We're As Good As It Gets?

[Lonan3]

LINK

 

Human evolution is grinding to a halt because of a shortage of older fathers in the West, according to a leading genetics expert.

Fathers over the age of 35 are more likely to pass on mutations, according to Professor Steve Jones, of University College London.

Speaking today at a UCL lecture entitled "Human evolution is over" Professor Jones will argue that there were three components to evolution – natural selection, mutation and random change. "Quite unexpectedly, we have dropped the human mutation rate because of a change in reproductive patterns," Professor Jones told The Times.

"Human social change often changes our genetic future," he said, citing marriage patterns and contraception as examples. Although chemicals and radioactive pollution could alter genetics, one of the most important mutation triggers is advanced age in men.

This is because cell divisions in males increase with age. "Every time there is a cell division, there is a chance of a mistake, a mutation, an error," he said. "For a 29-year old father [the mean age of reproduction in the West] there are around 300 divisions between the sperm that made him and the one he passes on – each one with an opportunity to make mistakes.

"For a 50-year-old father, the figure is well over a thousand. A drop in the number of older fathers will thus have a major effect on the rate of mutation."

 

[And it's entirely irrelevant that Prof Jones is 64!]

[Mutley]

That doesn't make sense at all. Until relatively modern times the life expectancy of males was something around the mid thirties anyway.

[Lonan3]

That doesn't make sense at all. Until relatively modern times the life expectancy of males was something around the mid thirties anyway.

I'm 60 - it makes perfect sense to me!

[bluemonday]

The illustration from the article is incorrect

 

Corrected version under:-

[Chinahand]

The illustration from the article is incorrect

Is the second to last one Neil Kinnock? I think we should be told.

 

Oh and the story's bollox - as Mutley said - but also there is the small point that it takes two to tango - anyone claiming that women are reproducing at a younger age now than in the past are nutters - or attention seeking scientists trying to get a news headline with a cheap simplification.

[Lonan3]

The illustration from the article is incorrect

Is the second to last one Neil Kinnock? I think we should be told.

 

Oh and the story's bollox - as Mutley said - but also there is the small point that it takes two to tango - anyone claiming that women are reproducing at a younger age now than in the past are nutters - or attention seeking scientists trying to get a news headline with a cheap simplification.

Not really sure that applies to The Professor

[Chinahand]

I'm sure he's distinguished, but the presentation of this is very very simplistic.

 

To be able to make claims about genetic variability of populations going into the future is massively complex - currently people with genetic mutations which would have killed a generation ago are surviving - who knows what side advantages these mutations might bring: there's research that says certain Jewish populations carry mutations which one gives them nasty genetic illnesses, but also gives them advantages in intelligence.

 

With increased travel populations which previously were unable to meet are now regularly getting together - to blithely claim this will result in homogenization is just simplistic - there will be vastly more interactions which will allow more unusual combinations come together.

 

In the Guardian article he laments that 98% of Londoners now reach sexual maturity, while previously over 50% died as children - he seems to be implying this will reduce genetic diversity in the population - erm - why?

 

This is in no way a mainstream theory, its been presented to the press to make headlines, and no doubt will be rebuted and the debate will continue, but I am certain the debate will be alot more nuanced than what is being reported in the press.

 

This is headline seeking and not science.

[jimbms]

I would say this is more like it

[Chinahand]

The trouble with these type of diagrams is that they imply evolution has a purpose - a teleology where one species turns into just one other one which turns into just one other one; with each one getting steadily more advanced.

 

Evolution doesn't really produce single successor species, but a tree of competing animals, often with their own nieches and ecological specialisms. Just because an animal has evolved from an earlier one doesn't mean its better - they can be driven to extinction, while the earlier species carries on.

 

This diagram sums it up far better than the diagram put up on the Times site.

 

 

See here for an explanation.

[Chinahand]

I'm in good company in panning this article - PZ Myers:

 

I'm really baffled by this bizarre report of a talk [steve Jones] gave. It's either a massive example of misreporting, or Jones has a solid grip on everyone's ankles and he's straining to pull our legs right off.

 

... I'm thinking Jones must be making some colossal joke here, or maybe he's testing his audience to see how much illogic and absurdity they will accept. That's the only way I can explain these strange claims.

 

Larry Moran:-

 

There's so much wrong with this article by Steve Jones that I don't know where to begin.

[VinnieK]

I'm sure he's distinguished, but the presentation of this is very very simplistic.

 

Go to his UCL page, it pretty much goes without saying that he is indeed distinguished as a geneticist.

 

In the Guardian article he laments that 98% of Londoners now reach sexual maturity, while previously over 50% died as children - he seems to be implying this will reduce genetic diversity in the population - erm - why?

 

He's not lamenting reduced genetic diversity, he's suggesting that evolution for humans will come to a standstill. Evolution is not the same thing as simple genetic diversity - it's the selection of specific random mutations by evolutionary pressures which confer advantage on adaptive traits and qualities. Professor Jones is arguing that by largely eliminating infant mortality you are removing a particular evolutionary pressure, the result being that the human gene pool remains a large mix of different genes and a particular selective process is greatly diminished.

 

This is in no way a mainstream theory, its been presented to the press to make headlines, and no doubt will be rebuted and the debate will continue, but I am certain the debate will be alot more nuanced than what is being reported in the press.

 

I'm not sure Jones, his supporters or the press ever suggested it was a mainstream theory (it's not even a theory - in science everything is hypothesis until proven). The Guardian describes it as controversial, for instance, whilst including quotes from other scientists pointing out that even if environmental selection is diminished, there remains sexual selection.

 

This is headline seeking and not science.

 

That's a little unfair. Headline seeking is when a group release a clearly preposterous study (usually commercial advertising under the guise of science, and rarely ever intended for publication in the peer reviewed journals) to the media, this sounds more like the media noticing a particularly controversial topic being spoken about at the RSE debate and contacting its speaker.