By Kelly Murray, CNN
From the darkest brown to the pastiest white and every shade in between, humans display a tremendous variety of skin colors. Human skin color is directly linked to our survival as a species as we lost our fur and developed a need for protection from the sun, and then migrated into cloudier regions of the globe. Over the course of evolution, scientists argue, skin color was influenced, among other factors, by our need for healthy bones.
To begin to explain this, we turn to Nina Jablonski, professor of anthropology at Pennsylvania State University. She is a well-recognized researcher in primate evolution, and specifically the evolution of human skin, and she was the subject of a Science Seat on CNN Light Years.
The story of human skin color begins with our furry ancestors about 6 to 7 million years ago in Africa, the last time that humans and chimpanzees shared an ancestor. Jablonski says that these ancestors, called Australopithecus, still had ape-like body proportions: fairly long arms and relatively short legs.
By Kelly Murray, CNN
Editor's note: The Science Seat is a feature in which CNN Light Years sits down with movers and shakers from different areas of scientific exploration. This is the eighth installment.
Being nice to others and cooperating with them aren't uniquely human traits. Frans de Waal, director of Emory University's Living Links Center at the Yerkes National Primate Research Center in Lawrenceville, Georgia, studies how our close primate relatives also demonstrate behaviors suggestive of a sense of morality.
De Waal recently published a book called "The Bonobo and the Atheist: In Search of Humanism Among the Primates," which synthesizes evidence that there are biological roots in human fairness, and explores what that means for the role of religion in human societies. CNN's Kelly Murray recently spoke with De Waal about the book.
By Elizabeth Landau, CNN
If you could time travel to 2 million years ago in South Africa, you might see a creature with humanlike hands and an ape-sized brain, walking upright with feet twisted inward.
Would you recognize this as your relative?
Anthropologists are keen on exploring the mysteries of human evolution presented by the fossilized remains of a species called Australopithecus sediba, or A. sediba for short. The latest collection of studies, published Thursday in the journal Science, presents more detail than ever about what this creature was like. Whether it's a direct ancestor of humans is controversial, however.
By Kelly Murray, CNN
Editor's note: The Science Seat is a feature in which CNN Light Years sits down with movers and shakers from many areas of scientific exploration. This is the sixth installment.
As primates, humans were once furry, much like the modern chimpanzee. But when, and why, did we lose this fur and become "naked"?
Nina Jablonski, professor of anthropology at Pennsylvania State University, studies primate evolution with an emphasis on human skin. Among numerous academic publications, she also wrote the book, "Skin: A Natural History."
CNN Light Years spoke with Jablonski about the evolution of human skin, from furry to naked. Here is an edited transcript:
Editor's note: Arthur Caplan is the Drs. William F and Virginia Connolly Mitty professor and director of the Division of Bioethics at New York University Langone Medical Center.
(CNN) – So now we know - there won't be a Neanderthal moving into your neighborhood.
Despite a lot of frenzied attention to the intentionally provocative suggestion by a renowned Harvard scientist that new genetic technology makes it possible to splice together a complete set of Neanderthal genes, find an adventurous surrogate mother and use cloning to gin up a Neanderthal baby – it ain't gonna happen anytime soon.
Nor should it. But there are plenty of other things in the works involving genetic engineering that do merit serious ethical discussion at the national and international levels.
Even though humans and chimpanzees share 98% of their DNA, there is a great disparity in intelligence between the two species. Scientific American reports that a new study has revealed one reason why: During the first two years of life, human brains undergo a huge expansion in white matter - the connections between brain cells - at a rate twice that of chimpanzee brains.
National Geographic reports that a new species of slow lorises has been discovered in Borneo. Like other slow lorises, the N. kayan produces a toxic bite by rubbing its hands around venomous glands near its armpits and applying the poison to its teeth. Its bite can induce a predator into lethal anaphylactic shock.
ScienceDaily reports that more microbial species than ever thought before are traveling across the Pacific Ocean from Asia to North America via Earth’s troposphere. This layer of atmosphere pools and transports microbes, including several species of fungi and bacteria, during “plume events.”
During spring 2011, scientists collected samples in plumes originating in Asia to detect aerosols and pollutants. Now, using a newer culturing method that looks at biomass in the form of DNA, researchers are able to study bacteria and fungi in these samples that are thought to affect weather patterns. Many of these species are specially adapted to travel long distances in harsh conditions, challenging the old notion that the atmosphere is just a transient place for life.
Scientists have reconstructed proteins and DNA from prehistoric yeast cells, Phys.org reports. By studying these enzymes, scientists can determine which types of sugars these ancient yeasts once digested, deepening their view of the evolutionary innovation of biological catalysts.
Many argue that plants are just as alive as we are. It is not news to scientists that plants are responsive to odors, but earlier instances of this were all plant-to-plant communication, phys.org reports. In a recent study, scientists determined that a tall goldenrod can sense a male fly’s sex attractant and start to prepare chemical defenses to protect itself from the female fly’s damaging eggs.
By Elizabeth Landau, CNN
Humans are picky eaters, and not just because we’re the only species that reviews restaurants. A new study suggests that our ancestors’ diets may have been different from our close primate relatives much earlier than we thought.
The human ancestor in question is called Australopithecus bahrelghazali. Remains of it were found in Chad at the Koro Toro fossil site. Researchers looked at fossils are more than 3 million years old.
Researchers examined the ratios of carbon isotopes present in the teeth of this early hominin, a word paleontologists use to talk about human ancestors. They reported their results in the journal Proceedings of the National Academy of Sciences.
Atheist. Biologist. Writer. Thinker. Richard Dawkins has developed an international reputation of spreading the word that evolution happened and that there is no "intelligent design" or higher being, as you might gather from the title of his book "The God Delusion."
But no matter what you think about his convictions, his ideas have gone viral - including the word "meme."
CNN caught up with Dawkins while he was passing through Atlanta earlier this year. His next U.S. tour is in October.
Here is an edited transcript of part of the conversation. Watch the video above for a more focused look at Dawkins' ideas about evolution vs. intelligent design.
From a finger bone, scientists have reconstructed the genetic world of an entire population of extinct human relatives called Denisovans. But questions still abound about who exactly they were.
They weren’t quite like modern humans or Neanderthals, but some other group entirely. Everything we know about the Denisovans is based on a finger bone and two teeth.
Those small remnants, found in a cave in southern Siberia, are enough to figure out a few important things about these ancient people - including that some people today share genes with them.
For the first time, scientists have sequenced the Denisovan genome, with a quality that is about as high as the genome of a person alive today. That means scientists can learn about as much genetically about a person who lived tens of thousands of years ago as they could about a living person. The findings, published this week in the journal Science, deliver a wealth of insight about ancient people who roamed the Earth tens of thousands of years ago.
The family tree of humanity as we know it - Homo sapiens - isn't as straightforward as "one species gave way to another." New evidence suggests that at least two different Homo species lived in Kenya about 2 million years ago.
Scientists report in the journal Nature that they have linked recently discovered fossils with a controversial cranium found in 1972 in Kenya. They believe these new remnants belonged to the same species as the skull, which has been dubbed Homo rudolfensis. The study is led by prominent paleontologist Meave Leakey.
The Homo rudolfensis skull, found near Lake Turkana, has a bigger brain case and a flatter face than specimens of Homo habilis, the other species of the Homo genus that appears to have lived around that time. Homo habilis is thought to have been a toolmaker because its hand bones were found next to stone tools.