Friday, December 30, 2011

Evolution: way cool!

A really good scientific theory explains things it hadn’t anticipated.

The Copernican, helio-centric model was designed to fix the calendar, and provide improved predictions of observable planetary motions.

As it turns out, with a fair amount of refinement, it also explains seasons: put the earth in elliptical orbit around the sun, with axis-of-rotation at something other than 90-degree angle to plane of revolution, and, VOILA! Seasons!

Similarly, Darwin’s ‘evolution via natural selection’ also contained an implicit prediction Darwin never contemplated.

As I understand Darwin (admittedly, not all that well), his view of inheritance was via some sort of ‘mixing’ model. ... as it turns out, a ‘mixing’ model of inheritance doesn’t really work to explain evolution via natural selection.

BUT: particulate inheritance – via genes – works like a charm!... and Mendel established the fact of particulate inheritance.

A frequent criticism of ‘evolution via natural selection’ – among those who seek to discredit it – is the claim that every individual in the population has to experience the same mutation at the same time.
If even one parent produces a competitive mutation, that’s all it takes.

The casino game ‘craps’ is actually pretty fair. Once upon a time I had an assignment to compute probability of the shooter winning at craps.
I don’t recall the answer, but it’s something like 49.3% – meaning the house has a 50.7% chance of winning.

If you play long enough, you’ll lose your shirt. (This is how casinos make money: most of the games are pretty fair... but the house always has the edge: if you play long enough, you’ll lose your shirt!)

Particulate inheritance works exactly the same way. If a single individual has a mutation that grants him/her only a tiny advantage in survivability (probabilistically), eventually his/her progeny will take over the species.
This can be simulated via computer. It’s easy to demonstrate. The house always wins in the long run.

Again: Tho’ Darwin didn’t realize it, his theory contained the implied prediction that inheritance is particulate! ... a prediction that has been confirmed!

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