Interesting Stuff Thread

Mercy, you are correct! Think of all the real live trolls without the internet to tap their ire and maleficence.

You can find concerns over human genetic decline expressed by writers as far back as the eras of classical Greece and Rome. I think these fears unfounded.

Arguably, humans have been under pretty strong selection for much of our recorded history. We've lived in constantly increasing numbers, packed together in ever growing cities, allowing epidemics to spread as never before. We've surrounded ourselves with domesticated animals that have been a source of many new and lethal diseases. We've fought each other viciously on battlefields all over the world, and enslaved and trans-shipped each other in horrific conditions. For most of this time we had no functioning medicine, and even today billions have little or no access to healthcare and other technologies. Has this had an effect? Well, now we can look, we're actually beginning to see the genetic signatures of infectious disease-driven selection in our genomes.

The scenario of genetic erosion due to comfort and technology really only applies to the wealthy nations, and even then, only to the last hundred to two hundred years or so. That's precious little time to allow any real genetic change*. I think it's more a sense that we have offended the natural order with our licentious living, and that we will have to pay a price. Were I to be mischievous, I might call it a religious instinct.

As for intelligence dying out, I'm not convinced we have anything to worry about. If the ancient Greeks were right to fear this, we mightn't expect to have progressed much in the 2000 years since, and I'd say we've done rather better than that.

And for the future - if we go further in embryo screening, and even tinkering with our genomes to put in bits we want and take away bits we don't - well perhaps I won't open a whole new can of ballgames.

*[science] It was suggested that >6 billion people means more chances of mutation, leading to greater mutational load for all of us. In fact, population genetic theory says that while more people = more chances for (once harmful, now neutral due to technology) mutations to happen, nevertheless when they do occur, they'll spread less rapidly due to the larger population, hence fixation rate for new neutral mutations is equal to mutation rate, and independent of population size. [/science]

Pretty good series of videos giving a good foundation about evolution

http://www.youtube.com/user/potholer54

Simon.d wrote: »

Got it the wrong way round, thanks! Just did a quick comment on figures pulled from google, thought it sounded a bit large (I blame tiredness!) .. Anyhow, I suppose the point still stands, figures just a lot less.. i.e around 10% of our population owes their survival beyond infancy to modern technology!

Yes, the additional number of us surviving infancy - and considerably more surviving childhood - is still pretty striking. This table shows global infant mortality by country for 1960 and 2001, showing that it fell on average from 126/1000 to 57/1000. The 2007 report shows that in the least developed countries, though, one child in ten dies before the age of one, compared with one in 200 in the most industrialised countries.

Regarding my statement about our own evolution via natural selection slowing down:

We are a population of middle-to-large animals numbering almost 7 billion and spread across the world. Because of our incredible, unheard of geographic diversity (except perhaps for the rat), coupled with our newfound mobility, even if a major evolutionary shift were to occur in one place, it would be totally absorbed into the overall population, and rather than becoming a dominant trait which allowed one group of us to survive at the expense of others, it would cease to be, or at the very most not pass beyond the community whence it came.

In evolutionary time, it is just an eye blink away before no one is struggling to survive, thanks to technology (assuming, as I like to, that in 1000 years we won't have destroyed ourselves and will have ended war and famine). Yes, in just 30,000 years we've gone from black skin, to red, white and yellow and loads of in-betweens, but this was a major change carried by a small number of highly isolated individual tribes who faced extremely harsh conditions. That kind of struggle is over, and without the extreme duress of that struggle, major changes across the whole human population are not going to happen. I also think that unnatural selection will totally out pace natural selection. Today we have issue with modifying the human genome, but who can say what people in 30,000 years (about how long we've been beyond Africa in our present form) will think of the idea?

Or maybe I'm way in over my head and need a lesson in human evolution?

ChocolateSauce wrote: »

Regarding my statement about our own evolution via natural selection slowing down:

We are a population of middle-to-large animals numbering almost 7 billion and spread across the world. Because of our incredible, unheard of geographic diversity (except perhaps for the rat), coupled with our newfound mobility, even if a major evolutionary shift were to occur in one place, it would be totally absorbed into the overall population, and rather than becoming a dominant trait which allowed one group of us to survive at the expense of others, it would cease to be, or at the very most not pass beyond the community whence it came.

In evolutionary time, it is just an eye blink away before no one is struggling to survive, thanks to technology (assuming, as I like to, that in 1000 years we won't have destroyed ourselves and will have ended war and famine). Yes, in just 30,000 years we've gone from black skin, to red, white and yellow and loads of in-betweens, but this was a major change carried by a small number of highly isolated individual tribes who faced extremely harsh conditions. That kind of struggle is over, and without the extreme duress of that struggle, major changes across the whole human population are not going to happen. I also think that unnatural selection will totally out pace natural selection. Today we have issue with modifying the human genome, but who can say what people in 30,000 years (about how long we've been beyond Africa in our present form) will think of the idea?

I draw a distinction between the notion that we are genetically undermining our species through breeding without regard for good genes - that way lies eugenics - and your suggestion that we in the technological world currently don't face the same selection pressures we might have even just a couple of hundred years ago.

Under Darwinian evolution, we adapt to fit our environment. However, we can now also adapt our environment to fit ourselves. Our success in doing so means our environment now includes clean water, abundant food, vaccines, antibiotics, surgical operations, central heating etc., meaning a lot more of us can rub along. Take away our healthcare and sanitation systems, our on-demand food and energy supplies, and I think we'd go back to the lifestyle of the middle ages, with its attendant high mortality from disease, famine and toil. I don't think, though, that our species would necessarily die out due to our having enjoyed a few generations when the going was good. I believe we're not so long out of our old way of life that we can no longer hack it genetically if civilisation follows banking over the cliff.

