Scientists Discover Mechanism That Gives Shape to Life 138
First time accepted submitter mcswell writes "Daniël Noordermeer and Denis Duboule, two researchers at Ecole Polytechnique Fédérale de Lausanne and the University of Geneva claim to have discovered how vertebrae get built in sequence in embryos (and by extension, how ribs, arms and so forth wind up in the right place). The story is that the DNA strands contain a linear series of HOX genes, and that the strands slowly unwind over a period of two days, successively exposing each HOX gene, thereby allowing it to be transcribed to form the segments of the vertebra. Snakes, it seems, have a defect that causes the system not to shut down; eventually it 'runs out of steam.' The same process is said to apply in many invertebrates, including worms (presumably segmented worms) and insects."
Hox genes are the basic sequence of embryogenesis (Score:5, Insightful)
TFA is saying that organisms are built in slices, from the tip of the head down to the tip of the tail. These slices are activated in order, from first to last. It is the same in fruit flies, worms, whales, dogs, monkeys, deer and humans. The HOX genes control the basic sequence, like a player piano roll or a series of punch cards.
The reason we get so many different organisms, like whales, fruit flies and elephants, is evolution [youtube.com].
Re: (Score:4, Insightful)
No, it merely affirms that all the other less precise mechanisms did not survive.
Re:Precision like a Swiss watch... (Score:2, Insightful)
If there's an omnipotent, omniscient creator of the world, then nothing can "happen by accident." Ergo, in such a universe you would have no means to distinguish accident from non-accident.
Snakes (Score:5, Insightful)
The sinuous body of the snake is a perfect illustration. A few years ago, Duboule discovered in these animals a defect in the Hox gene that normally stops the vertebrae-making process. “Now we know what’s happening. The process doesn’t stop, and the snake embryo just keeps on making vertebrae, all identical, until the process just runs out of steam.”
Looks more like a feature than a bug to me. Another fine example of evolution by mutations.