background preloader

Human

Facebook Twitter

Jaw-dropping theory of human evolution. Why Did Consciousness Evolve, and How Can We Modify It? Update 5/24/11: The conversation continues in Part II here.

Why Did Consciousness Evolve, and How Can We Modify It?

Rare Neurons Found In Monkeys’ Brains. A mysterious kind of nerve cell that has been linked to empathy, self-awareness, and even consciousness resides in Old World monkeys.

Rare Neurons Found In Monkeys’ Brains

The finding, published May 10 in Neuron, extends the domain of the neurons beyond humans, great apes and other large-brained creatures and will now allow scientists to study the habits of a neuron that may be key to human self-awareness. The Evolution of Grief, Both Biological and Cultural, in the 21st Century. Three months ago, I received an email informing me that a high school friend, Pat, had died.

The Evolution of Grief, Both Biological and Cultural, in the 21st Century

I read his obituary and my body stopped functioning. I froze on the spot, limbs tense but trembling. My mouth went dry, my vision blurred. As I waited for my train in the packed station, I could barely stand as my muscles turned to jelly and legs folded beneath my body. I tried to maintain composure in the public space, but my contorted face betrayed my sorrow. It was shocking to me: I felt real physical pain — a biological response brought about by stress hormones — in response to death.

Fast-Evolving Brains Helped Humans out of the Stone Age. Just like our animal skin–clad ancestors, we gather food with zeal, lust over the most capable mates, and have an aversion to scammers.

Fast-Evolving Brains Helped Humans out of the Stone Age

And we do still wear plenty of animal skins. But does more separate us from our Stone Age forebears than cartoonists and popular psychologists might have us believe? At first blush, parsing the modern human in terms of behaviors apparently hardwired into the brain over eons of evolution seems like a tidy, straightforward exercise. And 30 years ago, when the field of evolutionary psychology was gaining steam, some facile parallels between ancient and modern behaviors lodged themselves in the popular conceptions of human evolution. One gene helped human brains become complex - life - 03 May 2012. Read more: Click here to read a longer version of this story When it comes to brain development, slow and steady wins the race.

One gene helped human brains become complex - life - 03 May 2012

A single ancestral human gene that made two copies of itself may have helped the evolution of our large brains 2.5 million years ago, as our ancestors were diverging from australopithecines. Paradoxically, it seems the effect of the extra copies was to slow down individual brain development. This allowed time for neurons to develop more and better connections with one another. Gene duplications are rare in human history: only about 30 genes have copied themselves since we split from chimps 6 million years ago. Climate and Human Evolution. Missing Lincs. Nearly everybody knows that Frank Lloyd Wright designed Fallingwater, the house in Pennsylvania that sits above and appears to cascade into a waterfall.

Missing Lincs

I.M. Pei’s glass pyramid at the Louvre in Paris is similarly famous. And Frank Gehry is widely known for the curvi­linear shining steel Walt Disney Concert Hall in Los Angeles. Long strands of genetic material called lincRNAs (blue) may guide protein-DNA interactions, among other tasks. Was humanity born in the mother of all plagues? - health - 04 June 2012. Around 100,000 years ago, the human race was on the brink of extinction.

Was humanity born in the mother of all plagues? - health - 04 June 2012

Confined to Africa, our population had fallen to less than 10,000. Yet within a few tens of thousands of years, we began spreading around the world. New genetic evidence suggests that one factor contributing to the population bottleneck was a massive epidemic of bacterial disease. The bacteria were exploiting two immune system genes, turning them against us. So the solution was simple: get rid of the traitorous genes. Ajit Varki of the University of California, San Diego and colleagues looked at two genes called Siglec-13 and Siglec-17. Chinese human fossils unlike any known species - life - 14 March 2012. And so it begins.

Chinese human fossils unlike any known species - life - 14 March 2012

For years, evolutionary biologists have predicted that new human species would start popping up in Asia as we begin to look closely at fossilised bones found there. A new analysis of bones from south-west China suggests there's truth to the forecast. The distinctive skull (pictured, right) was unearthed in 1979 in Longlin cave, Guangxi Province, but has only now been fully analysed. It has thick bones, prominent brow ridges, a short flat face and lacks a typically human chin. "In short, it is anatomically unique among all members of the human evolutionary tree," says Darren Curnoe at the University of New South Wales in Sydney, Australia. Evolution Takes Asian Refuge. After ancient people left their African homeland, they migrated into Asia and Europe, taking refuge from ice age conditions in areas isolated from other populations, two new reports suggest.

Evolution Takes Asian Refuge

That isolation may have prompted the evolution of new Homo species, including a mysterious Asian population dubbed Denisovans and possibly an unusual-looking humanlike group now identified in China. New Ancestor Grasped At Walking. An ancient member of the human evolutionary family has put what’s left of a weird, gorillalike foot forward to show that upright walking evolved along different paths in East Africa.

New Ancestor Grasped At Walking

FOOTLOOSE HOMINID Eight toe bones (shown in the outline of a gorilla foot) found in Ethiopia belonged to a 3.4 million-year-old human ancestor that combined tree climbing with awkward walking. Y. Haile-Selassie/Cleveland Museum of Natural History A 3.4 million-year-old partial fossil foot unearthed in Ethiopia comes from a previously unknown hominid species that deftly climbed trees but walked clumsily, say anthropologist Yohannes Haile-Selassie of the Cleveland Museum of Natural History and his colleagues. Their report appears in the March 29 Nature.

Field Notes: A Visit to an Early Human Death Trap [Videos and Slide Show] In late November 2011 I went to Johannesburg, South Africa, to meet the newest member of the human family, a nearly two million–year-old creature dubbed Australopithecus sediba. First announced in 2010, its fossilized bones have caused quite a commotion in paleoanthropological circles—and with good reason.

They are some of the most complete early hominins (the group that includes modern humans and their extinct relatives) ever found, and they exhibit a combination of apelike and humanlike traits that no one would have predicted. Think ape arm with human hand, ape heelbone adjoining human anklebone. In the cover story of the April issue, I describe the unexpected discovery of the fossils and explore the latest thinking on where Australopithecus sediba fits in our family tree. First of Our Kind: Could Australopithecus sediba Be Our Long Lost Ancestor? Ancient Walking Gets Weirder. You Have Grandpa's Chromosome Tips. Men who become fathers later in life may pass a mark of longevity down to their paternal grandchildren. As men age, chromosomes in their sperm are tipped with longer telomeres — structures that protect valuable genetic information from deterioration during cell division and other processes. Longer telomeres have been associated with long life, whereas short telomeres have been linked to aging and disease.

Scientists have known for a while that telomeres increase in length for every year a man ages and that children of older dads inherit longer telomeres. But the new study by researchers at Northwestern University in Evanston, Ill., extends that inheritance to grandchildren. The new finding, published online June 11 in the Proceedings of the National Academy of Sciences, could point to a mechanism by which men can influence the health of their offspring for generations.