evolutionary biologist

Harriet, photgraphed with her loving crocodile-huntingoverseer on the occasion of her 175th birthday

To all our Australian-turtle-loving evolutionary-biologist readers, I would like to express condolences on behalf of all of us here at PopSci on this grim day: Harriet, the giant Galápagos tortoise supposedly captured by Charles Darwins famous expedition that you have grown to love like your own son or daughter, died today at home in the Australia Zoo at the spry (estimated) age of 176, ending her reign as the Earths oldest known living animal.

Its been a wild ride, Harriet. You were plucked from your luscious home in the Galápagos Islands to be studied by one of the greatest minds of modern science (well, maybe—Harriet belonged to a species indigenous to an island Mr. Darwin never personally visited. Mercifully, Harriet died still believing she was Charless best girl). Youve seen world wars come and go like mere hiccups of time. You recovered nicely from the psychological trauma of being mistaken for a male tortoise (Harry) for more than half your life. Your biggest daily concerns included which type of exotic and delicious flowers to dine on. And in your golden years you were owned by Steve Irwin, TVs crocodile hunter, whose despair we cant even begin to fathom.

Unsurprisingly, her keepers attribute her advanced age to a stress-free life. Its indeed been a good one, Harriet, and well miss you. But hopefully, somewhere in that great archipelago in the sky, Mr. Darwin cant wait to take precise measurements of your dinner-table-size shell. —John Mahoney

Although many jilted brainiacs might beg to differ, there´s no concrete evidence that women are more attracted to dumb men. Yet the same might not be true for some of our mammalian cousins. Consider, for example, the bat. After gathering available brain and testis size data for 334 species of bats, evolutionary biologist Scott Pitnick of Syracuse University found that males with the biggest cranial capacity were likely to have the smallest testicles, and vice versa.

Until recently, it might have seemed impossible. Some scientists estimate that 90 percent of Earth’s species have not yet been identified; you’d need an enormous army of well-equipped biologists working night and day to even make a dent in that figure. But evolutionary biologist Paul Hebert of the University of Guelph in Ontario believes that he has found a way of accelerating the process. He has discovered a “bar code” embedded in the DNA of all animal life, from bacteria to monkeys, that functions like a fingerprint.

When a male spider of the species G. cancriformis goes a-courtin', it's in his evolutionary interest to choose a virgin. That's because a female's first mate almost always gets to fertilize her eggs, while subsequent males wind up with nothing to show for their ardor. Which made Todd Bukowski, an evolutionary biologist at the University of Arizona at Tucson, wonder: How good are these male spiders at spotting virgins?