Science fiction regarding future human evolution

[Darwinist]

Stephen Baxter, in the Destiny's Children trilogy, talks about the future of human evolution.  He makes the frightening point that brains are expensive, and in an environment where they aren't needed we might lose them.

Baxter also wrote another novel, Evolution (see http://en.wikipedia.org/wiki/Evolution_%28Stephen_Baxter%29), which follows the course of humanity from 65 million years ago through the present (modern humans) and for another half-billion years.

This is one of my favs.  Can't believe he turned down EP.  I wonder why? 

[AarrowOM]

Thanks to my brand-new Sony PRS-505, I just read another Stephen Baxter piece about the next billion years of human evolution.  Unlike Evolution, "The Children of Time" (:::cough::: Doctor Who series 4 finale :::cough::: ) is a short story that focuses more on human social evolution and the evolution of domesticated non-human species (snakes, wasps).

[CammoBlammo]

Ooh, I forgot about this thread. I meant to come back and say thanks for the ideas. They really did help. I haven't got the paper back yet, so I don't know how I did, but i certainly did enjoy the process. If anyone's wondering, the set question asked:

Since evolution suggests that increasing complexity advances over time, how does an evolutionary  Chriistology account for the notion that Jesus was `less evolved' than other human beings? Will there come a time when humanity has evolved so far beyond where we are now that incarnation in Jesus will be seen as only an interim step in cosmic salvation?

Apart from the fact I'm not sure the lecturer fully understands biology, it was a really good question. I don't expect anyone else to agree with me, though!

[Zathras]

Threadomancy again.

It seems to me that Wells may have hit upon a real possibility in The Time Machine. 

Given:
Wealthier people live longer than people in poverty.
The "best and brightest" of the lower classes can move up.
Beauty, athletic ability, charisma, intelligence, and determination are valued attributes.

Then it is not only possibly but probable to have diverging evolution. 

Just a starting point, if anyone wants to continue this discussion.

Takes me back to Shadow vs Vorlon philosophy discussions I used to take part in.

[wintermute]

Threadomancy again.

It seems to me that Wells may have hit upon a real possibility in The Time Machine. 

Given:
Wealthier people live longer than people in poverty.
The "best and brightest" of the lower classes can move up.
Beauty, athletic ability, charisma, intelligence, and determination are valued attributes.

Then it is not only possibly but probable to have diverging evolution. 

Just a starting point, if anyone wants to continue this discussion.

Takes me back to Shadow vs Vorlon philosophy discussions I used to take part in.

The fact that "the best and the brightest" of the lower orders can move up (and equally, members of the upper class can fall on hard times)  means that the two populations are not reproductively isolated, and there is a constant, if small, flow of genes between them. This means no divergent evolution, any more than the populations of Australia and Russia will diverge from each other.

However, if the wealthy (or some other subset) were to use technology to reshape themselves to the point where they could no longer interbreed with baseline humanity, or were to completely isolate themselves completely (on another planet?), then you'd see two distinct evolutionary paths developing.

[Zathras]

What effects would birth rate have?  Would the culture with the longer life span wait until later in life to have children?

Consistently removing "the best" from one group would lessen the chance of creating more, would it not?

If the "best" move out of a group, what traits would be valued by that group, then?

I don't claim to know the answers, and may at time play devil's advocate.  Granted, we don't have this extreme seperation of cultures.

[slic]

Wouldn't the amount of divergence be completely in relation to the ease in which the changes could be enacted?  Lower classes attempting to acheive higher status would simply do what they could to "look" upper class - at the very least to ease any chance of mobility.  We do this now with hair, teeth, skin etc.  It's not a surprise that a stereo-typical hick is missing teeth and looks dirty.

Currently we can't easily genetically distinguish between the rich and the poor - instead we adopt trappings that give us cues.  Genetic changes would be very expensive at first (like good food and clothing was 200 years ago), and the rich would use it (think Sleepless by Nancy Kress) to gain an edge, maintain the status quo.  I suspect there would eventually be breakthroughs that would make it more cost-effective, though.

What effects would birth rate have?  Would the culture with the longer life span wait until later in life to have children?

I suppose in rich countries we have that now to a certain extent - but I don't really have an answer, just a comment that a friend of mine used to make that smart people need to have more children.  At the current rate, he'd say, the welfare crowd is going to eventually seriously outnumber all the rest and society would be in trouble.
 

