Your Environment May Change Your Genes

An anonymous reader writes "Recent experiments indicate that your environment alters your genes. The longer identical twins live apart, the more their "epigenomes" (genetic sequences that activate or suppress other genes) differ. This possibility could cause a radical shift in the assumptions of biological inheritance (namely that, with minor exceptions, an individual's genes do not change), and indicates the possibility of return of Larmarckian inheritance which had formerly been consigned to the dustbin of biology."

Comments

Genes or Jeans?

[FrontalLobe]

I'll be interested when my environment can change my jeans... I'm lazy...

Re:Genes or Jeans?

[Alsee]

I'll be interested when my environment can change my jeans... I'm lazy.

Be careful what you ask for. You might wake up and find yourself in a pair of bell-bottoms.

-

Not actually genes are changed

[helm]

I'm wondering if the epigenes that are changed, are passed on to the offspring. The article wasn't really clear on that.

-- helm

Re:Not actually genes are changed

[dannyitc]

I think it would be reasonable to assume the article was referring to DNA in somatic cells, as altered gene expression only has the capacity to change an organism in somatic cells, and thusly, would be the only type that would reasonably respond to envionmental pressures. My (somewhat educated) guess is that the gametes would remain untouched.

This really shouldn't come as a big surprise. Differential gene expression is one of the major unexplored areas of genomics, and we're just beginning to scratch the surface of how organisms as complex as humans can develop with a number of genes comparable to that of a roundworm. Changes in the environment controlling gene expression is something that's well documented in many different organisms.

Re:Not actually genes are changed

[reverseengineer]

For the most part, no. As the article mentions, the events right after fertilization strip off most methylation of genes and then add them back on- basically, assuming the methylation machinery works right, you start with an epigenetic blank slate- which is nice, because otherwise you'd start life with the methylation patterns of an x-year old- however old your parents and their germ cells were at your conception.

It's important to note that one of the critical functions of DNA methylation is to control expression of genes involved in replication and tumor supression. It is thought that one of the reasons cancer becomes more likely as we age is that these methylation patterns are altered- a methyl group falls off of a promoter for a gene that spurs cell division, for instance, and now that gene is causing cells to divide out of control. That of course feeds into what this article mentions, that your enviroment can modify these methylation patterns.

An example of this is the hormone Insulin-Like Growth Factor-II. The gene that codes for IGF-II is "imprinted." The copy you get from your father is unmethylated, and is therefore expressed at the normal rate. The copy from your mother, however, normally has a methylated promoter sequence, and is therefore silenced. However, should something happen to that methylation, be it exposure to mutagens or simply your body screwing up as it copies this silenced gene, then the copy from your mother is turned on. You get a double dose of the growth promoter IGF-II, which makes it more likely cells will enter a phase of uncontrolled growth- cancer.

Re:Not actually genes are changed

[rooBoy]

There is some evidence of epigenetic changes being passed on to offspring in other systems.
This article from nature talks about some work from Emma Whitlaws group that sees heritable variation in coat colour of mice that are genetically identical. http://www.nature.com/ng/journal/v23/n3/full/ng119 9_314.html Subscription required
http://www.mmb.usyd.edu.au/research.php?person=whi telae Lab Webpage

Heritable epigenetic variation is however not Lamarkian, it is Darwinian inheriance. You still need to have variation that is selected, even if it is epigenetic.

For example you still cannot make a striped giraffe by stretching a zebra's neck as no cells from the zebra's neck will end up in the next generation. The cells that make sperm and eggs were all determined before you got your hands around the zebra's neck.

This result (the twins not the zebra) is not at all surprising to people in the genetics field and helps formalize well established concepts of incomplete penetrance of genetic traits and somatic (non reproductive tissue) mutation

The twin study did not look at reproductive tissues, but if the variation in epigenetics holds true there children of younger parents should be more like their parents

Re:Not actually genes are changed

[RhettLivingston]

Probably not exactly by this mechanism, but undoubtedly, there is a means of passing adjustments to environment on to our children. You don't need "science" to see that physical differentiation amongst peoples, differences that had extremely low occurrences before the differentiation, happens to quickly to be due to Darwinian selection. There has to be either a mechanism by which the parent's physical adjustments to extremes in their environment is being passed on or one by which adjustments that the parent does not have are caused in the children in response to the same extremes. In other words, their is an undiscovered adaptation "kit" that is being employed.

It is also becoming more obvious that there is a lot more "nature" learning going on in the brain than we previously thought. Recent experiments in which mathematical algorithms were used to decode information from more than one individual without change in the algorithms hold great potential for answering the question "when I see blue and you see blue, do we really see the same thing". If relatively high level mental faculties can be passed on, and there is some means by which environmentally induced adaptations can be made to the next generation, it would go a long way to explain things like radical differences in average population IQ (actually, more of a reallocation of mental resources towards the things that we revere as "IQ" today) that have been observed over the last 130 or so years.

