Rapid Genetic Evolution Linked to Lighter Skin Pigmentation in a Southern African Population

By Karen Nikos-Rose

Populations of indigenous people in southern Africa carry a gene that causes lighter skin, and scientists have now identified the rapid evolution of this gene in recent human history.

The gene that causes lighter skin pigmentation, SLC24A5, was introduced from eastern African to southern African populations just 2,000 years ago. Strong positive selection caused this gene to rise in frequency among some KhoeSan populations.

Brenna Henn

UC Davis anthropologist Brenna Henn and colleagues have shown that a gene for lighter skin spread rapidly among people in southern Africa in the last 2000 years.

Measuring Wear in Bone Tools

A UC Davis anthropologist has been building a catalog of high-resolution 3D models of bone tools worn by working various materials, all in the name of archaeology.

UC Davis graduate student Naomi Martisius with a rib bone she has shaped as a leather-working tool. Bone tools like these are often found in archaeological sites with the tips broken off.

Humans have been using bone tools for about two million years, and by about 100 thousand years ago were processing bones to make tools for specific purposes, such as working animal skins into leather. Both the way tools are made, and the way they are used, leave tiny marks on the bones that could give information about how these tools were prepared and used.

The Whole Tooth: New Method to Find Biological Sex From a Single Tooth

A team led by UC Davis researchers have come up with a new way to estimate the biological sex of human skeletal remains based on protein traces from teeth.

Tooth of a European-American buried in San Francisco in the 1850s. A new technique developed at UC Davis allows archaeologists
to find a person’s biological sex based on a single tooth. (Jelmer Eerkens)

Estimating the sex of human remains is important for archaeologists who want to understand ancient societies and peoples. Researchers can measure features of bones that differ between males and females, usually the pelvis. But skeletons of children and adolescents don’t show these structural changes, and often sites may only yield a few pieces of bone.

Study Challenges Evolution of How Humans Acquired Language

By Karen Nikos-Rose

A gene implicated in affecting speech and language, FOXP2, is held up as a “textbook” example of positive selection on a human-specific trait. But in a paper in the journal Cell on Aug. 2, researchers challenge this finding. Their analysis of genetic data from a diverse sample of modern people and Neanderthals saw no evidence for recent, human-specific selection of FOXP2 and revises the history of how we think humans acquired language.

Brain graphic

What makes us human? The FOXP2 gene has been associated with uniquely human language abilities. But a new study with a wider variety of people shows no evidence of selection for FOXP2 in modern humans. (Image by Brenna Henn, UC Davis)

Podcast: Monkey See, Monkey Learn, Monkey Do

South American capuchin monkeys are curious animals that readily learn new skills. UC Davis graduate student Brendan Barrett talks about studying learning in these monkeys in this episode of the Three Minute Egghead podcast.

https://soundcloud.com/andy-fell/monkey-see-monkey-learn

Capuchin monkeys can learn new skills by watching each other. (Brendan Barrett/UC Davis)

Read the original story here.

 

Farming, Cheese, Chewing Changed Human Skull Shape

The advent of farming, especially dairy products, had a small but significant effect on the shape of human skulls, according to a recently published study from anthropologists at UC Davis.

Skull models

David Katz measured specific points on human skull bones (top) to create a wire frame model of the skull and jaw (bottom). Blue dashes indicate changes in skull shape from foragers to dairy farmers.

Put another way, our skulls were changed by the invention of cheese.

People Lived in Chilly Andean Highlands Year-Round Over 7,000 Years Ago

By Karen Nikos-Rose

A summer hike at 13,000 feet (4,000 meters) is challenging given the lack of oxygen, frigid temperatures, and exposure to elements. Now imagine living year-round at high elevation without your high-tech gear or modern foods.

High-altitude plateaus are challenging places to live, but archaeologists have found hunter-gatherers colonized the Andean Highlands 7,000 years ago. Photo by Lauren A. Hayes

Scientists debate whether early human populations could have done so, but a new UC Davis study confirms that intrepid hunter-gatherers—women, men, and children—called the Andean highlands home over 7,000 years ago.

Wallflower or Center of the Pack? Baboons Find Their Place

By Karen Nikos-Rose

Are you the kind of person who, at a party, tends to be surrounded by friends in the middle of the crowd, or do you prefer to find a quiet corner where you can sit and talk? Recent work by scientists at UC Davis shows that wild baboons behave similarly to humans —  with some animals consistently found in the vanguard of their troop while others crowd to the center or lag in the rear.

On early human migration, geography and culture

By Kathleen Holder

Our species, Homo sapiens, left Africa earlier than previously thought and our diverse cultures have been heavily influenced by geography, according to a recent review by Alexander (Sandy) Harcourt, professor emeritus of anthropology at the University of California, Davis.

The paper grew out of a keynote address to a National Academy of Sciences colloquium in Irvine earlier this year on comparative phylogeography, the study of the geographic distribution of species (Watch a video of Harcourt’s lecture below).

Often decried, polygyny may have some advantages

Is being a “sister wife” always a bad thing?

By Kathleen Holder

Much of the world frowns on the practice of polygamy. Most countries around the globe ban or restrict marriages to more than one spouse at a time. And polygyny—where one husband has more than one wife—is decried by the United Nations Human Rights Committee and women’s rights organizations as discriminatory to women.

But a new study of polygyny in Tanzania finds that the practice of sharing a husband may, in some circumstances, lead to greater health and wealth for women and their children.