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Has our BIOLOGICAL EVOLUTION ended?


charles brough

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Much like the sharks.

 

 

Gosh, I agree that we're grossly diminishing our genome as you describe--and also think of what vaccines and antibiotics are doing to our immune systems!

But we're not preventing mutations, just the selection part.

Eventually selection will happen, I imagine.

It's not as if we'll continue living in houses and driving cars for "another 100 million years."

 

Selection Happens [a new bumper sticker ?]

===

 

But our diets and living conditions have changed (and continue to change) at a rate magnitudes faster that the diet and living conditions of sharks.

I'd think our condition is much more similar to that of dogs (relative to wolves); a sort of new subspecies that has exploded into a new environment--with many new "purposes" to qualify fitness.

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What's going on here? Are we really suggesting sociology can replace biology? Should this thread be moved to a different forum? If biological development is no longer significant, then I guess we don't need to think about biological/environmental stressors as biological problems; they're social problems and need social solutions.

 

That just doesn't make sense to me.

 

I think I'm beginning to develop a theme in my posts. Don't extrapolate. Don't think that you can use one discipline in another discipline. That's good in art, but it's not good in science. (As a disclosure, I have spent most of my life on the art side.)

 

Fraser and the Durants are good at describing the life cycles of cultures. Strangely, those cycles don't seem to change, or evolve. The human bodies living in those cultures, and in our culture, do evolve. We're getting taller. That isn't social evolution. That's biological evolution.

 

--lemit

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But we're not preventing mutations, just the selection part.

Removing selection from the equation effectively nullifies evolution.

Eventually selection will happen, I imagine.

It might, but with us being the caring humans we are, at what point do you propose we'll say: "Let the babies die", in so doing allowing selection to do its bit?

It's not as if we'll continue living in houses and driving cars for "another 100 million years."

Our houses might look different, and our cars might look different, but we'll still need to sleep somewhere and go somewhere.

Selection Happens [a new bumper sticker ?]

I like that! If only we'll let it!

But our diets and living conditions have changed (and continue to change) at a rate magnitudes faster that the diet and living conditions of sharks.

Much like sharks fit their niche perfectly, I would venture to say that humans are so much in control of their environment that even dietary issues won't make any difference. For instance, "gluten-free" bread is now all the rage, where technology once again comes in to save those who cannot digest everyday stuff like gluten, and negates any negative effect that it might have on their chances to procreate.

I'd think our condition is much more similar to that of dogs (relative to wolves); a sort of new subspecies that has exploded into a new environment--with many new "purposes" to qualify fitness.
I'm not too sure I follow you here. Care to elaborate?
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What's going on here? Are we really suggesting sociology can replace biology? Should this thread be moved to a different forum? If biological development is no longer significant, then I guess we don't need to think about biological/environmental stressors as biological problems; they're social problems and need social solutions.

 

That just doesn't make sense to me.

 

I think I'm beginning to develop a theme in my posts. Don't extrapolate. Don't think that you can use one discipline in another discipline. That's good in art, but it's not good in science. (As a disclosure, I have spent most of my life on the art side.)

 

Fraser and the Durants are good at describing the life cycles of cultures. Strangely, those cycles don't seem to change, or evolve. The human bodies living in those cultures, and in our culture, do evolve. We're getting taller. That isn't social evolution. That's biological evolution.

 

--lemit

There is not a single branch of Science which stands independently of other branches. All branches are interconnected. Biology is as much an expression of organic chemistry as meteorology is physics writ large.

 

As far as your objection to sociology vs. biology in human evolutionary matters is concerned, you should keep in mind that the mating habits of humans (which would determined in a big way the direction human evolution will follow) would be better described with sociology rather than biology. The mechanics of it, however, will be a biological matter.

 

There is no way to separate the various branches of science when discussing matters ranging from technology to sociology in determining what would drive evolution amongst humans, and what would prevent it.

 

Its simply too broad in scope.

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Well, I'll grant that evolution is no miracle--in the same way that life is not a miracle--it's just the laws of physics and thermodynamics working on the elements; nothing magical or supernatural.

The vast diversity of evolutionary mechanisms--with complexities layered upon complexities--just makes evolution seem magical sometimes.

 

Anyway, I hope you get to watch that video. That they discovered another "complexity" layered within the already complex mechanisms for evolving diversity (& one that is unique to only a few higher primate species) opens up a whole new vista for potential human diversity.

AND this diversity-generating mechanism seems to be focused on cognitive functioning! Hello!?

 

Social interaction and social evolution, I would suggest, is exactly what this new "biological" mechanism is facilitating here.

