Jump to content
Free_Pepe

Natural Selection.... No s###!

Recommended Posts

Natural selection is self evident, there's not a person on the planet who disagrees with it! (if you die, you die! If you don't reproduce, you don't reproduce!)

But how come there seems to be so many people who take this blatantly obvious undeniable fact, and then assert that life is merely about our own survival/reproduction!?

(Just for the record, I'm not denying that life on our planet has developed gradually! The fossil record points to that fairly clearly!)

Share this post


Link to post
Share on other sites
1 hour ago, Free_Pepe said:

But how come there seems to be so many people who take this blatantly obvious undeniable fact, and then assert that life is merely about our own survival/reproduction!?

Whilst I won't say I have never met such a person I haven't met many.

What information do you base your statement on ?

It must be clear that unless your statement can be substantiated there is no case to answer M'Lud.

Share this post


Link to post
Share on other sites
On 7/25/2020 at 4:22 AM, Free_Pepe said:

Natural selection is self evident, there's not a person on the planet who disagrees with it! (if you die, you die! If you don't reproduce, you don't reproduce!)

But how come there seems to be so many people who take this blatantly obvious undeniable fact, and then assert that life is merely about our own survival/reproduction!?

I can't believe I'm defending an anti-evolution stance, but you're strawmanning their argument. The part they disagree with is natural selection leading to a change in species over time, not that traits are passed along without reproduction. You're making their argument too simple in order to discredit it, and that's using a fallacy to support your own argument.

Most anti-evolution arguments acknowledge what they call "microevolution", where children share traits from their parents. They just don't believe natural selection can account for a complete change in species.

Anybody who is looking only at their own life and reproduction isn't addressing evolutionary concerns. Natural selection is one way to change allele frequencies within a population over time.

Share this post


Link to post
Share on other sites

Help me out here because I left school when I was 15 to work in a factory so I had to work things out for myself instead of being told how it is by a teacher or an elder. So my understanding of evolution is that if you pick up ten thousand Africans and drop them in Ireland  where no other humans of any colour exist, then you return 100,000 later the general population would have evolved to Blue eyed blonds because as soon as they hit ground zero they would have realised that the climate was really cold and they should only choose lighter skin mates, and the cold would prevent the darker skin men from reproducing because of the cold and being of a darker complexion they couldn't resource food as well as the lighter skin men who had all the girls and could sneak up to a vegetable without scaring it away. Have I got it right?

12 hours ago, Free_Pepe said:

Natural selection is self evident, there's not a person on the planet who disagrees with it! (if you die, you die! If you don't reproduce, you don't reproduce!)

But how come there seems to be so many people who take this blatantly obvious undeniable fact, and then assert that life is merely about our own survival/reproduction!?

(Just for the record, I'm not denying that life on our planet has developed gradually! The fossil record points to that fairly clearly!)

A giraffe grew a long neck so that it could reach the leafs on the top branches, that is so clever!  

Share this post


Link to post
Share on other sites
2 hours ago, Polykephalous said:

So my understanding of evolution is that if you pick up ten thousand Africans and drop them in Ireland  where no other humans of any colour exist, then you return 100,000 later the general population would have evolved to Blue eyed blonds because as soon as they hit ground zero they would have realised that the climate was really cold and they should only choose lighter skin mates, and the cold would prevent the darker skin men from reproducing because of the cold and being of a darker complexion they couldn't resource food as well as the lighter skin men who had all the girls and could sneak up to a vegetable without scaring it away. Have I got it right?

Nope that is not how it would work. For the most part organisms do not know what adaptations are going to work (and even with extensive research it can be difficult to tell). Rather what happens is that the conditions the organisms live in create so-called selective pressures. What it basically means is that certain genetic traits are more likely to reproduce than others. But different pressures can have different strengths. So let's say lack of sunlight is a strong pressure. Also assume that folks with more melanin (i.e. who are darker) produce less vitamin D are are prone to vitamin D deficiency. What fist needs to happen is that there are either already folks with lighter skin in the population or that at some point mutants arise with lighter skin.  Let's further assume that this make folks less likely to reproduce so mutants with less melanin may be more successful in reproduction and over many generations the pool will be dominated by them. However, unless the selection is super strong, there is likely always going to be a mix. 

If a population is relatively homogeneous, more often than not another aspect is important, the so-called bottleneck effect. This is when there is a small starting population where drift can play a large effect, resulting in small population with low genetic diversity. This is one of the reasons why in Africa we have a large genetic variability compared to Europeans. 

