RE: Climate Change - Human Extinction
January 26, 2019 at 11:25 am
(This post was last modified: January 26, 2019 at 11:31 am by Anomalocaris.)
(January 26, 2019 at 9:03 am)Jehanne Wrote:(January 26, 2019 at 4:11 am)Anomalocaris Wrote: It’s not one specie of dinos that lasted hundreds of millions of years. Rather it is thousands of descendant species of Dinos that each came and went in its own time within those hundred million years, rather like individual bubbles come and go within a persistent head on beer in a glass, that kept the genetic lineages of the original ancesteral ur-dinosaur going all that time.
Even if our descendants are still in existence a hundred million years from now, we as the ur-sapien specie need not ourselves be particularly long lived and avoid extinction for all that hundred million years. We could emigrate from earth and quickly and prolifically speciation, leading within a few million years to many daughter species of human descendants better adopted to a wider array of environments and technology conditions, while we the original ur-specie either linger or go extinct. Some of our daughter species would in their turn spectate, but all of them will also go extinct sooner or later but mostly long before the hundred million years is up, leaving our genetic future in the hands of yet more generations of grand daughter species.
As a species with technology, we are not subject to intense natural selection, and so, our present form may last for millions of years, and be maintained via sexual selection only.
We certainly are. Natural selection swinging the composition of the gene pool in populations leading to speciation often is a very slow acting and subtle influence When compared to the time scale of the life of a single individual, and usually lacks any of the swift and dash imagery conjured up by “red in tooth and claw”. But it is natural selection nonetheless and continues to act on our population. If your lineage on average produces 1.9 live offsprings and 1.8 of them successfully reproduce, over hundreds of generation your genes would be at a massive disadvantage compare to another in the same population that on average produces 2.0 live offsprings and 1.9 of them successfully reproduce. All things being equal Over time the gene pool of your population will show ever more contribution from the other lineage and ever less from yours, just as over a few minutes lions might cull the genes of slow antelopes from the gene pool.
(January 26, 2019 at 9:58 am)Yonadav Wrote:(January 26, 2019 at 9:03 am)Jehanne Wrote: As a species with technology, we are not subject to intense natural selection, and so, our present form may last for millions of years, and be maintained via sexual selection only.
I don't know. By intense natural selection, you mean that death isn't doing the selecting anymore. We don't know what the fallout is going to be from that.
Death is itself irrelevant to selection. Reproduction resulting in offsprings whom themselves also reproduce is what counts. Whether the selection is natural is also a matter of arbitrarily drawn boundary. We are certainly still undergoing going processes that create vast divergences in the rates of successful reproduction in different parts of the population. So the gene pool of human population is still undergoing intense selection.