Tag Archives: biology

Why are human faces so unique?

What’s in a face? The amazing variety of human faces — far greater than that of most other animals — is the result of evolutionary pressure to make each of us unique and easily recognizable, according to a new study out of UC Berkeley.

Behavioral ecologist Michael J. Sheehan explains that our highly visual social interactions are almost certainly the driver of this evolutionary trend. Many animals use smell or vocalization to identify individuals, making distinctive facial features unimportant, especially for animals that roam after dark, he said. But humans are different.

In the study, Sheehan and coauthor Michael Nachman asked, “Are traits such as distance between the eyes or width of the nose variable just by chance, or has there been evolutionary selection to be more variable than they would be otherwise; more distinctive and more unique?”

As predicted, the researchers found that facial traits are much more variable than other bodily traits, such as the length of the hand, and that facial traits are independent of other facial traits, unlike most body measures. People with longer arms, for example, typically have longer legs, while people with wider noses or widely spaced eyes don’t have longer noses. Both findings suggest that facial variation has been enhanced through evolution.

“Genetic variation tends to be weeded out by natural selection in the case of traits that are essential to survival,” Nachman said. “Here it is the opposite; selection is maintaining variation. All of this is consistent with the idea that there has been selection for variation to facilitate recognition of individuals.”

Human faces are so variable because we evolved to look unique

Could cherry blossoms one day be blooming in winter?

Chery Blossoms

The cherry blossoms in Washington D.C.’s annual festival now bloom five days earlier than when the festival was celebrated in 1921 (on average). Scientists theorize that with the drastic warming of the globe, future decades could see blossom times not just a few days early but advanced by almost a month.

To better understand the situation, researchers need large amounts of data about different all types of plants in order to analyze. Gathering all of this data is not easy.

UC Santa Barbara’s Susan Mazer explains why researchers need the public’s help to gather this information:

Facebook for Nature

Can a status update from a tulip tell us anything about climate change?

The science of seasonal observation has always mattered, but never has it been so urgent. Each year, our seasons unfold. Perhaps they feel the same to us each time, or maybe we notice the slight differences. A lack of rain in the west, and a barrage of snow in the east. Flowers are blooming earlier, fruit is ripening sooner. OK, so what’s the big deal with some slightly confused flora? Well, that confusion ripples outward, and that matters because of how beholden all living things are to other living things. The timing of our ecosystem, complicated as it is in the most ideal of times, is off-kilter.

The California Phenology Project, a collaboration between UC Santa Barbara, the National Park Service, and The National Phenology Network endeavors to document plant ranges, flowering dates, and other relevant data to assess climate change responses throughout the state of California. In the UC Natural Reserve System there are 3,300 plant species. The list reads like a poem of plants you may have never heard of: Awned Fescue, Ripgut Grass, Winecup Clarkia. The idea is that when these plants bloom within the season (and how that differs year to year) is actually a clue, indicative of the world they are blossoming into.

The phenological observations of scientists and citizens alike will all contribute to the Pheonology Project’s online resource, Nature’s Notebook, a kind of Facebook for Nature (I would totally friend request the California Poppy, golden and archetypal as it is, and Winecup Clarkia too, in all its hot pink, magenta splendor). But unlike the existential quandaries posed by the ubiquitous social media site, this online notebook will begin to reveal some of the patterns of our natural world and what that might mean for us. Since the task at hand is too large for just the professional scientists, now is the chance for people to reconnect with their environment and become contributors to this project, citizen-scientists observing and noting the plant species in Golden Gate Park or in their own backyard. We are all capable of phenological observation. The California Poppy accepts your friendship request! What will you do now?

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Is that really red snapper on your plate?

tumblr_mil8vjJulj1rjatglo2_250A recent survey done by Oceana says that fish found at the market are not always correctly labeled.  So, scientists are working on a genetic sequence technique called fish barcoding that can positively identify fish species.

Marine biologist Ron Burton of UCSD’s Scripps Institution of Oceanography says it’s important for the public to make sure they’re getting what they think they’re getting:

“In a market like red snapper, we can be seeing red snapper at many fish markets and that would lead somebody to believe that the fish is very common, when in fact what’s being sold is a diversity of species – some of which are common, some of which aren’t. And so it can lead to a false impression about the abundance of species to the public.”

Read more stories on Science Today

Restoring oysters along the California coast

oystersIn response to global climate change, Jill Bible at the UC Davis Bodega Marine Lab shows us how her research with the Olympia Oyster is aimed at restoring this species along the west coast.

“My research will help us determine what populations of oysters are particularly vulnerable or particularly robust to future changes and will help us determine how to best restore the populations given some of the changes coming down the pipe for oceans.” – Jill Bible