An area that I think has the most potential (it fits best with what would solve the problem) and has had little exploration is the possibility of these adjustments occurring in the womb as opposed to at fertilization. Obviously, since only two cells are passed on from the parents, eggs and sperm are created after fertilization. There is thus a time, even in the case of eggs, for adjustments to be made to the genome after fertilization.

Note, that this still fits within the Darwinian concepts with only a minor adjustment. The adjustment is simply to include non-random mutations in the equation. This would in fact speed evolution up and increase its effectiveness.

Misleading headline

[Wandering Hoosier]

You've misrepresenting what the article says: Environment alters gene EXPRESSION, not genes. That makes the whole "Lamarckian" inheritance comment irrelevant, too.

Re:Misleading headline

[exp(pi*sqrt(163))]

Not completely irrelevant. Organisms may inherit features of the current state of gene expression from their parents. So even though the genome is unaltered by the environment, some inherited extra-genetic information is modified by the environment.

Re:Misleading headline

[Otter]

A few points:

1) The issue here is methylation and demethylation of DNA sequences, not the submitter's "genetic sequences that activate or suppress other genes".

2) Methylation patterns are heritable through mitosis, so he's not necessarily wrong to say that genes are being "changed".

3) I forget the details of methylation in embryos, but most of it is wiped out between generations. In any case, sperm and egg cells are segregated very early on, so the environment should have minimal effect on changes that get passed along to offspring. The article doesn't address the issue at all.

I applaud the submitter's enthusiasm, as well as his not putting in the usual stupid, inflammatory question at the end. ("Could epigenetics mean the end of Microsoft?") But he could have cut back on the speculation a bit...

Re:Misleading headline

[vandon]

Headline: Slashdot now banned in Kansas and Serbia!
Probably in a few other places too.

Re:Misleading headline

[Otter]

I applaud the submitter's enthusiasm, as well as his not putting in the usual stupid, inflammatory question at the end. ("Could epigenetics mean the end of Microsoft?")

In fact, he comes off even better now that we've gotten "Could this be the start of a Pleistocene park?" a few stories later...

Re:Misleading headline

[forkazoo]

Interesting. A bit like passing on the executable binary intact, but also inheriting the most current config file. What is the extra-genetic information, and what is the process of inheritence?

Re:Misleading headline

[exp(pi*sqrt(163))]

I can't find an article about it online. I read about it in a book a few years ago. Basically there is a frog or lizard that exists in two slightly different forms depending on whether its environment is wet or dry. This state is inherited from the parents but not as part of the genome. It may be something as similar as hormones that are supplied by the parent during development or something like gene inhibitors or promoters attached to the DNA. I'm not sure the mechanism was understood at the time I read about it.

Re:Misleading headline

[Anonymous Coward]

Chris Fromage: "What's funny about being told that the world is millions of years old when in fact it's only a hundred and fifty-seven years old-fact!-and its age does not change?"

Re:Misleading headline

[aminorex]

The ways in which genes are expressed are often determined by other protein and enzymatic structures in the cell. It's more like passing a byte-code file intact, and running it on copies of the same interpreter.
Really, you can't stuff rabbit DNA into a dog and get a dog. Not gonna happen. It takes a dog to make a dog, barring extreme measures, and even then it takes a very specific kind of dog to make a similar specific kind of dog -- and even that often doesn't work.

Watch out for the creeping delusion of arrogant determinism.

Re:Misleading headline

[astar]

I would call Lamarckian a useful shorthand for a class of largely ignored phenomena. For instance, there is a Russian plant, maybe a flax, that if you grow it in poor soil, it has one morphology, and you grow it in good soil, it has another morphology. Except if you grow it in poor soil and plant the seeds in good soil, the children plants has the morphology associated with the poor soil. Kind of cute. This sort of unreasonable result is where good scientific advances come from. And since it is so unreasonable, you have a hard time getting tenure by studying it.

I do not know if there has a been a detailed explanation of that case, but we now know that some organisms have multiple genomes that can be switched among. So the flax? is probably something like that. Not really Lamarckian with that explanation, but with no explanation, it support a Lamarckian view. Similarly, in the original story, if you leave out the subtlies of the explanation, then it supports a Lamarckian view.

Try entertaining the idea that Lamarckianism was legit science at its core, but got taken over by politics and wrecked. Ozone hole anyone?

