feb 9, 2014

if evolutionary biologists wanted to be real scientists, they wouldn't begin with the assumption of natural selection. it really is teleological.

rather, they'd take genetic drift as a null hypothesis and then attempt to build evidence for natural selection on a case-by-case basis.

i'm sure they'd agree with me, in principle. it's just a matter of pointing it out, then making fun of them until it becomes institutionalized.

then, you wouldn't get biologists talking about the difficulties in determining what the "purpose" of an "adaptation" is; rather, you'd be asking them first to rigorously demonstrate that a specific trait is an adaptation in the first place, rather than the result of chance. that's how real science works - you need to demonstrate a relationship, not assume it as a consequence of a philosophical principle.

kzg
If by teleological you mean that biological entities strive to maintain themselves alive yea. But even that is marginal. Final causality requires some minimum predictability and necessity.

Jessica Amber Murray
i've noticed there's a kind of cognitive dissonance in their writings. they try and self-regulate themselves. if you press them on it, they'll present the standard line "evolution doesn't have a final cause", but you can tell they tend not to actually believe that - that they're waiting for the day that it can be shown that it's part of a plan. there's libraries of books of them arguing with themselves over this, leveling accusations of "orthogenesis" at each other.

in practice, they look at a trait and assume it has a cause, then try and determine what the cause is. but, i would suggest that most observable traits don't have a cause. two things that just pissed me off were:

1) an article exploring the difficulties in understanding why female spiders eat their mates. there's an assumption this is an adaptation, and has a cause. no. it needs to be determined this is an adaptation rather than genetic drift (or a mutation that may have a negative effect on survival)

2) they found old dna in spain that was lactose intolerant and deduced it couldn't have had to do with sunlight. again, that's jumping to the assumption of natural selection. selection, here, needs to be demonstrated. it's entirely reasonable that the mutation may have developed as an adaptation further north and drifted south. at the least, finding the lack of mutation in the south does not prove it could not have been sunlight dependent.

but if you read biology journals, the idea that every trait is an adaptation with a cause is just engrained. it's a philosophical position that takes priority over evidence, and demands evidence uphold it. whatever the merit, it's not science.

kzg
What youre pointing out is not necessarily new. It has often been leveled against biology as a hard science. Heck crackpot creations argue somewhat along that line. But alot of this has to do with the positivist assumption that all science is derived from physics, if not directly, at least in terms of epistemological criteria. Ergo, only efficient and material causality is properly scientific. But of course this is rather gratuitous (can that be explained under its own parameters?) and it led to a bunch of weird shit like phrenology. Evolutionary biology does not fall under the usual criteria of repeatability and mathematisation. Hence efficient causes cannot be isolated. For that to be possible, organic matter would have to function mechanically, that is, within uniform time, not the cumulative time (duration). So this is ingrained in the discipline's world view which, really, is essentially historical. Narratives tend to have some sort of teleological pull. Im ok with that.

Jessica Amber Murray
i know the line of argument you're thinking of, but it's not entirely what i'm saying. i'm just suggesting that they really ought to be more focused on proving relationships that they take for granted, and that they're not reduces to the substitution of a guiding belief system in place of really skeptical science. there's certainly a different set of challenges when working in biology, but i don't think they're incompatible with a general hypothesis testing approach. i mean, to suggest they are is to give up. i'd be shocked to hear a biologist suggest as much. they're certainly doing hypothesis testing, they're just doing it at too weak a level of inquiry.

you can still - i suggest you must - look at a trait and ask the question "is this an adaptation, or merely the result of chance?" in a meaningful sense, by studying all the things around the hypothetical adaptive process and coming up with an argument that this is really the case. they don't actually do that, though. in the best case scenario, they'll grudgingly admit that maybe it might just be chance if they can't figure out the adaptive benefit. but this is really backwards thinking.

where it's a problem is when it leads to wrong conclusions. one of those examples is with the female spiders eating their mates before they mate with them. it's specifically related to a solitary species that only comes into contact with a mate once or maybe twice in a life time. that is, females are eating their male mates before they mate even though the balance of probabilities is that it's the only chance they'll get to mate. this is behaviour that doesn't make any sense in terms of passing on genes. a slow consensus is developing that the spiders just lack impulse control. they see food, they eat it; they lack the faculties to analyze the consequences. it's consequently the result of one type of adaptation (impulsive eating) having a negative effect on a necessary biological function (mating). that's a chaotic development that will harm the long term health of the species, not an adaptation.

yet, leading up to this realization, there were many arguments that the behaviour was an adaptive trait to ensure the proper spread of genes. the female spider somehow determined that the male was a bad mate, and ate it in order to ensure it's genes weren't going to a bad mate. serious people argued this in serious places.

in order to take such an argument seriously, there's a lot of questions that need answers. how? but, it's the procedural approach that was the problem. it's sort of an extreme example; the shift in thinking would be a lot more enlightening with a more subtle example, where it's not so obvious. but this works better to make the argument for that very reason. so, they looked at an organism, they saw a trait and (regardless of it's absurdity) they assumed it was an adaptation for survival - leading to ridiculous conclusions that are being acknowledged as such. yet, if they began with the assumption of random gene flow (as a sort of background process, as noise) leading to random mutations (that may or may not lead to increased chances of survival), and then determined if there's enough evidence to reject that assumption and deduce an adaptation then they would have come to the right answer in the first place.

and, we can debate about what is a better null hypothesis, but beginning with randomness requires less assumptions and is more appealing for that reason.

nor is any biologist actually going to argue with me on the point. they'll gnash their teeth and say "you're right, but we take shortcuts because we're biased towards darwinian thought. if we were to formally study it, we should do it like you're saying". which is just admitting that they're being unscientific. if you look at a microbiologist or a geneticist, they all study more formally. it's only evolutionary biology, which is peculiarly deductive in it's approaches, that doesn't bother.

if they want to be real scientists, they must take the process more seriously and realize that selection is something that must be proven to arise from randomness on a case-by-case basis every single time, not a monolithic force that can be assumed to be working in nature at all times.

to be a little more specific, i'm talking about the third and fourth axioms of the modern evolutionary synthesis, that state that natural selection is the main driver of change and genetic drift is a secondary factor. this is generalizing in too far an extreme. it may be roughly true, but these are statements that require demonstration on a case by case basis, not a general statement that glosses over specific changes. holding to those assumptions has the potential to lead to bad conclusions; methodologically, it's not very scientific.

rather, i would reformulate it to genetic drift is a constant driver of change and selection depends on forces that must be demonstrated to both exist and lead to the resulting changes.