Ohhh, occasion to post my favorite first line of a book the second time in so many days! Neal Stephenson, first line of chapter 1 of Cryptonomicon:
"Let's set the existence-of-god issue aside for a later volume, and just stipulate that in some way, self-replicating organisms came into existence on this planet and immediately began trying to get rid of each other, either by spamming their environments with rough copies of themselves, or by more direct means which hardly need to be belabored. Most of them failed, and their genetic legacy was erased from the universe forever, but a few found some way to survive and to propagate. After about three billion years of this sometimes zany, frequently tedious fugue of carnality and carnage, Godfrey Waterhouse IV was born, in Murdo, South Dakota, to Blanche, the wife of a Congregational preacher named Bunyan Waterhouse. Like every other creature on the face of the earth, Godfrey was, by birthright, a stupendous badass, albeit in the somewhat narrow technical sense that he could trace his ancestry back up a long line of slightly less highly evolved stupendous badasses to that first self-replicating gizmo--which, given the number and variety of its descendants, might justifiably be described as the most stupendous badass of all time. Everyone and everything that wasn't a stupendous badass was dead."
But even more likely was single-ancestor with some gene mingling. So a bit of both.
Seems like a bit of a false dichotomy going on here as this is a "degree of" question and not an either-or question (If I understood the article correctly)
No, it is two different dichotomies. One is one-ancestor vs. multi-ancestor, with the first being correct. The second is no gene transfer between descendants vs. gene transfer between descendants, with the second being correct. So there was only one species to begin with, but then later, after it diverged into multiple species, those branches traded genes back and forth.
The idea that all life shares a common ancestor does not mean that there was only one species to begin with. There could have been many species who contributed genetic material to a common ancestor, and then eventually died out. The article is poorly written because it doesn't make it clear whether the gene swapping occurred before or after the common ancestor.
I took it at first to mean common ancestor in terms of a single ancestor for a particular species. But then you guys seem to think it means a common ancestor for all life.
I found it confusing. Meta: I have no idea why my comment was voted down so much. I did not understand it, and I still do not. Seems like an admission of that along with an explanation from other commenters would be a good thing, right? Saying I don't know and having people help me -- reason for the board, or not?