Consistently removing "the best" from one group would lessen the chance of creating more, would it not?

If the "best" move out of a group, what traits would be valued by that group, then?

The first question doesn't hold.  Objectively it would be like any stock - all things being equal, as long as you didn't pull out more than was being made, it could go on forever.
As for the second question, we see the answer today.  If the goal is to escape the "worst" group then the traits of the "best" group are desired (studying, saving for college, getting a good job).  If the goal to to remain in the "worst" group (or to be fully aware of no real chance to escape it) then it's more about survival.  And you would see a dicotomy of values in those two sub-groups.


I question a serious divergence from ever really happening.  Isn't it proven to be self destructive when doing this?  Think about the inbreeding of many royal families (Egyptian, Japanese, European, etc.) this seems to lead to eventual ruination.

I suppose if there was a large separation (another planet as wintermute suggested) then over time we would see enviromental factors take over but only if they were lacking the technology to correct "abnormalities".  I've read articles about the death of the Deaf culture because of cochlear implants.  This can be considered an example of a divergence brought back to the mainline.

[Windup]

I suppose in rich countries we have that now to a certain extent - but I don't really have an answer, just a comment that a friend of mine used to make that smart people need to have more children.  At the current rate, he'd say, the welfare crowd is going to eventually seriously outnumber all the rest and society would be in trouble.

A couple buried assumptions, there.  One is that being a member of "the welfare crowd" is a function of factors set by genetics and early childhood events -- questionable, to say the least. How many great fortunes were founded and great works done by children of poor parents? The flip side is that becoming a "smart person" is also determined primarily by genetics and early childhood.  See any newspaper for stories of socially-worthless offspring of the rich and famous...

For a little more disciplined, rather than anectdotal view, if you look at societies over time, social mobility seems to wax and wane with social factors.  Groups that are "on top" for one cycle find themselves losing ground in another.  And vice-versa. 

[Zathras]

My point with the "best and brightest" moving up is that they are being removed from the genepool of the lower class.

If red hair is the most desired trait in the upper class, and nearly every red headed individual is moved out of the lower class before they can breed, eventually there will be no more red heads in the lower class.  This is an over simplified example. 

What possible societal pressures could cause a near complete separation of gene pools?  A virus?  Think of something as over-the-top as I am Legend.

Ok, there's meat for the grinder.

[Windup]

If red hair is the most desired trait in the upper class, and nearly every red headed individual is moved out of the lower class before they can breed, eventually there will be no more red heads in the lower class.  This is an over simplified example. 

What possible societal pressures could cause a near complete separation of gene pools?  A virus?  Think of something as over-the-top as I am Legend.

What you're describing isn't separation of the gene pools.  "Separation" would mean some insurmountable physical or social barrier prevented interbreeding between the two groups for a period of time meaningful on an evolutionary scale. Given the relative fragility of even the most durable human societies, a purely social barrier would have a tough time lasting long enough to make a difference.

What you're describing is a kind of sorting, in which individuals exhibiting desireable characteristics mate exclusively with each other.  (There's a technical term for it, but it escapes me at the moment.) Agricultural breeders have been at this for centuries, and it results in the improvement of selected-for traits at the expense of all non-selected-for traits.  The results are creatures like the domestic turkey, which is terrific at turning corn into breast meat, but is incapable of reproducing without human help and is the baseline for measuring stupidity in farm animals. 

So, on to your example, in which some sort of social barrier swept all redheads into the governing elite, where they enjoyed significant reproductive advantages, and those advantages remained in place long enough for real evolutionary change to occur.  My prediction is that the elite would do OK as long as they had continual infusions of fresh genes from the holi-poli.  Once the general gene pool was swept of all recessives inducing red-headedness, the elite gene pool would begin to stagnate.  After enough generations, an all-redhead elite burdened with an excessively large number of individuals with chronic genetic diseases, low intelligence, and other problems would eventually be overthrown by the more robust, non-readheaded masses. (If it gets down to a dogfight between the finalists for Westminster's "Best of Show" and a pack of mongrels from the animal shelter, who ya gonna bet on? Me, too...)

