Evolution is an amazing process. Any life form, from lowly sponges to massive whales, can show evidence of how the process of adaptation has worked to its advantage over many generations. Sometimes, an adaptation works so well that it becomes a defining characteristic of every branch of that life form’s family tree. Other times, they probably fail and die out. But the really interesting thing is when evolution rolls the dice a second time. Some trait, some adaptation, that arises in one life form, and then an entirely separate life form that is barely related, if at all, independently evolves similar traits. And this happens more often than you might think.
10. Things continue to develop into crabs in a process called cancerization.
Science has some bad news if you're not a fan of multi-legged, crawling life forms that scurry around and have claws. Nature wants everything to be a crab. In fact, nature wants things to be crabs so much that we have a word for it — carcinization It's a process of evolution from something that's not a crab to something that's a crab, and it's ongoing.
While we don't have to worry about turning into crabs one day, this process does seem to affect creatures that started life in a normal "crab-like" space. That is, crustaceans like lobsters or hermit crabs, which are not originally crab-shaped, are evolving toward crabs. This happened three times in a group of crustaceans called anomurans. What they evolve into is technically not a true crab, they can't change species, but they become crab-like . I think you saw a crab.
King crabs, those long-legged buffet staples around the world, are an example of this. The king crab is not a true crab, but a decapod anomurana. Its ancestors were actually hermit crabs Hermit crabs have to use the shells of other sea creatures because they have such a soft exoskeleton, so the evolution to the king crab, which has a really strong skeleton, is quite dramatic. Other examples include porcelain crabs and hairy stone crabs, which are also not “true” crabs. But their path to the crab world was an independent and very unusual example of convergent evolution.
9. Pitcher plants evolved independently at least six times.
Pitcher plants often fascinate people more than the average garden flower, if only because they are carnivorous. The idea of a stationary life form feeding on other life forms is unique. Or so it seems. However, evolution seems to love the concept. So much so that pitcher traps evolved completely independently of each other, at least six times . These plants belong to different families, including bromeliads, where you you will find pineapples .
Unrelated lineages of carnivorous plants are most prominent in three families . These plants should not be confused with the Venus flytrap, which catches its prey using a different mechanism. Instead, pitcher plants are defined as a kind of cup containing digestive fluid. Insects or other sources of nutrients are drawn into the cup, often by a slippery surface that has evolved independently in most species, and fall in. Different biological backgrounds.
8. Three-toed and two-toed sloths are not closely related.
The internet loves a good sloth video, and why shouldn’t it? Sloths represent the optimal life for many people. They relax, they chill, they eat, and they sleep. It’s kind of enviable. And we even have two sloths to choose from, a three-toed sloth and a two-toed sloth. While both of these creatures are known for being extremely slow, living in trees, and hanging upside down, it’s also clear that they don’t look much alike on the outside.
The two-toed sloth is the shaggier of the pair and is related to a giant prehistoric sloth called Megalonyx and Mylodon darwinii . Three-toed sloths are more closely related to Megatherium. But like the three-toed sloth, the two-toed sloth evolved to live upside down in trees, though none of his major ancestors did this did. And that means that this tree-dwelling is a defining characteristic of both species, which evolved independently. If the two species shared a common ancestor at all, scientists aren't sure when it might have been or what kind of creature it was. Their best guess is that if it did, it certainly didn't hang out in trees.
7. Falcons are more closely related to parrots than to eagles.
Many people are afraid of birds, and Alfred Hitchcock knew this. It doesn't help much when scientists tell us that dinosaurs evolved into birds, so basically every chicken is a tasty T-Rex.
In the world of birds, some are definitely more frightening than others. Birds of prey are naturally terrifying, thanks to their flesh-rending beaks and talons. Hawks, eagles, and falcons seem to have speed and ferocity on their side. But the odd thing here is that falcons are not like those two. Despite how easy it is to confuse a falcon with a hawk, they are only distantly related and are another example of convergent evolution in action.
Rather than being closely related to eagles, falcons are actually much closer to parrots . That the peregrine falcon is literally the fastest creature in the world , closer to a parrot than an eagle, seems somehow wrong. Despite this, DNA evidence shows that the two birds' common ancestor is much more closely related to each other than other birds of prey.
6. The eyes of humans and cephalopods are very similar
Every year it seems like new research proves that octopuses are amazingly smart animals, and we do them a disservice by ignoring that fact. But it's not just their brains that are unique; almost everything about octopuses as a species is remarkable. Take their eyes, for example. They act like same as and human eyes, but it is quite clear that they evolved completely independently. The same can be found in other cephalopods, such as squid. Somewhat more remarkable is that Behind our backs, both we and they are responsible for the same thing same genes .
