Pharyngula

Very peculiar

I’ve read Steve Jones’ books and enjoyed them — so I’m really baffled by this bizarre report of a talk he 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.

He claims human evolution is over. The reason? Because not enough fathers over 35 are having children. That’s bad because mutations are the source of evolutionary novelty, and older fathers are more likely to have accumulated errors in the replication of sperm, and therefore pass on more mutations.

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.”

This is true, but it makes no sense. It’s not as if younger fathers produce no mutations — they generate plenty. It’s a difference in degree, nothing more, so we still have plenty of new mutations percolating into the population. And of course, over most of human history parents have been relatively young, since you couldn’t count on living to the age of 35.

And then there’s this odd argument.

Another factor is the weakening of natural selection. “In ancient times half our children would have died by the age of 20. Now, in the Western world, 98 per cent of them are surviving to 21.”

That makes even less sense. Natural selection is going to eliminate variants; by reducing its effects, we permit more mutations to persist in the population. One moment he’s complaining that fewer mutations are being produced, the next he’s complaining that the mutants are thriving. Which is it?

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.


I see that Larry Moran has just thrown up his hands in exasperation at all the errors.

Comments

  1. #1 amk
    October 7, 2008

    Obligatory link to the Idiocracy intro.

  2. #2 jj
    October 7, 2008

    I’d always heard that the age of parents was increasing, not decreasing….

  3. #3 Karen
    October 7, 2008

    Peculiar is the right term, or at least a less foul version of my thoughts when I read the article. I’m hoping that the reporter just butchered the talk, but much of that article appears to be direct quotations…

    Seriously, WTF?

  4. #4 Richard V Harris
    October 7, 2008

    I heard this interview on BBC Radio 4. I normally respect Steve Jones’ statements, but there was a problem with his answers this time. I think that I know what he was trying to say, but maybe he was trying too hard to get his ideas over to an audience that he knows is likely to misunderstand him.

    Natural selection cannot be over for us humans until we can genetically engineer ourselves beyond its reach. He didn’t say that. He implied that NS wasn’t going to affect us significantly any more because we’re so good at keeping ourselves alive & able to reproduce. Hah! Just wait till there’s an evolutionary bottleneck effect – due to societal collapse maybe, or smothing cultural. But he didn’t mention genetic engineering, & that’s where the future lies, if we don’t suffer a total collapse of civilization.

  5. #5 spgreenlaw
    October 7, 2008

    I’m a student of the humanities myself, and even I know how completely wrong this stuff is. What the hell?

  6. #6 Kel
    October 7, 2008

    That’s an extremely odd thing to say. Maybe his point should have been that the current environment we live in removes almost all selection pressures, but that still doesn’t stop evolution.

  7. #7 Rev. BigDumbChimp, KoT, OM
    October 7, 2008

    He claims human evolution is over.

    I know a particularly insane ex vermontian professor who would be right on board with this guy.

  8. #8 Irene Delse
    October 7, 2008

    Bizarre statements in book by normally sensible author? Cynical hypothesis: ghostwriter.

  9. #9 Glen Davidson
    October 7, 2008

    Truth is, not too many fathered children past, say, 40 over the course of human evolution because not too many lived past then (unless the few who did were highly successful reproductively, which has not been shown to be the case). And no, it wasn’t just a matter of higher infant mortality rates, infectious diseases and accidents offed the adults pretty good, too.

    As far as whether or not evolution will continue, that’s a matter of culture and of society. If our society is ever-lasting, which only a fool would predict, would the issue of low natural selection be a problem.

    Religion may very well take over, partly because many religions help to increase the population over secular socieities. Alternatively, the world might just become intelligent, rid itself of religion, and accelerate evolution intensely via genetic engineering (this is not necessarily smart in and of itself, but would require intelligence for it to occur).

    Sure, Rome was going to last forever. And so will current unsustainable lifestyles. Actually, what is almost certain is that current lifestyles will not continue, whether through choice or because of necessity.

    Glen D
    http://tinyurl.com/2kxyc7

  10. #10 RickD
    October 7, 2008

    I think it’s clear that the evolutionary pressures on the human species are not the same as they used to be. But it would be quite silly to say “evolution is over”. From a practical standpoint, it would be much, much harder to achieve a stationary point on the path of evolution than to simply see the overall rate of evolution diminish.

    But clearly, evolution is not over. Is the genetic make-up of the human species the same as it was 100 years ago? My understanding is that birth rates in some parts of the world are much higher than in other parts of the world. (Compare India and Europe). It would be very difficult to reconcile that basic observation with any notion that evolution is “over”.

    I’m hoping that this speech does not mean that Steve Jones has wandered into Francis Fukayama territory.

    Hmm…I worked at UCL for two years. I’ll have to tell my friends there that this is embarrassing for UCL. Unless it’s some kind of stunt, or we are completely misunderstanding him.

  11. #11 Rienk
    October 7, 2008

    Well, his reasons are off but one can make an argument that our population size will slow down evolutionary change. We are so widespread and so numerous, and set up society in such a way (especially in the west, where we remove the selective pressure, in stead of coping with it), that certain mutations will not be greatly selected for. One could argue that significant phenotypical changes will not occur as often. Also, large gene pools have an averaging effect on the genotype of species as a whole.

  12. #12 rrt
    October 7, 2008

    I don’t think it’s actually possible to escape evolution at all, Richard. Unless you could assure a 100% error-free replication process and a population without variation, new genes and even accidental death. Given that I don’t see why we’d even want a variation-free population, I can’t even see us minimizing evolution all that much. Seems to me we’re just shifting selection around a bit, often much less than we’d like to think.

