Modern Humans And Evolution

[Keith&Co.]

But no idea is ever so marginalized that SOMEBODY won't suggest revisiting it...

 

[Jobar]

There is no evidence that the passenger pigeon is still evolving. I think we have discovered the way to stop species from evolving.

Heh. True enough. I was presuming that we manage to survive as a species- unlike the great majority of plants and animals that have existed since life began...

 

[skepticalbip]

But no idea is ever so marginalized that SOMEBODY won't suggest revisiting it...

That sounds like a corollary to a very old observation:

There is nothing so absurd that some philosopher has not already said it.

~ Marcus Tullius Cicero

 

[untermensche]

Blunt stubby teeth are not a lethal genetic defect when you have tools to help you mince your food. Otherwise, they might well be.

They are not a lethal defect period.

A lethal defect is something that will kill you no matter how you behave.

It is possible to eat many things with blunt stubby teeth.

The lack of insulin is not a lethal genetic defect when you have tools to help you control your blood sugar level. Otherwise, it might well be.

It is a lethal defect until human technology reaches a point it can be treated.

With enough humans (not) reproducing, patterns emerge in what you call "mere contingencies" that add up to significant selection pressures.

Astrology.

The humans that do not reproduce are not failing to reproduce due to some specific genetic abnormality.

No genes are being selectively removed.

It has no effect on the future gene pool.

One individual does not reproduce but their sisters do, or their nieces do.

No genes are removed by people randomly not reproducing.

I guess then living in herds for mutual protections, and those herds preventing shrubbery from growing with their grazing behaviour, is wildebeest alteration of the gene pool and not natural selection?

Living in herds is not a conscious choice.

It is not a technology.

It is a behavior.

 

[Jokodo]

They are not a lethal defect period.

In an environment where most of the food available requires sharp teeth to even get it into your stomach, they are. The notion "lethal defect period" doesn't make any sense. A trait is always a lethal defect relative to certain environmental parameters.

A lethal defect is something that will kill you no matter how you behave.

No, it's something that will kill you in your environment with the behaviours at your disposal. Not being able to hold the air for more than a minute surely counts as a lethal defect for a whale, yet there's nothing in principle stopping a whale from just staying at the surface, except maybe a lack of food.

It is possible to eat many things with blunt stubby teeth.

With the technologies of cooking and cutting at your disposal -- sure.

It is a lethal defect until human technology reaches a point it can be treated.

With enough humans (not) reproducing, patterns emerge in what you call "mere contingencies" that add up to significant selection pressures.

Astrology.

Statistics.

The humans that do not reproduce are not failing to reproduce due to some specific genetic abnormality.

No genes are being selectively removed.

It has no effect on the future gene pool.

One individual does not reproduce but their sisters do, or their nieces do.

No genes are removed by people randomly not reproducing.

True only if it's truely random. How do you know it is? Why would you even think it is?

I guess then living in herds for mutual protections, and those herds preventing shrubbery from growing with their grazing behaviour, is wildebeest alteration of the gene pool and not natural selection?

Living in herds is not a conscious choice.

Buying our food in the supermarket is not a conscious choice for most of us either. It's just how one gets food, period.

It is not a technology.

It is a behavior.

Technology is a (hard to define) subset of behaviour. What makes it so different that technology-behaviour changing selection pressures counts as "alteration of the gene pool" while non-technology-behaviour changing selection pressures still counts as natural selection? How can you draw such a sharp distinction when you can't even draw a line between technology-behaviours and non-technology-behaviours?

 

[Jokodo]

In fact, while selection pressure is somewhat reduced, the efficiency of selection is increased due to a large and widely intermixing population. In a small isolated population of say, 10 reproducing adults (and with 20 kids per generation, that is a base survival rate of 0.5), a slightly beneficial trait with an initial prevalence of say, 20% and carrying a benefit of 10% increased survival rate can easily go extinct. Running with those numbers, the chance that it goes extinct in a single generation is 4-5%, and a much larger chance that it decreases rather than increases in frequency, potentially going extinct at some point in the future. In a population of millions or billions, it's virtually guaranteed to increase in frequency, almost linearly.

 

[untermensche]

In an environment where most of the food available requires sharp teeth to even get it into your stomach, they are. The notion "lethal defect period" doesn't make any sense. A trait is always a lethal defect relative to certain environmental parameters.

You are talking about a change of environment. Not an organism already surviving in an environment.

If an environment changes then you don't talk of "lethal defects", you talk about maladaption to a new environment.

And humans have used tools to adapt to new environments.

But child onset diabetes is not maladaption to a new environment. It is a lethal defect.

 

[Jokodo]

In an environment where most of the food available requires sharp teeth to even get it into your stomach, they are. The notion "lethal defect period" doesn't make any sense. A trait is always a lethal defect relative to certain environmental parameters.

You are talking about a change of environment. Not an organism already surviving in an environment.