Matt Ridley's Nature Via Nurture

[Doug Dante]

Matt Ridley's book Nature via Nurture gives many examples where environment and genes affect one another:

For more than 50 years sane voices have called for an end to the debate. Nature versus nurture has been declared everything from dead and finished to futile and wrong - a false dichotomy. Everybody with an ounce of common sense knows that human beings are a product of a transaction between the two.

Re:Matt Ridley's Nature Via Nurture

[PakProtector]

Testify. I hate nothing more (well, maybe a few things more) than this God Damned John Locke 'Tabula Rasa' crap that's so prevalent these days.

If we were all blank slates when we were born then there should be Human Cultures without Love, without War, without Senses of Humor, etc.

You are a unique amalgam of your genes expressing in response to your enviroment. For example, if I have gene groups that code for huge frickin' wisdom teeth, and person B has gene groups that code for normal sized wisdom teeth, person B can still have larger Wisdom teeth than me if I recieve too little Calcium and other nutrients required for tooth development and/or he recieves a great deal above what is required.

Same for mental traits. We are all predisposed to certain emotions: Love, Hate, Anger, Jealosy, etc. However, our cultural conditioning tells us what we do with those emotions, how we direct them. Some people are directed to throw hissy fits when angry. Others are directed to maintain calm and see why exactly they are angry.

It sure does

[Apreche]

If your environment is a radioactive waste dump you can be damn sure it will change your DNA.

My problem with current evolutinary theory...

[narrowhouse]

Has always been the "random but useful" nature it relied on. Maybe it is just a matter of getting my head around the huge numbers involved in the statistical chances of enough random mutations piling up on each other to give an organism stereoscopic color vision. If this discovery turns out to support even a rudimentary "talk back" mechanism that allows the environment to have some say on the number and nature of mutations I think it goes a VERY long way it making Evolutionary Theory a much more elegant idea. I think some people have fewer "religious" objections to evolution and more "it just doesn't seem possible" ones than most scientists would like to admit.

Re:My problem with current evolutinary theory...

[dannyitc]

The environment does have a talk-back mechanism on the nature of mutations. It's called natural selection. Organisms with mutations that make them more fit for their environment will be selected for and the genetic makeup of that population will change.

Re:My problem with current evolutinary theory...

[BlockedThreads]

Evolution Theory already has a talkback mechanism. Its called "natural selection". It provides a powerful feedback mechanism that filters out the non-beneficial genetic variations in a population. The repair and maintainance of the DNA is part of the phenotype and is also subject to evolutionary pressures of course.

Re:My problem with current evolutinary theory...

[orasio]

You just need to learn more statistics.
Just imagine.
10 out of 100000 organisms get a light sensor.
They are better, so they become dominant.
Of the mutant offspring, lots do have a tendency to develop more than one light sensor.
More light sensors are better than one.
Now you have a fly-like eye.
Focusing lenses are easy.
The sensor must be protected by something, because it doesn't work otherwise, and the clearer the better, and those who have better focusing clear flesh covers for their eyes, can sense better their environment, and find better partners.
What you view as a huge advantage, can be broken into lots of incremental advantages that are easily explained by evolution.
Of course, it's almost magical that evolution can happen just by birth and death.
You never stop to think that all the tasks a modern computer can perform are just the result of the arrangement of "nand" gates, but there's no magic, and we understand it, because it's simple enough to be understood.
For evolution, it has the advantage of thousands of millions of years of incremental design.

Re:My problem with current evolutinary theory...

[Mr2cents]

4 billion years, 148,847,000 km of surface area, an astronomical amount of life per m, let that be a start to comprehension.

And don't forget that the genetic code is quite modular, so a single mutation could give you an extra arm, without the need to "re-evolute" the thing. Just to give a silly example. A better , real-life example is an extra nipple, some people have them.

Coincidentally, our fellow mammal species have a large variation in the number of nipples, so maybe it's not so strange that an extra nipple is more common than an extra eye? (Just thinking out loud). Maybe some genes are less protected against mutation than others?

Re:My problem with current evolutinary theory...

[Nasarius]

Yes, that's exactly what I was thinking when I read that post. I think the "problem" here is that the GP doesn't even understand the very basics of evolution.

Re:My problem with current evolutinary theory...

[dannyitc]

In the nipple vs eye debate, the main reason why ectopic nipples are much more common than eyes is the much complex nature of eye development. Having studied eye development a bit in a developmental biology course, there's a huge number of issues regarding tissue competancy, signalling, precursor tissue placement, and gradients of various signalling molecules that have to align perfectly just for an ectopic eye to form. Not to mention the nightmare of trying to guide an optic nerve with developmental cues from the eye in its ectopic spot to attach to the part of the brain where the eye would actually function so it could be selected for or against.