  13. #13 Aaron
    October 7, 2008

    It seems the argument he /wants/ to make is that there are less changes for beneficial mutations in the first instance, and more harmful mutations are surviving and being spread throughout the gene pool in the second.

    It seems he is saying that the best way to evolve is to have a lot of mutations with the negative ones dying off.

  14. #14 LightningRose
    October 7, 2008

    PZ, do you think humans are evolving in any meaningful manner? With modern medicine keeping folks with congenital issues alive long enough to breed who would have died by puberty a century ago, surely natural selection is no longer a driving force.

    Or, as the above linked video suggests (and as evidence I nominate the Palin family), are we self-selecting for stupidity, and doomed to a society outlined over 50 years ago in the short story, “The Marching Morons”?

    http://en.wikipedia.org/wiki/The_Marching_Morons

  15. #15 CJO
    October 7, 2008

    the current environment we live in removes almost all selection pressures, but that still doesn’t stop evolution.

    It couldn’t really, could it? It removes “red in tooth and claw” selection pressures (somewhat — infectuous diseases are what, red in protein coat and flagellum?) and replaces them with others. Really, since the dawn of modern homo sapiens sapiens, I suspect that most of the selection pressures on us have been social. In a sense, we are our own niche.

    The element of the modern human way of life that most confounds evolution, I would think, is our mobility and the ease with which genes flow throughout the population. The entire human race can be considered a single population, and obviously it’s very large for an animal of our size. A big, intermixing gene pool = slow evolution and no speciation.

  16. #17 Ichthyic
    October 7, 2008

    I know a particularly insane ex vermontian professor who would be right on board with this guy.

    He would love it so.

    Please don’t say his name. I’d hate to think it would somehow resurrect him here.

  17. #18 oldtree
    October 7, 2008

    Perhaps the author has information not fit for publication in support of the theory? Secret knowledge, super secret.

  18. #19 Paul Burnett
    October 7, 2008

    He claims human evolution is over. The reason? Because not enough fathers over 35 are having children.” – PZ

    Bull. Throughout most of the history of our species, males over 35 did not breed – because they were dead. Life was nasty, brutish and short.

  19. #20 Bing
    October 7, 2008

    I seem to remember in Dennett (in Consciousness Explained) talk about humans, with our big ol’ sciency brains, having greatly reduced a number of evolutionary pressures. Am I misunderstanding?

    HJ

  20. #21 Doug Little
    October 7, 2008

    IMO, I would think that if the solution space is not static then there will always be some form of selection pressure driving natural selection. I would think that the only way to stop it would be to completely control the environment.

  21. #22 CJO
    October 7, 2008

    humans, with our big ol’ sciency brains, having greatly reduced a number of evolutionary pressures. Am I misunderstanding?

    Not necessarily, but you are if you think that those big ol’ brains, gathered about as they are wont in conspiratorial (and competing!) cabals, don’t in turn create a whole host of novel selection pressures.

  22. #23 Curt Cameron
    October 7, 2008

    If men’s sperm has more mutations at 40 than at 20, wouldn’t that pretty much cancel out the population mutation rate over the long-term, because at 40 there are only half as many generations as there would be if males all procreated at 20?

  23. #24 yorktank
    October 7, 2008

    I heard this report on NPR today and immediately I knew it was a load of crap. For this I give all of my thanks to Pharyngula University!

  24. #25 PlainJane
    October 7, 2008

    What!!!?

    You mean the whole premise behind Heroes is false?!

    I sooo much wanted to fly….

  25. #26 Brent Royal-Gordon
    October 7, 2008

    His first point is sheer crazy, but the second is something I’ve wondered about myself. Besides deadly mutations and ones that cause severe social difficulties that prevent reproduction, what sort of selective pressures are still acting on humans (or at least humans in the developed world)? Which traits are generally being selected for, and which are being selected against?

    And if the answer is that the only selection today is against the severe issues I mentioned, what does that mean for us? Does that mean that the human genome will walk the search space randomly, with the only force keeping us together being that individuals who drift too far won’t be able to reproduce? And what will that mean when selective pressure returns with a vengeance–for example, as a virulent, treatment-resistant plague or some sort of societal collapse?

  26. #27 Chris (in Columbus)
    October 7, 2008

    Ha ha, I thought you said “Steve Jobs”, not “Steve Jones”. I was like, “What, now even Apple goes all fundie?!? Are we gonna get an iBible?!”

  27. #28 Ichthyic
    October 7, 2008

    what sort of selective pressures are still acting on humans

    you’d be far better off asking what selective pressures AREN’T acting on humans, and even then, preparing a list would be erroneous outside of any localized group.

    It’s a nonsensical question, basically.

  28. #29 AgnosticTheocrat
    October 7, 2008

    The whole “we are evolving to be dumber” cliche is really just disguised racism/classism. It seems disingenuous to suggest that somehow those people who have the most kids are stupid when what we’re really saying is that those people are the least educated and least urbane. My guess is it’s a subtle pat on the back combined with a certain paranoia.

  29. #30 Bjørn Østman
    October 7, 2008

    I think a large part of the crazy is that he claims nothing will happen in the next million years. If there is any variation at all, then a changing environment is going to push the average phenotype in some direction or other. He thus predicts that the environment is relatively stable for the next one million years, or that human technology and medicine can effectively nullify selection. A million years is a long time either way.

  30. #31 Brad D
    October 7, 2008

    Hah! I love Heroes, but I have to cringe almost anytime Mohindar talks, because a really big load of nonsense is likely to start flowing. It really starts killing my suspension of disbelief. That’s the problem with a lot of Sci-Fi these days. It honestly works better if you really don’t try to explain things using science, because at some point you have to stop doing that. That’s why I love Douglas Adams, he explained things using parodies of science that were more humorous the more science you know.

