After Darwin at AMNH: David Hurst Thomas

Thursday, January 28 4:29 pm

Curator David Hurst Thomas Tests Darwin in Archaeological Sites

Scientists at the American Museum of Natural History continue to celebrate the 200th anniversary of Charles Darwin’s birth and the 1859 publication of On the Origin of Species with a collection of vignettes describing expeditions and ideas with links to Darwin’s seminal work.

Part of the St. Catherines archaeology team shucking oysters to determine the amount of energy (in calories) that people can retrieve in relation to the amount of energy spent collecting and processing. Credit: Lorann S.A. Pendleton.

Deer, clams, oysters, alligators: if you walked the length of St. Catherines Island off of Georgia, what would you pop into your mouth? David Hurst Thomas, curator in the Division of Anthropology at the Museum, uses optimal foraging theory to interpret the remains of thousands of meals left behind in archaeological sites across the island.

Optimal foraging theory puts an evolutionary spin on what people chose to eat. The assumption that individuals decide what to consume in a way that maximizes the total energy return and minimizes the energy they must spend to search for, collect, and prepare food items in their environment. This approach is known as the “diet breadth model,” a series of testable hypotheses about what an efficient forager will pick (and not pick) from the array of available food.

“Darwinian evolutionary ecology allows us to frame some concrete expectations about what a forager should choose to gather,” says Thomas. “Suppose someone dropped a pot of coins. Some would be selective, picking up only silver dollars, and others would rush to pick up everything. The diet breadth model allows us to distinguish between these strategies in archaeological sites.”

Thomas and his team have spent more than 30 years excavating different archaeological sites throughout the island’s 14,000-plus acres. Recently, the team conducted a series of foraging experiments that, as Thomas puts it, “hook theory to dirt archaeology” by mapping the most efficient strategies for harvesting the available foodstuffs. They harvested oysters, dug up clams, butchered diamondback terrapins, and drank periwinkle soup. For each food type, the archaeologists recorded the length of time and amount of energy expended for collecting and processing. These data were then compared to the amount of available energy gained from food to answer a key question: if I invest one hour in foraging, what is the energetic return on that investment? The result, expressed as kilocalories per hour, allows researchers to compare different food types. Read more »

David Buss Answers Why Humans Have Sex

Tuesday, January 26 2:56 pm

Evolutionary psychologist David M. Buss, author of Why Women Have Sex, will lead a special Valentine’s Day edition of SciCafe on February 3 at the Museum. He recently answered some questions about the upcoming talk, discussing the deeper knowledge of human sexual psychology.

In 2007, you co-wrote Why Humans Have Sex. Why did you choose to focus on one gender in the follow-up, Why Women Have Sex: Understanding Sexual Motivations from Adventure to Revenge (and Everything in Between)?

Women’s sexual psychology is more complex than men’s. For example, men’s sexual orgasm tends to be predictable and reliable. For women, orgasm is profoundly affected by context, mood, circumstances, and how a partner looks, smells, and touches. Given the complexities of women’s sexual psychology, we concluded that women deserved a full book-length treatment.

During your research for Why Humans Have Sex, did you find the answers were significantly different for men and women? What are some of the differences?

Social status among peers, for example, is a stronger motivator of sex for men than for women. Although having sex to become emotionally close is a motivator for both men and women, it’s a stronger motivator for women. Also, because women’s sexuality is so highly prized and valued in men’s minds, women are often in a position of power when it comes to sex.

Is there scientific basis for love at first sight?

Love at first sight is a real phenomenon. Interestingly, men are more susceptible to love at first sight than are women. The reason is that physical appearance is substantially more important to men. Women place more importance on other qualities, such as emotional stability, intelligence, and personality, which take time to evaluate.

Which sense has the largest influence on mate selection?

For men, the visual sense is by far the most important in mate selection. Women use more of their senses. Smell, for example, is more important for women than it is for men. In fact, if a woman doesn’t like the way a man smells, it can be a sexual kill-switch, even if he has other desirable qualities

In your original study, you identified 237 distinct motivations for why humans have sex. Which reasons surprised you?

The most surprising reason is a rather nasty one: having sex in order to give someone else a sexually transmitted disease. I was also surprised by the “revenge” motivation. Some people have sex to get revenge on a friend who has “mate poached” their partner or to punish their own partner.

What can guests expect to take away from your discussion at the upcoming SciCafe?

A deeper knowledge of human sexual psychology and mating strategies.

