Daddy's No Boob
Milner, Richard, Natural History
DADDY'S NO BOOB According to some evolutionary biologists, mates will act to favor the reproduction of their own genes at the expense of their rivals' genes. Mate blue-footed boobies provide extensive parental care, including defending the nest, incubating the eggs, and helping to feed the chicks.
How can males prevent their prodigious labors in the seabird colony from profiting other males that may try to cuckold them white they are off gathering food? According to Marcela Osorio-Beristain and Hugh Drummond, of the Universidad NationaL Autonoma de Mexico, when an egg's paternity is in doubt, some male boobies push it out of the nest.
To test the mate birds' reactions to eggs that may have been fertilized in their absence, the researchers (working on Isla Isabel, off Mexico's Pacific coast) removed a number of mates from their nesting territory for ten to twelve hours and then returned them to their mates. One group of mates was removed a few days before their females fertile period (about a week before females lay their eggs); a control group had been temporarily isolated several weeks earlier. The scientists found that females did not suddenly become promiscuous white their mates were away. Some copulated with other mates, but the rate of these pairings was low. Yet of the mates sequestered just before the females' fertile period, 43 percent expelled the first-laid egg from the nest, although none of the control mates did so.
The researchers concluded that a Large proportion of male boobies will eliminate any possibility of lavishing their efforts on a "deadbeat dad's" offspring by destroying eggs of questionable paternity-even though some of them could be their own. ("Mate Boobies Expel Eggs When Paternity Is in Doubt," Behavioral Ecology 12:1, 2000)
SMART SLIME Scientists at the Bio-Mimetic Control Research Center in Nagoya, Japan, placed blobs of the singLe-ceLLed amoeba-like organism Physarum polycephalum inside a miniature maze in which four different routes led to food (ground oat flakes) placed at the start and end points. In a series of trials, the slime organism consistently chose the shortest path to reach the prize.
Classified as fungi, slime molds seem to share characteristics with both plants and animals. Like other fungi, they reproduce with spores, yet like amoebas, they can change shape and extend pseudo po dia-tube like legs with which they reach out to move and to absorb food. …