Jump to content


Photo
- - - - -

Has our BIOLOGICAL EVOLUTION ended?


  • Please log in to reply
116 replies to this topic

#86 charles brough

charles brough

    "overviewist"

  • Members
  • 531 posts

Posted 20 April 2009 - 03:32 PM

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.


It is strange, however, that people don't seem to accept that. They seem to feel that biological evolution is the only way to account for all the change in the way we live during the last some 40,000 years. Perhaps the reason they insist on coming up with pathetic examples of current genetic evolution in us is because the idea that we are bound together in societies by ideological systems instead of "Truth" is disturbing. It means that our "True" beliefs are really not "true" and that in belief systems, it is survival of the fittest!
They come and go and in the very long term, it is the most accurate ones that survive.

#87 Essay

Essay

    Explaining

  • Members
  • 793 posts

Posted 20 April 2009 - 05:24 PM

...coming up with pathetic examples of current genetic evolution in us...

...you expect to find examples of "evolution in us" within a few generations--like night vision? Well, I think we need to look more for metabolic and durability type of mutations, but....

Yes, I'm no expert in evolution, and I could use some help here...
...which is why this below is probably rambling a bit, but I think the general idea comes across.
[Also, nobody's yet fleshed out this aspect of evolution, but regarding one point that was mentioned: epigenetics can fade out--or become permanent--depending on the environment.]

But please, anyone who understands evolution better, please help out.
Am I attributing too much subtlety to the genetic mechanisms and the integrated, systemic nature of genomes?

===

The immune system; just think how we're changing that--witness the rise in allergies.
So many metabolic processes are coupled to circadian rhythyms--like the daily regeneration of rods in the eyes.
Nutritional signals to the genes are completely different from just a hundred years ago--for folks living within a 24 hours society.


But I see your point that if nothing "selects" or in some way decreases reproductive success, then it doesn't matter how we regress, devolve, or degenerate.

I think this is correct:
There are multiple, unstoppable mechanisms to generate and force variation into our genome.
Domestication allows this to proceed so that variation is outside the bounds that a wild environment would ordinarily limit by selection.
This can only go on for so long until the variation starts affecting overall fitness--witness domesticated crops and animals. That's why I brought up the example of wolves radiating to dogs.
In what way do you think we are different?

We do have the capability to change the environment so that those grossly varied crops and animals continue to survive--and we are very good at doing that for ourselves too, when needed. But eventually....
===

Here's what I'm trying to say, I think.

Sure, there is a "lull" in selection pressures (due to social organization), and during this "lull" rare advantageous mutations are not selected for.
...and of course you're assuming a continuing state of increasing domestication, I think? No pandemics, no meteors, no wars, or famines, cultural collapses--or climate shift to another glaciation?
...so therefore our evolution has ended, right? Sure, that makes sense.

But:

During this same "lull" a lot of deleterious mutation are not going to be deselected.
...and during this same time a lot of "neutral" mutations are going to build up.
That can only go on for so long before there is some sort of reorganization of genetic function and expression.

At some point--evolution will continue.

At most our biological evolution is lulling, not ending.

#88 CraigD

CraigD

    Creating

  • Administrators
  • 7278 posts

Posted 20 April 2009 - 06:18 PM

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.

Problems with this “survival of the fittest” metaphor for natural selection include
  • That what trait is or will be effectively “strong” or “weak” is hard to determine. For example:
    • Heritable diseases may provide critical resistance to future environmental or disease pathogens
    • Disable individuals may have a beneficial affect on society by filling peculiar social roles, or promoting beneficial social behaviors such as charity and compassion
  • Because the smallest unit of that which can live to reproduce or die without reproducing is the individual organism, not individual heritable traits, beneficial traits may be culled and detrimental ones perpetuated because they are present in an individual with other survival-impacting traits
  • Sometime the fit are just unlucky, and die, while the less fit are lucky, and survive
This is not to say “survival of the fittest” is not an apt and useful metaphor, only that it is an approximate, not an absolutely accurate, one.

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.

This claim presupposes that
  • Electric lights and other night-vision aids actually have tamed the night environment
  • Every possible enhancement of visual perception can be accomplished with better illumination, optical devices, image-enhancement software, etc.
While I’m transhumanist enough to imagine, and even wish for, a future in which artificial visual systems render our present fleshy, nervy orbs obsolete in every way, I realist enough to expect this may be a long time coming, or may never come.

