News24

Human evolution slower than thought

2011-06-13 07:28

Paris - Humans may be evolving a third as slowly as commonly thought, according to an investigation into genetic changes in two generations of families.

The genetic code comprises six billion nucleotides, or building blocks of DNA, half of which come from each parent.

Until now, the conventional theory among scientists was that parents each contribute between 100 and 200 changes in these nucleotides.

But the new study says that far fewer changes occur. Each parent hands on 30 on average.

"In principle, evolution is happening a third as slowly as previous thought," said Philip Awadalla of the University of Montreal, who led the study by the CARTaGENE group.

New ground

The discovery came from a painstaking look at the genomes of two families, each comprising a mother, a father and their child.

The study breaks new ground although its sample size is very small.

If confirmed on a wider scale, it will have a bearing on the chronology of evolution. It would change the way we calculate the number of generations that separate Homo sapiens from a primate forebear who is also the ancestor of the apes.

The study also challenged thinking about whether DNA changes are more likely to be handed on by the father or by the mother.

The mainstream notion is that DNA changes - known in scientific terms as mutations - are likelier to be transmitted by the man.

This is because mutations occur during cell division and DNA replication, and thus are much likelier to happen in sperm, for which many millions are made, than in eggs.

In one of the families, 92% of the changes were derived from the father.

But in the other family, only 36% of the mutations came from the paternal side.

"The mutation rate is extremely variable from individual to individual or... some people have mechanisms that reduce the likelihood of mutations," concluded Awadalla.

This variability could prompt a rethink on predicting the risk of inherited disease, caused by flawed genes bequeathed by one or both parents.

Some individuals might be at risk of misdiagnosis of a genetic disease if they have a higher natural mutation rate than the benchmark rate, he suggested.

Comments
  • Johan - 2011-06-13 07:44

    And in South Africa...?

      Dave Fourie - 2011-06-13 07:55

      Here evolution hasn't started yet.

      MoZaHo - 2011-06-13 08:37

      @Dave : ha ha ha ha. made my morning.

      TheUgly - 2011-06-13 16:12

      Name me one thing that's not slower in South Afrca.

  • dean369@24.com - 2011-06-13 08:16

    If you consider how we treat each other and the planet - one could hardly say we're evolving!

      Epicurius - 2011-06-13 10:37

      True, if we go by the comments in the 'Slut-Walk' thread, we definitely have a long way to go.

      Epicurius - 2011-06-13 10:58

      And even more so, based on the 'mob murder' thread.

  • Gazelle - 2011-06-13 08:31

    Ha Ha! Jokes on everyone! Evolution does not exist!

      shew - 2011-06-13 09:41

      if it doesn't exist then why would you click on a story about it - haha jokes on you!!!

      NuttyZA - 2011-06-13 10:07

      That's right Gazelle, we were all made from magic pixie dust by the Grand Oompah-Loompah 6347 years ago

      Johan van Zyl - 2011-06-13 11:21

      If evolution did not exists, we all would be as primitive as Juju, the headboy of the ANC's kiddie klub.

      zaatheist - 2011-06-13 12:06

      You will never get a straight forward answer to any straight forward question from a Creationist. The fairy tale they punt is based 100% on lies and deceit. The belief they espouse is pathetic and patently false superstition which supersedes the evidence and the informed evaluation of virtually all the scientists in the world It is crazier to believe that everything needs a creator except the creator himself.

  • frederick777 - 2011-06-13 09:17

    Evolution-biggest lie ever told! It does noy exist

      mbossenger - 2011-06-13 09:52

      Try reading beyond the creationist websites and you might be in for a surprise.

      Gazelle - 2011-06-13 10:07

      I am with you Frederick777 - Propaganda and lies started with Darwin and continued into our learning systems. People are just so enthralled by this fantasy that they can not even consider that there is even the slightest possibility that this is not true! I know it is not true!

      mbossenger - 2011-06-13 10:24

      @Gazelle - please tell us how you know evolution is not true.

      Epicurius - 2011-06-13 10:36

      @ Gazelle and Frederick777 - But let me guess, you see perfect truth in a myth which tells how a talking snake told a naked lady to eat an apple, prompting god to evict her and her hubby from his garden, forcing god to impregnate his own mother and come down to earth as his own son to vicariously redeem us for a sin he himself seemingly entrapped Eve into committing in the first place.

