Genetics suggests unexpected origins of hummingbirds

Caprimulgiformes is a group of night- and twilight-active (nocturnal–crepuscular), mostly insectivorous birds found on every continent except Antarctica. It includes birds with such colorful names as nightjars, oilbirds, potoos, frogmouths and owlet-nightjars. In addition to their activity times and diet, they tend to have weak legs and some species can even echolocate, using sonar to …

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Genetics of South American rodents points to evolution

Rodents are an extremely successful group of mammals. There are more species of rodents than any other type of mammal, and they inhabit nearly every stretch of land on earth. Some rodents are geographically restricted, however, with a number of groups being located entirely in the Americas. Chinchillas and viscachas (Chinchillidae) are exclusively found in …

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DNA points to reptilian ancestry of birds

As I discussed in the previous post, the fossil record tells a story that at first seems implausible: birds are descendants of dinosaurs. Part of what's surprising about this idea is that dinosaurs typically appeared very reptilian, whereas birds do not. Without providing a formal definition of "reptile", you probably have a general image in your head. This is because reptiles …

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DNA of wingless insects points to evolution

Perhaps you haven't thought of it much before, but relatively few species of insects completely lack wings. One kind of wingless insect is known as a silverfish, an animal that perhaps you have discovered crawling in your home or hanging out in your pantry. Typical of insects, they possess six legs, a chitinous exoskeleton, compound eyes and a pair …

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Genetics suggests predatory birds aren’t related

For eons, predatory birds have inspired people across numerous cultures. Religious texts have drawn upon them in metaphors, they have aided hunters in catching game fowl for millennia, America's founding fathers adopted one as a national symbol, one bird of prey in action adorns the Mexican flag, and various sports teams have chosen them as mascots. While few people may pull …

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Not all moles are created equal

Most people could probably identify the animals below:    Short stubby bodies, long powerful claws, regressed eyes, living underground: these are all moles. Aren't they? Counterintuitively, their DNA tells a different story. The mole at the top left is a true mole (Talpidae), a group of moles found in Eurasia and North America. Their DNA is not particularly similar to …

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Big birds don’t always flock together

If you had to think of the biggest bird you know, you'd probably conjure up an image of an ostrich (Struthio camelus). If you have some familiarity with Australian fauna, the emu (Dromaius novaehollandiae) might also come to mind. If you're a bird watching champion back home, you might even know about the cassowaries (Casuarius spp.) and the rheas …

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Genetics points to repeated leg loss in lizards

Typically when you one thinks of legless reptiles, snakes come to mind. Their long slithering bodies and forked tongues are unmistakable, and for many people, snakes conjure up their worst fears. If given the choice of holding a lizard or a snake, many people would not hesitate to choose the former. Despite the superficial dissimilarities between snakes …

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Echolocating bats are not all genetically similar

In addition to being able to fly, bats are relatively unique in having the capability to echolocate. Echolocation in bats, just like in a submarine, involves directing sounds out into the environment and detecting the reflecting sound waves. By comparing where the reflecting sounds come from, bats flying in the dark can estimate their distance from prey items and …

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DNA suggests sloths, armadillos and anteaters are each other’s closest relatives

When one thinks of sloths anteaters and armadillos it's difficult to imagine mammals that are more different from each other. Sloths look a bit like lorises and pottos: arboreal, tailless mammals that move quite slowly. Armadillos look somewhat like pangolins, with their scaly armor. Technically, pangolins, also known as scaly anteaters, probably have more in common with …

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