Skeptic Ginger
Nasty Woman
- Joined
- Feb 14, 2005
- Messages
- 96,955
In one direction, were there an alternative to evolution, I agree, it wouldn't disprove abiogenesis. But in the other direction, I don't see how you start evolution without abiogenesis. So I am asking how you start evolution without abiogenesis. Unless you hypothesize that life formed in the Big Bang, it had to start with molecules that formed due to chemical reactions.Forgive me, but I don't see how that is a response to my point.
Dinwar stated that evidence for abiogenesis is not evidence for evolution, and vice-versa, and disproving one (hypothetically) would not disprove the other, etc.
And, I was saying fine, we can remind people about that, on occasion. It is, strictly speaking, true. While adding that they both contribute to the larger picture of natural processes explaining all of life.
How is your question a response to this?
(If you are looking for third options, I might be able to think of a few, anyway. Not that they would be of scientific merit.)
To claim evolution theory starts anywhere other than the first replicating molecule(s) [in this case I am referring to making copies the way RNA and DNA do, not just growing by adding more molecules like a crystal does] is a position that would need to assume (IMO) that random mutation and natural selection didn't start with the first replicating strand of RNA or whatever replicating molecule it was.
Random mutation IS a chemical action. Selection pressures are going to impact that molecule whether it was the first replicating strand of RNA or some other as yet unknown replicating molecule. So if you have a chemical process going on that results in a replicating molecule developing, from that point on, selection pressures are going to act along with random mutation. And those selection pressures are no different be they the temperature, the pH or the abundance of certain amino acids or nucleic acids nearby, OR, how beneficial the bacterial wall structure is against a toxic surrounding. One is more complex is all, but selection pressures don't just act on something like a cell wall, they also act directly on the genetic molecules.
It seems to me people in this discussion have a concept of random mutation and selection pressures as something unique that only occurred at some point along the way after replicating molecules appeared. In my opinion this position stems from the archaic view of Darwinian natural selection: survival of the fittest or a survival/reproduction advantage.
Darwin's ideas were incomplete and it turns out natural selection is better described as selection pressures. And many many mutations are passed on that are actually neutral. They weren't all "selected". Even some disadvantaged mutations can be passed on because they weren't bad enough to prevent reproduction. Temperature, pH, and things like that which would impact a replicating molecule are also selection pressures.
A fetus begins as soon as the components come together with conception. As soon as the molecules come together to form a replicating molecule, selection pressures begin impacting that molecule. I understand what you mean that evolution theory would still explain change regardless if the first organism magically appeared. But what I don't get is how you leave the beginning out of evolution theory. You need to start with something or you got nothin'.
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