      Johan - 2011-06-13 10:39

      Bulls&*t baffles Common Sense. You just have to sound very clever to get people to believe in an unproven theory. Yes the keyword is believe. Evolutionists require much more faith than creationistm.

      Jimmy - 2011-06-13 10:46

      Im sure frederick, scientist have been using all their free time for the last 150 years to make up lies. ag please!! Are these not the same people that supply you with meds when you get sick and fix you when you get injured?? The process of evolution was revealed by carefully following the scientific method. A disbelief in evolution implies disbelief in the scientific method. The scientific method works, whether you believe it or not!!! Look around, you are surrounded by products of science 24/7; yet you go to church and thank god for everything. It’s easy to denounce science when you know nothing about it.

      mbossenger - 2011-06-13 11:14

      @barkers - so tell us why it's a lie

      mbossenger - 2011-06-13 11:16

      @Johan - here we go again. Scientific theories are never "proven".

      Jimmy - 2011-06-13 11:17

      OK barkers, can you please provide me with an alternate theory? Remember now, you have to provide EVIDENCE. Obviously you can show me the evidence in the comments section, a link to a peer reviewed journal would suffice.

      Epicurius - 2011-06-13 11:21

      @ barkers - Your 'Trust me I'm a doctor' speech might work on the candy-stripers (or porters, if you swing that way) at your hospital when you are enticing them into the broom closet, but you'll have to try a little harder here. Enlighten us, barkers. Was it god or the shape-shifting reptilian slave mongers that planted us here on earth in our present form?

      NuttyZA - 2011-06-13 11:24

      @Barker... WhoopeeDoo... so you are a Doctor... very impressive... You hold a doctorate in what exactly???? If you are a practising Medical Doctor, I am pretty damn glad that you are not my GP!

      Epicurius - 2011-06-13 11:34

      @ barkers - I usually give people the benefit of the doubt but I'm calling you out on this - I personally do not believe a medical professional, at least one who takes their role seriously, would go around using the mere fact (or lie) of their job-title as leverage in an argument, where the presentation of solid evidence is the obvious, and only, alternative. Your post lacks the maturity to convince me (and probably a few others on this forum) that it's coming from a true doctor - medical or scientific.

      barkers - 2011-06-13 11:41

      genetic data on hemoglobin (red blood cells). Hemoglobin has two chains, called alpha and beta. A minimum of 120 mutations would be required to convert alpha to beta. At least 34 of those changes require changeovers in 2 or 3 nucleotides. Yet, if a single nucleotide change occurs through mutation, the result ruins the blood and kills the organism!... The only thing Darwinism proves is that plants and animals can procreate! computer generated genetic algorithms, have just proved evolution wrong.. good for industrial applications... ends there. Do you people even know how complex a structure such as a protein is ??

      Epicurius - 2011-06-13 11:58

      @ barkers - that's a little more like it, a little. But please point us to peer-reviewed research on this concept. Nobody denies that proteins and heamoglobin are immensely compex but there is no reason to believe they could not have evolved rather than being created as is. Maybe it has not been fully understood yet, but what about the rest of the evidence regarding DNA similarities and even similarities in body structures / fossil evidence which indicate a clear heirarchy / phylogenetic tree.

      zaatheist - 2011-06-13 12:07

      You will never get a straight forward answer to any straight forward question from a Creationist. The fairy tale they punt is based 100% on lies and deceit. The belief they espouse is pathetic and patently false superstition which supersedes the evidence and the informed evaluation of virtually all the scientists in the world It is crazier to believe that everything needs a creator except the creator himself.

      mbossenger - 2011-06-13 12:08

      @barkers - The idea of a single mutation in hemoglobin being fatal is outright false. Many non-deleterious mutations in hemoglobin and even observed several beneficial mutations (such as increasing oxygen affinity) have been observed.

      NuttyZA - 2011-06-13 12:42

      Barkers, IF you were a real medical doctor and didn't just cut and paste that from a creationist website, you would have spelt the word Haemoglobin and not the Americanised, Hemoglobin... I am call you a fake!

      NuttyZA - 2011-06-13 12:45

      Barkers, also, you did a nice cut and paste job from this website (http://www.charlesdarwin.me/the-late-1960s)... verbatim... Medical doctor my arse...