  31. #32 Tony Sidaway
    October 7, 2008

    We’ve got a fair number of selection events on our medium horizon (odd little things like ice ages and what-have-you).

    The “dads over 35 are rare because the average has gone down” is a basic statistical blunder (and who care anyway? take ten dads aged 30 and you get the same effect spread over a wider range of blokes and thus a wider range of sexual partners).

    The reason why mutation matters to a geneticist like Jones is that he thinks the human genome is rather too uniform. He’s got a point there. Of course he’s missing the obvious solution: space exploration.

    Expose adventurous men and women to the hard radiation of interplanetary space, send supplies to keep them hard at work on a suitable neighboring planet generating greenhouse gases to trap solar radiation as heat; the implementation of this methodology might provide alternative occupation to those currently engaged in building autobahns and runways, sports cars and airliners.

    These aren’t dreadful, tremendous, species-changing evolutionary pressures. But the gulf between Earth and Mars does create scope for an experiment in breeding. Native Australians aren’t as different genetically from Europeans as some Africans are from other Africans. But what happens if we add lots of mutations?

  32. #33 Eyeoffaith
    October 7, 2008

    Many of the comments at the end of the article are terrible too. But I suppose they can be explained by ignorance. The body of the article doesn’t have that excuse. So, yes, very odd.

  33. #34 Ryan
    October 7, 2008

    Well I agree with (and there are good data showing) the point that certain selective pressures have decreased in certain populations and that populations have become increasingly mixed (diminishing the opportunity for beneficial local adaptations), but there is still a very high mortality rate for sperm, eggs and for fertilized eggs. Even in the developed world, about 20% of fertilized eggs are aborted—frequently for identifiable genetic problems. Not to mention the vast majority of gametes that don’t make it either due to chance or selection. That alone creates a pretty big purifying selective pressure. Then beyond that, there are still a number of genetic ailments that decrease the average number of children you’ll have, certianly things like Tay Sachs but I would bet (though I don’t have a citation) autism and many others of more subtle effect too. It is true that in the developed world we may *eventually* lose genetic resistance to malaria (that is only in the West due to population movements anyway) and to other diseases, but at our population sizes (and especially so long as our population is expanding) we will not lose them soon.

    It is demonstrably true that there is a greater slightly deleterious:beneficial mutation ratio in Europeans than Africans because of the relatively recent population bottleneck followed by population expansion in European populations. However thinking that science couldn’t keep up with that is false—even if our genes are slightly “worse”, rates of all sorts of problems are *decreasing* as we create cultural solutions to biological problems faster than the problems get to us (similar to our food production increasing faster than the number of mouths). Now is that sustainable indefinitely? No. But I’m willing to bet it’s sustainable a hulluva a lot longer than the growth in our food and fuel supplies are.

  34. #35 QrazyQat
    October 7, 2008

    Why not assume the most likely (like looking at the spouse when investigating a homicide); maybe he’s just climbing on the “human evolution is over, we’ve stopped evolving” train that goes around and around on a little track every year or so. Maybe he just wanted a ride.

    OTOH, keep him away from frozen waterfalls while he’s in this state. :)

  35. #36 Platypus
    October 7, 2008

    It’s crazy to think that evolution is “over”. The selective pressures are radically different than they used to be, but the gene variants that are successful will be the ones that get passed on.

    It does, however, give rise to an interesting evolutionary conundrum to consider.

    Human population growth must, at some point, stop. This is due to the finite number of resources we have — there is a maximum limit to how many people can be supported on this planet. But our capacity for procreation means that we (like every other species that hasn’t gone extinct yet) will always produce more offspring than can possibly survive.

    The answer for every other species is that populations are limited by external causes; famine, pestilence or predation. But it might be possible for humans to voluntarily constrain our own reproduction.

    This can be done by governmental limits (like China) or by social pressure against having lots of kids. But either one then sets up a huge selective payoff for those individuals that do reproduce. Any allele that increases your odds of having one extra kid is going to be favored. And with a proven doubling time of 20 years, it wouldn’t take very long (a century or two) for such a variant to become very prevalent in the human population.

    So the problem: Can a voluntary system to control the human population work over the long term? Or are we doomed to choose between famines or governmentally-imposed restrictions on breeding?

    And with that uplifting thought, I’m off to read the day’s stock market reports to cheer myself up.

  36. #37 I.M. Pissedoff
    October 7, 2008

    I googled the article author’s name — one would think someone writing for the Times would be credible and she certainly has some journalistic credentials, but not clear to me that she has much experience with biological science??? At any rate, her article is swirling around cyberspace, so if she’s badly botched it, surely a clarification will soon be coming from Jones.

  37. #38 Kel
    October 7, 2008

    It couldn’t really, could it? It removes “red in tooth and claw” selection pressures (somewhat — infectuous diseases are what, red in protein coat and flagellum?) and replaces them with others. Really, since the dawn of modern homo sapiens sapiens, I suspect that most of the selection pressures on us have been social. In a sense, we are our own niche.

    Agreed. Our main competition now is the microscopic world and our socio-economic environment.

    What would be interesting is to see what effect monogamy will play given that for the majority of our history it was all about polygamous behaviour.

  38. #39 shecky
    October 7, 2008

    a bit reminiscent of John Horgan’s book from some yrs. ago predicting the “end of science.” I occasionally like Horgan’s essays, but his argument here seemed waaay off base.

  39. #40 Tim G
    October 7, 2008

    A fascinating discussion between Steve Jones, Richard Dawkins and Lewis Wolpert is available for free on ITunes. (Just search for ‘Dawkins’ on the ITunes Store. The recording does cut off abruptly). In it, towards the end Steve Jones makes the second claim. Unless I misunderstood, or was not concentrating (both quite possible) the other two pretty much agreed.

