The Ultimate Human Body

[Zep Tepi]

Is the human body at its ultimate stage of evolution or given time, with the present environment, are there any changes that we could envisage taking place over the next few thousand years, if we can survive as a specie for that length of time.

[Der Trihs]

We are evolving as fast or faster than we ever have. New genes appear, diseases appear and the survivors are the ones who have resistance to it, Bob talks Carol into sleeping with him and she has his child instead of her husband's, etc. Although a few thousand years isn't much time in evolutionary terms, and long before then genetic engineering and such are likely to make natural evolution a secondary consideration at most.

[Mosier]

There really isn't even a coherent definition for an "ultimate" stage of evolution. Are we more (or better) evolved than bacteria? Cockroaches?

I can conceive of a hypothetical species that could out-compete humans and drive us to extinction. Doesn't that mean that we haven't evolved to the ultimate stage of evolution yet?

[Colibri]

Given that this requires speculation, lets move it over to IMHO.

Colibri
General Questions Moderator

[Colibri]

Originally Posted by Der Trihs

We are evolving as fast or faster than we ever have.

At this point, I doubt we're evolving much at all. Our global population is enormous, and due to increased facility for travel is becoming intermixed at an ever increasing rate. Under such conditions directional selection is very unlikely to be effective.

[Senegoid]

Originally Posted by Der Trihs

We are evolving as fast or faster than we ever have. New genes appear, diseases appear and the survivors are the ones who have resistance to it, Bob talks Carol into sleeping with him and she has his child instead of her husband's, etc. Although a few thousand years isn't much time in evolutionary terms, and long before then genetic engineering and such are likely to make natural evolution a secondary consideration at most.

Several viewpoints.

New diseases or mutant diseases, in particular the most deadly one that we can't seem to treat, might drive a major pulse of evolution. AIDS, in particular, may do it. Unchecked, it could wipe out some large cross-section of the population in relatively short order, leaving a relatively few naturally-resistant people to re-populate the planet with a new resistant strain (of people). This is one way that major spurts of evolution sometimes happen.

Debbie Duffield, marine biologist, studied Orca DNA chromatograms and reported her findings that the Killer Whale species had evolved fairly suddenly, fairly recently, due to some unknown evolutionary pressure. (ETA: This was in the 1970's or 1980's or so, IIRC.)

Another viewpoint:

Humans, uniquely among critters, have learned to manipulate the environment to suit their needs and comfort, orders of magnitude beyond what any other species has accomplished. Forget about beavers building dams and flooding rivers, or chimps collecting termites with sticks. Humans have built houses, chopped down forests, developed agriculture and domesticated animals for work and food, learned to use fire, learned to build and use elaborate tools, made clothing, and on and on . . .

By altering the environment to suit us, we have largely eliminated a lot of evolutionary pressures. Thus, human evolution has settled down to a slow crawl, if even that, since farther back than recorded history. This is in contrast to the occasional sudden evolutionary calamity like AIDS.

Final viewpoint: Who says we're advancing anyway? (Photo of a popular poster or T-shirt.)

[Superhal]

I subscribe to the argument that actually we're devolving. Autoimmune diseases are one of the key pieces of evidence. Now that our environments are so clean, our immune systems aren't able to handle what they used to. While the movie Idiocracy didn't make many waves, it's main argument, smart people have less children than dumb people, seems to be true. Most of the smart people I know wait too long to have kids, have fewer kids, or talk themselves into not having kids at all, while welfare moms are rewarded for popping out as many kids as possible. We've also convinced ourselves that being incredibly skinny is the pinnacle of beauty, when throughout history low weight has nearly always been a sign of shorter lifespans. Also, our medical technology has advanced to such a point that people who should be dead continue to breed, thus keeping their dna in the gene pool. Schizophrenics, for example, can lead relatively normal and productive lives thanks to medication, and thus pass along the gene that led to their schizophrenia in the first place.

In short, we're currently able to ignore, cure or otherwise live with factors that would otherwise cull defective DNA out of the system and drive evolution.

