Giraffes: They’re weird!
Their torsos are stunted to support their impossibly long necks. Their dangerously thin legs grow super straight, keeping them from bowing under pressure. Their blood pressure is twice as high as our own — which allows them to pump blood more than six feet up in a straight shot so it can make it all the way to the brain.
Scientists know that these adaptations all emerged relatively quickly (on an evolutionary scale, that is) because the giraffe only separated from a common ancestor with its closest relative, the okapi, around 11 million years ago. But the giraffe’s genes suggest that these radical changes were the result of a few subtle mutations. The first full genome sequences of the giraffe and the okapi were published in Nature Communications.
Instead of new genes, they found 70 genes with giraffe-specific mutations. “There’s a misconception that to make something novel in evolution you must be doing something very dramatic at the DNA level, but that just isn’t the case,” said research co-leader Douglas Cavener of Penn State University. “You can have these very subtle changes in DNA that create dramatic effects.”
Understanding how these creatures handle such high blood pressure without injury could help develop treatments for humans, researchers said.
Forests rise to carbon dioxide challenge
A recently established forest on abandoned farmland in Latin America, if allowed to grow for another 40 years, would probably be able to suck at least 31 billion tons of carbon dioxide out of the atmosphere, said lead author Robin L. Chazdon, a University of Connecticut ecologist who is working at the International Institute for Sustainability in Rio de Janeiro. That is enough to offset nearly two decades of emissions from fossil-fuel burning in the region.