Our mastery of our environment have effectively removed us from the set of animals subject to evolutionary adaptation to environmental change.

As with vision, this presupposes that our mastery of our environment is effectively absolute. Though I share the dream of this occurring, I don’t believe that it has, by a long shot, at present.

Though our tool use is of tremendous benefit to us – I’ll go so far as to believe they set us apart from other animals more than any other major collection of traits, as I don’t see dolphins or termites landing spaceships on Mars – artifice is not at present the best solution to every environmental challenge, and in some situations, is actually a detriment. For example, labor-saving devices are a major cause of physical under-exercise and obesity, a major factor leading to untimely death. Dwellings and conveyances limit our contact with the dirtiest parts of our environment, which appears to cause immune system malformation resulting in potentially fertility and life-threatening disorders.

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.

A point: evolution is not due entirely or even mostly to the acquisition of random genetic mutation, but in the large to acquiring old genes in different combinations via ordinary sexual reproduction.

Again, I agree, tools help, tremendously. However, purely biological advantages are also advantageous. All the present-day technology in the world is not enough to give selective advantage to a person with many heritable biological disabilities over a more biologically fit person – especially if the disabilities and fitness are related to fertility.

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.

It is strange, however, that people don't seem to accept that. They seem to feel that biological evolution is the only way to account for all the change in the way we live during the last some 40,000 years. Perhaps the reason they insist on coming up with pathetic examples of current genetic evolution in us is because the idea that we are bound together in societies by ideological systems instead of "Truth" is disturbing.

Another explanation for why people don’t accept that our mastery of our environment has removed us from the set of animals subject to evolutionary adaptation to environmental change is related to their perception of cause.

Most people, I think, agree that human planning, tool use, and other technology has and is affording us tremendous advantages we would not have if we lived much like other animals. However, our ability to think, communicate, and build appears to me and, I think, many others, to have been caused by biological evolution, rather than our biological evolution having been caused by it. The truth of how much of our continuing success is due to our social abilities and artifice, vs. how much is due to our biology, vs. how much is due to luck, is, I think, moot (in the old sense of the word).

#89 charles brough

charles brough

    "overviewist"

  • Members
  • 531 posts

Posted 21 April 2009 - 12:13 PM

Most people, I think, agree that human planning, tool use, and other technology has and is affording us tremendous advantages we would not have if we lived much like other animals. However, our ability to think, communicate, and build appears to me and, I think, many others, to have been caused by biological evolution, rather than our biological evolution having been caused by it. The truth of how much of our continuing success is due to our social abilities and artifice, vs. how much is due to our biology, vs. how much is due to luck, is, I think, moot (in the old sense of the word).


The advantages we have over the other primates are the product of evolution, but evolution does not account for the changes in the way we live going back some 40,000 years. History involves the rise and fall of societies and their civilizations, something that changes as our biology stays the same. The natural selection that accounts for this amazing progress on a being that has not significantly changed, has caused all that change. Ideological-system based societies compete with each other and the one with the ideological system the most advanced replacing older ones which have been outgrown. This is just a general description of a complicated process of social evolution which explains our grrowing cultural heritage and how we have managed to populate and take over the planet even without any important slow-paced biological evolution.

charles
the Atheistic Science Institute - home page   

#90 Galapagos

Galapagos

    Explaining

  • Members
  • 626 posts

Posted 21 April 2009 - 05:36 PM

WOW! That was a block of academic overload! The writer says brain evolution is going on, but how can any of us tell why or how or question in any way what his academeese unclearly states?


The authors of the article have actually been quite busy popularizing their findings lately, perhaps these articles will help you understand their work better.
Here is a summary on the blog of one of the authors, John Hawks:

Why human evolution accelerated | john hawks weblog
[...]
One day a couple of years ago, Greg Cochran and I were talking about brain evolution. You have to understand, this is long before we knew about any of these genome scans -- they hadn't come out yet. One of the main mysteries of human brain evolution is why it happened apparently gradually for such a long period of time. It is one of the best cases of evolutionary gradualism. But this is a problem, because directional selection would have too be too weak to take such a long time. Now, we know that brain size is constrained in two directions -- larger brains cost more energy to maintain, but smaller brains come with some functional disadvantages. So this creates a situation where new variants that satisfy both constraints -- costing little energy, or making great improvements in brain function -- must be very rare. It should be mutation-limited.