If an environment changes then you don't talk of "lethal defects", you talk about maladaption to a new environment.

And humans have used tools to adapt to new environments.

But child onset diabetes is not maladaption to a new environment. It is a lethal defect.

It's maladaption to an environment where insulin cannot be purchased at the chemists. That is, it's maladaptive and usually lethal in an environment not shaped by human technologies such as the pharmaceutical industry and reliable supply chains.

Blunt and stubby teeth are a maladaption to an environment where the food available is unprocessed. That is, it's maladaptive and usually lethal in an environment not shaped by human technologies such as cutting and cooking.

The analogy holds.

The fact that technology has been shaping the human environment long before it started to be referred to with the word "technology" in English, long before the English language existed, probably long before language as such existed, isn't going to go away from your refusal to acknowledge it.

 

[untermensche]

Maladaption to a new environment means you are surviving in one environment but when that environment changes you do not survive as well.

Diabetics were not surviving in any environment. It is a lethal genetic defect.

But since humans have changed the environment diabetics can survive.

This is not like the case of teeth where a certain kind of tooth allows survival but if the environment changes that tooth no longer is as effective.

That is a completely different situation.

In that case tool making allows expansion into a new NATURAL environment.

The creation of insulin is the creation of an artificial environment that never existed naturally.

 

[Jokodo]

The creation of insulin is the creation of an artificial environment that never existed naturally.

As is the creation of tools and cooking.

You aren't even trying to argue that point, so just accept that technology is older than you used to believe and move on.

 

[Underseer]

Science, technology, cheap centralized energy, and abundant food has taken humans out of natural selection. We live in an environment that has no mechanism for natural selection.

Natural selection does not really apply to humans anymore. Childhood inoculations minimize disease that would kill off children with weaker immune systems and genetic deficiencies. Those born with genetic problems survive due to science and technology who would normally not survive childhood.

Those who would likely die young pass on bad genes and harmful mutations.

Through the first half of the 20th century people had many kids because only a few wuld survive.

1. There is still sexual selection
2. We are still subject to natural selection by viruses and bacteria

We've been overusing antibiotics for generations now. One by one, bacteria that are dangerous to humans have been developing resistances and immunities to each and every antibiotic that we use. The day is coming soon that all bacteria dangerous to humans will be immune to all antibiotics. If we don't find an alternative means of dealing with bacterial infections by then (e.g. bacteriophage treatments), then we're all going to watch natural selection act on humans at a pretty horrifying scale.

Even if we do find a solution, depending on what solution we find, maybe only wealthy countries will be able to afford the treatment, and we will still be witness to massive amounts of human suffering.

 

[untermensche]

The creation of insulin is the creation of an artificial environment that never existed naturally.

As is the creation of tools and cooking.

You aren't even trying to argue that point, so just accept that technology is older than you used to believe and move on.

I never said technology began with insulin.

But it is a different change than developing tools to overcome weakness in an environment.

It is allowing some who would survive in no previous environment to now survive.

It is a technology that overcomes a lethal genetic defect.

 

[Jokodo]

The creation of insulin is the creation of an artificial environment that never existed naturally.

As is the creation of tools and cooking.

You aren't even trying to argue that point, so just accept that technology is older than you used to believe and move on.

I never said technology began with insulin.

But it is a different change than developing tools to overcome weakness in an environment.

It is allowing some who would survive in no previous environment to now survive.

It is a technology that overcomes a lethal genetic defect.

I hate to repeat myself, but here we go:

JUST; LIKE; COOKING.

If you can actually explain why you think the two are categorically different, go ahead and do so. So far you haven't.

 

[bilby]

I never said technology began with insulin.

But it is a different change than developing tools to overcome weakness in an environment.

It is allowing some who would survive in no previous environment to now survive.

It is a technology that overcomes a lethal genetic defect.

I hate to repeat myself, but here we go:

JUST; LIKE; COOKING.

If you can actually explain why you think the two are categorically different, go ahead and do so. So far you haven't.

I have never once seen this poster admit to an error of any kind.

Just put him on 'ignore' and move on. Engaging with him is a complete waste of time and bandwidth.

 

[untermensche]

I never said technology began with insulin.

But it is a different change than developing tools to overcome weakness in an environment.

It is allowing some who would survive in no previous environment to now survive.

It is a technology that overcomes a lethal genetic defect.

I hate to repeat myself, but here we go:

JUST; LIKE; COOKING.

If you can actually explain why you think the two are categorically different, go ahead and do so. So far you haven't.

I just explained it.

A person can survive in many environments without cooking.

Cooking is not something that allows somebody to live that could survive in no other environment.

The two are completely different situations.

The only environment a person can survive in that needs insulin is a man-made environment. There is NO natural environment they can survive in. Unlike people that somehow need their food cooked.

