Evolution's Master Switches (creation, hell, religion, science, Article)

[Jayhawker Soule]

Just part of a great article ...

Whether evolution worked fast or slow, theorists labored to explain how it could produce dramatic changes in body structure through incremental steps. Half an eye would be worse than none at all, creationists were fond of arguing. But "partial" eyes turn out to be common in nature, and biologists can trace eye evolution from the lensless flatworm eyespot to the complex geometry of vertebrate eyes. Now "evo-devo" biologists, who study how fertilized egg cells develop into adults, are discovering powerful new ways evolution can transform organisms. They are finding that changes in a handful of key genes that control development can be enough to drastically reshape an animal.

Master switches. The central discovery of evo-devo is that the development and ultimate shape of animal bodies are orchestrated by a small set of genes called homeotic genes. These regulatory genes make proteins that act as master switches. By binding to DNA, they turn on or shut down other genes that actually make tissues. All but the simplest animals are built in segments (most obvious in creatures like centipedes, but also apparent in human vertebrae), and the Hox family of homeotic genes interacts to determine what each segment will look like. By simple genetic tinkering, evo-devo biologists can tweak the controls, making flies with legs where their antennae should be, or eyeballs on their knees.

This might seem like little more than a cruel parlor trick, and the resulting monstrosities would never survive in nature. But small changes in these master-switch genes may help explain some major changes in evolutionary history. This past winter, evo-devo biologists showed that an important animal transition 400 million years ago, when many-legged arthropods (think lobsters) gave rise to six-legged insects, was due to just a few mutations in a Hox gene. In the past few months, researchers have found that a change in the regulation of a growth- factor gene could have resulted in the first vertebrate jaw. And, incredibly, researchers reported in the journal Science last week that a single mutation in a regulatory gene was enough to produce mice with brains that had an unusually large, wrinkled cerebral cortex resembling our own. (No word, though, on whether the mutant mice gained smarts.)

- see How evolution really works, and why it matters more than ever

[Scuba Pete]

Way cool deut... even though it was somewhat long for a simple man as I, it helpd my attention until the end.

[Jayhawker Soule]

Originally Posted by NetDoc

Way cool deut... even though it was somewhat long for a simple man as I, it helpd my attention until the end.

The article ends ...

"Somewhere in high school in this country is a student who's going to cure AIDS," Palumbi says. "That student is going to have to understand evolution."

That's one hell of a bottom line.

[painted wolf]

People forget how much of modern medicine and science is based on the ideas contained in the theories of heredity and evolution and how closely the two theories need one another.

Weakening science education is bad for all of us.
What is sad is reading the plethora of responces at the end...

wa:do