How does human evolution work?

  • 42 Replies
  • 17562 Views

0 Members and 1 Guest are viewing this topic.

*

Offline realmswalker

  • Sr. Member
  • ****
  • 205
    • View Profile
How does human evolution work?
« on: 13/08/2006 08:55:11 »
I think i have a grasp on the basics of evolution, so i have a question.

when a species allows for the survival of everyone, regardless of their genes (like ours), shouldnt it provide for the development of quick advances and changes in genes?
Normally, for new traits to appear, it has to be beneficial to reproduction, or neutral to it. Then later a bunch of neutral traits can combine to form a positive trait.
However in a society that allows for just about all traits to remain, then it opens up the possiblities, as potential negitives to reproduction (like ADD, for example) remain in the gene pool, instead of dying out. And later, a bunch of these can combine to make a sudden change...potentially...
Idk its late...and im just thinking, not very coherently, but when am i ever really coherent...?
« Last Edit: 24/12/2006 09:20:27 by chris »
 

*

Offline Mjhavok

  • Sr. Member
  • ****
  • 468
    • View Profile
    • http://cantmakeadifference.blogspot.com
Re: How does human evolution work?
« Reply #1 on: 13/08/2006 09:12:56 »
A mutation occurs and if that mutation allows the organism to be better suited to it's environment and survive when other organisms can't this this mutation will be passed down to it's offspring. Ultimately it's to pass on its genetic material but I would say that the "trait" benefits survival and then perhaps reproduction. I agree that some of the devlopments humans have made have slowed evolution down, it sounds bad but healing the sick is kind of slowing evolution down. That said new technologies will most like advance evolution, to use a media buzz phrase "designer babies".

Steven

In a time of universal deceit - telling the truth is a revolutionary act.
Steven
_______________________________________________________________
In a time of universal deceit - telling the truth is a revolutionary act.

*

another_someone

  • Guest
Re: How does human evolution work?
« Reply #2 on: 13/08/2006 11:00:24 »
Evolution is a lot more complex than that.

Firstly, evolution is about survival of the species, not survival of the individual.  It is quite conceivable that an individual who is less able to survive on their own may actually in some cases benefit the species (for instance, it may makes them more dependent upon co=operation with others, which benefits the species as a whole even if it makes them personally more vulnerable – in many social insects, a lone insect is wholly incapable of surviving outside its social group, but it is the social group that works and not the individual).

Secondly, it is wrong to say that we do not have evolutionary pressures upon us.  It is true that a far wider range of people are surviving, but actually there are probably far greater reproductive pressures than ever before (very many people today are surviving but not reproducing, or only minimally reproducing).

Thirdly, there are still sufficient wars going on that it will itself create local selective pressures.

Fourthly, to argue that a specific trait, such as ADD, is an evolutionary disadvantage is erroneous.  You cannot say what traits are or are not evolutionary advantages or disadvantages – just because they may make your life easier or more difficult does not demonstrate that they will not prove in some wider and more subtle way actually to benefit the species as a whole – or maybe even the start of a new and more successful species – one cannot predict.



George
« Last Edit: 13/08/2006 11:02:35 by another_someone »

*

Offline realmswalker

  • Sr. Member
  • ****
  • 205
    • View Profile
Re: How does human evolution work?
« Reply #3 on: 13/08/2006 20:11:47 »
Sorry, last night i was realyl tired and just thinking randomly...
BUt what i was saying sort of is related to Another_someones final statement.
If a trait, which would normally cause the death of an individual in the wild, is now taken care of, and that individual survives, it gives the traits positive benefits a chance to reveal themselves.
This allows for more genetic diversity in the species, as more traits and genes can survive.
Im just curious how allowing for this increased number of traits will affect the outcome of humanity...
 

*

Offline iko

  • Neilep Level Member
  • ******
  • 1626
    • View Profile
Re: How does human evolution work?
« Reply #4 on: 27/08/2006 22:51:55 »
The outcome of humanity will depend much more on economy and society than on preserving weak genes or destroying them! A new world war or a famine plus plague or epidemics could zap away all the weak and defective genes in less than one generation.
Nevertheless, biological diversity together with social and cultural differences should help the "global world" to go through this new millennium safely enough.  Unfortunately we still remember recent and tragic  experiments of "genetic cleanse" to reach the perfection in the human species.
iko

*

Offline weed4me

  • Jr. Member
  • **
  • 29
    • View Profile
Re: How does human evolution work?
« Reply #5 on: 28/08/2006 12:02:48 »
just a thought...but isnt ADHD present in all children until about the age of 6ish, where most of them learn to control it?? just that if it is, surely it cant be called a faulty trait, or even a trait at all, just a failure on the brain's part to pick up on, and control?

"You have to stay in shape. My grandmother, she started walking five miles a day when she was 60. She's 97 today and we don't know where the hell she is."
"You have to stay in shape. My grandmother, she started walking five miles a day when she was 60. She's 97 today and we don't know where the hell she is."