  40. #41 Michelle
    October 7, 2008

    um, I’m no biology major but… that guy’s contradicting himself on the age thing right there, isn’t it?

  41. #42 Colugo
    October 7, 2008

    Between Steve Jones’ ‘human evolution has stopped’ (also SJ Gould’s position) and the Harpending-Cochran (and Hawks) ‘human evolution is accelerating’ is the mundane reality: human evolution is muddling along.

  42. #43 Travis
    October 7, 2008

    This rubbish just showed up on the lunchtime TV news here in NZ. Some disagreeing scientists were given air time but not nearly enough; the report also treated Jones’ opinion as a fact for the most part, which bothered me as it seemed like nonsensical rambling. Is he really claiming that there’as no more genetic disease, medicine is 100% successful in all cases, and that genetic drift and fads in mate selection have stopped? Because that’s the kind of environment his claims need to be true.

  43. #44 Kel
    October 7, 2008

    the report also treated Jones’ opinion as a fact for the most part, which bothered me as it seemed like nonsensical rambling.

    Journalists without any scientific training shouldn’t report on scientific matters. Economists especially should be kept well away from all things science…

  44. #45 Frank
    October 7, 2008

    Odd – in Darwin’s Ghost, Jones makes much of the fact that according to British registry records, children sired by the aristocracy where the fathers were >50 years old had a shorter life expectancy (by about 1 yr) than those whose fathers were younger.

    It seems that a shorter life expectancy would reduce one’s fitness, unless of course, one had children at a younger age. Either the account is in error, or Jones is.

  45. #46 Travis
    October 7, 2008

    Something I forgot to comment on before, the last sentence of the article;

    “We are mixing into a glo-bal mass, and the future is brown.”

    Is is just me or does this statement come off a bit… well… racist?

    Is he implying being “brown” is a bad thing?

    Could this article really be a rant disguised as science?

    This is jsut the impression teh transcript gave me; I’d love to be shown that I’m wrong.

  46. #47 skinman
    October 7, 2008

    I’m doing my part. I’m a father three times over since I turned 35.

  47. #48 Barney
    October 7, 2008

    Here’s a 4 minute BBC interview (audio), in which Jones doesn’t say anything about the age of fathers, but does say that the number of children is important – he claims that with the vast majority of people born likely to survive to adulthood, and then have roughly the same number of children as each other, any variation won’t have a chance to out-compete the existing genes.

    Here’s another report, in which the age of fathers is mentioned, but doesn’t get the prominence that The Times gives it. Perhaps the reporter just found that the most surprising bit, and so wrote as if that was Jones’s main point?

  48. #49 uncle frogy
    October 7, 2008

    well I don’t know what he was tying to say but I doubt he meant what he said at least I hope so. Reproduction plus death = evolution (in a very simple way) unless you stop both I think you will get some evolution. I will grant the “traditional natural selection” has been interrupted by human technological development in the last 10K years. There must be some things that are influencing evolution. Poverty and ignorance seem to have an effect on birth rate and death rate, I am sure that other things could be identified.
    sounds like it was over simplified to me.

  49. #50 Another Primate
    October 7, 2008

    “Natural selection is going to eliminate variants; by reducing its effects, we permit more mutations to persist in the population.”

    Damn, I just had a thought about myself. Just one hundred years ago I would probably be dead! I have leukemia and I guess since it is now treatable and I’m expected to live a full if I can pass on more F-d up genes. Evolution rocks! I know I’m a sicko.

  50. #51 Barney
    October 7, 2008

    @Travis,
    No, I don’t think he’s being racist – here’s another BBC audio interview (7 minutes, this time), in which he mentions this at about 5:20.

  51. #52 amphiox
    October 7, 2008

    In our current “modern” society, does every individual/characteristic/trait have an exactly equal chance reproducing?

    Do genetic, as opposed to social/societal/behavioral, factors have no influence whatsoever on the chances of reproduction?

    Is it even possible to conceive of a realistic present future society/circumstance (aside from extinction) where you could honestly answer “yes” to either of the above?

    If the answer to any of the above is “no” then human evolution has not stopped and will never stop. (Again short of extinction).

    But I think one should be more specific with such claims with regards to what one means precisely when using the term “evolution.” Are we referring to an overall phenotype shift, an accumulation or loss of variation, a speciation event, etc? Because if we use “evolution” in its broadest sense, as “change over time” then pretty much every time a baby is born that is not 100% identical to its parents, the human species has evolved.

    It seems to me that in a circumstance like the present western world, with high populations and reduced selection pressures, variation would more readily accumulate but the phenotype would tend to remain stable. If the environment should change, however, new selection pressures on this newly accumulated variation could quickly push the phenotype in an entirely unexpected direction.

  52. #53 Katkinkate
    October 7, 2008

    I agree with Richard V Harris @ 4. At most the impacts of natural selection has been paused until our present period of exceptional affluence, massive gene flow (racial migrations and mixing) and improved health care is over, then there will be a huge buildup of genetic variety available to be pruned and molded into new shapes by evolutionary forces when peak oil, global warming and American empire collapse make their full affects known (or we get hit by an asteroid/comet, or Yellowstone blows up).

  53. #54 Pierce R. Butler
    October 7, 2008

    Glen D @ # 9: Actually, what is almost certain is that current lifestyles will not continue, whether through choice or because of necessity.

    Ryan @ # 36: The answer for every other species is that populations are limited by external causes; famine, pestilence or predation. But it might be possible for humans to voluntarily constrain our own reproduction. … Or are we doomed to choose between famines or governmentally-imposed restrictions on breeding?

    Optimists like y’all rarely mention another non-trivial probability: that the pattern of population spikes being followed by crashes will persist.

