Thoughts on Evolution

The Theory of Evolution is a hot topic these days. Unfortunately, most of the talk is just that. Anyway, I wanted to post some thoughts (just more talk, I suppose).

The part of Evolution that bothers me is the notion that one species of life form can evolve from another species. Some call this "macro evolution".

In my way of thinking, there are two types of genetic variation. One is the variation with which we are all familiar--blue eyes and green eyes, black hair and brown hair, that sort of thing. The other is a type of variation that results in a new species. I'm only talking about the latter.

Part of the problem is that we don't see it in nature. When was the last time your dog had a litter of kittens, for example?

Part of the problem is that genetic mutations don't seem to ever result in beneficial changes to an organism (not counting comic book super-heroes).

Part of the problem is that "survival of the fittest" always results in reduced genetic diversity, not increased genetic diversity. Nature kills things it doesn't like.

Part of the problem is that genetics are quantum in nature. You can't have a fraction of a gene. An organism can't evolve by added 1/1000 of a new gene each generation. This quantum nature acts as a barrier to evolution in the same way that digital data transmission is more immune to noise than analog transmission.

Could all possible combinations of genetic material result in viable life forms? I doubt it. There are probably a discrete number of "stable" states of DNA, which greatly increases the barrier to evolution. I believe this is the main argument of Intelligent Design (which I think is badly named, because it isn't about design but rather it is about the improbability of macro evolution).

There is a difference between taxonomy and genealogy that seems to be widely ignored. It is good and valuable to understand the structure of living organisms and to develop a system of classification. But it seems a huge leap to say, "Species B evolved from species A" on the basis of similarities in structure and in the absence of any evidence that evolution actually occurred. There's some circular logic hidden in there--"evolution is true because of similarities of structure, because similarities of structure result from evolution".

I shared a table at a dinner with a researcher in academia who went off about evolution. "I know it's true! I've seen it in the laboratory!" I believe he cited the case of fruit flies evolving over time. But in the end, they were still fruit flies. They weren't frogs or beetles. The flies evolved in ways that are supported by the structure and nature of genetics, but not in ways that are not.

There's the statistical problem. If the chance of life evolving unaided from inorganic materials is 0.0000000000001 (which number is many, many orders of magnitude greater than reality, but I didn't want to type all the zeroes), then the probability of it not happening is 0.999999999999, which is practically indistinguishable from certainty. How is it that we are supposed to believe that the passage of a great amount of time--say 15 billion years--makes a highly improbable event probable? Isn't it still highly improbable?

Okay, there is maybe a theoretical solution to the statistical problem, in that you could assign a time span below which evolution would be impossible, although its computation is extremely difficult--if not impossible--and would require data not available to us.

The concept is something like this: if you roll a dice every second for a year and graph the number of "streaks" of varying sizes, you will get a curve that matches the statistical probability. There is, however, a maximum streak size, dictated by the total number of rolls--you can't have a streak greater in length than the total number of rolls of the dice. Any streak of lesser size is mathematically possible. So, if we could figure out the number of genetic mutations per unit of time that result in a viable organism, and the total number of variations required in order to arrive at homo sapiens, and if we knew how long life has been evolving on earth, we could then determine whether evolution was inside or outside the bounds of possibility. But don't hold your breath on this one.