beyond persuasion

[pietillidie]

[3.14159]

[David]

WIAN is taking the piss, but my Dad has actually said that exact same thing about primates. Poe's Law, I think it's called.

[pietillidie]

[Wokko]

The only questions around evolution of humans are specifics such as Out of Africa vs multiregional theories. The fact that we evolved is not currently under question.

[pietillidie]

^IIRC another curious element concerns the potential of things like viruses to cause major changes in gene expression. But that's still not questioning evolution per se, only explaining how more radical mutations came about, and hence some gaps in the fossil record perhaps.

[Tannin]

^ OK, but we don't really need to explain gaps in the fossil record. The nature of fossil formation and preservation is so chancy that we have every right to expect gaps as routine.

In any case, evolution has nothing directly to do with mechanisms causing genetic change. Evolution simply rewards successful changes (from whatever cause) with continued survival and eliminates the unsuccessful. In order to function, it simply needs to be presented with some variety. Indeed, the ability to self-generate genetic variety itself is a very heavily selected evolutionary characteristic. Most species generate a moderate amount of variety. Species which generate a lot of variety (e.g., have naturally high mutation rates) tend to do well during times of rapid environmental change (because at least a few of them will be better fitted to the new circumstances than others) but less well during periods of stability (because too many young organisims are changed and thus less fit for survival). Some species are almost immune to mutation and change: the whole crocodile family, for example, barely varies from opne generation to the next. Crocodiles evolved to fit one particular niche and are really, really good at the niche. Any change, for a crocodile, is virtually certain to be a contra-survival change. The crocodiles of today got to be what they are by not changing enough to mention for more than 100 million years. When you are on a good thing, the crocodile genes say, stick to it!

Of course, one day there will be an environmental change which will require that crocodiles change to meet it, and they won't be able to. At that time, they will die out. Mind you, they have managed to survive around 100 times longer than we have so far, so we shouldn't sneer at their very conservative strategy: so far, it has served them well.

Most species, as I mentioned before, have a moderate variability, neither highly changeable like a fruit fly nor highly stable like a crocodile. In general, this is good enough to cope with stable times and still good enough to cope with fairly rapid change. One thing non-biologists nearly always get wrong is that they under-estimate the effect of evolutionary filtering at key change-points. Most species can evolve very, very rapidly when the selection pressures are strong. It is a big mistake to think that evolution is a very slow, steady process. Darwin thought it was, but Darwin lived 150 years ago and we have learned a very great deal since then. Evolution tends to work slowly or not at all for long periods, but can and does work very quickly indeed when circumstances require and permit it.

[HAL]

As a male that may not apply to me.

[pietillidie]

[3.14159]

[sixpoints]

[1061]

I didn't make it to year 9(form 3 in my day).

[stui magpie]

[Pies4shaw]

The science isn't 'changing' - its just becoming gradually more certain

[stui magpie]

^

Tomato, Tomahto.

But you acknowledge it's not certain yet and potentially more change in views is to come as it becomes more certain.