    We’re now, roughly, at 3-4 orders of magnitude above our pre-industrial numbers: do spikes of that range ever not decline, on a limited resource base?

    That growth took several centuries – the right-hand side of the chart, I’m told, tends to be steeper.

    Such processes are often turning points in species development, right? Especially when biomes collapse simultaneously on a planetary scale…

    Natural selection to the max, Prof Jones! Front-row seats at an era transition! It’ll be a great time for evolutionary biologists… uh, never mind.

    [please take my standard rant about ecological denialism on biology blogs as given]

    Hypothesis: Prof. Jones has a clear view of humanity’s impending natural & artificial selection process, and is testing (or test-marketing) psychological defense strategies.

  54. #55 Pierce R. Butler
    October 7, 2008

    Oops, that’s Platypus @ # 36 in # 54.

  55. #56 Pierce R. Butler
    October 7, 2008

    from the Times article: Speaking today … Professor Jones will argue …

    It being well past midnight in old Londinium by now, Jones has presumably delivered his lecture and retired with his snifter like a proper English intellectual, hours ago – years, they say, in Internet time.

    Surely by now someone with better google-fu than I should be able to locate & post multiple videos and Twittered transcriptions for such a provocatively publicized event before the majority of us on this side of the pond seek our own snifters (or six-packs, in Alaska – y’know, this Palin phenomenon takes a major load off us Southerners…)…

  56. #57 Lynnai
    October 7, 2008

    maybe he’s a middle aged male who subconsously wants to have sex with a lot of young women. ;)

  57. #58 razib
    October 7, 2008

    i asked an evolutionary biologist who knows jones. he says this is almost certainly real.

  58. #59 secularguy
    October 7, 2008

    Funny, I recall pondering this question around the age of 10 — wondering if the advancement of modern medical science would in some sense decrease natural selection and thus slow human evolution down.
    Some thoughts I had then: Sharks have changed little for millions of years, because their environment has changed little. But our environment has changed massively the last few thousand years, and continues to change. How does culture affect natural and artificial selection? There’s more to selection than just surviving to reproductive age.

    The comments to the Times Online article are scary.

  59. #60 Richard Simons
    October 7, 2008

    Quite apart from anything else, my understanding is that the presence of dioxins, plasticizers and other nasties in the environment has almost certainly increased the mutation rate.

  60. #61 John Scanlon FCD
    October 7, 2008

    Platypus #36:

    Human population growth must, at some point, stop. This is due to the finite number of resources we have — there is a maximum limit to how many people can be supported on this planet.

    Are we really allowed to say that now? Outside the biology departments, I mean? (Just don’t say it and then try and get elected, is all. Only denialists need apply…)
    Alright, given what we know, we apparently have a choice between letting natural selection have free rein (crash and burn, baby!), or trying to manage the transition to smaller and more stable population by applying some understanding of evolutionary processes. Seems to me that the latter would almost necessarily constitute artificial selection, a.k.a. the bugbear ‘eugenics’ (i.e. managing a demographic transition to be genetically/’racially’ selectively neutral would be highly nontrivial). Saying ‘the future is brown’ (supposing a global Brazilian-style melting pot) evades questions of timescale relative to the coming crash, as does the whole dads-over-35 thing. In the long run… so what, Dr Jones?

  61. #62 MartinH
    October 7, 2008

    There appears to be a common view that for most of human history adults didn’t live much past their thirties. If anyone has evidence for this, please post it.

    In the last thousand years, males, once adult, seem to have had a significantly longer life expectancy. A friend of mine boasted that her genealogy connected her to William the Conqueror 30 generations back. After acidly pointing out that we all have a billion lines of descent at that distance and therefore as an Englishman I am likely also descended from him, I realized that that was 30 years per generation – to me a surprisingly high age for average parenthood.

    Classical Greek and Roman historians – males – lived into their seventies. Perhaps it’s something about the academic pursuits.

    We are told that the Neolithic revolution with its unhealthy interest in animals ushered in the modern diseases. The introduction of agriculture in Europe allegedly reduced the stature and health of the population.

    Our Paleolithic ancestors – males who made it through childhood trials and not threatened by the risks of childbirth – may have lived to a ripe fruitful old age.

    Here’s an article on studies of hunter-gatherer tribes.
    johnhawks.net

    The Hiwis, the group with the highest mortality, still manage a life expectancy of 46 for a newly adult 15 year old. And the leading cause of adult male death seems to be fighting over women!

    It seems entirely plausible that our long prehistory was populated – in both senses – by relatively old men.

  62. #63 razib
    October 7, 2008

    There appears to be a common view that for most of human history adults didn’t live much past their thirties. If anyone has evidence for this, please post it.

    the mortality rate drops A LOT after the age of 5. so the expectation of 30 is skewed by the fact that the distribution is left-shifted in terms of age. once you make it teenagehood the mortality curve is pretty flat. yes, most people did not make it to 60, but many did make it past 30. people would just randomly die from things all of their lives (plague, starvation, infection, etc.) rather than starting to succumb A LOT in their 60s to 80s as it is now (because most people didn’t live long enough to develop cancer and other things that kick in at a late age).

  63. #64 Cujo359
    October 7, 2008

    Maybe it’s just anecdotal, but it seems to me that women are having babies when they’re older. Don’t older women also have a higher rate of mutation than younger ones?

  64. #65 ggab
    October 7, 2008

    Don’t know anything about the man.
    Could it be that he’s…let’s say… caught a Flew, if you know what I mean? Like of the Anthony variety.