Also, genes more closely related to the fitness of an organism are more "protected" against mutation, in the sense that if changing the gene in question would severely limit an organism's fitness (or even viability as an embryo), you will see very little change in that gene over time. For example, the genes that code for the histone proteins (necessary for packing DNA in every eukaryotic cell) have remained identical throughout millions of years of evolution.

Re:My problem with current evolutinary theory...

[Bowling Moses]

"I think some people have fewer "religious" objections to evolution and more "it just doesn't seem possible" ones than most scientists would like to admit."

First, neither religiously motived reasons nor arguments from personal incredulity are valid arguments for the rejection of sound science. Second, spend some time online reading what people who reject evolutionary biology write. It's been a hobby of mine for quite a few years now, and in my experience the overwhelming majority reject evolution because of literalistic interpretations of the Bible. Third, this really isn't earthshattering news. At the University of Oregon we've got a professor working on DNA methylation for about the last 25 years or so--DNA methylation being part of the epigenetics mentioned in the article. It's long been known that the environment can alter DNA by methylating nucleotides which can alter gene expression, and that these methylation events can be inheritable. This is a minor addition on the IMHO already elegant theory of evolution--for a quickie look check out wikipedia's page on epigenetic inheritance.

Re:My problem with current evolutinary theory...

[narrowhouse]

I "understand" the statistical models, but once you go from 10 in 100000 to 1 in 40,000,000,000 over a time period of 78,000,000 years, concurrent with a hundreds or thousands of other useful features (teeth, claws, scales, a sense of smell, orgasm, varios appendages, flame-throwing ducts, etc.) it all gets a bit more complex. When you add in the stastics for all of the parts as a whole you are talking about STAGGERING numbers.

And for all the "natural selection" comments thanks for pointing out the obvious hole in my comment. I have actually read a paragraph or two about evolution. Over the years the theory of evolution has changed quite a bit, when I was in school in the 80's the idea of slow and steady progression was dominant, but then there started to be talk of periods of sudden environmental "pressure" causing changes in (relatively) short periods of time. This new theory was thought to account for the lack of transitional stages in the fossil records. The problem with that theory was that conventional wisdom had said that there was no environmental factor in evolution EXCEPT natural selection. If that was indeed true then the fossil record should have shown the transitions much more clearly as nature tried and failed multiple combinations. Attempting to find OTHER ways that the environment might effect the nature and number of the changes was really the point of my comment.

Re:My problem with current evolutinary theory...

[narrowhouse]

I didn't say they were valid arguments. When I said "my problem", I fully acknowledged it was MY problem with evolution, not a grand theory refuting it. I think that many scientists would prefer to think that the reason some people don't accept evolution is religion. I have read what people have written about elvolution though clearly not as much as you. While agree that the majority do harp on the creationist view, I think there are some who have some concerns about the theory itself. How valid those concerns are obiously varies but I am sure the work of past critics has been used to improve our current understanding. As I have said in a previous post the theory of evolution has itself evolved extensively over time (Unless you think Darwin hit it on the nose with the first swing). Your professor's research is 25 years old at most, so it will take a few more years for its implications to to sink into the general populace's understanding of evolution. Your not-so-humble-opinion seems to be based in years of studying the subject, maybe you can see how those of us who have not devoted the same amount of time to the subject have a slightly fuzzier view.

Re:My problem with current evolutinary theory...

[Anonymous Coward]

> I think the "problem" here is that the GP doesn't even understand the very basics of evolution.

I don't see it that way. There are two problems with natural selection as the *only* model of evolutionary pruning. The first is, an animal can have the intelligence of a supercomputer, the eyes of a hawk, the speed of a bullet train... and still get hit by lightning. Or catch a cold. Etc. There are still statistical probabilities beyond just which animal is "better" in the genetic sense. Taking that into account, the probability of the right mutations occuring all in one genetic line to create color stereoscopic vision is astronomical. First you need eyes, then you need two eyes, then you need to sense colors, then you need the processing power in the brain, etc. Add to that avoiding predators, natural calamities, illness/cancer/misc. and it is really really unlikely. If you can add in a Lamark style change that can occur AFTER CONCEPTION and might even occur in more than one genetic line, then the probabilities are much easier to swallow.

Re:My problem with current evolutinary theory...

[TuringTest]

First, evolutionary pruning works on the whole population. The death of a single individual is not very important, since many others share the same genetic material.

Second, natural selection doesn't work only at the mutation level: sexual reproduction introduces big variance in each generation.

Third, those changes do not occur "in a line" or secuentially, they randomly accumulate without a purpose. There are not "right" mutations, there are mutations that remain and those that disappear.

