Jonathan Agnew said:
I think you're assuming that evolution constitutes progress. It does not. Evolution is descriptive. It describes the changes in the heritable traits of populations of living things and viruses over time.
I think evolution does generate progress in species.
About 3.5 Bn years ago, life began as simple cells that consumed energy, and divided. At some time about 1.7 Bn years ago, some archaic cell joined with another cell and became the first multi cellular life. It prospered. About 430 million years ago, the first creatures crawled out of the oceans and dragged themselves onto the land. About 150,000 years ago the first modern humans emerged from the previous hominid species as a distinct and new animal. I think this shows progression. It is progress.
Is progression morally superior?
Certainly not 'moral', and only superior in that species are re-shaped by random mutation and better tuned to survival - more fit for where they live. The mutations which do not increase fitness, die out.
In talking about fitness, one is talking about the survival and reproductive output of an individual, or a population in a given environment. That is all. It is not a value judgement, just a statement of fact. It works or it doesn't. The species lives and thrives, or it dies.
Jonathan Agnew said:
Given the environment in which a population finds itself constantly and abruptly change over geological time, there is no way for evolution - which lacks a mind, foresight or prophetic ability - to “plan ahead”. In what sense then can evolution be said to lead to “progress” if it has no way of “knowing” future conditions, let alone planning for them?
The history of the physical conditions and of life itself shows exactly this.
There is no disembodied mind planning changes and development. The planet changes because of physics and chemistry. There are individual species extinctions, and mass extinctions. Some forms die out, others continue, and change to suit the new conditions.
One of the earliest examples may be the extinctions of some classes of microbial life brought about by the atmospheric oxygenation about 2.4 Bn years ago. The oceans were full of menthanogens - anaerobic bacteria consuming hydrogen and co2 and producing methane like we produce co2. These were the first life forms. For them, free oxygen was deadly. It was given off by newly evolved cyanobacteria. Methanogens went from what was all of life to mostly dying out and the new aerobic strains predominated. The period is sometimes called 'The Great Oxygenation Event'. It was the first mass extinction. It was one of many.
Much nearer our own time, the woolly mammoth that had weathered ice ages in Europe and Asia, vanished as the Earth warmed into our own era. Why did this happen? Gravitational resonances caused by Jupiter and Saturn altered Earth's tilt and the plane of the planet's orbit. No plan. Just physics.
Evolution is mindless. Species suit their environment and adapt by random mutation, or they die out.
Sh|t happens. Species become tougher. They reproduce and survive, or they don't.
Coming back to my original point in this theme. Does medical intervention strengthen the species? Yes and no. On an individual basis, yes - individuals survive who would not have done. They reproduce and pass on their traits. This for the individual is a bonus.
Does it strengthen the species ability to survive in primeval circumstances? No. while we have medicine and the infrastructure to provide it, all is good. We live better healthier lives, but should the conditions of civilisation end, and they will do one day, the species will be weaker than it was before the medical revolution, because genetic traits will exist among the population that nature, red in tooth and claw, would have eliminated had it been left to do so.
No comments:
Post a Comment