Natural selection in action

In honor of Halloween, the Washington Post has a story on extreme pumpkin-growers. It's a great example of massive phenotypic change in a few generations:

Thousands of new growers, even including some in the warm, pumpkin-unfriendly climes around Washington, have been attracted to the mad-scientist thrill of growing a fruit the size of a boulder. For some reason, at least 80 percent of them have been men.
Over the years, more growers have meant more pumpkins, and more chances to cross one behemoth with another.
As this practice has become more popular, the seeds of certain well-known pumpkins -- such as a 723-pound New York specimen whose illustrious offspring have made it the Alydar of squash -- can bring hundreds of dollars at auction. At training seminars, growers will play "pumpkin poker," for one seed a hand.
Everyone's dreaming that these unions of big pumpkins will produce a generation that is bigger still.
"We've put a man on the moon. We've run the four-minute mile," said Ray Waterman, who runs a seed and supply company outside Buffalo. "And now we're going to grow a 2,000-pound pumpkin."

The world record size has gone from 400 pounds in the 1980's up to 1469 points this month. But it's not all genetics:

While the pumpkin's roots were sunk in the soil, Beauchemin shaded its prized fruit from the elements and placed it on a low-friction fabric. In the weeks to come, he knew, the mega-pumpkin would expand so fast that the roughness of the bare ground might slow it down.
"It never felt the dirt," he said. "And it never felt the rain."

With all their fertilizing and watering, these people are making a pumpkin secular trend. For fame, glory, and -- for the not-so-lucky -- the chance to cut the giant squash in half and fit a trolling motor for a spin around the river.