  65. #66 Stephanie
    October 7, 2008

    #50 ~ My son (12) also has leukemia (t-cell ALL) and is currently in treatment. 30 years ago the chance of surviving t-cell was nil, now about 85% of children survive and many of those will be able to go on and have children.
    The theory is that pediatric leukemia is caused by damaged dna.
    I am just SO grateful that science has given him a chance.

  66. #67 Stephanie
    October 7, 2008

    #50 ~ My son (12) also has leukemia (t-cell ALL) and is currently in treatment. 30 years ago the chance of surviving t-cell was nil, now about 85% of children survive and many of those will be able to go on and have children.
    The theory is that pediatric leukemia is caused by damaged dna.
    I am just SO grateful that science has given him a chance.

  67. #68 razib
    October 8, 2008

    Don’t older women also have a higher rate of mutation than younger ones?

    yes. but because of the way spermatogenesis occurs (lots of duplication) males probably have an order of magnitude (10X) more mutants at any given age than females.

  68. #69 llewelly
    October 8, 2008

    Platypus #36:

    [please take my standard rant about ecological denialism on biology blogs as given]

    Solar and wind power are already cheaper and faster to deploy than nuclear power. If the enormous health costs – to say nothing of ecological costs – of coal and oil could be brought into the reckoning, solar and wind would be cheaper than coal or oil as well. Off the shelf technology, no new breakthroughs needed. Solar and wind will not run out any time soon, and could potentially support much higher power draws.

    The overwhelming majority of scientific predictions of what restrictions are necessary for sustainable fishing have been shown to be correct. This shows we can make useful projections about the future of complex ecologies. Thus – sustainable use is another off-the-shelf technology. Like solar and wind, it only needs to be deployed.

    Contraceptives and education are highly effective at reduction population growth rates. In much of Europe population growth is already negative. Only religion stands in the way of stabilizing – or even slowly reducing – population.

    I could give many other examples, but while ecological denialism remains a serious problem, the technological tools for maintaining our present population are in our hands. We need only put them to use. If a crash happens, it will be because we lacked the proper social tools.

  69. #70 Platypus
    October 8, 2008

    Re: Pierce R. Butler @ 54:

    The “crashes” you are referring to are the outcomes of famines/wars/pandemics that I called “external forces” that limit population growth. You call me an optimist for positing a steady state, but my post was pondering if achieving such a steady state just causes natural selection to work against it.

    Re: John Scanlon FCD @ 61:

    > Are we really allowed to say that now? Outside the biology departments, I mean?

    I figured if we can be out and unrepentant athiests, the pointing out of a self-evident mathematical fact about exponential growth is pretty tame by comparison.

    Re: llewelly@69:

    >I could give many other examples, but while ecological denialism remains a
    >serious problem, the technological tools for maintaining our present population
    >are in our hands. We need only put them to use. If a crash happens, it will be
    >because we lacked the proper social tools.

    You missed the entire point of my post.

    My question is about how natural selection will turn the “proper social tools” into strong selection for those genes that are most able to ignore the “proper social tools”.

    If we all agree to only have 2 kids (steady state population), then any genes that increase the likelihood their carriers cheat on that arrangement will be strongly favored.

    (These all-in-one style of comment threads are a terrible way to hold a discussion.)

  70. #71 DuckPhup
    October 8, 2008

    I have often called out for recognition that there already seems to be a few sub-species of humans… Homo Rationalis (atheists/agnostics)… Homo Dumbassticus… Homo Moronicus… Homo Creotard…

    Anyway… sure, there are a lot of mutations floating around in the human gene pool… but things are unlikely to get really interesting until there is some kind of significant environmental stressor. A transition from gravity to no-gravity, for example, should do it. Here’s my prediction…

    After populations of humans have existed and reproduced in orbital habitats for hundreds of years, in a weightless environment, they will end up with a beachball shaped body, spindly arms and legs and a protruding, muscular, articulating, tube-like anus. They will subsist mainly on a diet of cabbage, peas, pork-and-beans and beer, and they will propel themselves about their environment via controlled flatulence.

    Oh, yeah… and their sense of smell will atrophy… and they won’t get many visitors.

  71. #72 Peter Ashby
    October 8, 2008

    I think perspectives on this may differ quite a lot on opposite sides of the Atlantic. Over in America your population is increasing. Here in Europe many populations have reproduction rates below the replacement level. IOW they are shrinking. To the Pope’s continuing chagrin Italy is about the worst.

    Now think about this, that the fundies have more kids may not present as a problem to you folks in the US. However if the fundies are breeding well above the replacement rate in a population whose overall rate is well below it AND you live in a democracy…

    This is concentrating minds and in our perhaps over PC world ways have to be found to discuss this without causing offense. I suspect this may have to be borne in mind when approaching these points.

    And finally. Last week’s New Scientist had an article which claimed that evolution runs fastest in populations when those Nature red in tooth and claw pressures come OFF. When life is really hard then being a brainy generalist is a hard place to get to, you have to cling to your niche in the storm. Only when pressures are off can those varied parts of your population play around outwith their niche.

    It has always seemed to me that the idea of the Out of Africa/mitochondrial Eve genetic bottleneck being due to some catastrophic climate event as perhaps missing the point. Perhaps the group(s) that worked their way out of Africa were going a Viking and in their absence the niche bound folks they left behind died out. The subsequent event not driving the first.

    The idea that there may be less evolution in Sub Saharan populations may be simply because basic life is hardest there than anywhere else except perhaps for isolated groups in deepest Amazonia or Highland New Guinea. We think we aren’t evolving because we define our niches so flexibly as not to matter, I think I’ll be vegetarian or maybe I shouldn’t eat fish? But maybe while we luxuriate our bodies the restraints are off our genes as others have pointed out in our societies many more people with genetic disease get to live to reproductive age.

