Friday, February 8, 2008

The miracle of instinct

Today's Science Journal (B1, subscription required) concerns monarch butterflies, migration, and "the molecular biology of time and travel." Behold the wonder:

In a majestic seasonal rite, a new generation of monarchs flies to Mexico every fall from summer breeding grounds in Canada. This past year, they formed a billowing wind-borne quilt of 55 million or more.

Now, in the depth of winter, the monarchs can sense spring. By March, they will be returning north. Unlike most migrating birds, fish or mammals, however, none of these individual insects will ever complete their species' entire 4,000-mile annual journey. These northward-bound butterflies will get only as far as the U.S. Gulf Coast, where they will lay eggs and die. Their descendants must finish the trip.

"With the Monarch butterfly, it is a multigenerational round-trip," said research biologist Richard Holland at England's University of Leeds. "It is the grandchildren or great-grandchildren who make it back to where the adults started the year before."

Sounds like instinct, doesn't it? Yet, according to neurobiologist Steven Reppert, this phenomenon may have more of a genetic basis than previously thought.

Seeking the secret of time and the butterfly, Dr. Reppert and his colleagues studied rhythmic molecular changes in the four brain cells that serve as the monarch's timing device. He discovered that two similar light-sensitive genes drive the clockworks. The first, common to plants and insects, is sensitive to blue light and appears to synchronize the cells to cycles of light and darkness.

The second gene "stunned" the scientists, Dr. Reppert said, because it so closely resembled one previously found only in humans and other mammals. It doesn't respond to light directly but, when triggered, makes a rising amount of protein that measures the passage of time since it was last activated.

The question now is, would those genes function the same if they were in connection to something other than a living organism? That question, depending on the answer, could either help to explain Darwinian evolution's requirement of abiogenesis or provide more evidence against it. To my evolutionist reader(s): If there is a satisfactory answer to that question, please link to a source explaining it or else explain it yourself. To my creationist readers: Keep up the good fight.

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