I remember very well, that at precisely the same moment, we both realized -- "Hey, maybe this great increase in human population size made a difference!" Because as we'll see later, the pattern of change in brain size really changed when populations started to get really big.[...]



Here is an article from SEED with some more of the authors discussing their work and its implications:

How We Evolve SEEDMAGAZINE.COM
When the previous generation of life scientists was coming up through the academy, there was a widespread assumption, not always articulated by professors, that human evolution had all but stopped. It had certainly shaped our prehuman ancestors — Australopithecus, Paranthropus, and the rest of the ape-men and man-apes in our bushy lineage — but once Homo sapiens developed agriculture and language, it was thought, we stopped changing. It was as though, having achieved its aim by the seventh day, evolution rested. “That was the stereotype that I learned,” says population geneticist and anthropologist Henry Harpending. “We showed up 45,000 years ago and haven’t changed since then.”

The idea makes a rough-and-ready kind of sense. Natural selection derives its power to transform from the survival of some and the demise of others, and from differential reproductive success. But we nurse our sick back to health, and mating is no longer a privilege that males beat each other senseless to secure. As a result, even the less fit get to pass on their genes. Promiscuity and sperm competition have given way to spiritual love; the fittest and the unfit are treated as equals, and equally flourish. With the advent of culture and our fine sensibilities, the assumption was, natural selection went by the board.


Here is one more recent article from the LA Times featuring two of the authors, Henry Harpending and Gregory Cochran:

Jewish legacy inscribed on genes? - Los Angeles Times
Ashkenazi Jews have a higher rate of some deadly genetic diseases -- and of high IQs. Scientists Gregory Cochran and Henry Harpending say that's no coincidence.

If anyone is curious about the views of Harpending and Cochran, they recently wrote "The 10,000 Year Explosion", which is more of their own interpretations and speculations based on their research.


Besides the above, it is silly to claim that our biological evolution has ended. By a minimalist definition of evolution, genetic change is happening in human populations; they are evolving. In fact, given that a lot of selection pressures our ancestors faced have been lifted, more random mutations that would normally be purged by selection are persisting and spreading, which means more variation, not less, ergo more evolution. Also, some random deleterious mutations are of course being selected out of the population as they occur.

Also, anywhere where child mortality is high(ie the 3rd world), there is still room for selection to potentially act. AIDS and malaria resistance are the obvious recent examples, and there are places in Africa where child mortality exceeds 25%, often times caused by similar diseases(typhoid, cholera, AIDS etc). If differential survival occurs before reproductive age, then there is opportunity for selection.

#91 Essay

Essay

    Explaining

  • Members
  • 793 posts

Posted 21 April 2009 - 06:25 PM

The authors of the article have actually been quite busy popularizing their findings lately, perhaps these articles will help you understand their work better.
Here is a summary on the blog of one of the authors, John Hawks:

Why human evolution accelerated | john hawks weblog
[...]
One day a couple of years ago, Greg Cochran and I were talking about brain evolution. You have to understand, this is long before we knew about any of these genome scans -- they hadn't come out yet. One of the main mysteries of human brain evolution is why it happened apparently gradually for such a long period of time. It is one of the best cases of evolutionary gradualism. But this is a problem, because directional selection would have too be too weak to take such a long time. Now, we know that brain size is constrained in two directions -- larger brains cost more energy to maintain, but smaller brains come with some functional disadvantages. So this creates a situation where new variants that satisfy both constraints -- costing little energy, or making great improvements in brain function -- must be very rare. It should be mutation-limited.

I remember very well, that at precisely the same moment, we both realized -- "Hey, maybe this great increase in human population size made a difference!" Because as we'll see later, the pattern of change in brain size really changed when populations started to get really big.[...]


