Close window | View original article
A major challenge to received wisdom on human evolution made the news recently. The Wall Street Journal reported on October 2 that a fossil named "Ardi," which has been dated more than a million years earlier than the much-discussed "Lucy" skeleton, suggests that there are fewer links between humans, chimps, and apes than had been thought. This triggered a major upset in academia.
Ardi's skeleton suggests that characteristics such as long, tusk-like canine teeth which were thought to have been found in the common ancestor between humans and chimps around 6 million years ago came after chimps and apes separated from humanity. Scientists had thought that humans lost the long canine teeth and that apes kept them. It now seems that our common ancestors had human-like canines and that apes and chimps picked up longer, more aggressive teeth over the years.
If true, this interpretation of the Ardi fossils validates Democratic indignation at a bystander who watched a monkey escape from a zoo and advised the keepers not to shoot it because it might be one of Michelle Obama's ancestors. At the time, mainstream evolutionary opinion held that chimps were ancestors of humans, so the comment was accurate if disrespectful. That "eternal verity" may no longer be true but we won't know until more research is written up.
These critters seem to have had hands that were well adapted for grasping and carrying, and had leg bones that indicated that they walked upright. This is another blow to conventional theory.
Evolutionists had thought that walking came about when our ancestors moved out of the trees and started walking around the plains, but these skeletons appear to have been associated with a forested area. What's the point of learning to walk when you can climb around in trees?
The National Geographic offered a more startling interpretation of the notion that humans had been able to carry objects in their hands while walking on two legs for millions of years longer than had been thought. Their article "Ardi's Secret: Did Early Humans Start Walking for Sex?" explored a theory why Ardi's relatives may have started walking before moving out of the forests on to the plains.
In apes-both modern apes and, presumably, the ancient ancestors of Ardipithecus-males find mates the good old-fashioned apish way: by fighting with other males for access to fertile females. Success, measured in number of offspring, goes to macho males with big sharp canine teeth who try to mate with as many ovulating females as possible. Sex is best done quickly - hence those penis bristles, which accelerate ejaculation - with the advantage to the male with big testicles carrying a heavy load of sperm. Among females, the winners are those who flaunt their fertility with swollen genitals or some other prominent display of ovulation, so those big alpha dudes will take notice and give them a tumble, providing a baby with his big alpha genes. [emphasis added]
The only way a lesser breed might be able to mate would be to offer a female some food when the alpha male wasn't looking. Female chimpanzees have been observed to reward males for bringing them something to eat. Prof. Owen Lovejoy of Kent State University believes that our ability to carry things in our hands and to walk on our two hind legs all come down to food and sex.
Males would be far more successful food-providers if they had their hands free to carry home loads of fruits and tubers - which would favor walking on two legs. Females would come to prefer good, steady providers with smaller canines over the big fierce-toothed ones who left as soon as they spot another fertile female.[emphasis added]
Prof. Lovejoy believes that the females of Ardi's tribe were as concerned about getting food from males as modern women. Whether this conclusion is a legitimate deduction from the fossil record or speculation based on observations of modern human behavior is a matter of opinion.
Lovejoy's explanation for the origin of bipedalism thus comes down to the monogamous pair bond. Far from being a recent evolutionary innovation, as many people assume, he believes the behavior goes back all the way to near the beginning of our lineage some six million years ago.
One wonders if human females have really been concerned with linking up with good providers for that many generations. Most researchers had placed the origins of monogamy much later, having assumed that smaller teeth which made it impractical to fight over females came long after apes and humans diverged.
Not everyone agrees with Prof. Lovejoy, of course. The New York Times reported:
Dr. Pilbeam [a professor of human evolution at Harvard University] disputed this conjecture, saying, "This is a restatement of Owen Lovejoy's ideas going back almost three decades, which I found unpersuasive then and still do."
One might be forgiven for thinking that the path of human evolution is not quite as clear as it's presented when apologists clash with creationists.
There's another piece to the puzzle, however, which isn't preserved in the fossil record:
If the female knew when she was fertile, she could basically cheat the system by taking all the food offered by her milquetoast of a provider, then cuckold him with a dominant male when she was ovulating, scoring the best of both worlds. The food-for-sex contract thus depends on what Lovejoy calls "the most unique human character" - ovulation that not only goes unannounced to the males of the group, but is concealed even from the female herself.
Concealed ovulation makes it harder for females to cheat, but it also gives a male incentive to take better care of her. If a male knew when she was ovulating, he could guard her and feed her during those times and leave her alone to fend for herself the rest of the month. Given that he doesn't know when she's fertile, however, he has to hang around and feed her all the time. This makes it possible for women to put more energy into bearing babies and taking care of them because they don't have to spend so much energy finding food.
Regardless of whether ovulation among Ari's tribe was secret or open, it's pretty clear that any female benefits if a male is willing to help her find food. Not surprisingly, modern researchers have uncovered evidence which they claim shows that women are better off with men who're willing to delay sex until after an extended period of dating.
In "Mathematicians' guide to first-date etiquette," the Independent reports:
Now mathematicians have proved what women have been counselling their friends for years: a woman increases her chances of getting a "good" man by not sleeping with a partner straight away. They used a numerical model to show that better partners were willing to date for a longer time before having sex, but "bad" men were more reluctant to hang around.
They didn't report whether "bad" men had bigger canines or other attributes such that they could fight for mates or score in some other way without having to hang around.
"Long courtship is a price paid for increasing the chance that mating, if it occurs, will be a harmonious match which benefits both sexes. This may help to explain the commonly held belief that a woman is best advised not to sleep with a man on a first date." The research is published in this month's Journal of Theoretical Biology. Dr Peter Sozou, of Warwick Medical School and the LSE Centre for Philosophy of Natural and Social Science, said: "The strategic problem a female faces is how to screen out bad males, and this is where long courtship comes into play. A male is assumed to always want to mate with a female, but a good male is more willing to pay the cost of a long courtship to claim the prize of mating."
When it comes to mating, it's either
Your grandmother's old-fashioned dating advice may be both older and wiser than researchers ever imagined.