A team of evolutionary biologists have demonstrated that some limb muscles known to be present in many mammals but absent in the adult human are actually formed during early human development and then lost prior to birth. These findings offer insight into how our arms and legs evolved from our mammalian ancestors, and also help explain rare limb anomalies found in humans born with congenital malformations.
Read moreResearchers have produced some of the first evidence that shows that artificial selection and natural selection act on the same genes, a hypothesis predicted by Charles Darwin in 1859.
Read moreSongs are a storehouse for ethnobiological knowledge and a means to construct, maintain and mobilize peoples' relations with their local environments.
Read moreBy looking at 90-year-old crocodile skulls in museum collections and double-checking with live specimens at a zoological park in Florida, researchers have just discovered a new species of ten-foot-long croc. The new species, Crocodylus halli, is from the southern part of New Guinea, and until now, scientists had thought it was the same species that lived on the northern part of the island.
Read moreAn evolutionary biologist has spent more than three decades studying the skulls of many species of large carnivores — including wolves, lions and tigers — that lived from 50,000 years ago to the present. She reports today the answer to a puzzling question.
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Mosasaurs were true sea monsters of late Cretaceous seas. These marine lizards — related to modern snakes and monitor lizards — grew as long as fifty feet, flashed two rows of sharp teeth, and shredded their victims with enormous, powerful jaws.
Giant, predatory croc-like animals that lived during the Triassic period in southern Africa preyed on early dinosaurs and mammal relatives 210 million years ago. These predators, known as 'rauisuchians' preyed on early herbivore dinosaurs and their mammal relatives living at the time.
Read moreEtched onto the steep walls of Arizona's 6,000-foot-deep, 277-mile-long Grand Canyon are clues that chronicle the sweeping changes the region has experienced during the past two billion years. The canyon's colorful layers narrate tales of ancient environments come and gone, from lofty mountain ranges and tropical seas to a Saharan-scale desert that once stretched across much of western North America.
Read moreScientists studying genetic transcription are gaining new insights into a process that is fundamental to all life. Transcription is the first step in gene expression, the process taking place within all living cells by which the DNA sequence of a gene is copied into RNA, which in turn (most generally speaking) serves as the template for assembling protein molecules, the basic building blocks of life.
Read moreMany people are familiar with the existence of Neanderthals, the humanoid species that was a precursor to modern humans, but far less is known Denisovans, a similar group that were contemporaries to the Neanderthals and who died out approximately 50,000 years ago. Researchers have now made a reconstruction of a Denisovan girl based on patterns of methylation (chemical changes) in their ancient DNA.
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