Australopithecus afarensis' Hip Bone Indicates She Could ...

When Lucy’s hundreds of fragments were assembled, she turned out to be a female of a new species, Australopithecus afarensis, dating back 3.2 million years. She was between 20 and 30 years old, 3.5feet tall, weighing a scant 60 pounds, and possibly afflicted with arthritis. But most important, she walked on two legs. How can we tell? From the way that the femur (thighbone) connects to the pelvis at one end and to the knee at its other. In a bipedally walking primate like ourselves, the fem...

 Postmating Competition

Sexual selection doesn’t end with the sex act itself: males can continue to compete even after mating. In many species, females mate with more than one male over a short period of time. After a male inseminates a female, how can he prevent other males from fertilizing her and stealing his paternity? This postmating competition has produced some of the most intriguing features built by sexual selection. Sometimes a male hangs around after mating, guarding his female against other suitors. Wh...

 Evolution as Entropy Versus Organization

'Evolution doesn't view earth's history as a conflict between good and evil. It does essentially view it as a conflict between life and death, between increased organization and more efficient energy use on the part of life, and an opposing tendency of nonliving matter to become disorganized and lose energy--entropy. But evolution doesn't see life as good and death as evil. Life cannot triumph over death in evolution. They don't fight to win. As with some of the older myths, wherein the natur...