon.

Interestingly, this same tactic has evolved in two very different environments: the sea and the sky. Even more amazing is that echolocation arose independently in each group and is done in different ways, but works thanks to the same genetic mutations. Two studies (independently conducted and appearing in the same issue of the same journal—talk about convergence) showed that bats and whales have experienced the same changes to a gene involved in sound processing, allowing them each to better hear the ultrasonic frequencies used for echolocation.

4. SHREWS AND LIZARDS: MASTERS OF THE SAME POISON

A Mexican beaded lizard. Image credit: Ltshears via Wikimedia Commons // Public Domain

The Northern short-tailed shrew and the Mexican beaded lizard are two animals you wouldn’t want to be bitten by. Both are venomous, and the toxins in their saliva can cause respiratory failure. While the species rely on two different toxins to give their bites some bite, both poisons evolved from the same digestive enzyme through very similar changes. In both species, the enzyme went through “almost identical” alterations, giving rise to two distinct toxins that do the same job.

5. CROSSING KINGDOMS: CATERPILLARS AND PLANTS

A bird's-foot trefoil in southern Sweden. Image credit: Fredrik Lähnn via Wikimedia Commons // Public Domain

Convergent evolution isn’t just limited to two types of animal. It can also happen with species that are in entirely different kingdoms of life. This is the case for a plant called the bird's-foot trefoil and the burnet moth caterpillar that feeds on it. Both the plant and the caterpillar protect themselves from predators with cyanide. The trefoil uses a trio of genes to convert a pair of amino acids into two cyanides. The caterpillars can absorb the plant’s poisons when they eat its leaves and use them to protect themselves, but researchers have found that caterpillars that don’t feed on trefoils contain the same toxins—which means they also make them themselves.

What’s more, the caterpillars produce the toxin in almost the same way as the plant. Scientists found that the caterpillars use a different group of three genes to turn the same starter chemicals into the same cyanides using the same chemical reactions. This is, the researchers say, the first example of identical biosynthetic pathways evolving convergently in two different kingdoms.

6. BUTTERFLIES AND THEIR JURASSIC-ERA LOOKALIKES, LACEWINGS

Structural diversity among lacewings. Image credit: composite image via Wikimedia Commons from Yang et al. in BMC Evolutionary Biology // CC BY 2.0

Tens of millions of years before butterflies appeared, another animal was doing a pretty good impression of them. Kalligrammatid lacewings were insects that flitted around Europe, Asia, and South America during the Mesozoic Era. They weren’t the ancestors of butterflies, but were strikingly similar to them in shape, coloration and, scientists think, ecology. Looking at lacewing fossils earlier this year, scientists found that one species, Oregramma illecebrosa, had patterns on its wings very similar to those of the modern owl butterfly. The researchers think they served the same purpose: mimicking the eyes of a larger creature to scare off predators. The two groups of bugs also evolved similar-looking long proboscises for getting the same food—nectar from plants. Even though the flowering plants butterflies feed on didn't exist back in the lacewings’ day, they seem to have hit on the same tool for tapping a different set of plants during a very different time.

7. GECKOS AND GECKOS: ADHESIVE TOES ARE A MUST

Convergent traits don’t always show up in organisms that are as wildly different as bats and dolphins or caterpillars and plants. Sometimes multiple members of the same lineage independently develop a new trait that their common ancestors didn’t have. Scientists used to think that the adhesive toes many geckos use to scale vertical surfaces evolved once in their common ancestor, but it turns out that the wall-crawling lizards all developed the trait on their own time and time again. Recent research suggests that adhesive toes evolved at least 11 separate times across the geckos’ family tree. The adaptation appears to have been ditched almost as often; it was independently lost on nine occasions.

8. TWO CRICKETS, TWO HAWAIIAN ISLANDS, ONE SILENCE

Pinned cricket of the speciesTeleogryllus oecanicus from the collection of the Zoologische Staatssamlung München. Image credit: via Franziska Walz via Wikimedia Commons

In another case of convergent evolution happening in the same group, two populations of the same cricket species converged on the same trait in different ways. About 10 years ago, field crickets on the Hawaiian island of Kauai started to go quiet. It’s not that they were just choosing to stay mum; they’d lost the ability to chirp because males were being born without sound-producing structures on their wings. A few years later, crickets on the island of Oahu similarly went silent. At first, scientists thought that the trait—dubbed “flatwing”—had spread because of quiet crickets making their way from one island to the other, but a look at the crickets’ genes revealed convergent evolution in action. The two populations had stopped chirping independently, with two different genetic mutations leading to two different, modified wing shapes and the same outcome—silence. But why go quiet? The crickets are sometimes targeted by a parasitic fly, which follows the cricket’s chirp to find them and lay its eggs inside them, eventually killing the host. The silent treatment seems to protect the crickets from the fly.

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Everything You Ever Wanted to Know About Dogs
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Dogs: They’re cute, they’re cuddly … and they can smell fear!