Young Naturalist Program Accepting Essays

Thursday, January 21 11:55 am

The American Museum of Natural History invites students in grades 7 to 12 to tackle questions about the natural world just as a scientist would—by formulating hypotheses, planning investigations, gathering data—and to write about their findings for the 13th Annual Young Naturalist Awards, a nationwide essay contest for students presented by the Museum and supported by Alcoa Foundation.

Contestants are invited to plan and conduct research about the natural world stemming from their personal interest. Entrants share their data, conclusions, and experiences in essays that describe their observations and findings. Last year’s winners’ research included such diverse topics as the feeding preferences of birds in the Red Oak Nature Center in Aurora, Illinois, the effects of controlled prairie fires on invasive plants in southern Michigan, and the microbes living in coral mucus collected in Hawaii.

Each of the 12 winners, chosen for their insight, originality, and accuracy in observation and research as well as creativity in writing and documentation through illustrations and photography will receive a free trip to New York City, a behind-the-scenes tour at the Museum with working scientists, and a cash award ranging from $500 to $2,500. In addition, winning contestants will have their essays published on the Museum’s website.

“The Young Naturalist Awards is a unique program offered by the Museum that acknowledges young people for their engagement in scientific research,” said Rosamond Kinzler, Director of the National Center for Science, Education and Technology. “In addition to the recognition provided for the 12 winners, every student that enters the contest receives a letter with feedback from the Museum’s expert panel of scientists and educators about their work. And for teachers, the program is a powerful tool they can use to provide their students with direct experiences in science, technology, engineering, and mathematics areas that are essential for standards-based science education.”

The deadline for submissions is March 1, 2010.  To learn more about the program, visit the Museum’s Young Naturalist Awards Web site, and for more information, email yna@amnh.org or call (212) 496-3498.

2009 Young Naturalist Awards winner Alexandra Day kayaks in Chesapeake Bay conducting research in nutrient pollution. Photo courtesy of Alexandra Day.

Celebrating Biodiversity, Parasite by Parasite

11:00 am

Parasites highlighted on the new blog include Hymenolepis microstoma, Wolbachia pipientis, and Sacculina carcini. Credit: Pete Olson, USCS and Hans Hillewaert.

For the next 365 days, Museum Curator Susan Perkins is going to wiggle through thousands of species, burrow through relationship networks, and siphon off the relevant and interesting facts for her new blog, Parasite of the Day. Perkins will post a daily profile of a parasite that she unearths as part of a celebration of the United Nation’s International Year of Biodiversity.

Parasites are those species that we blast with an arsenal of chemicals, pinch to remove from our pets and plants, and, well, generally try to shake off. But parasites have amazing evolutionary histories and biological adaptations, and Perkins, who studies malaria and other pathogens, is the perfect person to tout them.

Check out her blog each day to see what stories she finds. Recent posts include tapeworms that inhabit rodents via flour beetles, an insect-infecting bacterium that is a distant relative of Salmonella and sometimes feminizes males, barnacles that get crabs to care for them as if eggs, and Trypanosoma brucei, the single-celled organisms that use rapid costume changes to fool immune systems and cause the disease sleeping sickness.

Neil deGrasse Tyson Named Science Communicator of the Year

Friday, January 15 2:59 pm

Neil Tyson chats with visiting school children in the Rose Center for Earth and Space at the American Museum of Natural History Credit: AMNH

The Hayden Planetarium’s director, astrophysicist Neil deGrasse Tyson, is now EarthSky’s Science Communicator of the Year.

In a recent interview, Dr. Tyson focuses on the importance of scientific literacy and education. “Kids are born scientists,” he says. “They’re born probing the natural world that surrounds them. They’ll lift up a rock. They’ll pick up a bug. They’ll pull petals off a flower. They’ll ask you why the grass is green and the sky is blue, and they’ll experiment with breakable things in your house. It might mean they break a dish someday, because they’re experimenting with how dishes roll down the corridor. But they’ll learn something about how fragile something as brittle as glass can be.”

“There’s a lesson there,” he continues. “Yeah, you’ll break a dish. So you buy a new dish. And you say, ‘Well, that can be costly.’ But, as Derek Bok, who was president of Harvard, once said, ‘If you think education is costly, look at the cost of ignorance.’”

EarthSky began presenting Science Communicator of the Year awards in 2008. Dr. Tyson is the second recipient and was selected by an advisory committee of more than 600 scientists.