Fourth, having the changes at conception or during the life of the individual does not change at all the probabilities of survival of a species, what matters is if those changes are transmitted to the children. Predators, natural calamities & illness are the things that make HIGHLY likely that species as a whole adapt to the environment or are eliminated, since only those adapted will transmit their genes.

Re:My problem with current evolutinary theory...

[TuringTest]

1 in 40,000,000,000 is all that is needed, since that special 1 is who will survive and replace the other 40,000,000,000. Useful features develop in paralel, and there weren't many before sexual reproduction (the history of life is mainly that of single cell bacteria for a long, long time).

Also natural selection does not explain evolution. Natural selection + variation does. Natural selection can't change a species if all the individual to select from are identical.

The fossil record has plenty of holes in it and can't explain ALL changes, but what remains does show enough clear transitions and failed combinations to support that theory.

Re:My problem with current evolutinary theory...

[dtungsten]

I think you're right. Many people may be reluctant to challenge evolutionary ideas for fear of being labeled a religious fanatic or otherwise ridiculed.

While I believe that evolution is the best explanation given on the origin of species. I think there are major problems in the way that it is presented, if not the theory itself.

For example, people often say that animal's feature x was designed for such-and-such. Well, no it wasn't, if it was evolved.

Or people will say that thus and such happened, so animal evolved feature x, as if the animal consciously changed. No, what happened was that some random thing happened causing a feature (that was passable on to future generations) that had a slight or significant advantage.

Now, I'm a pretty smart person and I realize that billions of years is a very long time. So long that we humans (for the most part) cannot even readily comprehend it.

But still, I just don't see it happening the way current theory states. How is such a change passed on to new generations? The random change would have to take place in a sex cell, or maybe in the womb in a developing fetus. ok then this trait would have to become expressed (so no passive genes, unless you somehow get two) and this trait would have to have a significant enough survival advantage to eventually (over several generations) make a new species.

I'd like some information based on empirically collected data stating how long this takes, for example "it would take this long for one (or a set of) such change to occur in species x"

Something other than "well it's a real long time, so almost anything could have happened." That's no better an explanation than "God did it."

We actually know (or should know) how long (approximately) it took for some of these changes to occur, based on the fossil record (which I understand is not complete and why it is not complete).

I've never seen any such explanation on any science program or in any textbook. Why? Do scientist think laypeople are just too dumb to get it? I'm a nerdy guy, why haven't I read, seen, heard or gotten wind of *anything* like this?

Can't we at least pull *one* example and say this is probably how species x turned into species y?

Am I asking too much or am I thinking about it the wrong way?

Re:My problem with current evolutinary theory...

[Peeteriz]

If you are talking about a timescale that includes millions of generations (think how fast insect generations can change, within a few days for some of them) and population counts in uncountable billions (again, think about insects) then yes, a 1 in 1,000,000,000 mutation that grants a 0.01% larger chance to reproduce - such a mutation will get 'accepted' by 99% of the population within a few hundred years - an insignificantly small time, compared to the timescale of the evolution.

Do some simulations to try out the numbers, if you don't believe it, any coder can do it over a course of one evening.

Regarding the 'sudden changes' - these are the ones that drive the evolution. If the local circumstances change unfavourably, killing 99% of the population - then the 1% that survive will likely be genetically different, and they will form a new population. Any local 'mishaps' (scarcity of food, large fire, flood, drying of the only lake, etc) will accelerate evolution greatly in that small population, and that partly isolated, genetically different population will then diverge from the previous species.

Re:My problem with current evolutinary theory...

[lotus_out_law]

Then why do we not have three eyes ?
Two in front and one (atleast a rudimentary one) on the back.
This would have saved many a deer from being ambushed from behind ...

Also to have a very rudimentary eye behind the head doesnt look like it consumens too much energy for it to be a huge disadvantage during droughts
kR/\/

Re:My problem with current evolutinary theory...

[Alsee]

There's another far more powerful effect going on in evolution that people rarely hear about in the common explanations of evolution. The common explanation of evolution is as a sequence of individual beneficial mutations, like climbing a ladder. If that's how it worked then critics would be right, evolution would not have been able to produce the incredible variation and complexity we see today. That kind of advancement is about the least powerful mechanism in evolution.

In fact I'll even assume that every single mutation that occurs is either neutral or harmful and we'll still get the real and powerful mechanism of evolution. I'll give a relatively brief and superficial explanation, but it's a huge topic and this is still going to be fairly long.

