Working out massive evolutionary timelines

[Primitius]

Im in the middle of etching out a human timeline that starts in 2000 AD and stretches to 500,000 AD and beyond.
Does anyone know any good articles or resources relating to the timescale of evolutionary change, or perhaps know about this subject themselves?
I can't seem to find anything that I can actually read on a level that makes any sense, its all way to advanced for me ( i have very limited scientific knowledge).
Basically I just need to know at what time-scales it would'nt appear completely stupid for humans to have changed quite significantly.

I realise there is probably no definitive answer, but any push in the right direction would be greatly appreciated!

 

[j d worthington]

The following may be of help:

EVOLUTIONARY/GEOLOGICAL TIMELINE v1.0

(the number to the left is millions of years)

Evolution Timeline - AndaBien

Human evolution - A look at human origins through species profiles and hominid imagery

 

[Sapheron]

In the last five hundred thousand years we've gone through ice ages, desertification, predation and god only knows what else. The net result of this is that we've gotten a little bit taller, a little less hairy and out brain grew a tad. To change significantly (how much is that?) it would take longer than this. Much longer. Millions, maybe tens of millions, of years.

Also note that evolution is based on natural selection. With all our smarts, we've practically wiped this out already, and in the future we're only going to get better at it. This done, evolution stops; if everyone survives all the genes continue to the next generation, rather than just the most appropriate. So, my personal answer is that as long as we have our intelligence and technology, humans won't evolve however long you take us into the future. Or, at least, evolution will be so unbelievably slow that it would take much longer for us to show changes than other animals. Considering they can take millions of years already, we'll take a hell of a while.

 

[Nik]

Check out 'First & Last Men', then do it different...
Last and First Men - Wikipedia, the free encyclopedia

FWIW, if humanity survives the next century as a hi-tech species, our descendants may have immortality due digital uploading / emulation...

Check out the books by Asher, and Stross' 'singularity' tales.

One thing humanity *must* do is get off planet Earth.
Within your time-frame, we have some, um, interesting geology due. Sea-level rise, local or global, AGW or not, may innundate a bunch of cities and coasts. The Carib volcanic arc is likely to get jiggy. The Australasian plate is heading North-East at several inches a year. Your time-scale will crash it into Indonesia, much like India rammed Asia. Those sea-ways will close amidst violent vulcanism and subduction mega-quakes-- Be Not There.

The Cascades *will* spew. If StHelens had gone 'up' rather than side-ways, a lot of the MidWest would be toxic. Yellowstone hot-spot may produce another basalt flood. Santorini and Krakatoa are re-building, but Toba's the scary one. Last time it blew, HomoSap nearly died out.

Never mind local difficulties such as Vesuvius taking out Naples each millenium...

A new island is forming South-East of the Big H. Without fresh lava building, armoring the coast, the Big H will follow its older sibs and gradually subside, then slough great bites prompting mega-tsunamis across the Pacific...

 

[Primitius]

thanks for the replies and links folks!
Yes i should have realised the fact that natural selection is pretty much absent from modern human life, although I kind of already have a way around this - self-guided evolution.
Still, this poses all kinds of other questions like the technology needed to achieve this etc.
Also i presume this is an idea that has been used in sci-fi before, is it seen as 'cheating' or anything? like warp drives

 

[The Judge]

This will undoubtedly sound ridiculous to the scientific among you, and apologies if I'm using terms incorrectly, but presumably some evolutionary change is possible among some people even if it is not planet-wide?

If I'm understanding it correctly, at its simplest natural selection means that random genetic mutations are favoured if they produce an advantage in competing for scarce resources - a parent with this advantage will have a greater chance of mating, producing offspring with the same advantage, who then have a greater chance of mating etc. Human intelligence may have reduced the advantage given, because the competition for resources is not so acute, but it doesn't prevent the random genetic mutation in the first place does it? (Well, I suppose it might if there are advances in genetic screening.)

I recall reading that human fertility was being affected because of advances in techniques which have allowed those with limited fertility - and who in previous centuries would probably not have fathered/given birth - to have children, who have inherited this condition. I've no idea if this is true or not, but if it is, then this is itself a change among at least a group of people, albeit not one that is particularly helpful to the survival of the species.

And the kind of selective breeding which humans carry out on farm and domestic animals might be more hit and miss in humans themselves, and might take longer to achieve results, but over millennia could presumably still produce some change?

Does this make sense?

J

 

[chrispenycate]

Until recently it was considered that inducing changes in less that a few hundred generations involved killing off at least ninety percent of the population before they bred. This might work for insects, but I don't think any mammalian species could sustain this; certainly not humans without technological support. Anyway, isolated communities with physical adaptations to particular extreme conditions, like high mountain dwellers or pearl divers, have never speciated, become incapable of mating with, and reproducing with, individuals from the main, diverse mass of humanity, any more than a poodle with a whippet.

But isolated communities of insects have been found to have adapted to be incompatible with the original source population in, at most, eighty years – the same number of generations, in some cases. These populations might have originated with the eggs of a single female; census taking among bugs is not widespread, and at any rate the original genetic diversity was very low, and presumably non-viable offspring were majoritory. I could see space colonies hitting a situation like this if there were a reduction in budget, though probably a lot slower; humans have difficulties producing more than twenty or thirty infants in a life time (although they do enjoy trying).

If technology enters the fray, the situation changes rapidly. Oh, we're a long way from understanding the patterns in human genes, and, short of a regime willing to sacrifice a lot of potential citizens for a decade or two in experiments, this is not likely to change very fast, but change it will, and ultimately, if progress continues as it still seems to be doing, parents will have the option of selecting certain characteristics for their descendants. This will probably start with detecting and eliminating certain genetic diseases, but I would bet that within a generation there will be other characteristics includer: super sportsmen, supersoldiers, high intelligence and startling good looks, maybe even optimised Mars colonists or Asteroid explorers. Would these new races become true species, unable to cross-breed without technological assistance (will technological assistance become the norm, so no-one even notices the split?).

Mammalian evolution without these factors will take millions or at least hundreds of thousands of years, and might not go in the direction generally considered 'progress' (anyone read Tubb's "Half past human?) Human diversity is enormous and it'll take more than a few tens of generations to dilute it; the 'marching morons' are more a symptom of social collapse than genetic.

 

[Nik]

'marching morons'...

Um, there's currently a measles epidemic in Wales (UK-ish) due poor uptake of vaccination due MMR controversy a decade back.

A number of people are in 'intensive care', and deaths are expected...