Primary Source: Daily Dose of Science Blog
Cave divers in the Yucatan Peninsula of Mexico found a skull of a teenage girl they are calling ‘Naia’ over 12,000 years old amongst a collection of animal bones on the floor of a 100-foot deep chamber. Although the skull and the girl’s nearly complete skeleton were found in 2007, scientists just published an analysis of the remains in the journal Science. From the bones, scientists could tell that the girl was 15 or 16 years old when she fell through a hole at the surface into the then-dry chamber, and she broke her pelvis from the fall.The girl’s skeleton is very important for several reasons. First, her skull has several differences from today’s Native Americans (and my use of “Americans” here means for both North and South America), but DNA from Naia’s molar does share a distinct marker with current-day populations of native people. This provides evidence that the first early Americans and today’s native peoples both had the same ancestors from Beringia, the ancient land bridge connecting Alaska to Russia that allowed humans to colonize the Americas, counter to previous debate. The skull shape differences could be from evolution that occurred in the Americas or in Beringia.
Naia’s skeleton is the first scientists have found that shows a genetic link to Beringia from an early time in colonization of the Americas. Some scientists believe that there still could have been several colonization events, and current conclusions are based on a limited number of early skeletons that have been found.
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I'm a plant biology PhD student studying monarch butterflies in Michigan, but I'm interested in lots of other types of science, too.
I am interested in how breeding monarch butterflies choose their habitat based on floral species richness and abundance. Few studies have been conducted on optimal foraging theory when it involves an organism searching for two different kinds of resources, and butterflies are an ideal study system to investigate this, since many species are ovipositing specialists and only lay eggs on one species of hostplant, but are feeding generalists and nectar from a broad variety of flowering forbs.