Tuesday, February 24, 2009

Human evolution

[by JohnS]

My my, what did I start with my rebuttal, see A rebuttal to “Who was Cain’s wife?”. How did physics get into the discussion? How did time enter the discussion? There are at least three aspects of time, probably more. There is relativistic, Einsteinian, time, quantum time and classical Newtonian time. There are also two forms of evolution, physical evolution, the evolution of the universe and biological evolution, the evolution of flora and fauna on earth.

When we discuss human evolution, our discussion should be limited to classical time and biology. I’ll redefine my preposition. With the rise of mankind a third form of evolution arose within man, intellectual evolution. Humans are still subject to biological evolution however, intellectual evolution moves mankind at a much faster pace and allows humans to rise above and dominate nature. It may even allow humans to circumvent nature and biological evolution. It is improbable that any other earthly species will rise to compete with or replace humans. UNLESS humans disappear as the dinosaurs did.

Is it possible that any natural catastrophe can cause mankind to disappear? Can mankind cause his own downfall? Man is a very adaptable animal and I find it hard to conceive of his disappearance. Therefore, man will continue to dominate the earth until physical evolution makes the earth uninhabitable and by that time mankind may have gone into space.

5 comments:

Howard Pattee said...

I think I mostly agree with JohnS, but in evolutionary time I may be more pessimistic.

Whether human language will turn out to be a long-term evolutionary success is not at all obvious. We often refer to natural language as the defining characteristic of human intelligence. The power of language has dominated history and shaped all our cultures; but human language has probably existed for less than 100,000 years. This is only a momentary event in the evolutionary time scale.

Language has not helped to control population, pollution, genocide, wars, or weapons of mass destruction, any one of which could lead to extinction. Language also allows lies and propaganda that are persuasive for generating religious myths and unrealistic wishful thinking that avoid the basic biological survival necessities for the species.

Also, our technology that depends on language now allows us to design genetic messages that satisfy immediate human desires rather than long-term survival of the species. The fact is that with the power of language, humans manage to kill each other and other species faster than any other animals.

Howard

JohnS said...

I agree with Howard when he says, We often refer to natural language as the defining characteristic of human intelligence, IF he agrees that natural language is the vehicle with which man explores and communicates ideas. I agree that humans could not have evolved without language. However, the human intellect separates man from the remaining animal kingdom. Language is only one aspect of that intellect.

We should not condemn language for human’s misuse of language.

I do disagree with Howard if in his comment he implies that there has been no improvement in the condition of mankind over the years. Evolution moves erratically not in a smooth flow but intellectual evolution continues to advance mankind. When conditions arise, that are not conducive to man he changes. Read history! I can understand Howard’s impatience when he states, (l)anguage has not helped to control population, pollution, genocide, wars, or weapons of mass destruction, any one of which could lead to extinction. Still, I argue that we have advances in all of them. Take pollution, just a few years ago, we were polluting our lakes and rivers; we were dumping toxic material in our dumps. We are now in the process of cleaning up the mess others have left. That is progress even though on a small scale. A few years ago, women and blacks were second-class citizens, they had been second-class citizens or worse for hundreds of years, today, their status although not perfect is greatly improved - in just fifty years. Since the advent of civilization, slavery has been an accepted condition in all societies; within the last 200 years ago, it has practically been eliminated.

I can’t say mankind hasn’t made mistakes, he has. I can’t say he won’t make more in the future, he probably will however overall he advances.

Although not pertinent to this discussion, I am concerned that segments of the human population are still living in the middle ages and/or in appalling conditions. I could say human evolution has passed them by. We are aware of those conditions but can’t seem to improve their condition.

Howard Pattee said...

I agree that JohnS gives a fairer picture of human advancement. My only point was that evolution has a "habit" of allowing species to advance in fitness, but after enough time they become extinct rather suddenly. Nobody agrees why.

In the case of humans, I would guess the reason will be too much competition and too little cooperation with other humans.

Howard

JohnS said...

I agree Howard that evolution has a "habit" of allowing species to advance in fitness, but after enough time they become extinct rather suddenly. Nobody agrees why. Still, when I try to envision human extinction, I can’t come up with a plausible scenario. We could nuke modern civilization out of existence but probably not kill off all mankind. Even a “nuclear winter” would not devastate the entire world although the northern hemisphere could be devastates. I guess as asteroid hit could do it, if we haven’t advanced beyond the earth at that time or had time to prepare.

Ira Glickstein said...

Human extinction on Earth was a concern for famous physicist and cosmologist Steven Hawking. I quote his 2001 statement near the start of my free online novel:

"I don't think the human race will survive the next thousand years. Unless we spread into space. There are too many accidents that can befall life on a single planet. But I'm an optimist. We will reach out to the stars."

Hawking was concerned with a genetic engineering disaster or a nuclear war, or possibly natural destruction such as an asteroid hit. IMHO these are all plausible scenarios. That is why he thought it was so important for us to colonize space by settling on Earth-like planets. (In the novel, his great-granddaughter takes this as her life's mission.)

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In the Topic that started this thread, JohnS writes "Humans are still subject to biological evolution however, intellectual evolution moves mankind at a much faster pace and allows humans to rise above and dominate nature. It may even allow humans to circumvent nature and biological evolution."

The "intellectual evolution" JohnS refers to has a popular name "memes" (Dawkins) and has been featured in a TED talk on this Blog.

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I agree with Howard that species improve in fitness and then, sometimes suddenly (in geologic time terms) go extinct. Perhaps that is due to them evolving to become so perfectly (and narrowly) fit in the given environment that they no longer have the natural range of variability of offspring that would allow them to survive and continue to reproduce in the face of a relatively rapid change in that given environment.

For example, in case of drastic global warming (or cooling) or asteroid hit, etc., would modern humans be able to survive without the comforts of civilization? As we interbreed globally and perhaps reproduce by cloning, the human genome will become more standardized and a single virus or genetic engineering experiment that goes wrong may do us all in.

I also agree that "In the case of humans, I would guess the reason will be too much competition and too little cooperation with other humans." Certainly a genetic engineering disaster or nuclear war would be too much competition.

In the future an imminent asteroid hit could be anticipated in time to send a spaceship with a nuclear weapon to slightly modify the asteroid's orbit to avoid hitting the Earth. Saving human life and civilization for the future would require space travel. Both cases (asteroid hit and space colonization) require the services of technology developed due to military competition.

Ira Glickstein