*

Offline iko

  • Neilep Level Member
  • ******
  • 1626
    • View Profile
Re: How does human evolution work?
« Reply #6 on: 28/08/2006 13:04:01 »
We are still waiting for substantial evidence about ADHD: one defective gene? An abnormal enzyme? An environmental disease? A craving "intention to treat" by some?
Haemophilia would fit much better as an example of genetic disease (heavy on the males affected by the severe type) that requires expensive treatment and can be transmitted to the next generation.
As many other defects, it's rare enough and not a major problem for developed countries.
Speaking of the "global society" and economy: just approx.20% of haemophiliacs are treated in this world, the other 80% survive and become crippled over the years (because of repeated and untreated bleedings in their joints).
iko
« Last Edit: 31/08/2006 23:06:13 by iko »

*

Offline weed4me

  • Jr. Member
  • **
  • 29
    • View Profile
Re: How does human evolution work?
« Reply #7 on: 28/08/2006 21:52:21 »
but isnt this now less about evolution and more about adaptation?? seen as we dont seem to 'evolve' to conquer these defects, more like wait for science to conquer it. im not 100% on this, and a little drunk, so any backup would be nice lol

"You have to stay in shape. My grandmother, she started walking five miles a day when she was 60. She's 97 today and we don't know where the hell she is."
"You have to stay in shape. My grandmother, she started walking five miles a day when she was 60. She's 97 today and we don't know where the hell she is."

*

Offline iko

  • Neilep Level Member
  • ******
  • 1626
    • View Profile
Re: How does human evolution work?
« Reply #8 on: 28/08/2006 22:33:33 »
Wait wait wait...
Evolution of a species means years and generations for a specific mutation to prevail (random mutation, then positive selection by the environment).  Hundreds of years for humans, much less for insects.
The famous brown butterflies didn't adapt to the smokey trees changing colour by themselves: in a short while all the white ones were easily spotted by birds, so the few brown "mutants" took advantage of this casual camouflage and survived over the years, replacing the whole "pool" of white butterflies.
iko

By the way, did you find your grandmother in the end?
« Last Edit: 28/08/2006 22:53:04 by iko »

*

Offline weed4me

  • Jr. Member
  • **
  • 29
    • View Profile
Re: How does human evolution work?
« Reply #9 on: 29/08/2006 00:39:17 »
Well we live in doncaster so we figure she's in greenland by now....
i agree with what you say though, i laid in the grass on my lawn for 10 mins and didnt turn green.. so it MUST take years....although suspiously i wasnt attacked by birds either...

"You have to stay in shape. My grandmother, she started walking five miles a day when she was 60. She's 97 today and we don't know where the hell she is."
"You have to stay in shape. My grandmother, she started walking five miles a day when she was 60. She's 97 today and we don't know where the hell she is."

*

Offline iko

  • Neilep Level Member
  • ******
  • 1626
    • View Profile
Re: How does human evolution work?
« Reply #10 on: 29/08/2006 09:42:39 »
Probably the first mutant butterflies had just few darker spots in their wings...enough to prevail the white ones...
Do you know the "story" of thalassemia and malaria? It is quite a good example of a defect that had been preserved instead of being eliminated through generations of people.
I'll tell you this story if you are interested.

Your granny would freeze in Greenland, even walking all day!

iko
« Last Edit: 29/08/2006 09:45:13 by iko »

*

another_someone

  • Guest
Re: How does human evolution work?
« Reply #11 on: 29/08/2006 12:47:23 »
quote:
Originally posted by iko
Do you know the "story" of thalassemia and malaria? It is quite a good example of a defect that had been preserved instead of being eliminated through generations of people.



Yes, I had heard about the use of the traces thalassemia leaves in the bones being used by archeologists to give an indication of the level of malaria that had been prevelent in the local environment.



George

*

Offline iko

  • Neilep Level Member
  • ******
  • 1626
    • View Profile
Re: How does human evolution work?
« Reply #12 on: 29/08/2006 14:11:02 »
Someone is alive around somewhere!
Let me summarize thalassaemia and evolution (which we are discussing here).
The most common thalassaemic "trait" (called beta-zero) is a genetic defect in synthetizing beta-chains for haemoglobin. Adult haemoglobin is composed by 4 sub-units proteins: two alpha chains plus two beta chains, each one with an iron molecule for carrying oxygen and carbon dioxide back and forth (all those iron bits give a red colour to the blood...am I clever?).
Thalassaemia is an autosomic (not on X or Y chromosomes) recessive disease: if you have one defective gene on your pair, the other chromosome is doing the job and everything goes fine: you (actually me) are just a "carrier" (approx. 5% in the South of Italy).
When two carriers decide to have kids they face these possibilities:
25% will be perfectly normal (both chromosomes with ok genes), 50% healthy "carriers" like their parents, 25% sick children(both chromosomes with defective genes), unable to survive more than few years (now they are treated with transfusions and bone marrow transplantation in some). Those are just statistics, of course they might have 3 normal or 3 affected...but is much less probable.
This is just to show how such a defective gene should be lost in normal conditions.  In fact if there is a 25% loss each generation, any type of character tends to disappear quite soon.
But the thalassaemia genes (and sickle cell haemoglobin too) are still well represented in areas of the globe where malaria epidemics had hit hard over the centuries (Italy, Greece, Turkey, Middle East, Africa).