Here is an article from SEED with some more of the authors discussing their work and its implications:

How We Evolve SEEDMAGAZINE.COM
When the previous generation of life scientists was coming up through the academy, there was a widespread assumption, not always articulated by professors, that human evolution had all but stopped. It had certainly shaped our prehuman ancestors — Australopithecus, Paranthropus, and the rest of the ape-men and man-apes in our bushy lineage — but once Homo sapiens developed agriculture and language, it was thought, we stopped changing. It was as though, having achieved its aim by the seventh day, evolution rested. “That was the stereotype that I learned,” says population geneticist and anthropologist Henry Harpending. “We showed up 45,000 years ago and haven’t changed since then.”

The idea makes a rough-and-ready kind of sense. Natural selection derives its power to transform from the survival of some and the demise of others, and from differential reproductive success. But we nurse our sick back to health, and mating is no longer a privilege that males beat each other senseless to secure. As a result, even the less fit get to pass on their genes. Promiscuity and sperm competition have given way to spiritual love; the fittest and the unfit are treated as equals, and equally flourish. With the advent of culture and our fine sensibilities, the assumption was, natural selection went by the board.


Here is one more recent article from the LA Times featuring two of the authors, Henry Harpending and Gregory Cochran:

Jewish legacy inscribed on genes? - Los Angeles Times
Ashkenazi Jews have a higher rate of some deadly genetic diseases -- and of high IQs. Scientists Gregory Cochran and Henry Harpending say that's no coincidence.


If anyone is curious about the views of Harpending and Cochran, they recently wrote "The 10,000 Year Explosion", which is more of their own interpretations and speculations based on their research.


Besides the above, it is silly to claim that our biological evolution has ended. By a minimalist definition of evolution, genetic change is happening in human populations; they are evolving. In fact, given that a lot of selection pressures our ancestors faced have been lifted, more random mutations that would normally be purged by selection are persisting and spreading, which means more variation, not less, ergo more evolution. Also, some random deleterious mutations are of course being selected out of the population as they occur.

Also, anywhere where child mortality is high(ie the 3rd world), there is still room for selection to potentially act. AIDS and malaria resistance are the obvious recent examples, and there are places in Africa where child mortality exceeds 25%, often times caused by similar diseases(typhoid, cholera, AIDS etc). If differential survival occurs before reproductive age, then there is opportunity for selection.

Wow! Well this makes what wrote sound a bit lame (and certainly less well supported), but here it is anyway:
===

Charles, so you don't think our behaviour has changed during the past 40,000 years--or even the past several hundred?

It occurs to me that you see evolution as manifested by changes in our physiognomy only--looking for changes in our general form like extra fingers, muscles, eyes, or camouflage skin perhaps--which could give some survival advantage in the wild.

I think I'm focusing on the evolution of metabolic changes related to diet/health and immunity, but especially brain function. These areas would be severely limited, evolutionarily, in the wild; but within the context of civilization, they are going through a period of rapid diversification.
===

btw... In the background right now is an education show. They just asked: "Can you think of any way that taking an animal out of the wild would change its evolution?" They're talking about the domestication of wolves and foxes.
...Something about the Mongolian Four-Eyed Dog?

...and then there's the New Guinea singing dog (Canis hallstromi)
Journal of Zoology (2003), 261:2:109-118 Cambridge University Press
Copyright © 2003 The Zoological Society of London
doi:10.1017/S0952836903004060

In 1957, Troughton described the wild dog of New Guinea, naming it Canis hallstromi. Here the description given by Troughton is expanded by the addition of morphological, molecular and behavioural information collected from both captive and wild New Guinea singing dogs subsequent to the original description. The data support Troughton's identification of this canid as a unique taxon, although further studies are needed to clarify the exact level of taxonomic differentiation of this rare and possibly highly endangered canid.
CJO - Abstract - An updated description of the New Guinea singing dog (<em>Canis hallstromi</em>, Troughton 1957)


The show I'm watching says that this is more genetically different from wolves than are chihuahuas, daschunds or poodles--which are genetically indistinguishable from each other and wolves (so the show says: obviously they mean indistinguishable at the level where the New Zealand subspecies shows differences). They are saying that dogs don't even qualify as a subspecies of wolves; whereas the New Zealand singing dog does.

This (wolves and poodles) then, would be a good example of epigenetic changes (like racial differences maybe?).