A good place to start is with the common complaint of creationists that mutation and evolution "cannot create information". Well in the initial mutation phase they are right. When a mutation occurs it introduces noise, it tends to degrade information. But look what happens the moment that mutation gets passed on to an offspring. That mutation is now no longer random noise, it now carries a small bit on information. It carries a little tag saying "this is a nonfatal mutation". The presence of this mutation in the offspring is new created information, the discovery living record of a new nonfatal mutation. Over time the population builds up a LIBRARY of nonfatal mutations. This library is a vast accumulation of new information.

That information actually undergoes even more processing and synthesis. Over generations beneficial mutations would obviously multiply, but we're assuming there are none of those here. However entirely neutral mutations will also tend to accumulate and multiply. Nearly harmless mutations would also accumulate and multiply to a lesser extent. Somewhat harmful mutations will even accumulate, and extremely harmful-but-nonfatal mutations will pop up and disappear at the rarest frequencies. So not only do we build up a library of nonfatal mutations, the mutations get tagged with a tagged with a frequency, the percentage of the population carrying that mutation. Each mutation is tagged with a measurement. Every mutation now carries a cost/benefit information tag at the population level. The best ones have a high percentage representation and the most harmful ones have a near zero representation percentage. Our library now contains far more valuable and sophisticated newly created information.

The individuals in the population are on average going to carry a roughly stable load of harmful mutations, a roughly constant "cost" in harmful mutations. Individuals loaded with more than the average cost are generally going to die and remove a more-than-average load of harm out of the population pushing the average up, and individuals with a less than average load will multiply and pull the population average upwards. The cleansing effect of selection removing "damage" from the gene pool will automatically scale to offset the exact rate that mutation is causing "damage". Harm/cost/damage will be weeded out by selection at the same rate it is added by mutation. Neutral mutations will steadily accumulate in the library, and negative mutations will remain at a roughly fixed level constantly measured and scaled by the cost of each. Some mutations will dissappear while new ones appear.

The real power in evolution is the recombination. Every offspring contains a random mixture of mutations from that library. every offspring is a test case searching for a jackpot beneficial combination of mutations. Lets assume an individual has a million random mutations across its entire code. There are 500,000,000,000 mutation-pairs being simultaneously tested within that individual in parallel. Perhaps one is a mutation creating a toxin and another mutation for mutant skin pores. Either mutation alone may be harmful, but the pairing could be breakthrough protecting against predators.

Re:My problem with current evolutinary theory...

[orasio]

Animals that are often prey can see almost 180 degrees around, because their eyes are almost opposite from each other.

Those who aren't, can use them better on the front.

Re:My problem with current evolutinary theory...

[JAHA]

It's even better than that really because a light sensor is pretty complicated. But the structures in a light sensor can be useful in many other areas. So they can evolve independently without the light sensor coming to spontaneously exist. Then one day these components evolve to come together and wammo...you have a light sensor. This is one of the main places that Intelligent Design people get it wrong. They say the eye is too complex to have evolved from randomness...but that is predicated on the belief that the structures that make up the eye aren't useful to other biological processes...which is wrong.

Re:My problem with current evolutinary theory...

[Anonymous Coward]

> Can't we at least pull *one* example and say this is probably how species x turned into species y?

This isn't full species differentiation, but I think may be an illustrative example:

When humans all lived in Africa, it's a pretty good bet that they were all dark-skinned, because dark-skin is better able to withstand the effects of the intense sunlight near the Equator. (There is also a theory that dark-skin genes also code for sickle-cell anemia, which renders a person more resistant to Malaria.) Then some people migrated out of Africa into the rest of the world. For those that migrated North, dark skin wasn't a great advantage any more, so when some mutations that occurred that produced lighter skin, those people survived, whereas in Africa they might have died before reproducing. Eventually, more and more light-skin mutations propogated throughout the population, until everyone had light pink (so-called "white") skin. Now, some of these people migrated back toward the equator (e.g., India, Southeast Asia, Australia, etc.), and the dark-skinned mutations became more beneficial again, so their skin turned darker again.

Another, more recent example is vision defects. Near-sightedness (Myopia) was a severe disadvantage before the invention of corrective lenses (and far-sightedness only slightly less so), so people with vision defects tended to die and not pass on their defective vision genes to the next generation. After the invention of corrective lenses, these people had a better chance of survival. As a result, a higher percentage of the population has defective vision today than, say, at around the time of the Roman Empire. However, in non-industrialized areas, where corrective lenses are not (and have not been) available, the percentage of people with defective vision is probably no greater than it was 2000 years ago.

These are both examples of divergent evolution in action: in the first case, geographic; in the second, indistrial level.

I saw that as

[FLAGGR]

Your enviroment may change your jeans.

I'm glad I just write software

[museumpeace]

I'd hate to be a biologist just now finding out Lysenko might have been on to something.