      NuttyZA - 2011-06-13 12:47

      Barkers... and this one http://www.pathlights.com/ce_encyclopedia/Encyclopedia/20hist12.htm ...

      Jimmy - 2011-06-13 12:53

      @barkers, that sounds quite interesting. Can you please provide me with a link or the title of the journal article; I would very much like to read it. I do not know an enormous amount about hemoglobin, but enough to query the above mentioned study. In what organism did they attempt to convert the alpha unit to a beta unit? I they attempted to do this with any higher organism then I would object to the study. The ancestor of the alpha and beta unit must have arisen in a very primitive vertebrate, so if the study was done in a higher vertebrate then study is inaccurate. Furthermore, the alpha and beta unit as we know it in humans must be different in sequence to that of the ancestral alpha subunit. So, mutating the present beta subunit to the present alpha unit is also inaccurate. Do you c how easily it is to critique a study that isn’t constructed very well? Im not saying that is the case in this study as I haven’t read the original journal article. Im simply trying to show that there is a lot to consider when constructing a study that is scientifically sound. If you can give a link or a title then I can determine if that applies to this article. I can c ur disbelief in evolution has been reached by your own inquiry. I respect u for that :) For most people I cant say that.

      barkers - 2011-06-13 14:13

      @Mbossenger, you talk crap... regarding haemoglobin, what is your argument exactly. facts... and I don't want to hear about sickle cell anaemia. @NuttyZA... Yes a good cut and paste indeed. The difference is I understand what I'm reading and pasting... you don't! as you have no scientific background. Also some of us work!

      daaivark - 2011-06-13 14:51

      @Gazelle: Propaganda!? What? What exactly does who gain from this so-called propaganda.

      barkers - 2011-06-13 14:51

      @Epicurius...Try this..The cornerstone of Darwinism is the idea that major (complex) improvements can be built up through many minor improvements; that the new organs and new systems of organs which gave rise to new orders, classes and phyla developed gradually, through many very minor improvements. We should first note that the fossil record does not support this idea, for example, Harvard paleontologist George Gaylord Simpson "It is a feature of the known fossil record that most taxa appear abruptly. They are not, as a rule, led up to by a sequence of almost imperceptibly changing forerunners such as Darwin believed should be usual in evolution...This phenomenon becomes more universal and more intense as the hierarchy of categories is ascended. Gaps among known species are sporadic and often small. Gaps among known orders, classes and phyla are systematic and almost always large. These peculiarities of the record pose one of the most important theoretical problems in the whole history of life: Is the sudden appearance of higher categories a phenomenon of evolution or of the record only, due to sampling bias and other inadequacies?" .... Please tell us Epicurius??

      mbossenger - 2011-06-13 14:54

      @barkers - Modiano et al., Nature, 414, 305-308 (2001)

      NuttyZA - 2011-06-13 15:00

      Barker, How do you know what background I do or Do Not Have??? I also work... seems you have as much free time on your hands as myself?? Not too many patients to see????

      barkers - 2011-06-13 15:34

      @MBossenger... nice try, But I knew you were going the sickle cell anaemia / maleria route before you even started..... Sickle crisis occurs when red cells sickle and clog the arteries to parts of organs. Organs then undergo infarction (death from lack of blood supply). Without medical support the homozygotes are likely to die in young to middle age. But there is one positive. Heterozygotes in Africa, where malaria is endemic, are more resistant to malaria than people with normal hemoglobin, and the heterozygote genotype may have a survival advantage, but only in those areas. Could this be a limited example of evolutionary progress? Not really. When the mutant sickle gene is latent (i.e., sickling isn't occurring), there is a survival advantage in areas with malaria. But whenever sickling occurs, in the heterozygote or the homozygote, it obstructs blood vessels and causes pain and death to organs.... Evolutionary indeed!! Ha! Ha!

      Epicurius - 2011-06-13 15:46

      @ barkers - You're talking about the same George Gaylord Simpson who was quoted as saying - 'Man is the result of a purposeless and natural process that did not have him in mind.' and 'I don't think that evolution is supremely important because it is my specialty; it is my specialty because I think it is supremely important' Yes, I copy/pasted this from Wikipedia. Don't tell me he also supposedly had a deathbed recantation of his entire life's work - just as creationists claim Darwin did. What Simpson was pointing out was things he found peculiar about 'Most' taxa. Not all taxa. How about you explain the recurrent laryngeal nerve to us.