...oh and hey!
That's another one--how our skin color has changed (along with metabolic changes affecting reproduction) over just 20,000 years!
Although to be fair, that's really an example of reproductive success driving our skin color--bolstering your side that only reproductive selection will drive biological evolution--but....
===

But you don't think our skin and hair will continue to evolve, or our sense of smell, or our social and cognitive abilities?

#92 lemit

lemit

    Creating

  • Members
  • 1115 posts

Posted 22 April 2009 - 03:05 AM

It is silly to claim that our biological evolution has ended. By a minimalist definition of evolution, genetic change is happening in human populations; they are evolving. In fact, given that a lot of selection pressures our ancestors faced have been lifted, more random mutations that would normally be purged by selection are persisting and spreading, which means more variation, not less, ergo more evolution. Also, some random deleterious mutations are of course being selected out of the population as they occur.


Thank you, Galapagos. I'd been trying to find a way to explain that evolution speeds up as cultural development increases. The protection of mutations is it.

I also saw the educational program Essay referred to and was also impressed with the fact that as we domesticated dogs we increased their diversity.

I love the simple logic you described: if you work at eliminating deselection, you will of necessity increase selection. I didn't say that as well as you did.

--lemit

#93 Michaelangelica

Michaelangelica

    Creating

  • Members
  • 7797 posts

Posted 22 April 2009 - 09:57 PM

Humans, along with most living things, are subject to epigentic changes to DNA expression - even before conception - and certainly after it.
To even suposse we have stoped evolving is a biological nonsense.

As long as our environment changes we will change.
Many say the only sure thing in life IS change.

Humans are a work in progress.
(God or gods' help us)

#94 Boerseun

Boerseun

    Phantom Cow of Justice

  • Members
  • 6056 posts

Posted 22 April 2009 - 11:42 PM

Problems with this “survival of the fittest” metaphor for natural selection include

  • That what trait is or will be effectively “strong” or “weak” is hard to determine. For example:
    • Heritable diseases may provide critical resistance to future environmental or disease pathogens
    • Disable individuals may have a beneficial affect on society by filling peculiar social roles, or promoting beneficial social behaviors such as charity and compassion
  • Because the smallest unit of that which can live to reproduce or die without reproducing is the individual organism, not individual heritable traits, beneficial traits may be culled and detrimental ones perpetuated because they are present in an individual with other survival-impacting traits
  • Sometime the fit are just unlucky, and die, while the less fit are lucky, and survive
This is not to say “survival of the fittest” is not an apt and useful metaphor, only that it is an approximate, not an absolutely accurate, one.

True, true. But aside from nitpicking, what we are doing when we go to every conceivable effort to ensure the survival of each and every newborn baby, as happens in each and every maternity ward in the developed world, regardless of the baby's genetic benefits or drawbacks, something big is happening. We have now effectively removed humans from the set of animals who, from the very start, is expected to survive based on genetic fitness alone. Plenty newborn humans spend their first years in oxygen tents whilst their malfunctioning lungs are repaired. They were not supposed to live past day 1. The point whether any particular set of genetic variants is "good" or "bad" is moot - it doesn't matter at all. What does matter, is that we've opened the evolutionary filters through technology - everything gets through.

This claim presupposes that

  • Electric lights and other night-vision aids actually have tamed the night environment

If you mean the area of the night environment occupied by humans, then yes. But its not a presupposition, it's a fact. Illumination is only a light-switch away. If there's a part of the nighttime environment not claimed and tamed by humans, you merely take a portable torch or lamp with you. This should be, pardon the pun, glaringly obvious.

Every possible enhancement of visual perception can be accomplished with better illumination, optical devices, image-enhancement software, etc.

Yes...?

While I’m transhumanist enough to imagine, and even wish for, a future in which artificial visual systems render our present fleshy, nervy orbs obsolete in every way, I realist enough to expect this may be a long time coming, or may never come.As with vision, this presupposes that our mastery of our environment is effectively absolute. Though I share the dream of this occurring, I don’t believe that it has, by a long shot, at present.