The hypothesis is that the "carrier" condition, with its slight instability in the mechanisms of haemoglobin production, assemblying and red cells formation, does not represent an optimal environment for malaria parasites.  Not a complete protection, just a decreased risk of successful infestation.  Good enough to let survive some people, when all the village succumbed to a malaria epidemic.
That is random-mutation, environmental selection, i.e. evolution.

"Il caso e la necessità" by Jaques Monod.

iko
« Last Edit: 29/08/2006 23:56:26 by iko »

*

Offline weed4me

  • Jr. Member
  • **
  • 29
    • View Profile
Re: How does human evolution work?
« Reply #13 on: 29/08/2006 14:43:44 »
quote:
Originally posted by iko


25% will be perfectly normal (both chromosomes with ok genes), 50% healthy "carriers" like their parents, 25% sick children, unable to survive more than few years (now they are treated with transfusions and bone marrow transplantation in some).
iko



This is my point though, medical science helps overcome these factors, not evolution!! im not tryin to contradict you in ANY way, (seen as im so far out of my depth, its like throwing a 2yr old into the deep end of a pool and expecting him to swim) but if we are using medicine to secure that even the people that in normal circumstances would die, are we not in fact tampering with evolution??....why is the basis of science contradiction? lol

"You have to stay in shape. My grandmother, she started walking five miles a day when she was 60. She's 97 today and we don't know where the hell she is."
"You have to stay in shape. My grandmother, she started walking five miles a day when she was 60. She's 97 today and we don't know where the hell she is."

*

Offline iko

  • Neilep Level Member
  • ******
  • 1626
    • View Profile
Re: How does human evolution work?
« Reply #14 on: 29/08/2006 15:31:15 »
quote:
but if we are using medicine to secure that even the people that in normal circumstances would die, are we not in fact tampering with evolution??....why is the basis of science contradiction?
weed4me

I see your point (It took me quite a while).
In my personal opinion, maybe we find many more defective genes in our developed countries, compared to the 3rd world still endangered by starvation, epidemics (not only AIDS: in certain countries it is "normal" to carry several species of human parasites at the same time...) and wars.  They have much better genes, like the Irish immigrants to the USA after decades of starvation (2x10E6 dead).
But in what we'd call inhuman conditions, those selected genes help in surviving, not in living a life as we mean it.
Wealth and technology allow people with more genetic defects to live a better life anyway.  As far as I see all these healthy people around being in shape and getting older and older I do not worry so much about genetic defects increasing. It is a new world. It is up to us to defend it, protect it or destroy it.
This is just my personal opinion of course.
iko
« Last Edit: 29/08/2006 15:49:00 by iko »

*

Offline iko

  • Neilep Level Member
  • ******
  • 1626
    • View Profile
Re: How does human evolution work?
« Reply #15 on: 29/08/2006 15:58:16 »
I forgot an example for you:
 
quote:
Haemophilia would fit much better as an example of genetic disease (heavy on the males affected by the severe type) that requires expensive treatment an can be transmitted to the next generation.
As many other defects, it's rare enough and not a major problem for developed countries.
Speaking of the "global society" and economy: just approx.20% of haemophiliacs are treated in this world, the other 80% survive and become crippled over the years (because of repeated and untreated bleedings in their joints).
iko


Haemophiliacs grow up and have kids anyway.
The ones treated in the world (20% in developed countries) do not suffer and have a normal life.  All of them (100%) even the untreated and crippled ones preserve and transfer their defective genes. By special prenatal tests their wives (<20% in hyperdeveloped countries!) may know in advance if a male-fetus is haemophiliac or not. Some decide to have a child with their own defect. I can't blame them, here they do live a normal life.

iko
« Last Edit: 30/08/2006 23:00:01 by iko »

*

Offline weed4me

  • Jr. Member
  • **
  • 29
    • View Profile
Re: How does human evolution work?
« Reply #16 on: 29/08/2006 23:29:11 »
my brain now hurts lol. but thanks for attempting to clear it up 4 me.

"You have to stay in shape. My grandmother, she started walking five miles a day when she was 60. She's 97 today and we don't know where the hell she is."
"You have to stay in shape. My grandmother, she started walking five miles a day when she was 60. She's 97 today and we don't know where the hell she is."

*

Offline rosy

  • Neilep Level Member
  • ******
  • 1018
  • Chemistry
    • View Profile
Re: How does human evolution work?
« Reply #17 on: 30/08/2006 23:48:44 »
quote:
All of them (100%) even the untreated and crippled ones preserve and transfer their defective genes.

Not true, surely... I think quite a lot of untreated haemophiliacs die in childhood of otherwise minor injuries? Some make it to parenthood, but many don't... I'm sure the proportion of reproductively successful haemophiliacs is higher in the developed countries!

