An Étude for Egg Laying
Some male canaries sing better than others. Now ornithologists at the Max Planck Institutes in Germany have found that female canaries that hear recordings of mating songs with complicated sequences of buzzes and trills—which scientists call "sexy syllables"—lay bigger eggs than females who hear simpler songs. Although big eggs are more taxing to produce, they tend to yield healthier offspring. So the researchers speculate that females devote more resources to reproducing when they think they’re mating with the most skillful singers.
Fruits Of Their Labor
A handful of 11,400-year-old dried figs have whetted the appetites of anthropologists. The figs, found in the abandoned village of Gilgal 1 in the Lower Jordan Valley in Israel, appear to be the first domesticated plants. Researchers from Harvard University and Bar-Ilan University in Israel say the figs came from an unusual variety of tree whose fruit grows sweet and soft—but happens to be sterile. Thus the people of Gilgal must have learned to cultivate new trees by planting shoots.
A shrub from the South Pacific island of New Caledonia is the sole survivor of the oldest line of flowering plants. Now William Friedman of the University of Colorado reports that Amborella trichopoda makes egg cells in a way similar to that of non-flowering plants. The find may shed light on how flowers evolved, which he says remains, as Charles Darwin called it, an "abominable mystery."
On Its last Legs
Whales and dolphins are descended from four-legged creatures (one ancestor was Pakicetus) that lost their hind limbs 34 million years ago. How? A new study focuses on a gene dubbed sonic hedgehog (after a video game) that guides limb formation in many species. Northeastern Ohio Universities College of Medicine researchers and co-workers found no evidence of the gene in the vestigial hind limbs that appear briefly in dolphin embryos. Presumably, it became inactive over millions of years, explaining the shrinking hind limb in the whale family fossil record.
Name: Castor canadensis, or American beaver.
Residence: Village of the dammed.
Relationships With The Neighbors: Better than you'd expect.
They Go With The Flow? No, they create the flow. Researchers studying two beaver dams near the headwaters of the Colorado River have discovered unexpected downstream benefits. During floods, water diverted by dams flowed into larger areas and for longer periods than in non-dammed valleys. As a result, areas below dams had lesser declines in their water table during dry periods. "This study," says lead author Cherie J. Westbrook of Colorado State University, "broadens the view of the importance of beavers in the valley bottoms."