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.
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.
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: The Science Seat is a feature in which CNN Light Years sits down with movers and shakers from many different areas of scientific exploration. This is the fourth installment.
Ever wondered why some tomatoes taste great, and many others don’t?
Professor Harry Klee, a horticulturalist at the University of Florida in Gainesville, is on a mission to improve the taste and quality of supermarket tomatoes. He was elected to the National Academy of Sciences in 2012 for his efforts.
Klee presented his research in Boston recently at the American Association for the Advancement of Science annual meeting. CNN Light Years spoke with Klee before the conference. Here is an edited transcript:
What would it take to change sexes? In humans, it involves complicated surgeries and rigorous hormonal therapies, not to mention hefty social and psychological ramifications. But in the Eastern Pacific Ocean, tiny orange-and-blue fish are naturally transitioning from female to male, and male to female, all the time.
Bluebanded goby fish, about 2 to 2.5 inches long, are able to change their sex when it suits their position in social hierarchies.
Check out some of the latest headlines in evolution and biology:
Fungi produce variances in wine grapes
Fungi growing on grapes may contribute to flavor differences between post-harvest grapes from the same vineyard, Phys.org reports. A new study sent researchers to three adjacent, well-established vineyards: traditional, organic and biodynamic, to sample the aromatic and fermentative qualities of the grapes. The least treated vineyard had more variety of fungal species than the others, but the researchers noted that temperature and sun exposure greatly influences the type of fungi present on the grapes.
Sommeliers, take note: Your idea of the best wine may depend on microbes!
Birdsong: Is it really music?
A new Emory University study suggests that when female white-throated sparrows hear a male’s birdsong during breeding season, the same reward system in the brain is activated as when humans listen to music they enjoy, ScienceDaily reports. Neural imaging maps show and compare neural responses to these signals that are “evolutionary ancient mechanisms necessary for reproduction and survival,” according to researcher Sarah Earp.
This suggests that birdsong and music may have similar functions or evolutionary precursors, but there are limitations - many brain regions in humans that respond to music are not found in birds.
Retired chimps face financial challenges
The New York Times notes that while the National Institutes of Health is tapering its use of chimpanzees in biomedical research, it is having financial difficulty in placing retired chimps into retirement facilities and sanctuaries.
Sanctuaries like Chimp Haven in Louisiana provide retired chimpanzees with a more natural environment and social setting than research institutes. The organization says the monetary cap to move and support these chimps will likely be reached this fiscal year.
Two new species of orchid discovered in Cuba, revealing evolutionary history
Researchers in Cuba have uncovered two new species of orchid, ScienceDaily reports. Many orchids have a special type of reproduction, called "deceit pollination," relying on their colors and shapes to attract insects and birds, not on nectar or other substances. One mystery the researchers are trying to solve is whether deceit-pollinating orchids have greater diversity than other nectar-producing species.
By examining the flowers’ petal shapes and sizes, they’re also trying to determine their evolutionary relationship with those on a neighboring island.
Human intelligence mysteries explained by chimpanzee brains
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.
Primate with venomous armpits discovered
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.
Microbes ride troposphere from Asia to North America
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 use yeast to resurrect extinct enzymes
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.
Read more on this story.
Goldenrod plant can smell danger
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.
Light Years strives to tell the stories of science research, discovery, space and education. This is your go-to place on CNN.com for today’s stories, but also for a scientific perspective on the news and everyday wonders. Come indulge your curiosity in all things space and science related, brought to you by the entire CNN family.
July 19thAtlas V launch of US DOD MUOS-2 satellite, notable for large "551" config of Atlas
Aug 3rdJapanese HTV-4 flight to ISS on cargo supply mission
Aug 14thSpaceX launch of Canadian satellite in the first launch from their new Vandenberg facility, and first launch of upgraded Falcon 9 v1.1 launch vehicle
Aug 28thDelta IV Heavy launch of NROL-65 spy satellite
SeptemberSoyuz TMA-08M flight returning Expedition 36 crew from ISS to Earth (Kazakhstan)
Sept 12thOrbital Sciences maiden flight of Cygnus cargo vehicle on Antares rocket to ISS
Sept 25thSoyuz TMA-10M flight launching Expedition 38 crew to ISS
Dec 9thSpaceX Dragon launch by Falcon 9 v1.1 on CRS-3 cargo supply mission to ISS
recurringfirst powered test flights of Scaled Composites' SpaceShipTwo commercial vehicle, to be used by Virgin Galactic for sub-orbital tourism