Is there evidence of recent evolution?

[SkyWriting]

What evolutionary changes are evident in the age of modern man?

We don't die from as many diseases intended to weed out the unfit from reproducing.
That's new.

 

[OldWiseGuy]

We don't die from as many diseases intended to weed out the unfit from reproducing.
That's new.

Thankfully I had all my kids before my health problems set in.

 

[OldWiseGuy]

Couple things...
First, "behaviors" (like bodybuilding, hiking, diving,...) doesn't change your dna.
Second, calling "selection" by a different name (like "adaption") doesn't change the facts.

No, the Tibetans wouldn't have evolved unique gene sequences which increases red blood cell production, allowing for more oxygen capacity, if they didn't live at high altitudes.

That's what natural selection does: it favours those genes which match the circumstances better.

This is why Tibetans have unique genes that help them living at high altitudes.
This is why the Bajau have unique genes that help them dive more efficiently.

It has nothing to do with "behaviour" and everything with mutation + selection.

If DNA is unchangeable it must have appeared fully developed in the earliest life forms.

Isn't it fortuitous that the very mutations these people need developed very quickly given the painfully slow evolutionary time scale? Wouldn't the time needed to evolve large spleens and develop the ability to pass it on far exceed the actual history of those people? Does everyone have the 'large spleen gene' just waiting to be turned on?

 

[Speedwell]

If DNA is unchangeable it must have appeared fully developed in the earliest life forms.

Isn't it fortuitous that the very mutations these people need developed very quickly given the painfully slow evolutionary time scale? Wouldn't the time needed to evolve large spleens and develop the ability to pass it on far exceed the actual history of those people? Does everyone have the 'large spleen gene' just waiting to be turned on?

No. Human spleens vary in size from one individual to another, because of underlying genetic variations. If larger spleens provide a survival advantage, there will already be individuals in the population who possess them to some degree.

 

[DogmaHunter]

But don't cats and dogs, and everything else living, have the same common ancestor?

Yes and the common ancestor of cats and dogs, which are both mammals, was a mammal.
Every organism ever born, was of the same species as its direct parents.

Evolution is a gradual process.

Consider languages, which is a near perfect analogy in that sense.
Italian, French, Portugese, Spanish,... = roman languages. They all derive from Latin.
Latin is the "common ancestor" of these languages.

At no point in history did a latin speaking mother raise a spanish speaking child, however.
Every human ever raised, spoke the language of the parents it was raised by.

English, Dutch, German etc are Germanic languages.
They do not derive from latin.

Latin didn't turn into English. Latin rather turned into "sub-species" of Latin. Those being French, Spanish, Italian, etc.

 

[DogmaHunter]

So epigenetics plays no role in physiology?

In the case of the Bajau, the Tibetans, etc... it is a case of genetic mutation + selection.

Read up.

 

[DogmaHunter]

If DNA is unchangeable it must have appeared fully developed in the earliest life forms.

DNA is not unchangeable. I don't even know where that statement comes from.
I guess what I said got seriously muffled once it reached your ears, which are firmly lodged in the ground with the rest of your head.

Isn't it fortuitous that the very mutations these people need developed very quickly given the painfully slow evolutionary time scale?

It is not at all a surprise that mutations wich improve survival rates in a population ends up spreading in that population, no.

That's what natural selection does.

[utoe]
Wouldn't the time needed to evolve large spleens and develop the ability to pass it on far exceed the actual history of those people?[/quote]

No. And you're making a hindsight mistake here.
Take Tibetans and people in Latin america that also live at high altitudes.
They both have genetics that make them more suited to live at such altitudes.
But they don't have the same genetics to accomplish this.

Different pathways exist to accomodate better survivability.
The pathway taken by Tibetan genetics, is different from the one in Latin America.
Yet both have adapted / evolved to accomodate living at high altitudes.

Does everyone have the 'large spleen gene' just waiting to be turned on?

Assuming it is a single mutation, then sure, anyone could have the mutation.
But the effect it has on fitness would not be the same.

So unless it has other effects which would be beneficial for our fitness, there would be no selection pressure favouring it. We, after all, don't spend 60% of our time in the sea, like they do.

That's the difference.