Surely the point is that at present we can (afford to) make it possible for more people with genetic conditions such as haemophilia and indeed many others to have children, so the genes which cause those conditions are more common amongst the next generation, and the next, and so on, than they would be if some or all of those affected by the condition died of it. So yeah, we're altering the path of evolution. Is that a bad thing? Well, we're certainly going to wind up increasing the dependence of society as a whole on "modern medecine"... which is fine if we assume that our current technologies ain't going to come crashing down round our ears (I've got an open mind on that one), but a bit tough on generations to come if at some point a wheel drops off and suddenly we can't afford the resources to keep all these people ticking over who will at best suffer very unpleasantly if those resources are withdrawn..

Equally, having converted some formerly strongly negative genetic traits into relatively minor inconveniences* we may find that at some point in the future the same trait that caused such a problem previously is exactly the get-out-of-jail-free card that the species needs to overcome some catastrophic change in conditions, allowing affected individuals to survive when the rest die out (personally I doubt that one'll be haemophilia but who knows..)

*I know, to some extent, whereof I speak... I was born with a cleft palate (probably not genetic, actually, but it can be genetically linked). I owe my continued existence to the cunning modern science of reconstructive plastic surgery or I'd have starved to death as a result of being unable to eat. Just an example of a potential catastrophe relegated to a minor inconvenience.

*

Offline weed4me

  • Jr. Member
  • **
  • 29
    • View Profile
Re: How does human evolution work?
« Reply #18 on: 31/08/2006 01:18:07 »
i always thought evolution was natural and was for the benefit of humankind on the whole, surely changing gentetics is not helping us evolve, but merely doing what humankind has been doing for so long...striving for perfection and immortality. yes i know, we wont acieve immortality through changing a few genes but still,  by using medicical science to 'evolve' its more adaptation to achieve perfection rather than evolution no?

"You have to stay in shape. My grandmother, she started walking five miles a day when she was 60. She's 97 today and we don't know where the hell she is."
"You have to stay in shape. My grandmother, she started walking five miles a day when she was 60. She's 97 today and we don't know where the hell she is."

*

Offline rosy

  • Neilep Level Member
  • ******
  • 1018
  • Chemistry
    • View Profile
Re: How does human evolution work?
« Reply #19 on: 31/08/2006 01:41:56 »
quote:
i always thought evolution was natural and was for the benefit of humankind on the whole

Well, evolution's certainly natural, but it's no more "for the benefit of humankind" than gravity is.
Some genes confer an advantage in a certain situation so not unnaturally the individuals with those genes breed more successfully, and so their offspring will have more and better opportunities.. continue for a number of generations and if the benefit the gene gives is strong enough its carriers will outcompete the rest (or become a whole seperate species) and evolution will have happened.
Whether it benefits the species in the long term rather depends on how conditions develope... for example I read an article a bit ago that suggested that sexual selection for stupidly big antlers among some sort of Irish moose type animal resulted in the entire species dying out, the antlers having become unsustainable.

*

Offline Simmer

  • Sr. Member
  • ****
  • 229
    • View Profile
Re: How does human evolution work?
« Reply #20 on: 31/08/2006 22:14:01 »
quote:
Originally posted by rosy
Well, evolution's certainly natural, but it's no more "for the benefit of humankind" than gravity is.


Exactly! Evolution's so last millenium - in a few years we'll be able to make changes in one generation that would take evolution a thousand.  

Sea level rising? Gills please, with a side order of webbed feet. Oh and hold the haemophilia! [:)]
 

*

another_someone

  • Guest
Re: How does human evolution work?
« Reply #21 on: 31/08/2006 22:44:00 »
I think the point people are missing here is that evolution is not the process by which things are changed, but the consequence of change and selection – the actual processes by which change and selection happen do not alter the reality of evolution, only its outcome.

Nor is evolution a particularly biological process – evolution applies as much to commerce (where some corporate entities dominate and others die off), and to political entities, and even to technology itself.



George
« Last Edit: 31/08/2006 23:02:30 by another_someone »

*

Offline realmswalker

  • Sr. Member
  • ****
  • 205
    • View Profile
Re: How does human evolution work?
« Reply #22 on: 01/09/2006 00:59:27 »
and i think no one got my original statement

some genetic mutations, were this 10,000 years ago, or even 2000 would result in death, and a lack of offspring, therefore they would have died out.
However now adays, those same mutations no longer result in death (because of medicine, science, etc) and the people with them can produce offspring before they die.
So this gives those mutations a chance to produce benefits, when they survive, and possibly exist with other mutations whose combinations wouldnt have occured in the past

 

*

Offline rosy

  • Neilep Level Member
  • ******
  • 1018
  • Chemistry
    • View Profile
Re: How does human evolution work?
« Reply #23 on: 30/08/2006 23:48:44 »
quote:
All of them (100%) even the untreated and crippled ones preserve and transfer their defective genes.

Not true, surely... I think quite a lot of untreated haemophiliacs die in childhood of otherwise minor injuries? Some make it to parenthood, but many don't... I'm sure the proportion of reproductively successful haemophiliacs is higher in the developed countries!

