Humans still evolving

June 26, 2007
Humans Have Spread Globally, and Evolved Locally
By NICHOLAS WADE

[...]

A notable instance of recent natural selection is the emergence of lactose tolerance — the ability to digest lactose in adulthood — among the cattle-herding people of northern Europe some 5,000 years ago. Lactase, the enzyme that digests the principal sugar of milk, is usually switched off after weaning. But because of the great nutritional benefit for cattle herders of being able to digest lactose in adulthood, a genetic change that keeps the lactase gene switched on spread through the population.

Lactose tolerance is not confined to Europeans. Last year, Sarah Tishkoff of the University of Maryland and colleagues tested 43 ethnic groups in East Africa and found three separate mutations, all different from the European one, that keep the lactase gene switched on in adulthood. One of the mutations, found in peoples of Kenya and Tanzania, may have arisen as recently as 3,000 years ago.

That lactose tolerance has evolved independently four times is an instance of convergent evolution. Natural selection has used the different mutations available in European and East African populations to make each develop lactose tolerance. In Africa, those who carried the mutation were able to leave 10 times more progeny, creating a strong selective advantage.

Researchers studying other single genes have found evidence for recent evolutionary change in the genes that mediate conditions like skin color, resistance to malaria and salt retention.

[..]

Original Source

More evidence ...

Interesting read. Humans are always evolving though and always will be.

I read a little while ago that the brain is evolving to absorb information a lot faster but we are having shorter attention spans. This is due to new technologies and what not.

I'm going to look for the article that I found this in. If I do I'll definatly post it.

thats very interesting
because it totally disproves any claim that an invisible man in the sky made us in his own image

Originally posted by Marduk
thats very interesting
because it totally disproves any claim that an invisible man in the sky made us in his own image

Sorry, no it doesn't. It is hard to deny evolution once you look into it in enough detail. However, the rules/laws can be set then allowed to proceed from the initial conditions. The thing that puzzles me is the selective advantage conferred by these constitutive lactase mutations. Do these peopple survive more easily and are then able to pass on their genes or are mutations on a survival spectrum from neutral mutation to lethal mutation?

Originally posted by Heronumber0
Sorry, no it doesn't. It is hard to deny evolution once you look into it in enough detail. However, the rules/laws can be set then allowed to proceed from the initial conditions.

A "God" could have spawned the universe and set the initial physical laws but might not be involved with life on Earth or might not even know we exist.

Do these peopple survive more easily and are then able to pass on their genes or are mutations on a survival spectrum from neutral mutation to lethal mutation?

The ability to digest lactose into adulthood at the time and still is a gigantic survival bonus.

The ability to digest lactose into adulthood at the time and still is a gigantic survival bonus.

I have to disagree Darkside. There is not a survival advantage in environments where there is a varied diet. However, there is local genetic variation from meiotic events that generate gametes (sperm and egg). However, it would be intriguing if some of the lactase genes are made by transposition or from the 'switching on' of previously silent genes.

IMHO, there is a spectrum of mutations in humans from errors during DNA replication. Some are neutral and have no impact on protein structure. Some may have a slight difference on structure, for example by substitution of one hydrophobic amino acid for a similar amino acid. Some are life threatening, for example 'large scale' changes in DNA structure.

If you look at the histocompatability locus or T-cell receptor genes you will find a huge range of variation. Variation predisposes to evolution events, it does not point to evolution per se.

Originally posted by Heronumber0

Originally posted by Marduk
thats very interesting
because it totally disproves any claim that an invisible man in the sky made us in his own image

Sorry, no it doesn't. It is hard to deny evolution once you look into it in enough detail. However, the rules/laws can be set then allowed to proceed from the initial conditions. The thing that puzzles me is the selective advantage conferred by these constitutive lactase mutations. Do these peopple survive more easily and are then able to pass on their genes or are mutations on a survival spectrum from neutral mutation to lethal mutation?

Actually....Marduk is right. Adam and Eve supposedly looked like we do now right? So if we're still evolving, that means we had evolved prior, which in turn gives evidence that we didnt look like Mr. Adam and Mrs.

Originally posted by Heronumber0
I have to disagree Darkside. There is not a survival advantage in environments where there is a varied diet. However, there is local genetic variation from meiotic events that generate gametes (sperm and egg). However, it would be intriguing if some of the lactase genes are made by transposition or from the 'switching on' of previously silent genes.

It is. An individual that can digest lactose as an adult is more likely to survive than an individual that can't. Especially in a world without Tesco's and McDonald's and where your dependant on migrating herds.

It is. An individual that can digest lactose as an adult is more likely to survive than an individual that can't. Especially in a world without Tesco's and McDonald's and where your dependant on migrating herds.

I beg to differ again. You and I could easily survive on vegetables which do not have lactose. C'mon DS it is about survival of the fittest dude...And this scenario does not cut it.

Originally posted by Heronumber0
I beg to differ again. You and I could easily survive on vegetables which do not have lactose. C'mon DS it is about survival of the fittest dude...And this scenario does not cut it.

But milk is an easy and relatively abundant source of animal protein which are vital. And it obviously had an advantage since it is extremely rare for a human to not be able to digest lactose. You might survive on vegetables, but you won't be as healthy and energetic as those that eat meat, and there the ones that reproduce.

About nowadays, I'm not sure survival of the fittest applies at all unless we're put in conditions of extreme poverty or isolation.

As soon as we gain a little more insight into our genetic makeup, and are able to manipulate it with some degree of skill, I expect humanity to split up into as many different kinds of physical beings as there are Internet discussion forums.

Then I guess it will just be a matter of which particular odd splinter of humanity can be made relatively immune to the rampaging waves of superviruses that will scour the Earth, also a result of that same genetic manipulation.

With the process moving ahead so rapidly, and with the new environmental variable of artificially intelligent machines thrown into the mix, I still say that mankind as we now know it is unlikely to exist in its currently familiar form for more than a few thousand years, 5,000 years at the outside. Not very long in the history of the world, really. Oh, well. It was a pretty good run while it lasted.

Here's one:

5 signs humans still evolving

1. We Drink Milk

2. We're Losing Our Wisdom Teeth

3. We're Resisting Diseases

4. Our Brains Are Shrinking

5. We Have Blue Eyes

These are supposed to be evidence seen relatively recently (the past few thousands years) but for some reason it doesn't seem compelling to me.

And to DarkSide:

About nowadays, I'm not sure survival of the fittest applies at all unless we're put in conditions of extreme poverty or isolation.

With all our medical tech and not being eaten by lions, seems like the majority are surviving nowadays, unless you rule out the big diseases and dying to stupid stuff like speeding down the highway or drugs.

So how will the human race look like in 10 000 years?

Thread necromancy

originally posted by: Topato
not being eaten by lions,

I am especially glad for this

So how will the human race look like in 10 000 years?

like this


only with caterpillar tracks

a reply to: DarkSide

Of course humans are still evolving. It is a fallacy to assume that we are at the pinnacle of evolution. Humanity isn't an evolutionary destination. It is just one stop along the long railway of living evolution. Nice evidence though. Always good to confirm things even if they are blisteringly obvious.