[Senegoid]

Originally Posted by Superhal

I subscribe to the argument that actually we're devolving. Autoimmune diseases are one of the key pieces of evidence. Now that our environments are so clean, our immune systems aren't able to handle what they used to. While the movie Idiocracy didn't make many waves, it's main argument, smart people have less children than dumb people, seems to be true. Most of the smart people I know wait too long to have kids, have fewer kids, or talk themselves into not having kids at all, while welfare moms are rewarded for popping out as many kids as possible. We've also convinced ourselves that being incredibly skinny is the pinnacle of beauty, when throughout history low weight has nearly always been a sign of shorter lifespans. Also, our medical technology has advanced to such a point that people who should be dead continue to breed, thus keeping their dna in the gene pool. Schizophrenics, for example, can lead relatively normal and productive lives thanks to medication, and thus pass along the gene that led to their schizophrenia in the first place.

In short, we're currently able to ignore, cure or otherwise live with factors that would otherwise cull defective DNA out of the system and drive evolution.

Possibly a right idea, but your examples are all wrong. Smart people having fewer kids? Political system that cares for the sick? Fashion trends that favor anorexia? That's all very short term, here-this-decade-gone-the-next-decade piddle. Global and regional economies swing from extreme to extreme, as do fashions, politics, etc., in just decades or a small number of centuries. That isn't going to do much for evolution unless it really kills vast numbers of people (like AIDS has been doing).

The trends I mentioned above make the same point. But taming fire, building houses, domesticating animals, developing agriculture, etc., are the really LONG-TERM trends that have squelched human evolution.

[Superhal]

Originally Posted by Senegoid

The trends I mentioned above make the same point. But taming fire, building houses, domesticating animals, developing agriculture, etc., are the really LONG-TERM trends that have squelched human evolution.

Well, unless you don't believe in Moore's law. If the limits of technology double every X number of years, we're squelching more evolutionary opportunities in the past 50 years than the past 50,000.

Graph of human population, note the increase since 1800.

Article on immortality by 2045.

[Der Trihs]

Originally Posted by Mosier

There really isn't even a coherent definition for an "ultimate" stage of evolution. Are we more (or better) evolved than bacteria? Cockroaches?

I think the OP meant "ultimate" in the sense of "endpoint"; as in, have we evolved as much as we are going to.

Originally Posted by Senegoid

Thus, human evolution has settled down to a slow crawl, if even that, since farther back than recorded history.

Not true, apparently.

Human evolution has been moving at breakneck speed in the past several thousand years, far from plodding along as some scientists had thought, researchers said on Monday.

In fact, people today are genetically more different from people living 5,000 years ago than those humans were different from the Neanderthals who vanished 30,000 years ago, according to anthropologist John Hawks of the University of Wisconsin.

<snip>

Beneficial genetic changes have appeared at a rate roughly 100 times higher in the past 5,000 years than at any previous period of human evolution, the researchers determined. They added that about 7 percent of human genes are undergoing rapid, relatively recent evolution.

[Superhal]

Originally Posted by Der Trihs

Not true, apparently.

I'm going to have to track down the original study, but I doubt I'll understand it though. From the Reuters summary, I have some serious doubts about the methods they used:

270 total subjects.
Able to trace mutations back 80,000 years.
"have appeared at a rate roughly 100 times higher in the past 5,000 years than at any previous period of human evolution"

My issues:
1. Unless there's some cavemen trapped in amber I don't know about, wouldn't they need actual 80k year old human dna to compare to?
2. With only 270 total subjects, how do they know it's a mutation, not a mutate? What if environmental factors like radiation or pollution caused the mutation?
3. How do they know what the rate of evolution was in 3000 BC?
4. They also do not mention the number of non-beneficial mutations. "Evolution" means that the mutations that don't work don't survive. If everybody survives, it's not evolution? Without the culling of the "bad" mutations, that doesn't mean we improve as a whole.

[Alessan]

I think that when human genetic engineering becomes common in a few more decades, we'll all look at "natural" evolution as quaint and old-fashioned.

[Gagundathar]

We certainly are not optimal either physically or mentally.
But, natural selection pressures appear to have been diminished by our ability to manipulate our environment. Given that, we may well be at an end-point until such time as we gain the ability to direct our own progeny's genetics.

ETA: Or what Allesan said.