Mutation is random with respect to fitness.
A mutation allowing more efficient use/intake of oxygen, wouldn't have the same effect on fitness in us Belgian folks, as it would have on people that live at high altitudes. We do just fine with our current oxygen use. But we'll get altitude sickness if we move to Tibet. We don't have that problem here, living at little above sea-level.

Selection pressure. You seem to be doing your best to ignore the importance of it.

 

[OldWiseGuy]

DNA is not unchangeable. I don't even know where that statement comes from.

The statement arises from my questioning your assumption that genetic mutation, not epigenetics, is responsible for those large spleens. Under what conditions does DNA change?

It seems to me that adaption to different environmental conditions is built into us by design, within reasonable limits of course.

 

[OldWiseGuy]

Yes and the common ancestor of cats and dogs, which are both mammals, was a mammal.
Every organism ever born, was of the same species as its direct parents.

Evolution is a gradual process.

Consider languages, which is a near perfect analogy in that sense.
Italian, French, Portugese, Spanish,... = roman languages. They all derive from Latin.
Latin is the "common ancestor" of these languages.

At no point in history did a latin speaking mother raise a spanish speaking child, however.
Every human ever raised, spoke the language of the parents it was raised by.

English, Dutch, German etc are Germanic languages.
They do not derive from latin.

Latin didn't turn into English. Latin rather turned into "sub-species" of Latin. Those being French, Spanish, Italian, etc.

So we don't really have a common ancestor, or common language in our history? Of course I believe the different languages came from the Tower of Babel dispersion.

 

[VirOptimus]

So we don't really have a common ancestor, or common language in our history? Of course I believe the different languages came from the Tower of Babel dispersion.

Tower of Babylon? That is a disproven myth. We know quite a lot about languages and their history.

 

[Goonie]

What evolutionary changes are evident in the age of modern man?

Bodies Remodeled for a Life at Sea

 

[DogmaHunter]

The statement arises from my questioning your assumption that genetic mutation, not epigenetics, is responsible for those large spleens. Under what conditions does DNA change?

It seems to me that adaption to different environmental conditions is built into us by design, within reasonable limits of course.

Seriously, read the research concerning the unique gene sequences of for example the Tibetans responsible for their traits that help at high altitude.

They are mutations.

 

[DogmaHunter]

So we don't really have a common ancestor, or common language in our history?

Yes we do. And they are branching trees.
Spanish, French, ... are on the "roman" branch with Latin as a common node.
English, German, Dutch,... are on the "germanic" branch with some germanic language as common node.
That germanic language and Latin are both in turn on a branch with as common node some earlier language.

But french, spanish, etc... all flow from the Latin node. They don't apear in the lineage under germanic.

Just like felines and its subspecies are on a branch flowing from the common node feline. You will not find any dogs there.

Canines and felines themselves are "cousins" with a common node that was some kind of mammal.

You won't find dogs in de feline branch and you won't find cats on the canine branch.

Don't you know how nested hierachical trees work?

Of course I believe the different languages came from the Tower of Babel dispersion.

yea, you believe a lot of false things, it seems.

 

[DogmaHunter]

Tower of Babylon? That is a disproven myth. We know quite a lot about languages and their history.

It's actually quite interesting that you can map out roots of language and overlay them on migration patterns of our ancestors using DNA like in the genographic project.

The geographic spread of languages pretty much follows the same spread the genes of the populations that speak those languages.

In language, "variation" (in the genetic sense) comes down to the amount of different "sounds" in said language. Not be confused with alphabets. But the actual phonetic sounds included in the various languages.

Where do we find languages with the MOST "phonetic" variation?
My, my... in exactly the same place as where we find the most biological genetic variation: africa. Migration out of africa created a bottleneck in both biological genetic variation as well as in the "genetic" variation of languages themselves.

It's actually quite amazing how much the spread of phonetic variation matches with actual genetic variation in the same populations. Especially since it isn't genetically determined what the phonetics of the language of the individual are like.

It simply follows the same "variation" patterns as what we see in genetics with bottlenecks created by migration waves.


Even in terms of "overlap", where words are borrowed from other cultures, there will also be some kind of overlap of genetics. Because to borrow words, you need contact. And when there's contact, there's bound to be interbreeding as well.

Saw a docu on this once a long while ago and I remember being blown away.