Hello there all,
About a day ago StarTrekAngel mentioned that an idea was put forward by a JW that sexual reproduction was an argument against evolution. Here's StarTrekAngel's quote: "Is this some kind of talk being spread around in congregations? The funny thing is that a while ago someone tried to make the same argument, saying they could disprove evolution because no one can explain how we evolved male and female at the same time. Not much later than that, a friend of mine (a JW) told me the same thing. I thought either he read the same post or this is going around the congregations as a means to challenge evolution. I know my friend and I know he does not come around this website."
Well I have now come across this as well. A close relative of mine who is a JW made the same argument in writing that gender had to emerge very rapidly, therefore pointing to the idea of divine creation rather than natural selection. My first thoughts on this was quite straight forward:
Without even looking at the scientific evidence, one could reason that if evolution was true then the further back one went into living organism history up to single celled organisms, the more asexual reproduction would be the primary method of heredity in organisms, with a combination of sexual and asexual reproduction becoming more prevalent over time, and then the emergence of a proto-sexual reproduction method before the sexes are fully defined.
So then I turned to the interwebs:
I went looking for the oldest organisms to emerge in the animal kingdom which turns out to be Sponges in the phylum porifera (pore bearers). It seems that they can reproduce 4 ways: 3 ways asexually and also 1 way sexually without the use of gonads. So sexual reproduction could therefore have evolved slowly and become more defined while asexual reproduction was primarily being used.
At about the same time the animal kingdom shows up in the fossil record, other Eukaryotes (organisms with defined cell membranes and a nucleus) also appear namely Ciliates (protozoans with hair like organelles). They don't have sexual reproduction per se (they also have various asexual methods) however they can exchange genetic material with each other through a process called conjugation. I would call this a proto-sexual process.
Going back even further in living organism history one gets to a process called horizontal gene transfer (which is still happening today in bacteria) where even totally different species can exchange DNA material and the reproduction boundaries are utterly blurred. To me it seems as if these ancient one celled organisms were a bunch of hedonistic miscreants! Incidentally this process of horizontal gene transfer makes the identification of LUCA (the Last Universal Common Ancestor) seemingly highly improbable.
Is my logic reasonable?
Is there a simpler/better way to explain this?
Are there any good books on this particular topic?