Wednesday, October 25, 2006

Evolving the Approach 

Being scientifically-minded, it often boggles my mind that people cannot seem to understand the concept of evolution -- how well-documented are so many examples of the process; and what the process is.

Then I remember the typical degree of science education for the modern American -- none. And I'll run across a sloppily-worded statement in a science magazine designed for the masses.

From both the print and online November editions of Discover:
When Burch and Gallup tested samples of human semen, they found luteinizing hormone and follicle-stimulating hormone, both of which can induce a woman to release eggs earlier than normal. Those hormones were conspicuously scant in semen from primates, like chimpanzees, that advertise their most fertile periods with red, swollen backsides.

Sexual evolution is like an arms race, Burch says. When women evolved concealed ovulation, men most likely developed semen full of hormones to wrest back control of paternity. [Emphasis Added]
Now, if you do know how the concept of evolution works, you won't look twice at the bolded sentence. You know what they're saying; an evolutionary pressure conferred a benefit, and so a different genetic variation was perpetuated within the species.

But, from the point of view of someone who doesn't know Darwin's Natural Selection from Miller Natural Lite, that sentence sounds quite different. What it says to them is this: "Women stopped having outward signs that they were ovulating, and men reacted with this sudden 'Bang! Fixed!' change to their sperm." Or, in other words, something happened which most people would consider just as magical as some deity creating the world in six days. Female human primates stopped having red asses, men instantly started producing special sperm to make the females ovulate.

One sloppy sentence in a science article actually subtly re-enforces all the brickbats that Creationists love to throw (wrongly) at Evolution.

Here's the real scenario. At some point, primates evolve out of the red-ass = ovulating mode (most likely because at some point previously, male primates decided that bright red asses were a big turn-off). Suddenly, the males can never be sure when the females are ovulating, so they probably start screwing like bunnies. (Side-effect: the non-monogamous behavior of non-red-assed primates.) Meantime, there are certain males whose semen just happens to contain the hormones that make an egg pop out at just the right time. It was a trait that was always there (or had been there for a long time) among some of the males, but not all of them. Except, with the change in female behavior, suddenly the guys with the special semen tended to knock up more females.

Repeat for X number of generations; special semen males make more babies, on average. Those babies have a statistically higher chance of having special semen (much higher if it's a dominant gene), and so are more likely to reproduce. Over time, more and more of the species carries the gene and the advantage becomes overwhelming. Eventually, over enough generations, it becomes the only genetic variation, or becomes such a vast majority that people without the special semen are considered to be the rare mutations.

There was nothing planned about it at all. And yes, it's technically correct to say that males "developed" the special semen, but that's to shortcut the process in a way that does not educate the people who need the education.

Evolution in a simple sentence: those organisms that possess some trait which will give them a reproductive advantage each generation will slowly begin to outnumber the organisms without said trait, until all organisms of the species living in the same conditions will bear that trait. Time and time again, that process has been tested and proven. Evolution has been proven.

And our popular science writers owe it to everyone else to be a little more precise in their language and not accidentally give the un-informed more reason to doubt.

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