    @Brent Royal-Golden what this means is that when the next big shock happens we in the West will actually have the greatest genetic diversity. However that does not guarantee that the requisite mutations will be present in our population. It just increases the odds.

  72. #73 Derek Huby
    October 8, 2008

    Pierce@56:

    “like a proper English intellectual”.

    He’s Welsh.

    Nationality aside, I’m surprised that some here have never heard of him at all – he’s a very well-known writer in the UK – a prominent scientist and atheist. They should have a look at his Wikipedia page – it’s bang up to date, and enough to show that he’s one of the good guys. Not sure where he’s going with this stuff though – I wasn’t paying much attention to the R4 interview yesterday, but it did seem a trifle odd.

  73. #74 Mrs Tilton
    October 8, 2008

    ggab @65,

    Could it be that he’s…let’s say… caught a Flew

    Unlikely in this case, I’d think.

    Flew engaged with religion seriously; that was his professional metier. Jones simply doesn’t believe religion worth wasting much time thinking about (or at least that is the impression I have from the few times he mentions the topic in those of his books that I’ve read). The former sort of person is, I think, much likelier to end up a convert than the latter.

    Haven’t read the article. (And I won’t either, because PZ has declared that it is Tosh and I always accept without question whatever I am told by Authority.) But at least part of Jones’s argument (if that is indeed what it is) doesn’t sound a milion light years away from something Bill Hamilton wrote years ago. Assuming Hamilton was right (a big assumption, but let’s make it arguendo), a world in which natural selection had, for humans, lost much of its force would not be a nicer one.

    Razib @68,

    males probably have an order of magnitude (10X) more mutants

    For an interesting discussion of this and a number of other fascinating topics that don’t get much airing in the rest of the PopSci literature, people might want to have a look at Mark Ridley’s Mendel’s Demon. For the non-professional, it’s a bit of a hard slog (not because Ridley doesn’t write well — he does — but because a lot of the material is tough); but it’s well worth the effort.

  74. #75 Peter Ashby
    October 8, 2008

    Also this idea that any genes are selected by *city* living needs squashing well and truly. Sustainable cities, those whose population can sustain itself have only been seen since urban sanitation was invented. Prior to the early 1800s London needed a constant influx from the countryside to stop itself depopulating. We get this idea that we humans have been consistently urban from all the city ruins dotted about the world. From Moheno Daro through Rome or Alexandria to the Mayan cities. But the point is these places are RUINS, they did not persist. Medieval Rome was a village.

    In my family my paternal Grandfather was the first to live in a city so my Father was the first to be born in one. My Mother wasn’t. Of me and my siblings only my eldest sister was born in a city. The rest of us were born in a small town. I have only lived in cities since I was 6.

    For more on this stuff check out Greg Clark’s talk at Beyond Belief 2:
    http://thesciencenetwork.org/BeyondBelief2/watch/clark.php

    I can also recommend his book. A Farewell to Alms ISBN-10: 0691121354

    So what if anything is being selected for in ‘Western’ populations is not ‘urban living’. It is agrarian living in small villages growing staple crops and living with domestic animals. And not just in Western Europe either. In much of Asia and particularly China too. Also those parts of New Guinea where they had their own agriculture.

    Jared Diamond is onto it in his noticing that Western European derived populations have significantly lower rates of Type 2 diabetes relative to just about every other population (except iirc the Chinese). He puts it down to having had food security for a long time. That is the one big advantage of Feudal societies you see. Those food taxes that the lord takes and keeps safe in his castle/manor house are there when famine hits. So in those societies it is more likely that you will enter type 2 early and thus be insulin dependant in your late teens, iow dead.

    Also there is evidence that being heterozygous for the cystic fibrosis mutation is protective against diarrhoeal disease. Under what conditions are you most likely to suffer these? when you live in close proximity to animal shit, on a farm.

    We are selected to be farmers, not city slickers.

  75. #76 Torbjörn Larsson, OM
    October 8, 2008

    Yes, peculiar. According to paleoanthropologist John Hawks, human evolution has measurably accelerated a factor 100 or so in historic times, and in all likelihood continues to do so. (Note the first figure on relative number of new adaptive variants proceeding to fixation is trending more or less exponentially increased in the last millenniums; admittedly the uncertainty in his statistics increases when going very far back or near.)

    The reason is AFAIU that increased effective population and dramatic changing environment has pushed evolution over from drift to increasingly effective selection.

    We are so widespread and so numerous, and set up society in such a way (especially in the west, where we remove the selective pressure, in stead of coping with it), that certain mutations will not be greatly selected for.

    Seems selective pressures are greater than ever, due to population size effects, but also because of cultural (environmental) effects.

    John Hawks:

    Instead, it is when a new environment is imposed that natural populations respond. And when the environment changes, larger populations have an intrinsic advantage, as Fisher showed, because they have a faster potential response by new mutations.

    From that standpoint, the ecological changes documented in human history and the archaeological record create an exceptional situation. Humans faced new selective pressures during the last 40,000 years, related to disease, agricultural diets, sedentism, city life, greater lifespan, and many other ecological changes. This created a need for selection.

    Larger population sizes allowed the rapid response to selection — more new adaptive mutations. Together, the the two patterns of historical change have placed humans far from an equilibrium. In that case, we expect that the pace of genetic change due to positive selection should recently have been radically higher than at other times in human evolution. [My bold.]

  76. #77 Nick Gotts
    October 8, 2008

    maybe he’s a middle aged male who subconsously wants to have sex with a lot of young women – Lynnai

    I do assure you, it’s a very rare middle-aged man who subconsciously wants such a thing.

  77. #78 Mrs Tilton
    October 8, 2008

    Nick Gotts @77,

    I do assure you, it’s a very rare middle-aged man who subconsciously wants [sex with a lot of young women].

