Posted by: Lister | June 12, 2007

This explanation is better than my last

Some definitions of evolution. It’s an observed phenomenon, like gravity — not a theory. My favourite definition: “Evolution can be precisely defined as any change in the frequency of alleles within a gene pool from one generation to the next.”

The theory of evolution tries to explain what’s going on. The reason it is not called a law of evolution is that a law would be kind of like an equation: relating observations of one variable to observations of a related variable.

To convince you of the theory, I ask a few questions:
1. Do you believe that there is variation in a general population?
2. Do you believe that traits can be inherited?
3. Do you believe there is competition for resourses?

If you answer yes to those three questions, then you have to accept the theory of evolution.

There is competition, and the competitors are not identical? Then some of the competitors will have an advantage.

Traits are inheritable? Advantageous traits will become more common in the population. ie: evolution. Because the change in frequency of particular traits cannot happen without a change in frequency of alleles in the gene pool.

That’s the best I can describe it. (My degree is in maths, not biology!) Note that evolution is not the particular history of life on Earth. It would have been possible for life to come about twice, 3 times, any number of times. The evidence suggests that on Earth it only happened once.

The theory of evolution is not the claim that humans and chimps have common ancestors — that is the most likely history of life on earth. IE: theory applied to the data we have available.

Life from lifelessness is actually abiogenesis, not evolution. From the definition, you have to start with a gene pool to have evolution. According to the theory, you have to have a system of inheritance for evolution.

Also, a point about theories not being inferior to laws. Especially: Extra certainty does not lead to theories getting promoted to laws.

Newton had laws of gravity, Einstein had theories.
But it is Einstein who is more accurate. We know for a fact that Newton was wrong (in the sense of not absolutely right).

Due to a debate on MPACUK


Leave a comment

Categories