I don't think you understand what I was trying to say. Technological mastery of the night environment, for instance, does not imply a kind of a technological implant or anything genetic to occur. A simple torch in the hand is mastery of the environment enough. It's a technological invention that negates the need for any specific biological developments or adaptations to do the job. Someone who can see perfectly well in the dark has no, absolutely no reproductive advantage over someone who can flip a light switch. So, there is no evolutionary impetus for his perfect night-sight to be selected for. A thousand generations down the line, him and his buddy who could merely flip light switches, have spread their genes through the gene pool roughly equally - and by doing so, by allowing each and every nitwit, dimwit, genius, retard, savant, you-name-it, to breed like we're currently doing, their respective genetic oddities have become so diluted as to not become expressed.

Though our tool use is of tremendous benefit to us – I’ll go so far as to believe they set us apart from other animals more than any other major collection of traits, as I don’t see dolphins or termites landing spaceships on Mars – artifice is not at present the best solution to every environmental challenge, and in some situations, is actually a detriment. For example, labor-saving devices are a major cause of physical under-exercise and obesity, a major factor leading to untimely death.

Nope. Sorry - the example you named above, leads to obesity and untimely death - true. But not early enough. It kills too late. By the time Billy Bob will die of atherosclerosis in his mid-forties, he already has five kids. And it is also a statistical fact that the unemployed generally breed more than the employed and more well-off. And, of course, MedicAid (or whatever your country's version thereof might be) will go all-out to save the lives of each and every single one of his kids' lives with public tax money. It's like a termite colony out of control.

Dwellings and conveyances limit our contact with the dirtiest parts of our environment, which appears to cause immune system malformation resulting in potentially fertility and life-threatening disorders.

Exactly. And that's my whole point. And through technology, we invent respirators (ala Michael Jackson) and air filters and convert our homes into hermetically sealed units so that no ill can befall us inside. We have tamed the environment, and no amount of allergies or sniffles or any general "unfitness" in the classical sense will make us breed less. Any new discomfort will be shunned into some dark corner by some New! Improved! technology.

A point: evolution is not due entirely or even mostly to the acquisition of random genetic mutation, but in the large to acquiring old genes in different combinations via ordinary sexual reproduction.

True - and combinations thereof might be detrimental or beneficial. The point is, whatever good (or bad) might come out of a random genetic coupling between two individuals is nullified in the maternity ward and general medical care for the rest of the new individual's life. And if he by some change acquired a beneficial trait, there is nothing in our approach to the whole matter that would raise his chances of reproduction any higher than the next individual (who was actually destined to die a few days after birth from a genetic heart defect that was picked up in time and operated upon.)

Again, I agree, tools help, tremendously. However, purely biological advantages are also advantageous.

Well, I agree with you fully, if only us humans weren't so hell-bent on our technology! Because, by using our technology, we have levelled the playing field between those biologically advantaged and biologically disadvantaged. They have equal opportunity to procreate. With the nett effect that any genetic advantage the first individual might have had over the second, will be diluted into oblivion in the gene pool. His kids will find no benefit from their genetic inheritance, because, like their father, they are pitched into the dating game on an equal footing with all the rest - due to the technology in the maternity ward and general medical care thereafter. So, once again, technology is the big equaliser - and nullifies any genetig advantage.

All the present-day technology in the world is not enough to give selective advantage to a person with many heritable biological disabilities over a more biologically fit person

Now that's a bit of a jump, in my book, at least.

] – especially if the disabilities and fitness are related to fertility.

Au contraire!

Fertility treatment is one of the biggest causes of multiple births in not only the US, but the World!

So - you have a father and a mother, who for some reason cannot have kids. Then, they take some of the father's sperm and some of the mother's eggs and do their thing in a test-tube. Let's say the sperm can't swim, for some reason. Then, they take the fertilised eggs and plant them into the womb. And, because the failure rate for individual sessions is high, they implant muliple fertilised eggs. With the nett result that this father and mother, who are explicitly unfit for procreation (if they weren't, they would've) end up getting triplets, quadruplets, or, god help us all, eight - like the infamous octomom. Which means the genes that originally caused the fertility problems will spread even faster than what a gene would that was inherited the normal way, with only one live birth. And don't pounce on the "failure rate for individual sessions is high" bit, because those that can afford fertility treatment normally go back if the first round is unsuccessful. Persistant lot, those genetically unfit buggers!
But, because of the vast size of our gene pool, and our insistence to save every baby born, whatever gene was inherited (evolution) would dilute away. (Which brings us back to the Shark scenario, and our mastery of our environment that allows that very same dilution...)