===

 

I like your comparison of competing societies as being somewhat analogous to different species competing within a defined biome. Evolution is a wonderful analog for many comparisons, from the development of language to the development of corporations (from the alpha to the omega?), but I'm not sure I see how you can say "BIOLOGICAL evolution is now insignificant and SOCIAL evolution has mostly taken its place."

[but] At least this is better argument (more debatable) than the premise that our biological evolution has "ended."

 

For whom has biological evolution ended: the small percentage living as jet-setters or as the bourgeosie (for a generation or so), or would that be for the billions re-living subsistence, agrarian generations?

I would argue that domestication, and social pressures and accommodations have just added more (both additional and/or different) pressures or forcers to our biological evolution. One might expect that our biological evolution would speed up, I'd think--especially with the recent mixing of geographically-isolated, genetically-drifted, gene pools.

seems to me that we have had crowded cities, wealthy jet-setters, poor destitute laborers in societies all over the mainstream world for the last 5,000 years. Societies since then have continued to mix, people traded for goods from thousands of miles away. People then lived in a world that was no more complex than it is now, it is just that what we know now is much more complex than they understood and what is complex to us will be simple to the science a century from now or less.

 

We have no reason to think, I believe, that---a "typical" baby born 5-40,000 years ago were brought up today (were it possible!) it would turn out to be no different than the "typical" one today. The difference is not biological. Children left and grown up in the wild are much like the animals they grew up with---"victor" for instance.

 

Are you perhaps talking about epigenetic change?

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We have no reason to think, I believe, that---a "typical" baby born 5-40,000 years ago were brought up today (were it possible!) it would turn out to be no different than the "typical" one today.

....Are you perhaps talking about epigenetic change?

I think you're talking about a snapshot in our evolutionary history that still encompasses a lot of change in our environment. We haven't even had a chance to begin adapting (biologically) yet, I'd think.

 

I can't be sure, but I just think there is so much more that we don't yet understand about adaptive mechanisms (like the one mentioned above in that link) that evolution will happen regardless of what we think we are doing to our evolutionary "forcers."

We don't even know what the forcers are, do we?

What do you think living in air-conditioning does? That's a new factor...

...and look how our diet has changed in the last 20 years... 50 years... 100 years....

Dogs live in the same "stable" environment, yet look how they continue to evolve.

 

And if we brought a baby forward, wouldn't he go the way of all new societies we contact--ravaged by diseases unfamiliar to their (genetically conditioned) immune system?

 

But yes... mechanisms that we don't know about yet, epigenetics, and that new mechanism, unique to humans....

 

~bbl Gotta see a man about some dogs....

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...and look how our diet has changed in the last 20 years... 50 years... 100 years....

Dogs live in the same "stable" environment, yet look how they continue to evolve.

Dogs, cows, sheep, chickens, all domesticated animals are not exposed to the laws and results of natural selection anymore.

 

They are subject to the whims of humans when it comes to breeding, and this results in artificial selection.

 

Or, as we call it, the Science of Animal Husbandry.

 

This artificial human meddling have resulted in docile cows painted in highly-visible dappled schemes, visible to any predator, but visible also to the herdsman who keeps the predators away. A domestic cow today will probably not survive a single day in the wild.

 

Anything and everything to do with humans are removed from the "natural" scheme of things - including "evolution" in the classical sense. And only because humans are the masters of their environment, not the other way around as it is for all other animals.

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I'll try to say a bit more about the dogs later, but for now:

Anything and everything to do with humans are removed from the "natural" scheme of things - including "evolution" in the classical sense. And only because humans are the masters of their environment, not the other way around as it is for all other animals.

This may just be semantics, but maybe we have different definitions of evolution. I'm speaking of the change in the genome and I think you're talking about population dynamics--or maybe morphological expression. Oh, I've got it; you're confusing evolution with selection--or I'm confusing evolution with genetic change.

 

Your points seem to make more sense viewed from that perspective of phenotypic expression, and an individual's fight for survival--fitness. I'm looking more at change on the molecular, genotypic level, and species "fitness" when I say:

 

I think the very fact that a domesticated cow wouldn't survive a day in the wild is a statement that a lot of genetic change has occurred in that cow--and the same would be true for many of the new breeds of dogs!

 

Just because we're doing artificial selection doesn't mean that mutation rates decrease or that stability is "locked" into the genome.

The genes don't know if they're being artificially or naturally selected.

They continue to mutate and modify their relationship with their environment.

 

We still contain from one to three hundred point mutations (compared to our parents genes) regardless of whether we live as hard-working paleoliths or lazy suburbanites--and 10% of us also have microdeletions or duplications.