      Justin.A - 2011-06-13 16:44

      //Bulls&*t baffles Common Sense.// No its called scientific evidence, and often goes contrary to common sense. //You just have to sound very clever to get people to believe in an unproven theory.// Yes creationism fools many people by sounding scientific, except of course its not and has no evidence whatsoever. //Yes the keyword is believe. Evolutionists require much more faith than creationistm. // Sorry evolution has evidence, 150 of scientific evidence. You have nothing, whatsoever. Of course I could be wrong, mind posting some links to scientific journals?

      Justin.A - 2011-06-13 16:50

      //Yet, if a single nucleotide change occurs through mutation, the result ruins the blood and kills the organism!... // Except for the serval variants of human alpha hemoglobin found in living humans, plus the difference between human and ape hemoglobin by anywhere from two to eight amino acids which renders your argument completely fail. How you think this disproves 150 years of evidence is beyond me. Fortunately its not up to me or you, its up to science which has hard evidence. Your conjecture is interesting but the only place the conflict is, is in your head. Of course science could be completely wrong, you are welcome to link us to credible sources showing evidence for the alternative to evolution.

      Justin.A - 2011-06-13 16:52

      //@ barkers - You're talking about the same George Gaylord Simpson who was quoted as saying - 'Man is the result of a purposeless and natural process that did not have him in mind.' // Barkers creationist quote mining FAIL!!!

      bmpdragon - 2011-06-13 21:56

      Barkers: most of your Dr Dino posts have been dealt with/answered in previous article forums. And yet you (and TrueBlue&Real)still persist with the same dribble and lame arguments (culled from Hovind's sorry excuse of a website). By misquoting George Gaylord Simpson, you clearly show your misaligned agenda and ignorance. Simpson was talking about the evolutionary theory of "Punctuated Equilibrium". Please stay away from these forums if you are not going to engage honestly. There is a term for people like you: "TROLL".

  • Morne Loubser - 2011-06-13 10:41

    In the wise words of the movie "Evolution"...ka kaaaaaa..ka kaaaaa!

  • Gazelle - 2011-06-13 11:18

    People have been trying to discredit the Bible and God. Darwin was an atheist and he obviously tried his very best to come up with a story that would make the Biblical Creation a lie. The Devil had his work cut out for him but achieved making this lie believable to the world. When something is being hated THAT much and if an idea is being shot down that much without even looking at the alternative real scientific evidence - then you should ask yourself, why is this being done? Who will it hurt if the Creation is being taught alongside the Evolution theory? Ask yourself - have you got the chance to hear the evidence brought forward by Creationist Scientists? Do yourself a favour, because how can you make an educated decision when you have not heard both sides of the story?

      CapeTownJunk - 2011-06-13 11:32

      Darwin followed the evidence. If there was evidence of your god's existence, you wouldn't need faith to believe it. You'd just need common sense. You mention both sides of the story. One side is the truth. The other is an elaborate lie, crafted by generations of power-mongers to enslave the gullible. And there's no such thing as Creation Scientists. Just liars trying to twist science into supporting their own personal beliefs. Nothing to do with real science.

      Gazelle - 2011-06-13 11:41

      There are scientific evidence for Creation - you have just not had the opportunity to hear/see it. Because the power-mongers that you talk about have kept it away from us. -Watch on this documentary on youtube - Expelled: No intellegence allowed - and you will see how society works to keep real evidence from the massas! And yes there are Creation Scientists! There are quite a few! Your first comment does not make any sense - how much better if you have both evidence AND faith!

      mbossenger - 2011-06-13 12:00

      @Gazelle - oh dear - Expelled, really? You mean the movie where every one of the so-called expelled people lied? Sternberg - not employed by the Smithsonian, actually a research associate. Followed incorrect procedures in geeting a paper published. Crocker - employed on a course by course basis, not fired. Egnor - publisehd an essay on a blog and was subsequently criticised by members of the medical profession. Marks - set up a website that made it seem the university he was associated to supported intelligent design. Used university servers to support the web site. Read more here: http://www.scientificamerican.com/article.cfm?id=ben-steins-expelled-review-john-rennie

      Justin.A - 2011-06-13 12:45

      //and he obviously tried his very best to come up with a story that would make the Biblical Creation a lie// thats a nice guess, care to address the last 150 years of evidence in favour of evolution, including genetics? //Ask yourself - have you got the chance to hear the evidence brought forward by Creationist Scientists? Do yourself a favour, because how can you make an educated decision when you have not heard both sides of the story?// Because an educated guess would revolve around research, peer review, credibility and evidence. Of which creationists have none. Whatsoever. A yes, I have looked.