I don't think it really matters if you choose a "more meaningful" characteristic or set of characteristics as the selection criteria.  Being human is such a complex proposition, and the world is such a changeable place (especially over spans of time meaningful to evolution), that a narrow genetic base will eventually prove fatal.

[Zathras]

I wish I could think of something to stir the pot right now.  Windup's thoughts on this have been fascinating!

[wakela]

Sorry if this had been mentioned before, but this discussion seems to be focused on a class-based separation, and it doesn't have to be.  I'm reminded of the Hasidic Jews of New York City.  They are like a different culture living among the New Yorkers, and chose not to associate with them, and inter marriages are extremely rare.  They've been maintaining their distinct culture for a very long time, but I don't think they could keep it up long enough to make it impossible for them to mate with non-Hasidics.

I think for this to happen in any meaningful time frame you would need genetic manipulation.  Is some group of people decides to make a race of genetic superpeople who end up only being able to mate with each other.  Maybe their DNA becomes too different or maybe, like the turkeys, they lose the ability to have sex the standard way (too bad for them).  Or you could have a virus tweak a groups DNA to get the same result.

There was a time in human history when groups were separated for very long periods of time, and they evolved into the different races.  But not long enough to lack the ability to interbreed. 

[Zathras]

Ah, but if we go back far enough to the same ancestor we share with other primates, we see that it has already been done.

[Windup]

Ah, but if we go back far enough to the same ancestor we share with other primates, we see that it has already been done.

Yes, but it takes a really, really long time.  I think the common ancestor of humans and great apes lived something like 5 million years ago or so.  By contrast, even 2,500 years is a really, really, long time for a human society to exist.  And it typically changes a lot during that time, even if it does manage to hang on. 

It's hard for me to envision a class or ethnicity barrier remaining meaningful long enough to make an evolutionary difference. 

[Zathras]

So the general consensus is that societal differences are extremely unlikely to cause a large enough genetic drift?

Now, a physical event, such as isolation or mutation could create two different gene pools, but it would take thousands of generations to make differences that would create two different species?

[wintermute]

So the general consensus is that societal differences are extremely unlikely to cause a large enough genetic drift?

Now, a physical event, such as isolation or mutation could create two different gene pools, but it would take thousands of generations to make differences that would create two different species?

Exactly. Apart from a slight quibble about you use of the term "genetic drift".

My money's still on it requiring interstellar colonies.

[Zathras]

I used the wrong term, but couldn't think of a better one at the time.  How about diverging evolution?

[Windup]

My money's still on it requiring interstellar colonies.

Maybe interplanetary, if you posit the creation of self-sustaining colonies though terraforming or really efficient, self-renewing "artificial" environments that wouldn't need infusions of material from a "natural" ecosystem or human intervention to function, followed by a general collapse that cut off travel between the colonies. But even that's a stretch.  It probably would take interstellar distances  to keep us apart long enough to make an evolutionary difference, and even then, something would have to cut off the flow of genetic material between colonies. 

I think we're more likely to exterminate ourselves than we are to speciate.

[Planish]

I forget where I read it, but apparently you only have to go back 50 generations (usually much fewer) to find a common ancestor between any two people on Earth, no matter how isolated they may be from each other.

[CammoBlammo]

I forget where I read it, but apparently you only have to go back 50 generations (usually much fewer) to find a common ancestor between any two people on Earth, no matter how isolated they may be from each other.

I've heard that, and I cannot see how it's true. Let's say a generation is forty years long (25 might be more accurate, but I'll allow this grace.) Fifty times forty is two thousand years. Is it likely that the Chinese guy next door and I have a common ancestor that was born in a year we'd label CE? It's certainly possible, but I would think unlikely.

And I would lay good money on the Australian Aboriginal lady in my church having no ancestors in common with me in the last, oh I don't know, 40,000 years. Again, it's possible, but not so possible that it would be a good bet.

[Windup]

I forget where I read it, but apparently you only have to go back 50 generations (usually much fewer) to find a common ancestor between any two people on Earth, no matter how isolated they may be from each other.

I've heard that, and I cannot see how it's true. Let's say a generation is forty years long (25 might be more accurate, but I'll allow this grace.) Fifty times forty is two thousand years. Is it likely that the Chinese guy next door and I have a common ancestor that was born in a year we'd label CE? It's certainly possible, but I would think unlikely.