And we get those epigenetic changes also from our parents--and either amplify or attenuate those changes in our lives--and then pass those new modifications on to our children, for them to modify....

 

Shift Happens! ...Whether Selection Happens or Not!

The few parameters (of environmental influence on the genes) that we do control can not be expected to be the limiting factors on biological mechanisms of gene modification.

===

 

Ultimately I think we're losing a lot of robustness from the genomes as we domesticate ourselves and other species.

 

We're endangering the very mechanisms that stabilize our genes, because those no longer are needed to maintain strict limits of fitness. Faulty repair mechanism can be passed on because they aren't weeded out by selection anymore.

 

Developing a" lack of fitness" in a species (due to lack of "strict" selection) is still evolution in my book; it's genetic change.

It's common to equate evolution with only progress, or progressive development, or betterment--but I think that view is too narrow; any change should qualify--expressed or not. Building up a lot of hidden changes (due to lack of selection) doesn't mean that evolution has ended.

===

 

I probably could have said that a lot more simply, but do you see the difference I'm driving at--and does it make sense?

 

Evolution is all about change, stability, and robustness of the genome--not our preferences or judgements about what phenotype is better for today or tomorrow.

 

p.s. Maybe I should have just said that "artificial selection" is just a "different environment" as far as the genes are concerned. The genes will continue to adapt to the new environment.

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Thanks, Boerseun, your explanation was a lot better than mine.

 

We need to remember that diversity in disciplines is like other diversities. Interrelationships do not erase differences. They simply recognize the differences between equals.

 

I forgot to mention that. Thanks for the clarification.

 

--lemit

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Evolution is all about change, stability, and robustness of the genome--not our preferences or judgements about what phenotype is better for today or tomorrow.

 

p.s. Maybe I should have just said that "artificial selection" is just a "different environment" as far as the genes are concerned. The genes will continue to adapt to the new environment.

 

In other words, you are saying that there is no such things as an "artificial environment." You are seeing evolution only from the gene's perspective, not ours. Could that be treasonous?:):lol:

 

While on the subject, I ask you to enlighten me on the subject of epigenetic change. Since you get into the detail of the genetic subject, help me understand. I read that it is genetic-like change that peters out in a few generations. Is that what is happening now to the US public which is growing fat, seeing big increases in autuism, diabetes, knee discus degeneration, etc. Is it the Malthus triad that restores public health in each civilization as it collapses?

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I think you're talking about a snapshot in our evolutionary history that still encompasses a lot of change in our environment. We haven't even had a chance to begin adapting (biologically) yet, I'd think.[/i]

 

I don't think we need to. Our social evolution changes environments so often and so fast and in different places among different people that slow-spaced genetic evolution only results in negligable change that may well amount to nothing in a single millenium or two as for as the whole human race is concerned.

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We need to remember that diversity in disciplines is like other diversities. Interrelationships do not erase differences. They simply recognize the differences between equals.

 

. . . between equals? Oh how our secular civilization would or will fail when our doctrines fail! "All is equal," we say and to say otherwise is a "hate crime," "intolerance," even "anti-" whatever. Perhaps unfortunately, there really never is "equality" because it is impossible for any two things to be exactly equal. There is always differences and those differences are what everyone intuitively seeks out and, because they are different, takes subtle pride in not having them and, hence, being "superior," "better," or whatever. It is human nature (especially so in us more egotistical men) but because of our ideology, we hide it from each other as much as we can and certainly do hide it most effectively from ourselves. . .:)

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I'm sorry. I shouldn't try to write at four in the morning.

 

What I was trying to convey was that both sociology and genetics are respectable disciplines. I'm sorry for the little linguistic detour.

 

Now, the point I'm trying to make is that when people are physically changed by their environment, either their physical environment or their social environment, the resulting change is still physical. Regardless of the cause, the effect is still biological. So, if "social evolution" refers to cause, I'm fine with that. If it refers to effect, I'll have to respectfully disagree.

 

--lemit

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Removing selection from the equation effectively nullifies evolution.

Now I know it's unfair to quote you from a different thread...

What if we let our entire society work in shifts?

but this is an example of the sort of "social environment" that will influence evolution--influences that I think will continue to drive our genetic progression (or regression).

Circadian rhythms and all that....

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but this is an example of the sort of "social environment" that will influence evolution--influences that I think will continue to drive our genetic progression (or regression).

Circadian rhythms and all that....

I don't mind the cross-thread quote.

 

As to the above, there is nothing in the idea of letting society work in shifts that will induce evolutionary selection to come into place. Evolutionary selection requires death to weed out the weaklings, bettering the odds for those with beneficial genes to procreate.

