Human Evolution, Walking and FoxP1

The Smithsonian has an interesting article on hox genes and how a discovery may inform about how walking came about:

What does a mouse have in common with a cartilaginous fish known as a little skate?

At first glance, you might think not much. One’s fluffy, with big ears and whiskers; the other breathes with gills and ripples its way around the ocean. One is a lab animal or household pest; the other is most likely to be seen in the wild, or the bottom of a shallow pool at an aquarium. But it turns out these two vertebrates have something crucial in common: the ability to walk. And the reason why could change the way we think about the evolution of walking in land animals—including humans.

A new genetic study from scientists at New York University reveals something surprising: Like mice, little skates possess the genetic blueprint that allows for the right-left alternation pattern of locomotion that four-legged land animals use. Those genes were passed down from a common ancestor that lived 420 million years ago, long before the first vertebrates ever crawled from sea to shore.

According to the story, when the researchers removed the FoxP1 gene (short for Forkhead Box P1) from the skates, they couldn't walk.  Further analysis revealed that the same thing happened to mice.  They simply lost the ability to coordinate their legs.  They couldn't walk.  This research suggests that the gene that allows us to do the simple act of walking originated over 400 million years ago.  Neat stuff.

Holy Jurassic Park, Batman!

Wired has a story on “How to hatch a dinosaur” by Thomas Hayden. He writes:

Over the past several decades, paleontologists—including [Jack] Horner—have found ample evidence to prove that modern birds are the descendants of dinosaurs, everything from the way they lay eggs in nests to the details of their bone anatomy. In fact, there are so many similarities that most scientists now agree that birds actually are dinosaurs, most closely related to two-legged meat-eating theropods like Tyrannosaurus rex and velociraptor.
But “closely related” means something different to evolutionary biologists than it does to, say, the people who write incest laws. It’s all relative: Human beings are almost indistinguishable, genetically speaking, from chimpanzees, but at that scale we’re also pretty hard to tell apart from, say, bats.

That's funny. Here's where the Jurassic Park comes in:

These regulatory genes—the master switches of development—contain the recipes for making certain proteins that stick to different stretches of the genome, where they function like brake shoes, controlling at what time during development, and in what part of the body, other genes (for things like growth-factor proteins or actual structural elements) get turned on. The same basic molecular components get deployed to make the six-legged architecture of an insect or fish fins or elephant trunks. Different body shapes aren’t the result of different genes, though genetic makeup certainly plays a role in evolution. They’re the result of different uses of genes during development. So making a chicken egg hatch a baby dinosaur should really just be an issue of erasing what evolution has done to make a chicken. “There are 25 years of developmental biology underlying the work that makes Horner’s thought experiment possible,” says Carroll, now a molecular biologist at the University of Wisconsin-Madison. Every cell of a turkey carries the blueprints for making a tyrannosaurus, but the way the plans get read changes over time as the species evolves.

That is one of the best definitions of hox genes that I have ever seen. The problem is that you are looking at a developmental level that is very basic.  It will be interesting to see how this is applied in the next few years.