See my update to the original post.

I enjoy your writing.

I have a question about one sentence you wrote. (I’m a biologist, but I’m pretty ignorant about evolution or splicing, so treat me as an amateur.)

You wrote:
“Once an intron was wedged into the middle of a gene, a cell had to be able to recognize its boundaries in order to skip over it when making a protein.”

You sound like saying that an intron is a random sequence of DNA inserted into a previously-intronless gene. Is there evidence for this? I’m asking this because:
1) I know cases when genes lose introns (for example when genes are integrated into retroviruses) but I didn’t know about reverse cases.
2) Self-splicing introns (which are admittedly minority of introns) are hardly random sequences and I recall that even splicing of the majority of introns that are not self-splicing is catalyzed by a similar mechanism.

Basically, I’m curious, as a non-expert, about the origin and evolution of introns and they relate to divergence of prokaryotes and eukaryotes. And how about archea?

Anyway, keep up the good work!

The term ‘laziness’ typically has judgmental overtones. It is nearly always a good thing to look for a short cut.

I do like this argument about drift having a bigger role in evolution. This argument has its origins in the development of neutral theory by Kimura and Nei. Recently, this is coming to the fore in human evolutuion, viz, which model better accounts for the diversity DNA research uncovers in humans a result of adaptations (regional selection) or simply neutral variability? I am inclined to think ‘isolation by distance’ and drift have played a significant role in human evolution.
Carl, what information have you on this topic? Are there any papers supporting modeling key human characteristics by non-selective forces: say, upright walking, enlarged brains etc. These key features have always been interpreted as arising from purely selective forces. Not to mention population specific diseases and loci, which may themselves be simple effects of non-selective forces.

Charlie Wagner

“With Charlie’s bait and switch above, he has clearly demonstrated that he doesn’t actually want to be bothered with investigating the evidence. If he needs someone to summarize this information for him, then perhaps he should refrain from making blanket statements about it.”

Your conclusion that there is a component of laziness involved is misguided. I’ve read dozens of articles on this subject, including many that are on your list by Woese, Doolittle, Margulis and others. I have come to the conclusion by analyzing the evidence that there is no credible reason to believe that eukaryotes “evolved from” prokaryotes.
Perhaps you are confusing relatedness with phylogeny. Because forms have similar structures and processes, doesn’t mean they are necessarily phylogenetically linked.
I don’t think it’s asking to much for you to summarize the reasons why you are making this claim. I’ve looked at the same evidence that you have and obviously reached a different conclusion. It’s up to you to clarify your thinking on the matter. You’re the one making the blanket statements.

“Re Charlie Wagner’s comments: There are quite a few “shreds,” for those who would actually like to consider them. See here for starters.”

Instead of asking people to wade through dozens of journal articles, (a tactic often used to dissuade people and create obfuscation) why don’t you just take a moment and summarize the key pieces of evidence that supports the claim you made?
Since you made the claim, It seems to me that it’s your responsibility to defend it yourself instead of asking me to prove to myself what I don’t believe is true.
After all, you are a science writer and popularizer of science topics and you generally write for laypersons, surely you can state your points in a simple and understandable manner for anyone with a reasonable intelligence to understand.

“Evolutionary biologists generally agree that humans and other living species are descended from bacterialike ancestors. But before about two billion years ago, human ancestors branched off.
This new group, called eukaryotes, also gave rise to other animals, plants, fungi and protozoans.”

With all due respect, there is not a shred of empirical evidence, either observational or experimental that supports the audacious claim that eukaryotes “evolved” from prokaryotes, much less that drift and/or selection was the mechanism.