Evolution and complexity

Evolution proceeds semi-randomly. The variation in complexity among different organisms is no different than the variation in size, or in color, or in hairiness, or any other trait.There's no evolutionary drive towards complexity. Certain organisms evolved in complex ways as adaptation to environment, but complexity isn't the only way to adapt; it probably isn't even the best way.As much as we tend to think of life on Earth as lions and tigers and trees, etc., the vast, vast majority of life on Earth is still bacteria; algaes, plants insects, and fungi make up almost all of the rest. Complex macrofauna, like you and me and the oak in your front yard? Counts for hardly any of the total mass of living things ("biomass") on Earth. Nobody "evolves more" than anybody else. All living things on Earth have experienced the same amount of evolution. Evolution is not a drive towards a distant goal; it's an explanation of how survival in the here-and-now drives long-term changes in species over time.Evolution is no more a drive towards complexity than it is a drive towards being tall, or having hair, or being fast or strong. Certainly many species evolved those characteristics, but evolution isn't driving everything to be complex, because complexity isn't always a successful adaptation in every environment. It's only an argument against evolution if you don't really know what evolution is. Evolution is the scientific model that explains the history and diversity of life on Earth as the result of natural selection and random mutation.The "diversity" part is important. If evolution does have one long-term effect you could point to in nearly every species, it would be diversity. Evolution says that over time, species will tend to become more diverse. Diverse levels of complexity, like diverse heights, or diverse land speeds, or diverse coloration, are just a part of that increasing diversity.

I don't see it that way, I guess. You're just conflating evolution with selection pressure; but those are two different things. Evolution is the result of selection pressure, among other things, but it doesn't follow that more pressure means more evolution.Evolution isn't a thing that you have amounts of. It's the result of species living over time. Since all species on Earth go back to the same individual, they're all the result of the same amount of time, which means that it really doesn't make any sense to talk about who's "more evolved." Not unchanged; just, unchanged recently. You're ignoring the fact that alligators have their own evolutionary history, too. They weren't just created in situ in swamps, after all.But you're privileging recent adaptations over less recent ones without giving any reason for doing so. Ultimately, I think all such attempts to play evolutionary one-upsmanship will be equally specious.

Yeah, but you've just proved that he was right, when you ask: No, why would it? You would only leap to that conclusion because you're still thinking of evolution as a ladder instead of a tree.Here's one of the ways it works. Imagine you have a population of hill-dwelling skroats. (It doesn't matter what a skroat is; assume we're talking about a sexually-reproducing organism.) They vary, individually, like individuals of all species do; because of sexual recombination and mutation, all skroats are not clones.A skroat hunting party (made up of the largest individuals) is on the next hill over when a flash flood happens, cutting them off permanently from the main population. (I guess skroats can't swim.) They settle down and begin to breed amongst themselves. Since they were already the largest skroats, their children are large too. This goes on for very many generations. They accrue mutations that begin to represent substantial changes from the genetics of the "original" skroats.After a thousand years, the lake between the hills subsides. Suddenly it's possible for a skroat to go from one hill to another. But when the two populations meet, they don't recognize each other as mates because the individuals on the second hill are so much larger, and they have other characteristics (like different-colored fur). Moreover, even if they could physically mate, they're genetically incompatible because of all those generations of accruing mutations. Human biologists come by and identify two species of skroat.Splitting populations like that - splitting gene pools - is where new species come from. From the example you can see that Skrotus maximus evolved from Skrotus regularus, and genetic studies would confirm that, and the "original" population of skroats didn't disappear simply because Big Skroats evolved from them. Because your grandparents don't die, and your cousins don't cease to exist, just because you were born.

Lol! I guess if you hang out here long enough you know all of the "official" examples for stuff, huh?

How do you survive peer-review with such a thin skin?

Does anybody know what the hell he's talking about?

I had the best scores in the class in my Intro to Logic undergraduate class, and I have no idea what you're talking about.A logical argument (or a "syllogism") has premises and a conclusion. I've never heard of a "warrant" being a part of that. I think I've heard the term in competitive debate; but that venue has a certain rigid structure that arguments are supposed to follow.That's not really how it works here. Valid arguments traditionally:1) Expose fallacious reasoning in the opponents argument, or
2) Support one's own position with evidence from scientific sources. I don't think any of us know what you're talking about. It would be better for you to refute Dwise's argument by showing his premises don't support his conclusion, or that the evidence he's used is methodologically invalid, superceded by more recent research, or irrelevant - rather than concentrating on the supposed absence of "warrants", whatever that means.

I just want to point out, again, that "warrant" was part of no logic class I ever took, nor was it ever covered in any discrete math class I took pursuant to the CS degree I was working on (where Boolean algebra was covered), so again, "warrants" just aren't a part of developing logical syllogisms as logic is currently taught, at least in my experience.But, again - we talk about science in this forum; and while it wouldn't be accurate to say that scientific reason shouldn't be "logical" (that is, in an informal sense, meaning "reasonable"), it's certainly not the case that science proves things with logic.Rather, scientific arguments are supported by evidence. Nit-picky criticisms about logical forms simply don't have a place in science. See, this isn't even right. Syllogisms are comprised of three parts, the major premise, the minor premise, and the conclusion. "All men are mortal" can't be evidence, because it's not possible to have made an observation that proves that all men, every single one who ever lived and ever will live, are mortal. Obviously at any one time there are more than 3 billion men right now whose mortality has yet to be established, because they're not dead, yet."All men are mortal" is the major premise as it has the widest scope.
"Socrates is a man" is the minor premise, being of narrower scope.
"Socrates is mortal" is a simple application of categorical logic.None of this has anything to do with science - a process where observation leads to hypothesis, which leads to testing (via experiments or further observation), which leads to refinement of theory, which ultimately leads to communication and verification of results, the most important step. At no point does anything like a logical syllogism occur.

And, you know, thank God that it isn't. I occured to me the other day how little confidence people have in the judicial system - often specifically because of stringent evidence rules that exclude some crucial, probative piece of evidence on some legal technicality, leading to a conviction everyone knows is obviously false.Because, in the courtroom, confidence in evidence is essentially a bivalent quantity - either we have confidence in that piece of evidence, or we do not, in which case it is excluded from consideration. In science we can approach confidence in a much more continuous way, where evidence can be considered with the weight our confidence in its validity gives it. Oddly enough, science's looser requirements in our confidence of the validity evidence is what leads to the conclusions of science being much more accurate than the conclusions of the courtroom.

Wait, what? Why would you think we have formal debates here?That's not at all what scientific discourse is like, and for good reason. That's not "adjusting your terminology"; that's demanding the rest of us follow suit. I don't see any justification for doing so, and I repeat - complaining about a lack of "warrant" when such a thing is not required is nitpicky and contrary to a spirit of rigorous debate.