Jurassic Genome

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Science, March 9, 2007

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Tyrannosaurus rex, it turns out, had a pretty small genome. A team of American and British scientists estimates that it contained a relatively puny 1.9 billion base pairs of DNA, a little over half the size of our own genome.

The scientists who came up with this estimate—along with estimates for the genomes of 30 other dinosaur species—had no ancient DNA to study. T. rex, after all, became extinct 65 million years ago, and its genome is long gone. Instead, they discovered a revealing correlation: Big genomes tend to be found in animals with big bone cells. By comparing the size of cells in dinosaur fossils to those of living animals, the scientists got statistically sound estimates for the sizes of the dinosaur genomes.

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Question of the Day: How Do You Get Crabs From A Gorilla?

Posted on by Lori Jia

If pubic lice are not the sort of thing you want to be seen reading about, let me give you the opportunity to close your browser window right now. But if you’re at all curious about the secret that pubic lice have been keeping for over three million years, the tale of a mysterious liaison between our ancestors and the ancestors of gorillas–read on.

Many parasites tend to stick close to their hosts. A parasitic wasp may wander through forests and fields to find a caterpillar from a single species of butterfly in which it will lay its eggs. Blood flukes taste the water of their ponds for molecules from human skin. 

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A Biological Hot Spot in Africa, With New Species Still to Discover

Posted on by Lori Jia

The New York Times, March 6, 2007

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The Eastern Arc Mountains of Tanzania may not be terribly tall — only half the height of their famous neighbor, Mount Kilimanjaro. But to scientists who tally the planet’s biodiversity, they tower over the rest of the world. The forests that cover their flanks contain the highest density of endangered animals anywhere on earth.

“This is a really important place,” said Neil Burgess, an expert on the Eastern Arc Mountains at the University of Cambridge and the World Wildlife Fund. “Biologists who go there just keep finding more and more species.”

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New Species For the Picking

Posted on by Lori Jia

Josh at Thoughts from Kansas makes some good points today about the need for more systematists (scientists who describe new species), launching his musings from an article in today’s New York Times about the remarkable Eastern Arc mountains by…d’oh! That was by me. Man, I have got to do a better job of staying ahead of the blogging curve. 

Originally published March 6, 2007. Copyright 2007 Carl Zimmer.

High-Achieving Genes

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Forbes, March 2, 2007

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You make partner. You get tenure. You conquer the known world. You achieve greatness in your lifetime. But in the great scheme of things, how much does any of that really matter? After you die, they come to empty your desk. They take down your plaques from the wall. The grand statues you had built for yourself crumble in the desert winds.

One way to overcome your own mortality is to produce a dynasty. A thriving flock of descendants can sustain themselves, generation after generation, passing down your name … or at least your DNA. That’s what Genghis Khan did, and did with astonishing success. An estimated 16 million men today, plus an uncounted number of women, are his direct descendants.

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