As to where evolution will take us if we continue on our present trajectory, I have no idea, particularly if we start choosing our children's genomes à la carte. And turning to where people think evolution ought to be taking us - that one really is for the philosophers.

Eugenics is a load of BS, and hasn't really got any basis in science. It's just people who don't understand genetics trying to make certain humans "better".

Goduznt Xzst wrote: »

Am I right in assuming that evolutionary theory doesn't really concern itself with where a species or genus is going, rather where it has come from and where it is? Is this more to do with eugenics or transhumanism in regards to our own species?

Evolutionary theory by itself doesn't really have the power to predict how any given species will evolve in the future. Its predictive power lies more in its ability to extrapolate transitional and intermediate forms in the past. The reason for that is because we can get a good idea of what came before and after a given unknown form in the fossil record and/or genetics as well as having at least some information on the other species present and the environment at the time.

The problem with trying to use the theory to look forwards is that we only know the starting point and we know nothing at all about the future environmental and technological parameters. Before we can use evolutionary theory in this way, we'll need to develop means to accurately predict these other elements of the equation. The system is essentially chaotic (ie not practically predictable) beyond the very near future. The number of possible outcomes for a given species rapidly becomes mind-boggling.

None of this stops some futurist types from attempting to extrapolate our future evolution anyway, but it would be a mistake to label that "science". It's speculation.

Eugenics and transhumanism are another matter entirely, though they may be just as foolish. Both are attempts to shape our future evolution. So desirable outcomes are defined on our terms. The problem with this is that what evolution finds fit and what we judge it to be will automatically differ (otherwise why would we need to pursue these methods at all?). In the long term, evolution will always win that particular fight. But also we once again run into the problem of predictability. There are so many parameters (20,000 genes interacting with each other, with an environment with unpredicatble properties, with technologies with unpredictable growth and direction) that we really have no clear idea how any of the changes we make will do in the long term. In the short term, perhaps these are things which can be used to solve immediate problems (such as using GM crops in a drought), but the notion that we may meaningfully shape (or predict) our future evolution is very naive.

It's a beautiful but maddeningly complex system, even when you look backwards.

darjeeling wrote: »

One thing we can do is look at an ecological level, and predict that in most ecosystems there will be photosynthesising organisms, grazers that eat them and predators that eat them in turn. And we can predict some of the attributes that we'll find in organisms in each group. However, predicting which of today's species might come to inhabit a particular niche in any future ecosystem would again be much more difficult, if not impossible.

Generally, I guess we can, so long as we know enough about the current and starting conditions. Our prediction is rather nebulous though.

Goduznt Xzst wrote: »

Really? I thought it was widely accepted that Artificial selection and the prediction of phenotypes can work under quantitative genetics. Examples being the Belgian Blue cows, race horses or breeds of dog. If eugenics has been thrown out as having no basis in science I'd be interested in reading about it if you have any sources.

Looking at our domestic animals, the results of intensive selection, we see all kinds of problems resulting from a rather cack-handed approach. Though we're getting better at selecting now, we still have to work with the stock that generations of selection has left us. Strong selection for favoured traits has let undesirable ones sneak in, as well as causing more general fitness problems. Many of our domesticates are prone to disease, have low fertility and show little genetic diversity. They survive in the controlled environments we create for them, but if we could release them back into the prehistoric environments from which we took them, I doubt they'd stand a chance.

Would the same problems have arisen if humans had gone about their own breeding the same way? The results of closed breeding in European royal families offer a clue. Anyway, when human eugenics was instituted in the pre-Watson/Crick past, there wasn't much science behind it, and it was done with complete disregard for human rights. If it has a modern reincarnation, in the short term, it'll more likely be parents choosing between embryos and rejecting those destined to develop genetic disorders. In the longer term, you'd have to guess what future societies will see as acceptable or not.

Goduznt Xzst wrote: »

But do we not have enough information to run simulations? I mean given enough parameters can we not predict how humans will evolve under certain circumstances?

Given that we think anatomically modern humans have been around for about 100,000 to 150,000 years, it's unlikely we're going to start shape-changing now, unless we do start subjecting ourselves to the same breeding regimes we now reserve for our pedigree beasts, or directly meddling with our dna. Leaving those options aside, evolution says we're in for the long haul, so we're looking at forecasting over hundreds of thousands or even millions of years.

Now, going back to the chimp/human ancestor we estimate lived around 5 to 7 million years ago, could we have predicted that one branch of its descendents would go on to have all the attributes of modern chimps and another branch those of modern humans? For one thing, we'd have to have known the climatic variation to come, and the changes in ecology - tricky, given the role of chaos. And on top of that, we've the Rumsfeldian unknown unknowns. If we could, pace Gould, reset the evolutionary clock time and again, I wonder how many times would we end up with us?

Looking forward, we've similar uncertainty, which is why I agree with AtomicHorror that any predictions we come up with are a bit of fun speculation, but no firmer than that.

darjeeling wrote: »

Looking at our domestic animals, the results of intensive selection, we see all kinds of problems resulting from a rather cack-handed approach. Though we're getting better at selecting now, we still have to work with the stock that generations of selection has left us.

Yeah I agree. I think the process of breeding traits is wrong, as, like you said, it can yield unknown problems. In regards to humans though I imagine all the artificial selections of which traits the human will have will be decided before birth. Like the recent baby that was born without the cancer gene. I suppose only time will tell how successful this will actually be.

Just thought I'd add these links to the list, pretty good blog:

http://scienceblogs.com/pharyngula/

Good article from his blog: Does Evolution Imply Atheism?

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