On top of it there are other random effects which have nothing to do with geography. For example if a in a population no mutations for blue eyes occur (which is basically traced to a mutation in a single gene), there will never be blue-eyed folks. 

Share this post


Link to post
Share on other sites

The kids that didn't get rickets would do better and go on to have more and healthier kids as adults - bigger families - than those that did get rickets. That sounds like natural selection, not sexual selection yet mate selection would be part of it. I'm not sure how obvious any connection with skin colour would be; there will be different susceptibility to deficiency illness according to lifestyle and dietary differences as well.

The more obvious mate selection criteria might be the unattractiveness of bow legged sick youths - choosing for health, not skin colour - but I suppose an enduring mate preference for lighter skins, as a sign of good luck re healthy children could emerge. But then again maybe we get coastal fisherfolk with dark skins and forest hunter gatherers with lighter skins.

Share this post


Link to post
Share on other sites
On 7/26/2020 at 1:38 PM, Ken Fabian said:

The kids that didn't get rickets would do better and go on to have more and healthier kids as adults - bigger families - than those that did get rickets. That sounds like natural selection, not sexual selection yet mate selection would be part of it. I'm not sure how obvious any connection with skin colour would be; there will be different susceptibility to deficiency illness according to lifestyle and dietary differences as well.

The more obvious mate selection criteria might be the unattractiveness of bow legged sick youths - choosing for health, not skin colour - but I suppose an enduring mate preference for lighter skins, as a sign of good luck re healthy children could emerge. But then again maybe we get coastal fisherfolk with dark skins and forest hunter gatherers with lighter skins.

So does that mean that any Africans who move to Ireland and don't take vitamins will have a high probability of being afflicted with rickets?  

Share this post


Link to post
Share on other sites
22 minutes ago, Polykephalous said:

So does that mean that any Africans who move to Ireland and don't take vitamins will have a high probability of being afflicted with rickets?  

No, it their vitamin D levels are, on average, lower. While this increases risk somewhat, only a small subset actually develop a disease.

Share this post


Link to post
Share on other sites

Am I wrong in believing that if a primitive group relocated to another environment that was unpleasant but not deadly, then there would be no need to evolve? Is it more possible that variants of humans originated in different parts of the world and mixed with each other?      

Share this post


Link to post
Share on other sites

Evolution is never a need. It is just something that happens if the genetic composition of a group starts changing. This can be due to random events, but also due to selective pressures (i.e. there is different reproductive success). 

With regard to human origins, DNA evidence strongly support divergence from a central group originating in Africa. From there we have multiple waves of migration. Also note that skin colour as  a whole is only a tiny part of our genetic history, it is mostly historical baggage that emphasizes it so much.

Share this post


Link to post
Share on other sites
On 7/29/2020 at 3:59 AM, CharonY said:

Evolution is never a need. It is just something that happens if the genetic composition of a group starts changing. This can be due to random events, but also due to selective pressures (i.e. there is different reproductive success). 

With regard to human origins, DNA evidence strongly support divergence from a central group originating in Africa. From there we have multiple waves of migration. Also note that skin colour as  a whole is only a tiny part of our genetic history, it is mostly historical baggage that emphasizes it so much.

I do hope no one was offended by my using skin colour as an example, it wasn't meant as a superior or inferior reference to any race.

Share this post


Link to post
Share on other sites
On 7/25/2020 at 11:35 PM, Polykephalous said:

A giraffe grew a long neck so that it could reach the leafs on the top branches, that is so clever!  

In what way was this clever - ie a display of learning something ?

There is another effect, not quite the same as Natural Selection that works like this.

Consider a room where there is an efficient fly killer, that kills and removes flies in range.
Now consider a naturalist who measures the average fly density in that room and in adjoining volumes.

Unsuprisingly he finds that the fly density is lower in the room than elsewhere nearby.
He also notices the lethal killer.
Based on the fly density comparisons he comes to the conclusion that the flies have learned to avoid the danger zone.

Was his conclusion correct ?

Share this post


Link to post
Share on other sites
2 hours ago, Polykephalous said:

I do hope no one was offended by my using skin colour as an example, it wasn't meant as a superior or inferior reference to any race.

That's fine, the issue is that one has to be very careful with extrapolating things, especially if the basic assumption is flawed. Such as that evolution only happens under certain challenges.

The reason for being careful is of course that there are certain folks that weaponize such misunderstandings or flawed premises to create narratives that imply inferiority of certain groups.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.