    Oh, come now, Nick; gay middle-aged men aren’t as rare as all that.

  78. #79 Nick Gotts
    October 8, 2008

    Mrs. Tilton,
    Come now (no pun intended), how dare you assume gay men have subconscious heterosexual desires? ;-)

  79. #80 the Kardinal
    October 8, 2008

    Ohhh, this conversation drives me crazy…This is one more instance where we need to remind ourselves that we are NOT special!
    The world was not created for us. The sun does not go around us. We are not the center of the universe. And evolution will continue to occur.
    An apt analogy for what Jones is saying: now that we understand what causes the weather, we humans will be unaffected by it.
    Tell that analogy to the Katrina victims, the people who die every year in the heat/cold, the tornado victims, etc. etc.

  80. #81 Nick Gotts
    October 8, 2008

    As long as there are heritable differences between people that affect mean inclusive fitness, human evolution by natural selection will continue. However, cultural change is so much faster, that this is of little practical importance. Does anyone doubt that if industrial civilisation persists another century or two, we’ll be genetically engineering ourselves, so the main process altering the human gene pool will itself be a result of cultural change?

  81. #82 Mrs Tilton
    October 8, 2008

    Nick @79,

    how dare you assume gay men have subconscious heterosexual desires?

    Well, we all know they do, Nick. They just need lots of prayer and a spell at Restorative Therapy Camp to move those desires up from the subconscious. And then, once they’ve unleashed their inner Ned Flanders, watch out ladies!

    Seriously, I think we were saying essentially the same thing.

  82. #83 Pablo
    October 8, 2008

    I’d always heard that the age of parents was increasing, not decreasing….

    That’s my response as well. For starters, as others noted, parents were more likely to be dead before 35 than they are now.

    But even outside of that, more people are waiting longer to have kids. I am 40 and expecting my first, for example. My wife is 38.

    Speaking of that, I don’t know about dads, but for sure mothers are older than they have been in the past. In fact, there is an important consequence of that – more mothers are having twins than they used to (even accounting for the fertility meds). That is because older women are more likely to have twins.

    So even if fewer men over 35 are having kids, what about the fact that more WOMEN are? Don’t they count in evolution?

  83. #84 Nick Gotts
    October 8, 2008

    Mrs. Tilton – yes of course we are! I just had to defend my reputation against the groundless implication that I hadn’t thought about gay men when making my comment ;-)

  84. #85 ggab
    October 8, 2008

    Mrs Tilton
    I didn’t really mean a “Flew” in the sense of religion.
    What I’m asking is, could it be that he’s gone a little loopy.
    If his ideas are as obviously misguided as some suggest, could he have lost a couple marbles?
    It’s been known to happen.

  85. #86 Russ
    October 8, 2008

    With my not-a-biologist credentials displayed firmly on my sleeve:

    1.) Amount of variation is the same or greater than ever, but
    2.) Lowered mortality from all causes means Natural Selection has a greatly lessened effect on which particular gene-carrier gets to breed, so
    3.) Specific gene-carriers don’t get so aggressively selected for, and that (plus lack of isolation) prevents speciation

    Therefore modern humans don’t transition into new forms driven by (non-social, non-man-made) selection pressures, and evolution by natural selection doesn’t really apply to us as a species any more.

    Where did I go wrong…?

  86. #87 the Kardinal
    October 8, 2008

    Russ @ #86

    Here is where you go wrong:
    “lower mortality rate from all causes”
    Humans, with the advancment of science and societies, have lowered the mortality rate in the past several centuries. That’s great, but its not a flick of time on the evolutionary scale. Humans diverged from our latest ancestors over 150,000 years ago.
    I’ll take that bet that in 150,000 years in our current rate of evolution (or “non-evolution” that Jones claims)we’ll have diverging species.

  87. #88 central texas
    October 9, 2008

    Did Steve, perchance, just have a birthday? A 35th birthday?

    Just curious.

  88. #89 Thanatos
    October 18, 2008

    “Here is where you go wrong:

    That’s great, but its not a flick of time on the evolutionary scale. Humans diverged from our latest ancestors over 150,000 years ago.
    I’ll take that bet that in 150,000 years in our current rate of evolution (or “non-evolution” that Jones claims)we’ll have diverging species.”

    Guys I think you are missing the point,
    of course the time scale is small,of course eventually there will be dramatic changes,catastrophes or perhaps space exploration and colonization etc,of course of course of course ….
    But try to think at this point in short term time scales,imagine that our present western-like society (Torbjoern don’t count the whole historic period but set globalization and westernization as the starting point)
    won’t collapse (or migrate to space) for a while etc but instead for a short period will get really global etc.
    For that period evolution (meaning here -without caring about what came before or what will come after- “variation or the road to speciation”) seems to pause,don’t you think?

    In other words :
    Torbjoern I think that it’s higly probable -judging by whence you come- that you are fair haired and blue eyed,
    let’s imagine that for the next 10000 years the planet,our species,our society
    will remain at this semi-imaginary condition,
    do you think that fair haired,blue eyed people will still exist in 9999 years
    or
    do you think that in 9999 years there will be many human “races” around or just one big grey-brown “race”?
    Again have in mind that we must keep in mind this specific imaginery period and not what happened before or what will come afterwards.

    P.S. I think that it is better to leave the (anti-)racist and moral arguments outside of this.They are irrelevant to the discussion and after it’s a(semi-)imaginary situation.

  89. #90 Thanatos
    October 18, 2008

    Sorry,my last phrase should read :
    “..and after all it’s a (semi-)imaginary situation (scenario).”

The site is currently under maintenance and will be back shortly. New comments have been disabled during this time, please check back soon.