There’s a gene called Pax6 that controls the basic structure of the eye in almost every creature. It’s found in a wide variety of animals, which means it predates evolutionary diversity. So it’s been around for over 500 million years. Think of it as a master gene that controls how an eye forms – it could be a complex insect eye, a lizard eye, a bird eye, and so on. But when it comes to humans and cephalopods, they each evolved a very similar structure that we call a camera eye. There’s a lens, an iris, a fluid-filled interior, and so on. And over 500 million years and two species, one on land and one in the sea, convergent evolution has produced the same basic structure in both.
5. New World and Old World vultures are not closely related.
In the world counted 22 species birds called vultures. You can usually recognize a vulture as a fairly large bird, usually bald and prone to scavenging. In general, they seem a little rough by human standards, because their heads are constantly buried in rotten carcasses, but they do provide a great service by cleaning up all that toxic, bacteria-laden meat, so don't be too hard on them.
These 22 species of birds can be divided a little further into Old World and New World , that is, the vultures found in Europe, Africa, and Asia, and then the vultures found in North and South America. Despite the striking similarities between the New and Old World species, there are genetic differences that indicate that many of these birds have evolved convergently.
Old World vultures seem to have evolved from birds of prey, they are an offshoot of raptors. However, New World vultures can trace their origins from storks .
4. Six different lines of electric fish evolved separately
There are many unique and even terrifying creatures in the sea. One of the most unusual is the electric eel. They can generate up to 500 volts (some say 600 volts) at a current of one ampere. But this is not the only electric fish. And others that have the same ability are not related to the eel. In fact, electric fish have evolved independently for at least six different cases All of these animals use the same genes, they just did it all over the world at different times and in different places.
While eels live in fresh water, electric rays can be found in the Atlantic Ocean. Like all rays, they are broad and flat, almost the opposite of an eel in appearance. But their electrical generating abilities are very similar. And since we know that most fish cannot generate electricity, the idea of a common ancestor among the various electrically charged species makes no sense. The ability arose uniquely and independently. It has happened only half a dozen times.
3. Sugar gliders are not related to flying squirrels.
Sugar gliders and flying squirrels are two of the most delightfully strange little mammals you'll find in the treetops. Both have wide flaps of skin under their arms that allow them to glide from branch to branch, both have long tails and big eyes, and if you didn't know much about either species, you'd probably have no idea how to tell them apart from a cursory glance.
It is noteworthy that these similarities very superficial. Sugar gliders are marsupials and raise their young in pouches, while flying squirrels do not. While there are 50 species of flying squirrels in the world, there are only 6 Types of Sugar Gliders , and they are native to Australia. Like most other marsupials, they evolved in isolation from creatures like the flying squirrel, making their similarities an example of convergent evolution. The flying squirrel is actually more closely related to primates , than with sugar gliders.
2. Humans and koalas have very similar fingerprints.
Koala bears are perhaps Australia's most memorable residents, right up there with kangaroos but perhaps more popular for their adorable appearance. As cute as they are, you'd never mistake a koala for a human because they're two-foot-tall, tree-dwelling grey bears. Koalas are marsupials and are most closely related to wombats, possums and, yes, kangaroos. However, in a very unique case of convergent evolution, their little marsupial toes have fingerprints that are soclose to human, that even experts can hardly tell them apart at first glance.
To find a common ancestor between humans and koalas, you have to go back about 100 million years back , long before Tyrannosaurus rex walked the earth. However, their fingerprints look and potentially work just like ours. Since koalas only eat eucalyptus leaves, and only certain ones, it’s likely that tactile function is important to help them choose the right leaves, and these fingerprints will come in handy. They need a precise grip and sensitivity, just like humans, so it seems that their fingerprints evolved along the same lines as ours.
1. Bats and dolphins have almost identical echolocation abilities.
Bats and dolphins are about as different from each other as it is possible for any two mammals in the world to be. Yet despite their incredible differences, there is evidence that convergent evolution has taken place in both species, leading to the development of their remarkably similar echolocation abilities.
By analyzing several species of bats, as well as dolphins, scientists have found similar genetic signatures in 200 regions of the genome , associated with echolocation. The researchers expected to find only 10 to 30 genes in common. When they looked at bats that did not use echolocation, none of these genetic similarities showed up.
In particular, bats and dolphins have had mutation in protein called prestin, which affects hearing. That this mutation could occur in two very different species and have the same effect was unexpected, and showed that convergent evolution goes far beyond the physical adaptations we see on the surface, and involves genetic adaptation as well.
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