      TheUgly - 2011-06-13 16:34

      Really?... REALLY?... How long do you think it takes a creationist to evolve into a realist?

      Justin.A - 2011-06-13 19:17

      //Because the power-mongers that you talk about have kept it away from us// So every single scientist working in paleobiology, paleontology, geology, zooology, organic chemistry, ecology, genetics, and molecular biology (to begin with) have been keeping a global conspiracy which in every single scientific paper (millions) reaching the high standards for peer review, providing not only solid justifications from proven concepts within the respective qualifications but also critial evidence, over the last 150 years in across multiple establed respected scientific journals, has deliberately been edited to omit the work of a handful of people who write opinions in which they have no qualification about a predetermined conclusion? And you wonder why we don't take you seriously! "You shall not bear false witness against your neighbor"

  • rantoftheday - 2011-06-13 12:28

    Hope my re-post makes more sense! Is it possible that human evolution is only slowing down now as we are at a fairly stable time in our history (stable in terms of living environments, that is)? For the most part humans live a fairly comfortable existence and don’t need major genetic adaptations to survive. Could this slow down evolution? Answers anyone?

      mbossenger - 2011-06-13 12:52

      That wouldn't necessarily change the number of mutations from one generation to the next.

      CapeTownJunk - 2011-06-13 13:29

      rantoftheday: "Is it possible that human evolution is slowing down...?" Who knows? It's not like evolution is a directed process, aiming at a specific goal. Besides, evolution doesn't happen in big leaps from one generation to the next. It takes many generations for evolutionary trends to become apparent. That's many hundreds of years, at very least. Evolutionary change is most easily observable when there's a short time between generation n and generation n+1. Since we only live for 3 or 4 generations each, and the tools we have to measure evolutionary change are relatively new, humans aren't the best guinea pigs for measuring evolutionary change. So the answer is... maybe. But human evolution is not going to happen in a way that's noticeable, measurable or tangible within our own lifetimes.

      liesl - 2011-06-13 13:30

      Actually, that is an interesting thought ... aren't mutations often a response to changes in the environment? If things do stay fairly stable, and mutations are stimulus-driven it makes sense.

      Epicurius - 2011-06-13 13:36

      Also, mate selection is no longer as much about physical prowess and hunting/gathering abilities as it used to be.

      pieter.bosch - 2011-06-13 13:57

      Evolution is not driven by the environment, but the chance products of evolution that are best suited to the environment will survive and therefore become more common.

      Flamewulf - 2011-06-13 20:21

      Two words for you, rantoftheday: Genetic drift.

      bmpdragon - 2011-06-13 21:42

      Flamewulf, don't you mean "Punctuated Equilibrium"? Genetic drift can either increase or slow down the mutation rate, depending on the variety within the isolated gene pool and the percentage of dominant and recessive genes.

  • TheRealist - 2011-06-13 15:27

    Loving these evolution vs religion battles

  • TheUgly - 2011-06-13 16:25

    This article is hogwash! Humans evolve much quicker. Especially the last 3 generation are dramaticly stronger and smarter than the previous since humans are forced to adapt and survive in a completely new environment. PS: If you would like to find out more about exponential modern evolution google "The singualrity".

      Tiens - 2011-06-13 19:37

      No theUgly, we are mutating faster because with no natural enemies left, there is no way for natural selection to filter out the mutations which doesn't kill us before puberty. If anything, we are devolving. Just look at the comments posted above if you have any doubt...

      bmpdragon - 2011-06-13 21:47

      Nope TheUgly: what you are seeing (compared to previous human generations) are better expressed phenotypes due to a modern lifestyle (medication, nutrition, etc.). An example: the genotype for height can only be properly expressed if there is the correct diet and stimulus (sunlight, exercise, no hormonal diseases, etc.).

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