Evolution continuing to happen in humans?

[Fuzzy Fungi]

Hello!

I do know that evolution is a neverending process, and that it is still happening in humans today. However, I do not know of any examples of recent adaptations that humanity has gained.

What are some examples of relatively recent or current changes occuring in humanity?

Another question I have is in relation to a figure I read in another topic of about 100+ mutations per individual. What sort of things would these effect? How noticable are these in a person's phenotype?

Thanks!

 

[notto]

A few beneficial adaptations that seem to become fixed in human popluations would include
1) Oxygen retention in high altitude populations
http://www.gnxp.com/MT2/archives/001868.html?entry=1868
2) Resistence to Malaria
http://sickle.bwh.harvard.edu/malaria_sickle.html
3) Resistence to AIDS
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Abstract&list_uids=9132277

 

[michabo]

Aron Ra posted some interesting adaptations which have prospered in human populations:

1. The Vadoma tribe, AKA the "Ostrich People", a family in Zimbabwe who share a disctintive inherited mutation in their feet, (and sometimes in their hands also) which deprives them of all the bones for their three middle toes. These people claim the advantages of this include their ability to run faster and climb trees much better than normal-footed people.

2. A family in Connecticut with a specific mutation that parallel's the Bruce Willis character in Unbreakable. Members of this family have hyper-dense, "unbreakable" bones, easily the strongest bones of any humans on the planet. http://info.med.yale.edu/external/pubs/ym_au02/findings.html

Genetic samples from some members of this family are being tested to find a possible cure to osteoporosis.
http://www.stopgettingsick.com/Conditions/condition_template.cfm/5636/19/1

3. A family in in the village of Limone Sul Garda in northern Italy have a mutation which gives them better tolerance of HDL serum cholesterol. Consequently this family has no history of heart attack dispite their high-risk dietary habits. This mutation was traced to a single common ancestor living in the 1700's, but has now spread to dozens of descendants. Genetic samples from this family are now being tested for potential treatment of patients of heart disease.
http://www.eurekalert.org/features/doe/2002-05/dbnl-tmm061302.php

4. Sixty years after Hitler, Germany is finally breeding supermen. The immediate ancestors of this example are all unusually strong, but one of their children was born with twice the muscle mass of a normal human, and only half the fat! This child's genes may yeild new treatment for muscular dystrophy.
http://wcco.com/health/health_story_175140250.html

And this is to say nothing of the fact that incidence of sickle-cell gene in African-Americans is apparently decreasing over time, some Europeans descendants of Medieval Black Plague survivors are finding that they're also immune to AIDS, and there is now a growing number of people with tetrachromatic eyes, enabling them to see into the ultraviolet spectrum, invisible to normal humans!
http://slate.msn.com/toolbar.aspx?action=print&id=2079371

Source: http://www.christianforums.com/t1126612-define-your-central-terms.html&page=8

 

[fromdownunder]

One that was certainly emerging before modern dentistry was the loss of wisdom teeth.

Norm

 

[Hydra009]

2. A family in Connecticut with a specific mutation that parallel's the Bruce Willis character in Unbreakable. Members of this family have hyper-dense, "unbreakable" bones, easily the strongest bones of any humans on the planet. http://info.med.yale.edu/external/pubs/ym_au02/findings.html

Genetic samples from some members of this family are being tested to find a possible cure to osteoporosis.
http://www.stopgettingsick.com/Conditions/condition_template.cfm/5636/19/1

3. A family in in the village of Limone Sul Garda in northern Italy have a mutation which gives them better tolerance of HDL serum cholesterol. Consequently this family has no history of heart attack despite their high-risk dietary habits. This mutation was traced to a single common ancestor living in the 1700's, but has now spread to dozens of descendants. Genetic samples from this family are now being tested for potential treatment of patients of heart disease.
http://www.eurekalert.org/features/doe/2002-05/dbnl-tmm061302.php

That's incredible!

 

[ushishir]

Hello!

What are some examples of relatively recent or current changes occuring in humanity?

Lactase persistance is one example and the gene has very strong signatures of recent (~5,000-10,000 years) selection:

Genetic Signatures of Strong Recent Positive Selection at the Lactase Gene
Todd Bersaglieri et. al.
Am. J. Hum. Genet., 74:1111-1120, 2004
http://www.journals.uchicago.edu/AJHG/journal/issues/v74n6/40869/40869.html
(free full text)

The duffy blood group gene has strong evidence of selection as an allele provides resistance to the malaria Plasmodium Vivax - sadly not the one we think of as malaria - P. falciparum.

There are also alot of signatures of selection that have been detected but not tied to a particular phenotype or even a particular gene. For example a recent study has identified 385 regions of the genome that have experienced recent positive selection but in only a handful of cases the selection can be linked to a particular genetic variant or agent of selection identified.

