Humans do not have tails, but do we have “what it takes” for a tail? Hens don’t have teeth, but they have the genes for it. With atavism, it is as if our genomes serve as archives of our evolutionary past.
Posts tagged Evolution.
Oldest Hominin DNA Sequenced: Mitochondrial Genome of a 400,000-Year-Old Hominin from Spain Decoded
Dec. 4, 2013 — Using novel techniques to extract and study ancient DNA researchers at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, have determined an almost complete mitochondrial genome sequence of a 400,000-year-old representative of the genus Homo from Sima de los Huesos, a unique cave site in Northern Spain, and found that it is related to the mitochondrial genome of Denisovans, extinct relatives of Neandertals in Asia. DNA this old has until recently been retrieved only from the permafrost.
Chromosome 2 - What separates chimps from humans?
At the genetic level chimpanzees are almost indistinguishable from humans, so how did the formation of human chromosome 2 lead to our divergence from our primate relatives?
Geneticist Aoife McLysaght heads to Dublin Zoo to explain more…
Early Tree-Dwelling Bipedal Human Ancestor Was Similar to Ancient Apes and ‘Lucy’ but Not Living Apes
Dec. 4, 2013 — An analysis of the femur of one of the oldest human ancestors reveals the six-million-year-old “Millenium Man” was bipedal but lived in the trees. The research, led by Stony Brook University researchers and their team of international paleoanthropologists, could provide additional insight to the origins of human bipedalism and is published inNature Communications.
New Fossil Species Found in Mozambique Reveals New Data On Ancient Mammal Relatives
Dec. 4, 2013 — In the remote province of Niassa, Mozambique, a new species and genus of fossil vertebrate was found. The species is a distant relative of living mammals and is approximately 256 million years old. This new species belongs to a group of animals called synapsids. Synapsida includes a number of extinct lineages that dominated the communities on land in the Late Permian (260-252 million years ago), as well as living mammals and their direct ancestors.
New Evidence Suggests Neanderthals Organized Their Living Spaces
Dec. 3, 2013 — Scientists have found that Neanderthals organized their living spaces in ways that would be familiar to modern humans, a discovery that once again shows similarities between these two close cousins.
The findings, published in the latest edition of the Canadian Journal of Archaeology, indicate that Neanderthals butchered animals, made tools and gathered round the fire in different parts of their shelters.
Beak evolution in some dinosaurs likely associated with diet, not flight, study shows
Beaks are a typical hallmark of modern birds and can be found in a huge variety of forms and shapes. However, it is less well known that keratin-covered beaks had already evolved in different groups of dinosaurs during the Cretaceous Period.
Employing high-resolution X-ray computed tomography (CT scanning) and computer simulations, Dr Stephan Lautenschlager and Dr Emily Rayfield of the University of Bristol with Dr Perle Altangerel (National University of Ulaanbaatar) and Professor Lawrence Witmer (Ohio University) used digital models to take a closer look at these dinosaur beaks.
"What a piece of work is a [human]!" remarks Hamlet. "How noble in reason, how infinite in faculty!" And yet [human], this "paragon of animals," is no source of delight to Shakespeare’s contemplative prince.
One can hardly blame him.
Consider what a “freaking mess” the human brain is, after all. David Linden, professor of neuroscience at Johns Hopkins University, peers into the hardware that [humans have] been given, and finds the most primitive operating system:
"We have two visual systems in our brain, a subconscious one and a conscious one. We have two auditory systems in our brain, a subconscious one and a conscious one. No engineer ever would have designed it like this."
No wonder that Hamlet, plagued as he is by visions of ghosts and thoughts of suicide, has such a difficult time sorting things out. He has to take in information from two different streams and fuse them together. That’s what creates our behavior.
And so if God designed our brain, you could call him a really bad engineer. Or, to put it another way, as François Jacob famously said, evolution is a tinkerer and not an engineer. When you’re a tinkerer, David Linden explains, "you throw things together to solve the problem at hand. You don’t build elegantly and you don’t build the way an engineer would build to try to consider all the possible contingencies. You’re just solving the one problem that circumstances have dealt you at this moment."
That is why we should avoid falling into the trap of believing that just because something evolved means that it is useful to us today. Our brains are impressive, Linden says. But the engineering behind the brain “is completely insane.”
Mysteriously Intact T. Rex Tissue Finally Explained
The controversial discovery of 68-million-year-old soft tissue from the bones of a Tyrannosaurus rex finally has a physical explanation. According to new research, iron in the dinosaur’s body preserved the tissue before it could decay.
The research, headed by Mary Schweitzer, a molecular paleontologist at North Carolina State University, explains how proteins — and possibly even DNA — can survive millennia. Schweitzer and her colleagues first raised this question in 2005, when they found the seemingly impossible: soft tissue preserved inside the leg of an adolescent T. rex unearthed in Montana.
How whales made the dramatic evolutionary shift from land to the sea
All whales and dolphins are descended from terrestrial mammals, ancient creatures that were very similar to the modern hippopotamus. Now, a fascinating new genetics study shows the incredible evolutionary changes these animals had to experience to become the perfectly adapted marine animals we see today.
Biologists aren’t entirely sure which creature modern cetaceans (dolphins, whales, and porpoises) are descended from. The traditional theory suggests mesonychids, an extinct order of carnivorous ungulates (hoofed animals) which resembled wolves. But more recent genetic analysis points to artiodactyls, a hippo-like creature. Regardless, all cetaceans were land mammals at one point in their evolutionary history — and they had to undergo some rather remarkable changes to adapt to underwater life.