And I would lay good money on the Australian Aboriginal lady in my church having no ancestors in common with me in the last, oh I don't know, 40,000 years. Again, it's possible, but not so possible that it would be a good bet.

The folks at Wikipedia have laid out a great deal of information on this subject: http://en.wikipedia.org/wiki/Most_recent_common_ancestor

Looks like some estimates place the most recent ancestor of all humans as recently as the first millenium CE, though the person doing that estimate gives it as part of a range that starts in the 6th millenium BCE. 

Note, however, that this is dramatically different from the dates for the common ancestor of humans and our closest primate relatives, which is what Zathras was talking about.

[CammoBlammo]

I forget where I read it, but apparently you only have to go back 50 generations (usually much fewer) to find a common ancestor between any two people on Earth, no matter how isolated they may be from each other.

I've heard that, and I cannot see how it's true. Let's say a generation is forty years long (25 might be more accurate, but I'll allow this grace.) Fifty times forty is two thousand years. Is it likely that the Chinese guy next door and I have a common ancestor that was born in a year we'd label CE? It's certainly possible, but I would think unlikely.

And I would lay good money on the Australian Aboriginal lady in my church having no ancestors in common with me in the last, oh I don't know, 40,000 years. Again, it's possible, but not so possible that it would be a good bet.

The folks at Wikipedia have laid out a great deal of information on this subject: http://en.wikipedia.org/wiki/Most_recent_common_ancestor

Looks like some estimates place the most recent ancestor of all humans as recently as the first millenium CE, though the person doing that estimate gives it as part of a range that starts in the 6th millenium BCE.

I can see that most people who's ancestors had contact with the Europeans in the last 1000 years could find a MCRA (Most Common Recent Ancestor) in that time. The problem I have is that there are people groups who only started having contact with the Europeans in the last few hundred years. The example I gave was the Aboriginal Australians. Standard estimates suggest they came to Australia about 40,000 years ago and had very little contact with the rest of the world until around three hundred years ago. Tribes in the north of Australia had some contact with Indonesian fisherman in the last four hundred years, and there were the odd band of Europeans who came along as well before white settlement began in 1788.

There is also evidence of trade going on between Aboriginal tribes and we know intermarriage happened. However, the sparse human population and lack of well-maintained roads meant that the mixing of the gene pool wouldn't have happened as quickly as it might have in a similarly sized area anywhere in, say, Europe.

The wikipedia article makes the point:

The possibility remains, however, that a single isolated population with no recent "mainland" admixture persists somewhere, which would immediately push back the date of humanity's MRCA by many millennia. While simulations help estimate probabilities, the question can be resolved authoritatively only by genetically testing every living human individual.

[Heradel]

The was an article in the Economist earlier this month that seemed, well, apt for this discussion:

THERE are few better ways of upsetting a certain sort of politically correct person than to suggest that intelligence (or, rather, the variation in intelligence between individuals) is under genetic control. That, however, is one implication of a paper about to be published in Intelligence by Rosalind Arden of King’s College, London, and her colleagues. Another is that brainy people are intrinsically healthier than those less intellectually endowed. And the third, a consequence of the second, is that intelligence is sexy. The most surprising thing of all, though, is that these results have emerged from an unrelated study of the quality of men’s sperm.

Ms Arden is one of a group of researchers looking into the connections between intelligence, genetics and health. General intelligence (the extent to which specific, measurable aspects of intelligence, such as linguistic facility, mathematical aptitude and spatial awareness, are correlated in a given individual) is measured by psychologists using a value called Spearman’s g. Recently, it has been discovered that an individual’s g value is correlated with many aspects of his health, up to and including his lifespan. One possible explanation for this is that intelligent people make better choices about how to conduct their lives. They may, for example, be less likely to smoke, more likely to eat healthy foods or to exercise, and so on.
[...]

[Zathras]

One of the researchers was on Fox News today talking about the sperm count.  Evidently, New Yorkers have a higher sperm count than Los Angeleans, too.

(I listen to Fox News on my satellite radio.) 

[wakela]

Not really apropos to the question, but slightly related.  I heard on the scientific American podcast (I think) that scientists are racing the world trying to collect DNA samples from different cultures.  The reason is that this is the last time in human history when it will be possible to trace a population's history through its DNA. 

Still I don't think you need lots of time to make a new human species.  You could whip one up in the lab.