Genomic signatures of positive selection in humans and the limits of outlier approaches
Joanna L. Kelley, Jennifer Madeoy, John C. Calhoun, Willie Swanson, and Joshua M. Akey
genome research (in press)
http://www.genome.org/cgi/content/abstract/gr.5157306v1

 

[rmwilliamsll]

Hello!

I do know that evolution is a neverending process, and that it is still happening in humans today. However, I do not know of any examples of recent adaptations that humanity has gained.

What are some examples of relatively recent or current changes occuring in humanity?

Another question I have is in relation to a figure I read in another topic of about 100+ mutations per individual. What sort of things would these effect? How noticable are these in a person's phenotype?

Thanks!

here are a few interesting essays on the topic:
http://www.futurepundit.com/archives/cat_brain_evolution.html
http://www.futurepundit.com/archives/003177.html
http://www.nytimes.com/2006/03/12/weekinreview/12wade.html?ex=1152936000&en=9211c0a5153cf0ef&ei=5070
http://www.economist.com/science/displaystory.cfm?story_id=4032638

all on brain evolution in the recent past...

 

[Byelotsar]

I don't know if this qualifies, necessarily, as adaptive evolution, but I do know that we can see a clear if general trend in the average height of a human (or at least a European... my own familiarity with this topic doesn't include other world regions until the modern age) over the last, oh, two thousand or so years. I don't know to what this increasing height might be an adaptation though. Maybe somebody can flesh this conjecture out or tell me where it's wrong.

 

[JohnR7]

I do not know of any examples of recent adaptations

Here is a recent adaption that makes it easier for people to shake hands.

 

[Hydra009]

I don't know if this qualifies, necessarily, as adaptive evolution, but I do know that we can see a clear if general trend in the average height of a human

Iirc, that's due to medicine and nutrition, not genetics.

 

[Fuzzy Fungi]

Thank you everyone for your examples and links I have to get ready for work so I don't have time to read all of them, but I read a few of them and they were all very interesting. Keep them coming!

Here is a recent adaption that makes it easier for people to shake hands.

So shaking hands better gets you more mates? Why didn't anyone else think of this before? I outta start a course on handshaking with this guarantee. I'll make millions!

 

[sfs]

Aron Ra posted some interesting adaptations which have prospered in human populations:

These are mutations with interesting effects, but unfortunately there is no evidence that they are increasing in frequency because of natural selection (or for any other reason). The mutation that confers resistence to AIDS did have genetic evidence for positive selection, but it kind of fizzled.

 

[billwald]

Sentient beings do not evolve because we intentionally choose mates and also permit the unfit to contaminate the gene pool. Evolution is a random process.

 

[ObbiQuiet]

Sentient beings do not evolve because we intentionally choose mates and also permit the unfit to contaminate the gene pool. Evolution is a random process.

No it's not. You must mean that, "mutations are random."

 

[Byelotsar]

Sentient beings do not evolve because we intentionally choose mates and also permit the unfit to contaminate the gene pool. Evolution is a random process.

Even sentient beings are subject to genetic mutation. At this point (and note that phrase), we are extremely good at mastering our environment without the need for evolutionary adaptation. This doesn't mean it doesn't happen. Just look at the examples given, right here, in this very thread!

 

[michabo]

These are mutations with interesting effects, but unfortunately there is no evidence that they are increasing in frequency because of natural selection (or for any other reason). The mutation that confers resistence to AIDS did have genetic evidence for positive selection, but it kind of fizzled.

Well, since these mutations are recent, they definitely have increased. Are you saying that they haven't increased rapidly enough for you, or increased beyond a certain point?


I recall something that Dawkin was saying about the evolution of finches in the Galapagos. Studies measured the length of the beaks, and after several years, they reported that the length increased by about 1mm. It was very small, but statistically significant. It's really a question of time, especially with the diluting effect of such a large population size as ours.

 

[fromdownunder]

I recall something that Dawkin was saying about the evolution of finches in the Galapagos. Studies measured the length of the beaks, and after several years, they reported that the length increased by about 1mm. It was very small, but statistically significant. It's really a question of time, especially with the diluting effect of such a large population size as ours.

See "The Beak of the Finch" (Grant and Grant). A very reader friendly book.

Norm

 

[Kahalachan]

Resistance to diseas is a very good example.

The problem with humans is that if bottlenecking due to a disease wipe out a bunch of us leaving the few that are resistent to the disease, those left behind may not survive because they are too dependant on technology.

 

[sfs]

Well, since these mutations are recent, they definitely have increased. Are you saying that they haven't increased rapidly enough for you, or increased beyond a certain point?

The HIV mutation isn't recent (I assume the reference was to the CCR5delta32 mutation), and it isn't increasing in any measurable way. Most of the others are extremely rare, new mutations that are overwhelmingly likely to disappear again, so I don't see them as contributing much to human evolution.

 

[sfs]

A recent review paper and online seminar on natural selection in humans (free access) is available at:

http://www.broad.mit.edu/mpg/pubs/

The supplemental material includes a list of every gene proposed as a site of positive selection, prior to the recent genome-wide surveys.