Surely the point is that at present we can (afford to) make it possible for more people with genetic conditions such as haemophilia and indeed many others to have children, so the genes which cause those conditions are more common amongst the next generation, and the next, and so on, than they would be if some or all of those affected by the condition died of it. So yeah, we're altering the path of evolution. Is that a bad thing? Well, we're certainly going to wind up increasing the dependence of society as a whole on "modern medecine"... which is fine if we assume that our current technologies ain't going to come crashing down round our ears (I've got an open mind on that one), but a bit tough on generations to come if at some point a wheel drops off and suddenly we can't afford the resources to keep all these people ticking over who will at best suffer very unpleasantly if those resources are withdrawn..

Equally, having converted some formerly strongly negative genetic traits into relatively minor inconveniences* we may find that at some point in the future the same trait that caused such a problem previously is exactly the get-out-of-jail-free card that the species needs to overcome some catastrophic change in conditions, allowing affected individuals to survive when the rest die out (personally I doubt that one'll be haemophilia but who knows..)

*I know, to some extent, whereof I speak... I was born with a cleft palate (probably not genetic, actually, but it can be genetically linked). I owe my continued existence to the cunning modern science of reconstructive plastic surgery or I'd have starved to death as a result of being unable to eat. Just an example of a potential catastrophe relegated to a minor inconvenience.

*

Offline weed4me

  • Jr. Member
  • **
  • 29
    • View Profile
Re: How does human evolution work?
« Reply #24 on: 31/08/2006 01:18:07 »
i always thought evolution was natural and was for the benefit of humankind on the whole, surely changing gentetics is not helping us evolve, but merely doing what humankind has been doing for so long...striving for perfection and immortality. yes i know, we wont acieve immortality through changing a few genes but still,  by using medicical science to 'evolve' its more adaptation to achieve perfection rather than evolution no?

"You have to stay in shape. My grandmother, she started walking five miles a day when she was 60. She's 97 today and we don't know where the hell she is."
"You have to stay in shape. My grandmother, she started walking five miles a day when she was 60. She's 97 today and we don't know where the hell she is."

*

Offline rosy

  • Neilep Level Member
  • ******
  • 1018
  • Chemistry
    • View Profile
Re: How does human evolution work?
« Reply #25 on: 31/08/2006 01:41:56 »
quote:
i always thought evolution was natural and was for the benefit of humankind on the whole

Well, evolution's certainly natural, but it's no more "for the benefit of humankind" than gravity is.
Some genes confer an advantage in a certain situation so not unnaturally the individuals with those genes breed more successfully, and so their offspring will have more and better opportunities.. continue for a number of generations and if the benefit the gene gives is strong enough its carriers will outcompete the rest (or become a whole seperate species) and evolution will have happened.
Whether it benefits the species in the long term rather depends on how conditions develope... for example I read an article a bit ago that suggested that sexual selection for stupidly big antlers among some sort of Irish moose type animal resulted in the entire species dying out, the antlers having become unsustainable.

*

Offline Simmer

  • Sr. Member
  • ****
  • 229
    • View Profile
Re: How does human evolution work?
« Reply #26 on: 31/08/2006 22:14:01 »
quote:
Originally posted by rosy
Well, evolution's certainly natural, but it's no more "for the benefit of humankind" than gravity is.


Exactly! Evolution's so last millenium - in a few years we'll be able to make changes in one generation that would take evolution a thousand.  

Sea level rising? Gills please, with a side order of webbed feet. Oh and hold the haemophilia! [:)]
 

*

another_someone

  • Guest
Re: How does human evolution work?
« Reply #27 on: 31/08/2006 22:44:00 »
I think the point people are missing here is that evolution is not the process by which things are changed, but the consequence of change and selection – the actual processes by which change and selection happen do not alter the reality of evolution, only its outcome.

Nor is evolution a particularly biological process – evolution applies as much to commerce (where some corporate entities dominate and others die off), and to political entities, and even to technology itself.



George
« Last Edit: 31/08/2006 23:02:30 by another_someone »

*

Offline realmswalker

  • Sr. Member
  • ****
  • 205
    • View Profile
Re: How does human evolution work?
« Reply #28 on: 01/09/2006 00:59:27 »
and i think no one got my original statement

some genetic mutations, were this 10,000 years ago, or even 2000 would result in death, and a lack of offspring, therefore they would have died out.
However now adays, those same mutations no longer result in death (because of medicine, science, etc) and the people with them can produce offspring before they die.
So this gives those mutations a chance to produce benefits, when they survive, and possibly exist with other mutations whose combinations wouldnt have occured in the past

 

*

another_someone

  • Guest
Re: How does human evolution work?
« Reply #29 on: 01/09/2006 02:40:59 »
quote:
Originally posted by realmswalker
However now adays, those same mutations no longer result in death (because of medicine, science, etc) and the people with them can produce offspring before they die.
So this gives those mutations a chance to produce benefits, when they survive, and possibly exist with other mutations whose combinations wouldnt have occured in the past



One of the interesting things that has occurred in modern society concerns people who are deaf due to a genetic mutation.  In the past, the difficulty these people had in communicating with hearing individuals, they tended to marry less, and have fewer offspring; and more significantly, they were as likely as not marry someone without the mutation that caused deafness.