 

[steve_bank]

Itwasn't too far back when isolated tribes were found in the Amazon jungle. As I heard it said, they are as comfortable in the jungle as we are in our living room.

They had fire and cooking. Humans leasrned by observation that cooked meat was less likey to cause problems.

I expect in isolation selction occurred in infant mortality. Weaker immune systems did not survive. They can probably drink water without boiling.

In South America natives at high altitude have high lung capacity and more red blood cells. When they move to sea level it gradually fades over generations andn intermarriage.

Sherpas have higher concentrations of blood vessels in legs.

So, maybe I was incorrect at least partly. Some selection occurs in some places, but in the industrialized west it is minimized.

If society collapsed the healthier and stronger offspring would survive as selection by the environment.

 

[Underseer]

I think what you're trying to say is that speciation is unlikely, which is probably true at least for a very long time. But we're certainly still evolving and changing.

We are socially growing by social natural selection. The failure of global communism and the success of the western systems.

Muttaions occur and are passed on, but there is little in the way of selection to promote benficial mutations over other genes. The impact of passing on bad genes is lessend by tyhe large gene pool and wide open mating.

Procreation has to favor those new beneficial mutations for an evolutionary step by selection.

Evolution doesn't have any kind of 'progressive directionality'.. the direction it moves is the direction it moves.

'Beneficial mutations' are anything that leads to more babies given the current social/environmental context, *not* what makes humans as a whole flourish.

Ugh.

That gets so tiresome.

That idea that evolution operates with a purpose of some kind.

I blame images like this:



That gives people the impression that some species are "more evolved" while others are "less evolved." Of course that's stupid because all life has been evolving for the same amount of time. If anything, species with shorter life spans have more total generations between now and the start of life, so if anything is "more evolved," it's bacteria and other single-celled organisms, not humans.

The above image just confuses people and makes them think of evolution as a linear process.

Instead of the above, they should be showing this:



It's a lot more accurate.

 

[Jokodo]

I never said technology began with insulin.

But it is a different change than developing tools to overcome weakness in an environment.

It is allowing some who would survive in no previous environment to now survive.

It is a technology that overcomes a lethal genetic defect.

I hate to repeat myself, but here we go:

JUST; LIKE; COOKING.

If you can actually explain why you think the two are categorically different, go ahead and do so. So far you haven't.

I just explained it.

A person can survive in many environments without cooking.

Cooking is not something that allows somebody to live that could survive in no other environment.

The two are completely different situations.

The only environment a person can survive in that needs insulin is a man-made environment. There is NO natural environment they can survive in. Unlike people that somehow need their food cooked.

The only environment a person who needs their food cooked can survive in is a man-made environment. That's all of us - compare our teeth to a chimps if in doubt.

The only environment a wildebeest or other herd animal can survive in is a wildebeest-made environment.

The only environment an ant can survive and reproduce in is a ant-made environment. While the workers might be able to survive in isolation for a while, they're infertile - and the queen surely wouldn't.

Your insistence to categorically distinguish between technological and behavioral advances of the last couple centuries as "unnatural", while calling the ways other species are altering the environment, or the ways earlier human technologies have altered our environment for hundreds of thousands of years, as good and "natural", lacks a basis in reason.

 

[untermensche]

The only environment a person who needs their food cooked can survive in is a man-made environment.

What person is that?

No such person exists.

Humans do not need to cook their food to eat it.

Why don't you just admit you are wrong and move on?

The only environment a wildebeest or other herd animal can survive in is a wildebeest-made environment.

They survive just fine in captivity. Isolated.

There are quite a few isolated horses doing just fine.

Isolated pack animals too.

 

[Random Person]

Science, technology, cheap centralized energy, and abundant food has taken humans out of natural selection. We live in an environment that has no mechanism for natural selection.

Natural selection does not really apply to humans anymore. Childhood inoculations minimize disease that would kill off children with weaker immune systems and genetic deficiencies. Those born with genetic problems survive due to science and technology who would normally not survive childhood.

Those who would likely die young pass on bad genes and harmful mutations.

Through the first half of the 20th century people had many kids because only a few wuld survive.

1. There is still sexual selection
2. We are still subject to natural selection by viruses and bacteria

We've been overusing antibiotics for generations now. One by one, bacteria that are dangerous to humans have been developing resistances and immunities to each and every antibiotic that we use. The day is coming soon that all bacteria dangerous to humans will be immune to all antibiotics. If we don't find an alternative means of dealing with bacterial infections by then (e.g. bacteriophage treatments), then we're all going to watch natural selection act on humans at a pretty horrifying scale.

Even if we do find a solution, depending on what solution we find, maybe only wealthy countries will be able to afford the treatment, and we will still be witness to massive amounts of human suffering.

I think you have a point. It's hard to see natural selection taking place in a snap shot.

In my community texting and heroin addiction may be a selector in preventing humans from passing on their genes.