 

Humans can work this "shift-system" for the next million years, and as long as we have electric lights and all the other mod cons of human engineering that tames the night environment, not a single jot or title in the human genome will change (be selected for) in order for humans to better work or live at night.

 

There is simply no need for such a change, and no individual born with night sight (for instance) will have any advantage over a human who can simply flip a light switch.

 

Our mastery of our environment have effectively removed us from the set of animals subject to evolutionary adaptation to environmental change. We say "to hell with darkness" and invent a light bulb. Other species wait for millions of successive generations to evolve light-emitting organs or develop sonar. Humans can do what glow-worms and bats do without evolving specific genes. And anybody who is born with such random mutations have no advantage at all over individuals who only has to learn how to apply existing technology.

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A new human mutation? babies have been born with a mutation that causes them to have far more muscles than normal babies

Gene mutation makes baby super strong

Very neat find. :magic:

 

I remember thinking about this in early 1998, when I first read about the discovery and suppression of the myostatin gene by McPherron and colleagues in mice – the “mighty mice” experiments (Regulation of skeletal muscle mass in mice by a ne...[Nature. 1997] - PubMed Result, and lots of popular press – note that in 1997, myostatin was known as GDF-8), again when I saw a TV show that featured “bully whippets”, a “muscle doubling” mutation believed to occur rarely if ever in any dog breed but the whippet, and after seeing the 2005 movie version of Frank Millers “Sin City”, when asked afterwards if a super-strong human like the story’s character “Marv” could exist. I commented at the time that it might be that a myostatin gene mutant – a human version of the bully whippet – who was coincidentally physically large (myostatin suppression doesn’t make you taller or broader, only more muscular – in the case of whippets, it actually causes shorter legs) and athletic, might somewhat resemble the fictional Marv.

 

I strongly suspect this is the case, and recent increased reports of “superbabies” don’t indicate an increased rate of occurrence of the trait, but increased reporting as more clinicians and other people become aware of the condition.

I don't think this can be dismissed in that way, more than just this one kid is involved, they are superior to normal humans in strength and display the same intelligence and other physiological factors. From what I've gathered it has already spread with more than 100 babies born so far. It's classic case of a good mutation starting to spread into the population.
As mentioned above, I suspect that the myostatin gene mutation is many times more common than reported, and is not “new” or “spreading”.

 

The genetics of this kind of “muscle doubling” (as it is commonly termed, though the increase in number of muscle fibers and total muscle mass is increased by only approximately, not exactly, a factor of 2) are well understood. Mutated copies of the gene must be inherited from both parents, who each must have at least a single copy. Subsequently, if a child with 2 copies of the gene grew up and had a child with someone who also had 2 copies, their child would almost certainly inherit the trait (this is how McPherron and others bred a true-breeding “mighty mouse” population). If his or her mate had zero copies of the mutant gene, however, as most of the population does, their child would have only a single copy, and children of that child’s by another zero-copies mate, a 50/50 chance of having. So, unless people with the inhibited myostatin gene purposefully breed, the trait will usually disappear from their family line within a few generations. I suspect social factors, such as an increased likelihood of elite athletes having children with other elite athletes, increases the size of the single copy population, and the incidence of children with double copies of the mutant gene.

 

Having only a single copy of the gene results has a similar but slighter affect. For example, recent analysis of genetic testing of normal-appearing whippets shows that, as one would expect, many whippets have single copies, and that race dogs that do are more likely to be top performers. The mother of the born 2004 “Berlin superbaby” featured in the chinadaily article, who upon testing was found to have a single copy, is reported to be a former world-class pro athlete, specializing in the 100 m dash.

 

If the effects of having two copies of the gene in whippets are an indication of its effects on humans, this is likely a case of “less is better”. Although not dramatically less healthy than normal whippets, bully whippets are unable to run as fast or as far as normal for the breed, and look to me uncomfortable, having reduced flexibility and range of motion. :)

 

I think another significant survival disadvantage muscle-doubling incurs on humans is that, if my guess is correct, such people have such high average body density that they will sink in water so forcefully that they will be barely able to swim, a disability shared by many genetically normal non-human apes, such as chimpanzees.

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if "social evolution" refers to cause (of physical change), I'm fine with that. If it refers to (the) effect (of physical change), I'll have to respectfully disagree.--lemit

 

I agree with you. The natural selection process going on among ideological systems and the societies they bond does not change us genetically, but societies that are failing can end up with epigenetic change which tend to be restored later on by Malthusian conditions. And social evolution is not caused by any genetic/biological change.

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