With the advent of sign language, not only are deaf people finding it easier to develop relationships, and ultimately to marry; but they are finding it relatively easier to communicate, and so develop relationships, with other deaf people (who also know sign language) that with hearing partners (who, more often than not, are not conversant in sign language).  What is thus happening is that increasingly one is building an isolated (from the breeding perspective) sub-population that perpetuates these mutations for deafness.



George

*

Offline iko

  • Neilep Level Member
  • ******
  • 1626
    • View Profile
Re: How does human evolution work?
« Reply #30 on: 01/09/2006 17:42:25 »
quote:
With the advent of sign language, not only are deaf people finding it easier to develop relationships, and ultimately to marry; but they are finding it relatively easier to communicate, and so develop relationships, with other deaf people (who also know sign language) that with hearing partners (who, more often than not, are not conversant in sign language).
someother_anyone

I'm fascinated by seeing how fast and interestingly this evolution topic is...evolving!
Yes, in the next crazy (and hopefully peaceful) brand new world we'll have many more blind musicians, deaf sculptors and crippled scientists all together.
 
quote:
So this gives those mutations a chance to produce benefits, when they survive, and possibly exist with other mutations whose combinations wouldnt have occured in the past
realmswalker



...and this is exactly right!
Let's forget about invisible defects, genes, DNA and CSI for a while.
iko
« Last Edit: 01/09/2006 23:10:14 by iko »

*

Offline Soul Surfer

  • Neilep Level Member
  • ******
  • 3345
  • keep banging the rocks together
    • View Profile
    • ian kimber's web workspace
Re: How does human evolution work?
« Reply #31 on: 02/09/2006 12:26:25 »
I would like to add one further comment on the subject of evolution.  That of sexual selection.  the partners chosen by males and/or females can also have a big effect.  A good example in nature that has been taken to extremes is the apperance of male birds of paradise where their flamboyant plumage impedes their ability to get food but the females like their mates to be "pretty" accorfing to the current fashion!  this is also an example of fashion in nature.
It has seriously been suggested that "intelligence" is a sexually selected trait in which females included intelligence in their choice when selecting a partner or alternatively the craftiest males managed to have the most children (whether or not their chosen sexual partners knew about it!)

OK  we've now run through all the basics I think, but the root of the question is still missing an answer.

Some people suggest that in modern western society evolutionary pressures have stopped.  
This is clearly not so.

Some people fear that the ability to counter genetic defects and/or the fact that more intelligent and succesful people tend to have small families will result in a degradation of the quality of intelligence or fitness of human beings.

What then are the true evolutionary pressures in human society?
What are the likely results?
and
Should we take notice of them and try to adjust our attitudes or behaviour?

Learn, create, test and tell
evolution rules in all things
God says so!
« Last Edit: 02/09/2006 18:22:07 by Soul Surfer »
Learn, create, test and tell
evolution rules in all things
God says so!

*

another_someone

  • Guest
Re: How does human evolution work?
« Reply #32 on: 02/09/2006 18:09:04 »
quote:
Originally posted by Soul Surfer
What then are the true evolutionary pressures in human society?
What are the likely results?
and
Should we take notice of them and try to adjust our attitudes or behaviour?



This I think highlight the major issue that has been ignored – the difference between pressures on human society and the pressures on the human individual.

The human individual has quite a wide latitude in traits if he can sustain the social structures that provide him with a defence against the outside world.  It is a little like the variations that an individual cell might be able to posses so long as it remains part of a total multicellular organism that can offer it protection from the environment (the average liver cell would not last long when exposed naked to the environment, but performs a valuable function to the human body, and will survive so long as it is offered the protection of that body).



George

*

Offline iko

  • Neilep Level Member
  • ******
  • 1626
    • View Profile
Re: How does human evolution work?
« Reply #33 on: 23/09/2006 13:45:13 »
Human society is probably the centre, 'core' of human evolution.
A superior level of organization: cells, tissues, organs, body + brain and...society.
This is conditioning our future, where genetic characters may play a minor role.
Is it too corny?
iko

*

another_someone

  • Guest
Re: How does human evolution work?
« Reply #34 on: 23/09/2006 16:01:22 »
quote:
Originally posted by iko

Human society is probably the centre, 'core' of human evolution.
A superior level of organization: cells, tissues, organs, body + brain and...society.
This is conditioning our future, where genetic characters may play a minor role.
Is it too corny?
iko



Firstly, one must ask the question as to what extent human society is itself governed by genetics, insofar as human society is governed by inter-human relations, which to soem extent are guided by genetics.

Beyond that, one then can ask to what extent one should move the focus of  the study of human evolution from genetics to memetics.