Another explanation for why people don’t accept that our mastery of our environment has removed us from the set of animals subject to evolutionary adaptation to environmental change is related to their perception of cause.

Most people, I think, agree that human planning, tool use, and other technology has and is affording us tremendous advantages we would not have if we lived much like other animals. However, our ability to think, communicate, and build appears to me and, I think, many others, to have been caused by biological evolution, rather than our biological evolution having been caused by it. The truth of how much of our continuing success is due to our social abilities and artifice, vs. how much is due to our biology, vs. how much is due to luck, is, I think, moot (in the old sense of the word).

The "mastery" I claim we have over our environment is not old enough to have really influenced our obvious genetic constitution very much. A Roman born with a genetic heart defect would have died in his mother's arms. Today, it's a completely different story. But due to our technology, today people with no business being alive genetically are roaming the streets looking to procreate on an even footing with those that are genetically sound. And surely that will have the biggest impact on our genetic development in the future - and it's all thanks to our technology. Carrying on like this, pretty soon not a single baby in the developed world will be able to live through its first 24 hours without vast and comprehensive medical assistance. Yes, technology once again.

#95 Essay

Essay

    Explaining

  • Members
  • 793 posts

Posted 23 April 2009 - 01:04 AM

And surely that will have the biggest impact on our genetic development in the future - and it's all thanks to our technology.


So you're saying technology will greatly influence our evolution--impact on our genetic development?

...or are we defining evolution differently?

~ :lol:

#96 lemit

lemit

    Creating

  • Members
  • 1115 posts

Posted 23 April 2009 - 04:46 AM

The "mastery" I claim we have over our environment is not old enough to have really influenced our obvious genetic constitution very much. A Roman born with a genetic heart defect would have died in his mother's arms. Today, it's a completely different story. But due to our technology, today people with no business being alive genetically are roaming the streets looking to procreate on an even footing with those that are genetically sound. And surely that will have the biggest impact on our genetic development in the future - and it's all thanks to our technology. Carrying on like this, pretty soon not a single baby in the developed world will be able to live through its first 24 hours without vast and comprehensive medical assistance. Yes, technology once again.


Your statement and your example show a great understanding of the interrelationship between technology and evolution. Technology definitely affects evolution. It has from its inception, it does today, and it will as long as we're here to create technology and to adapt to that technology.

So, as technology and evolution continue their Manichean struggle, both our science and our biology will change. Our bodies and the biosphere we occupy will be the battleground. I don't think we'll be able to declare a victor any sooner than in that other Manichean struggle.

--lemit

#97 charles brough

charles brough

    "overviewist"

  • Members
  • 531 posts

Posted 23 April 2009 - 02:56 PM

Besides the above, it is silly to claim that our biological evolution has ended. By a minimalist definition of evolution, genetic change is happening in human populations; they are evolving. In fact, given that a lot of selection pressures our ancestors faced have been lifted, more random mutations that would normally be purged by selection are persisting and spreading, which means more variation, not less, ergo more evolution. Also, some random deleterious mutations are of course being selected out of the population as they occur.

Also, anywhere where child mortality is high(ie the 3rd world), there is still room for selection to potentially act. AIDS and malaria resistance are the obvious recent examples, and there are places in Africa where child mortality exceeds 25%, often times caused by similar diseases(typhoid, cholera, AIDS etc). If differential survival occurs before reproductive age, then there is opportunity for selection.


I appreciate all the quotes and references. I know it took time to put it all up, but the articles were unconvincing. The whole point of them is just that the academic consensus has shifted again, but it is opinion only. They have no evidence which which to compare the mind of man 40,000 years ago with now. They (and you) keep dwelling upon little things such as shifts in disease resistance. What has that to do with the immense growth in the human cultural heritage and the rise and fall of civilizations?

Of course we all know that nothing ever stays exactly the same. We are not EXACTLY how we were 40,000 years ago. But any effort to use that pathetically small changes that have come is only magnified by them in an effort to infer they can explain the rise of civilization and thus magnify their importance in science.