Re:I'm glad I just write software

[Kesha]

I wasn't sure who Lysenko was, so I did a search on google and this turned up:
http://www.comms.dcu.ie/sheehanh/lysenko.htm

It's a very interesting article.

Paul.

Re:I'm glad I just write software

[Anonymous Coward]

and given how much you know about expression vs inheritance, we are /all/ glad you don't do biology.

Field day

[centauri]

Man, are the Creationists going to have a field day with this, whether or not they've take the time to try to understand it.

Re:Field day

[museumpeace]

Its odd the NYT article doesn't mention Lysenko whose promotion in stalinist russia [ok, here it comes: in soviet russia the traits determine your genes. satisfied?] was, amongst other things, a refutation of darwinian evolution, which did not fit comfortably in to Salin's idea of how the state should be able to make a new, improved kind of human being.
I think the lesson is that

1. you don't want to get on the wrong side of a government that has its own ideas about biology (are you listenin' Dubya?) and
2. ANYTHING that touches your ability to reproduce yourself (reputed to be a natural and extremely strong urge, though I myself am just a nerd so ;) is dangerous turf that religions have all staked out.

Re:Field day

[Anonymous Coward]

ANYTHING that touches your ability to reproduce yourself... is dangerous.....

NOBODY touches my ability to reproduce myself except me and my mate.

Re:Field day

[Anonymous Coward]

Wow, look, no flame war! Disappointed yet? How about now? Now? Awww, nobody took your bait.

Not convinced

[bubblewrapgrl]

It seems to me that what the article is talking about is expression of genes in normal cells. (Note, I didn't read the article because of the whole subscription thing, although I have heard some discussion of this.) Personally, I was always taught that an individual's genes could change via mutation. Mutations in the genes that regulate cell cycles, for example, can cause cancer.

Inheritance is a separate issue, though. The genes for your children are controlled by the genes in eggs or sperm. These are separate from the genes that are expressed in your cells on a day to day basis. In order for inheritance to be changed, the environment has to act on those cells.

From what I've heard, I don't know that this will change much in terms of the return of Lamarckian inheritance. I'm definitely interested to hear others thoughts on the subject.

EVERYTHING is epigenetic

[Anonymous Coward]

Those cold, dead DNA strands that have been sequenced are far removed from the living runtimes that exists in vivo. The sexual process creates DNA and demethylates it to be combined with the egg DNA. The DNA is then remethylated. This is where the imprinting occurs to determine whether mother or father genes will be expressed. The methylation is responsible for differentiating the cells to go from embryo to adult and is the primary difference between a real, live embryo and the man-made ones used in cloning. None of this action is in the actual genome we have sequenced. We know nothing and have so much to learn. I bet DNA methylation turns out to be one of many mechanisms used to control the runtime genetic environment. And one more of the things we will have to understand. I to think some were thinking that understanding the DNA sequence was going to turn out to be some biological endgame, but it turns out to be just the beginning of understanding.

Well of course it does!

[BigZaphod]

If there's a lot of dirt or grime around and I get dirty I have to change my jeans. You can't expect the environment to just stay off of them, after all - especially if you have to kneel down in it.

Oh.. wait..

Yes I know..

[Mr2cents]

It should be km^2 and m^2, I used the special square char but /. stripped it out..

No need to panic, you can safely continue your life.

Hmm..

[Neeze]

I guess I should start spending more time at fashion shows...

Pleistocene park!

[Anonymous Coward]

It's Jurassic Park with tits!

Genes altered by the environment

[TheUnknownCoder]

Genes altered by the environment:

Gene Hackman: Jailed as a teen in 1946 for stealing candy & soda pop from a convenience store now lives a wealthy life in New Mexico.
What's causing the mutation: With more than 70 movies to date, strong light sources constantly shining on his forehead can be traced as the culprit.

Demitria Gene , a.k.a. Demi Moore: From spending her minimum-wage hard-earned money with coke to earning $12,500,000 per movie and dating a kid who could be her grandson.
What's causing the mutation: Not really sure... Could be frequent exposures of her bare body to the cameras or the many plastic surgeries she had done.

Re:statistics

[vertinox]

The way I deal with it, is to believe there is infinite amount of time in universe and multi-verse (ie there is a probability that other universes will exist even though this one may end through Heat Death or the Big Crunch).

Therefore, there is infinite time for anything to happen. You exist don't you? Or at least think you are self aware? Now what is the probability of that happening? Very very extremely low... Not only did you not have to not die today, but you had to survive up until this point and before that your parents had to meet and you be born and their parents had survive to me and bear them. Not only survive but actually meet.