George

*

Offline iko

  • Neilep Level Member
  • ******
  • 1626
    • View Profile
Re: How does human evolution work?
« Reply #35 on: 23/09/2006 18:28:54 »
I think we finally ended up in sociobiology for a change:
 
quote:

Sociobiology is a synthesis of scientific disciplines that attempts to explain behaviour in all species by considering the evolutionary advantages of social behaviours.
 It is often considered a branch of biology and sociology, and it also draws from ethology, evolution, zoology, archeology, population genetics, and other disciplines. Within the study of human societies, sociobiology is closely related to the fields of human behavioral ecology and evolutionary psychology.

Sociobiology has become one of the greatest scientific controversies of the late 20th century. Criticism, most notably made by Richard Lewontin and Stephen Jay Gould, centers on sociobiology's contention that genes play a decisive role in human behavior, suggesting there are limitations to reducing traits such as aggressiveness. In response to the controversy, anthropologist John Tooby and psychologist Leda Cosmides launched evolutionary psychology as a centrist form with less controversial focuses

Definition
Sociobiology is the biological basis for animal social behavior. It is based on the idea that animals will act in ways to improve their own inclusive fitness (Kin Selection). It is a selfish genes hypothesis that states the individual is not as important to the population as its genes.

Therefore, animal behavior can be explained by how they act to preserve their genes in the population. It can be used to explain why a lioness will nurse not only her own young, but the young of her close genetic relatives in the pride (nephews and nieces). It can also be used to explain why a new dominant male lion will kill cubs in the pride that do not belong to him. Killing the cubs causes the nursing females to come into heat faster, thereby giving the male lion an opportunity to get his genes into the population much faster.

.....

From Wikipedia, the free encyclopedia



...and I am afraid I have to read a bit more of this stuff before going on with our discussion (and I need a massive dose of 'cod').
iko
« Last Edit: 23/09/2006 21:40:06 by iko »

*

Offline Sona

  • First timers
  • *
  • 1
    • View Profile
Re: How does human evolution work?
« Reply #36 on: 03/10/2006 01:53:25 »
No longer survival for fittest but survival of the smartest.

Seems like the only place we would evolve in would be bigger brains.
 

*

Offline nannham

  • Jr. Member
  • **
  • 15
    • View Profile
    • http://www.fairbloodydinkum.com/
Re: How does human evolution work?
« Reply #37 on: 04/10/2006 05:33:22 »
Apparently with the advent of human civilization, our biological evolution slowed down because there was no longer a need to compete in the wild with other animals for food or territory.
 
Now human evolution had included another factor, a new equation so to speak, as Iko says above ... society ... no Iko, not too corny ...

And as you say, Sona, now not so much survival of the fittest but the smartest ... it makes perfect sense.  

 

*

another_someone

  • Guest
Re: How does human evolution work?
« Reply #38 on: 04/10/2006 12:24:39 »
quote:
Originally posted by nannham
Apparently with the advent of human civilization, our biological evolution slowed down because there was no longer a need to compete in the wild with other animals for food or territory.
 
Now human evolution had included another factor, a new equation so to speak, as Iko says above ... society ... no Iko, not too corny ...

And as you say, Sona, now not so much survival of the fittest but the smartest ... it makes perfect sense.  



Evolution has never been about 'survival of the fittest', and is not 'survival of the smartest'.

I am not sure how one measures the rate of biological evolution?  If you are talking about the number of mutations in the population, there is no evidence that the number of mutations is declining, or the number of humans with DNA mutations surviving and reproducing is in any way declining.

That humans have not split into separate sub-species that cannot interbreed has not happened in the last 250,000 years, but the same could be said for many other species of animals.

We do know that typical physiology of humans has changed even over the last millennia, partly even within a stable population, but even more so as a consequence of conquest causing one population of humans to encroach, and even displace, territory that was previously held by a different population.

We now also see changes caused by differential birth rates between different populations that could well cause further changes of the sub-populations of people living in different parts of the world.

That many of the forces that favour one population over another are social in nature is without question, but the consequences are visible changes in population.  How much the social changes are themselves biological in origin is itself open to debate (i.e. to what extent are social values genetically determined?).

One thing I would state categorically is that social advantage is not determined by such one dimensional concepts as who is the 'smartest'.



George

*

Offline iko

  • Neilep Level Member
  • ******
  • 1626
    • View Profile
Re: How does human evolution work?
« Reply #39 on: 04/10/2006 22:35:46 »
quote:
One thing I would state categorically is that social advantage is not determined by such one dimensional concepts as who is the 'smartest'.

another_someone



Don't worry, I don't think anybody here is talking of the deformed humanoids of the future with enormous skulls and atrophic bodies that we saw in some old movies!
We probably have to define better who is the 'smartest'...
It could mean not the brightest, the most clever, the successful person, but the tolerant, adaptable and capable of facing new realities and change (who cannot change...won't survive)
I have a vague memory (Dr. Alzy is making my brain fall into pieces...) of a psycological study comparing IIWorldWar survivors (USA parachuters I recall) to normal people: they were found to have a particular attitude and positive reactions in facing difficult and stressful situations...plus other interesting findings I can't remember.
Smart could mean too many different things!
LOL (lots of lies)

iko
« Last Edit: 04/10/2006 23:10:44 by iko »

*

Offline nannham

  • Jr. Member
  • **
  • 15
    • View Profile
    • http://www.fairbloodydinkum.com/
Re: How does human evolution work?
« Reply #40 on: 10/10/2006 17:11:15 »
quote:
Originally posted by another_someone

That many of the forces that favour one population over another are social in nature is without question, but the consequences are visible changes in population.  How much the social changes are themselves biological in origin is itself open to debate (i.e. to what extent are social values genetically determined?).

