Category: Blog
Dinosaur-eating Mammals (You heard me right): Jeff Hecht at New Scientisthas a good write-up of the discovery of a dog-sized 130-million year old mammal with dinosaur bones in its gut. Most mammals may have been humble little critters during the Age of the Dinosaurs, but at least a few seemed to have turned the tables.
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The more time I spend talking to biologists, the more they remind me of detectives. I have two stories in tomorrow’s New York Times that make this connection particularly clear. In the first, E.O. Wilson attempts to solve the mystery of a plague of ants that devastated some of the earliest Spanish settlements in the New World. In the second, I look at another mystery–is there life on Saturn’s moon Titan. The space probe Huygens will be falling into its hazy atmosphere on Friday to see what lurks under its cloak. I inteviewed University of Florida chemist Steven Benner who will be trying to search for signs of life in Huygens’s data. But if Titan does have life, it may not be based on DNA or even need liquid water. So how do you look for something you’ve never seen before?
Not long ago I had a remarkable experience: I got to visit the nursery for what might prove to be a new form of life. At Michigan State University, a group of computer scientists, biologists, and philosophers run the Digital Evolution Laboratory. There, they are developing software called Avida which allows them to create virtual worlds swarming with digital organisms. Avida’s residents show a lot of the important features that scientists consider essential requirements for life. Their evolution is particularly impressive, because it parallels evolution in the wet world in all sorts of subtle ways. And because you can run through a hundred thousand generations in a matter of hours, the Avida team can carry out experiments on some of the most important aspects of evolution that biologists could previously only study by looking at the natural world.
When you consider a tapeworm or an Ebola virus, it is easy think of them as being evil to their very core. That’s a mistake. It’s true that at this point in their evolutionary history these species have become well adapted to living inside of other organisms (us), and using our resources to help them reproduce themselves even if we get sick in the process. But one of the big lessons of modern biology is that there are no essences in nature–only the ongoing interplay of natural selection and the conditions in which it works. If the conditions change, organisms may evolve into drastically different things. Even the most ruthless parasite may discover the virtues of peace and harmony–if the conditions are right.
Evolutionary biologists face a challenge that’s a lot like a challenge of studying ancient human history: to retrieve vanished connections. The people who live in remote Polynesia presumably didn’t sprout from the island soil like trees–they must have come from somewhere. Tracing their connection to ancestors elsewhere hasn’t been easy, in part because the islands are surrounded by hundreds of miles of open ocean. It hasn’t been impossible though: studies on their culture, language, and DNA all suggest that the Polynesians originally embarked from southeast Asia. We may never be able to retrieve the full flow of history that carried people thousands of miles to the middle of the Pacific, but we can know some things about it, and we can rest assured that some things are definitely not true (such as the sprouting-from-the-ground theory).