Don't you know that competition and status are tremendously important in science as in other professions? This is a subject that demands immense objectivity.

If you still think significant biological evolution is still occurring, then explain why you think it is significant. What in the rise of civilization and science is the result of it and how? Why do you think any significant change could come in a mere 40,000 years when most of our evolution is measured in millions of years?

#98 freeztar

freeztar

    Pondering

  • Members
  • 8432 posts

Posted 23 April 2009 - 07:54 PM

If you still think significant biological evolution is still occurring, then explain why you think it is significant.


That has been done. Viruses and other external stimuli force populations to evolve. This has never changed.

What in the rise of civilization and science is the result of it and how?


The effect mentioned above can clearly be seen by monitoring multiple generations of bacteria and their reactions to antibiotics.
The human immune system is similar. Some people die from diseases, some do not. Through multiple generations of sexual selection, the genes responsible for the particular ailment are either eradicated, or significantly reduced. That is evolution!

Why do you think any significant change could come in a mere 40,000 years when most of our evolution is measured in millions of years?


That's a bit like asking, "How can you possibly envision a staircase when you can only see a couple steps". :)

#99 Boerseun

Boerseun

    Phantom Cow of Justice

  • Members
  • 6056 posts

Posted 23 April 2009 - 11:49 PM

The human immune system is similar. Some people die from diseases, some do not. Through multiple generations of sexual selection, the genes responsible for the particular ailment are either eradicated, or significantly reduced. That is evolution!

And that's the gist of my whole argument.

While it is true that some diseases might kill you, unfortunately for evolution, us altruistic humans simply won't let it. We will put you in ICU, pump you full of meds and dope and fix whatever ails you. To send you home again to keep on breeding, and bestow your inability to fight that particular disease upon the next generation.

A hundred or so years ago, it was like you say. But today, it's a completely different ball game.

The integrity of our genome is falling to pieces as we let every imaginable genetic oddity carry on into the next generation. And we have effectively removed all environmental selection filters. In other words, Evolution has stopped for the human race. There are no selection filters in place.

Not to say that it won't start up again.

But it will take a disaster of global proportions, bigger than what our medical institutions can cope with, for us to experience evolution in the proper sense again.

#100 lemit

lemit

    Creating

  • Members
  • 1115 posts

Posted 24 April 2009 - 01:16 AM

Charles,

Are you saying that to make you consider changing your views, all we have to do is to chronicle 40,000 years of human history, listing each mutation and providing supporting data?

Is that all? I'd do that right now, except that something has come up. Sorry. Maybe next week.

--lemit

p.s. Maybe not.

#101 sman

sman

    Questioning

  • Members
  • 215 posts

Posted 24 April 2009 - 08:04 AM

The integrity of our genome is falling to pieces as we let every imaginable genetic oddity carry on into the next generation. And we have effectively removed all environmental selection filters. In other words, Evolution has stopped for the human race. There are no selection filters in place.


I think sexual selection is still operating even if natural selection has been halted by medicine, but the products of sexual selection are chaotic and probably outside of whats being reffered to as "evolution" here.

By the way, this statement should only apply to the developed world. Let's not forget that much of the world today is still subject to some selection that internet users are not.

#102 charles brough

charles brough

    "overviewist"

  • Members
  • 531 posts

Posted 25 April 2009 - 09:33 AM

That has been done. Viruses and other external stimuli force populations to evolve. This has never changed.

The effect mentioned above can clearly be seen by monitoring multiple generations of bacteria and their reactions to antibiotics.

The human immune system is similar. Some people die from diseases, some do not. Through multiple generations of sexual selection, the genes responsible for the particular ailment are either eradicated, or significantly reduced. That is evolution!

That's a bit like asking, "How can you possibly envision a staircase when you can only see a couple steps". :cup:

The problem here is that you see only a few of the steps. You see viruses affecting human immunity, but that changes with one race and group or another all the time but does not affect the ability of any people to advance civilization. It is a millions of years-long progress that has had no significant effect on the total human race in the last 40,000 years. You cannot seem to see that natural selection is going on much faster between the ideological systems that bind people into groups, nations and societies or their civilizations. That has replaced the pathetically small biological evolution you see as a few steps. It accounts for the rise and fall of civilizations.