Today on Scatterbrained, John Green and friends go beyond the floof to reveal some fascinating facts about our canine pals—including the story of one Bloodhound who helped track down 600 criminals during his lifetime. (Move over, McGruff.) They’re also looking at the name origins of some of your favorite dog breeds, going behind the scenes of the Puppy Bowl, and dishing the details on how a breed gets to compete at the Westminster Kennel Club Dog Show.

You can watch the full episode below.

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Sploot 101: 12 Animal Slang Words Every Pet Parent Should Know
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For centuries, dogs were dogs and cats were cats. They did things like bark and drink water and lay down—actions that pet parents didn’t need a translator to understand.

Then the internet arrived. Scroll through the countless Facebook groups and Twitter accounts dedicated to sharing cute animal pictures and you’ll quickly see that dogs don’t have snouts, they have snoots, and cats come in a colorful assortment of shapes and sizes ranging from smol to floof.

Pet meme language has been around long enough to start leaking into everyday conversation. If you're a pet owner (or lover) who doesn’t want to be out of the loop, here are the terms you need to know.

1. SPLOOT

You know your pet is fully relaxed when they’re doing a sploot. Like a split but for the whole body, a sploot occurs when a dog or cat stretches so their bellies are flat on the ground and their back legs are pointing behind them. The amusing pose may be a way for them to take advantage of the cool ground on a hot day, or just to feel a satisfying stretch in their hip flexors. Corgis are famous for the sploot, but any quadruped can do it if they’re flexible enough.

2. DERP

Person holding Marnie the dog.
Emma McIntyre, Getty Images for ASPCA

Unlike most items on this list, the word derp isn’t limited to cats and dogs. It can also be a stand-in for such expressions of stupidity as “duh” or “dur.” In recent years the term has become associated with clumsy, clueless, or silly-looking cats and dogs. A pet with a tongue perpetually hanging out of its mouth, like Marnie or Lil Bub, is textbook derpy.

3. BLEP

Cat laying on desk chair.
PoppetCloset, Flickr // CC BY-NC-ND 2.0

If you’ve ever caught a cat or dog poking the tip of its tongue past its front teeth, you’ve seen a blep in action. Unlike a derpy tongue, a blep is subtle and often gone as quickly as it appears. Animal experts aren’t entirely sure why pets blep, but in cats it may have something to do with the Flehmen response, in which they use their tongues to “smell” the air.

4. MLEM

Mlems and bleps, though very closely related, aren’t exactly the same. While blep is a passive state of being, mlem is active. It’s what happens when a pet flicks its tongue in and out of its mouth, whether to slurp up water, taste food, or just lick the air in a derpy fashion. Dogs and cats do it, of course, but reptiles have also been known to mlem.

5. FLOOF

Very fluffy cat.
J. Sibiga Photography, Flickr // CC BY-NC-ND 2.0

Some pets barely have any fur, and others have coats so voluminous that hair appears to make up most of their bodyweight. Dogs and cats in the latter group are known as floofs. Floofy animals will famously leave a wake of fur wherever they sit and can squeeze through tight spaces despite their enormous mass. Samoyeds, Pomeranians, and Persian cats are all prime examples of floofs.

6. BORK

Dog outside barking.
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According to some corners of the internet, dogs don’t bark, they bork. Listen carefully next time you’re around a vocal doggo and you won’t be able to unhear it.

7. DOGGO

Shiba inu smiling up at the camera.
iStock

Speaking of doggos: This word isn’t hard to decode. Every dog—regardless of size, floofiness, or derpiness—can be a doggo. If you’re willing to get creative, the word can even be applied to non-dog animals like fennec foxes (special doggos) or seals (water doggos). The usage of doggo saw a spike in 2016 thanks to the internet and by the end of 2017 it was listed as one of Merriam-Webster’s “Words We’re Watching.”

8. SMOL

Tiny kitten in grass.
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Some pets are so adorably, unbearably tiny that using proper English to describe them just doesn’t cut it. Not every small pet is smol: To earn the label, a cat or dog (or kitten or puppy) must excel in both the tiny and cute departments. A pet that’s truly smol is likely to induce excited squees from everyone around it.

9. PUPPER

Hands holding a puppy.
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Like doggo, pupper is self-explanatory: It can be used in place of the word puppy, but if you want to use it to describe a fully-grown doggo who’s particularly smol and cute, you can probably get away with it.

10. BOOF

We’ve already established that doggos go bork, but that’s not the only sound they make. A low, deep bark—perhaps from a dog that can’t decide if it wants to expend its energy on a full bark—is best described as a boof. Consider a boof a warning bark before the real thing.

11. SNOOT

Dog noses poking out beneath blanket.
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Snoot was already a dictionary-official synonym for nose by the time dog meme culture took the internet by storm. But while snoot is rarely used to describe human faces today, it’s quickly becoming the preferred term for pet snouts. There’s even a wholesome viral challenge dedicated to dogs poking their snoots through their owners' hands.

12. BOOP

Have you ever seen a dog snoot so cute you just had to reach out and tap it? And when you did, was your action accompanied by an involuntary “boop” sound? This urge is so universal that boop is now its own verb. Humans aren’t the only ones who can boop: Search the word on YouTube and treat yourself to hours of dogs, cats, and other animals exchanging the love tap.

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