When you throw in the fact that we haven't been hit with a meteor or blew our selves up or just gotten sucked up in a neutron star passing in a span of 4 billion years, I'd say the figures of your probability statistics of existing are very very very low.

But you exist? Right?

So with that in mind, anything that relies on extreme amounts of time can be possible (or at least theoretical). I mean given enough time it's possible that all matter in the universe will cease to exist.

Basically, life and evolution is just the universe trying to try all possible combinations. Since it has unlimited or at least a very large scale of time at it's disposal, it can eventually create a working combination that leads to intelligent life or at least beings that are aware of themselves to ask these kind of questions about where did they come from?

kinda like Horizontal transfer

[lazy genes]

I think the genome is too complex for any god to have created it.For any creature to live beyond its reproductive years is proof that something is missing .For life to combat an always changing climate on less than 40000 genes is a joke.I think the other 95% of the genome must play a very important role.I am not convinced that a god is needed to explain the missing details.

Misleading... the genes are still the same

[Biologist]

The genome (the actual sequence of A, T, G, and C that make up the genes) is still still the same (for the most part, see below). The notion that changes in chromatin structure (the way that DNA is wound up in higher order structures) or that MODIFICATIONS of the ATGC's take place (the fundamental base sequence is still the same) is not surprising, nor is it new. And, of course, these changes may have an effect on how the genes are read out (i.e. the resulting phenotype/appearance of the organism is going to differ because of the physical or chemical alterations of basic DNA sequences). I'm sorry, but Lamarck was still wrong (the giraffe's neck didn't get longer because his father stretched to eat the leaves and then passed this trait on to his offspring; his neck got longer because over generations his ancestors RANDOMLY had a mutation which resulted in a longer neck and this made him eat better and have more energy to get it on and pass on his genes...). Yes, there is more fluidity in the genome than is generally recognized among the lay-folk (T and B cells in the immune system rearrange parts of genes and mutate the actual base sequence of certain genes extensively in order to generate a large variety of receptors to recognize bacteria, viruses, etc.; transposons jump around; mutations occur in the DNA sequence of somatic/non-sperm-non egg cells and lead to cancer; some mutations occur in and are passed through the germ/sperm-egg cells and we get evolution). As far as this whole twins thing: people are a product of the interaction between their genes and their environment. So, one twin lives the rock star life-style and ends up with wrinkles and cirrhosis at age 45; the other one lives the life of a monk and looks 10 years younger. Now, with molecular biology, we can also see a MOLECULAR effect of these differences in life style (the rocker twin also has some different modifications of his DNA).

Lamarckian Inheritance

[Anonymous Coward]

Is it just me, or does sound like a bunch of lamarky to you too?

Re:My problem with intelligent design...

[Lars T.]

If life is too complex to have developed on its own, where the hell did the all-powerfull and totaly incomprehensible being come from that created it all with a snap of his finger?

Lamarck was right!

[Maximum Prophet]

More and more we're finding out that evolution is driven by Darwinian and Lamarckian influences.
If he hadn't faked the frog experiments, his theories might have been studied more. There are examples of Bacteria exchanging DNA in response to environmental factors. If your mother was a crackhead, guess what, you're born addicted to crack. There are drugs that affect you if your *grandmother* took them.

- Mike

Re:Lamarck was right!

[billy reuben]

There are drugs that affect you if your *grandmother* took them.

And then there are drugs that could affect you if any ancestor took them: mutagens.

Re:Lamarck was right!

[Maximum Prophet]

Right, but mutagens are Darwinian in that they don't necessarily produce the same change in the parent as the child. Background radiation works this way too.

Designer Epigenes

[Doc Ruby]

In mice, recent discoveries indicate that methylation of embryonic epigenomes can be controlled by diet. Feeding pregnant mice one, rather than another, diet caused offspring to be yellow, or not, as determined by methylation. In rats, methylation was partly "blank" at birth, and "set" by a parent's incessant licking the newborn. Even if the parent was adoptive, they reproduced their methylation in the adopted offspring.

So even in relatively closely related species, there are big differences in epigenetic transmission. I'd love to see comprehensive research in how environmental factors like diet can control epigenetic traits. For example, I'd like my children to be tall, but I'm not tall enough to usually attract especially tall women. If the pregnant mother of my children could eat "tall food", we could have tall children. Who could choose a different, shorter diet, if they disagreed with that decision their father made investing the family jewels.

YO! Eds! toss this in the metamodding queue

[museumpeace]

how the hell was my little post off topic?..lysenko was, for all the wrong reasons of course, one of the first biologists to claim genetics alone did not determine, at birth, all that an organism would be and do. That /is/ the topic of TFA!