One thing I would state categorically is that social advantage is not determined by such one dimensional concepts as who is the 'smartest'.


George



I see what you mean here ...






 

*

another_someone

  • Guest
Re: How does human evolution work?
« Reply #41 on: 11/10/2006 12:35:43 »
quote:
Originally posted by iko
Don't worry, I don't think anybody here is talking of the deformed humanoids of the future with enormous skulls and atrophic bodies that we saw in some old movies!
We probably have to define better who is the 'smartest'...
It could mean not the brightest, the most clever, the successful person, but the tolerant, adaptable and capable of facing new realities and change (who cannot change...won't survive)
I have a vague memory (Dr. Alzy is making my brain fall into pieces...) of a psycological study comparing IIWorldWar survivors (USA parachuters I recall) to normal people: they were found to have a particular attitude and positive reactions in facing difficult and stressful situations...plus other interesting findings I can't remember.
Smart could mean too many different things!
LOL (lots of lies)

iko



I don't even think it is likely to be the most extreme in any particular psychological model.

One has tp be careful in extrapolating from any research done in one particular environment (particularly when the environment is as extreme as warfare), that the same may not necessarily carry over to other environments.

The whole point about human beings is their adaptability, that they can survive in many environments.  Each of those environments will need a different kind of human being.  There is no doubt that there are some traits that will make certain human beings particularly suitable for certain extreme environments, but unless that environment becomes the norm for most human beings over a prolonged period of time, then it is likely that those humans will thrive in that environment, but will be disadvantaged in other environments.  Thus one would expect within humanity that there be different types of human being, each thriving in some circumstances, and disadvantaged in others; but overall, so long as all those environments remain part of the challenges that humans will face, then all of those humans will have some arena in which they can flourish.

If we were to lose some types of human being, then we would also probably lose our ability to thrive in certain environments.  This would be a likely scenario only if humans cease to continue to occupy that environment.  There is no doubt that as time progresses, humans do face different challenges, and many of the environments that neolithic man faced we no longer face today, and so have less need for many of the capabilities that neolithic man required; but we have no less need for flexibility and diversity, on the contrary, our need for diversity has increased as the range of environments we occupy increases.

Ofcourse, it may come that one day we will create such an artificial environment for ourselves that we remove much of the need for the diversity to meet the diversity of natural environments; and when that day comes, it could be that the human animal will become more specialised and the species more homogeneous.

It may also come about that external factors may force us to relinquish occupation of many of the environments we occupy today, thus requiring that we become more specialised in those environments that we will continue to occupy.  If this were to happen, it would ofcourse demand a massive reduction in population, as well as a reduction in the diversity of population.



George
« Last Edit: 11/10/2006 12:39:11 by another_someone »

*

Offline dkv

  • Sr. Member
  • ****
  • 299
    • View Profile
How does human evolution work?
« Reply #42 on: 29/09/2007 11:06:24 »
I think i have a grasp on the basics of evolution, so i have a question.

when a species allows for the survival of everyone, regardless of their genes (like ours), shouldnt it provide for the development of quick advances and changes in genes?
The behaviours turned out to be the way they are. It was not needed.
Thats what is expressed by Evolution. Even the most lenient interpretation
of natural selection doesnt guranetee anything more than greater presence of particular genes in a population.
Quick advances and changes require extra time in the developement of computer programs. Too quick more errors.More errors less chances of survival.From replication point of view it turns out this rate of change is suitable of survival. If animals wouldnt have survived then we would not have seen them.For some strange reason survival gets promoted in the
random evolutionary process. This is UNexplained.
Who can explain this ?
I can.
All life forms reinforce themselves.whether gene or species or any life structure.
How do they reinforce themselves?
All life forms search for a biological state which is equivalent to Happiness in humans.
This is expressed as Towards Sustainable Pleasure or TSP.


=======================
Quote
Normally, for new traits to appear, it has to be beneficial to reproduction, or neutral to it. Then later a bunch of neutral traits can combine to form a positive trait.
However in a society that allows for just about all traits to remain, then it opens up the possiblities, as potential negitives to reproduction (like ADD, for example) remain in the gene pool, instead of dying out. And later, a bunch of these can combine to make a sudden change...potentially...
Idk its late...and im just thinking, not very coherently, but when am i ever really coherent...?
REP: Incoherent or not the truth is replication doesnt provide any purpose..
The natural selection can lead to extinction as well.