You're far more than your genes

Herding Hemingway's Cats: Understanding how our genes work by Kat Arney
My rating: 5 of 5 stars

Throw out what you thought you knew about genes, DNA, etc.

Several great things here.

First, the book explains in good detail things I've already known about how genes can code for proteins for various things, whether in combination with one, two or ten or more other genes.

Second, it explains in good detail what I've known about non-gene "control switch" areas of DNA, including how they usually act more like dimmer switches than on/off straight up/down switches.

Third, it revealed a lot I didn't know.

First, the DNA near the center of the nucleus is generally more "active." Arney talks about this, the relation to histones in positioning segments of DNA and more.

Second, coding areas on DNA evolve much more rapidly than genes themselves and are usually the primary driver of evolutionary change.

Third, epigenetics, while not all wet, probably needs more skepticism than it's gotten at times. She gives some detailed insight into this, and the exceptions to it.

Fourth, after splashing cold water on epigenetics, she brings to a boil something I wasn't aware of — micro-RNA. Apparently this has at least as much effect on inheritance as the biggest touters of epigenetics have claimed for it in the past. For example, sperm cells appear to have micro-RNA, and are NOT, therefore, just a load of DNA and that's it.

Also note that there are multiple different types of micro-RNA.

Fifth, although these discoveries aren't quite "Lamarckianism," nonetheless (and she barely touches on prions, speaking of) they put "genes" in a whole new context.

In short, the Human Genome Project and similar likely won't be in that much better position to tell us that much more about "you" and "me" twenty years from now than it is today.


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Lewontin crushes Dawkins, Sagan, and reminds us of problems with #scientism

Very, very interesting. Just over halfway through this in-depth, and somewhat crushing, review of Sagan's "Demon Haunted World," Richard Lewontin notes that something like ... well, like epigenetics was on the empirical eyeballs of biologists back in the 1930s. But, because the observations didn't fit the empirical framework, into File 13 they went!

Here's the relevant point:

In the 1930s well-established and respectable geneticists described "dauer-modifications," environmentally induced changes in organisms that were passed on to offspring and only slowly disappeared in succeeding generations. As the science of genetics hardened, with its definitive rejection of any possibility of the inheritance of acquired characteristics, observations of dauer-modifications were sent to the scrapheap where they still lie, jumbled together with other decommissioned facts.

And, here's the important preceding background:

 Second, it is repeatedly said that science is intolerant of theories without data and assertions without adequate evidence. But no serious student of epistemology any longer takes the naive view of science as a process of Baconian induction from theoretically unorganized observations. There can be no observations without an immense apparatus of preexisting theory. Before sense experiences become "observations" we need a theoretical question, and what counts as a relevant observation depends upon a theoretical frame into which it is to be placed. Repeatable observations that do not fit into an existing frame have a way of disappearing from view, and the experiments that produced them are not revisited.

A reminder that #scientism can work by the via negativa as well as the via positiva, if nothing else. The via positiva is the highly expansive claim of what all falls in the purview of science. The via negativa is just what theorizing is allowed within that expansive purview.

Sure, it's easy to say science covers everything, if you cut everything to a scientism-Procrustean bed.

Beyond that, though, the epigenetics angle shows that, even short of a full-grade scientism, the methodology of science, in actual practice, will always remain no more than human.

Are conserv-lib diffs genetically rooted? Not as much as Mooney implies

Chris Mooney/Wikipedia

Chris Mooney, he of "motivated reasoning" discussion, reviews here two books that discuss this issue. They are "Predisposed: Liberals, Conservatives, and the Biology of Political Differences," by John Hibbing et al, and "Our Political Nature: The Evolutionary Origins of What Divides Us," by Avi Tuschman.

The biggest caveat? Mooney never claims that evolution does select for political differences, but let's make that clear, because he wants to have his cake and eat it on this issue in general, specifically concerning political conservativism. The titles of the two books should indicate that.

So, again, let's be clear.

Evolution does not "select" for political differences. Psychological differences that are part of political differences, like anxiety/neuroticism, openness to experience, etc., may well be selected for, but political experience is not. That's just like religious belief is not "selected for," but rather, things like pattern recognition and agency imputation, which likely are selected for, become part of an overarching system that develops into religious belief. Mooney does halfway acknowledge this, as I note below, but, it's cursory, and probably not even halfway.

And, in terms of sexual reproduction, evolution certainly selects for many things, not just five personality issues.

Let's start right here with what's wrong:

Again and again, when they take the widely accepted Big Five personality traits test, liberals tend to score higher on one of the five major dimensions—openness: the desire to explore, to try new things, to meet new people—and conservatives score higher on conscientiousness: the desire for order, structure, and stability. Research samples in many countries, not just the U.S., show as much. And this finding is highly consequential, because as both Hibbing et al. and Tuschman note, people tend to mate and have offspring with those who are similar to them on the openness measure—and therefore, with those who share their deeply rooted political outlook. It’s a process called “assortative mating,” and it will almost certainly exacerbate our current political divide.  

First, men and women pair up for many reasons other than political inclinations. That includes perceived health by facial and bodily similarity, fat deposits in certain parts of the body (ahem), perceived ability to be a provider and much more. Note that those items I all spelled out are all purely physiological. No psychology involved.

So, once again, per the eponymously named (by me) intellectual shortcut, Mooney appears to be "pulling a Mooney."

If political inclinations were a primary driver of human mating, we'd see a lot more division than we currently do.

This is more nuanced than some of Mooney's writing on this issue, but not fantastic.

So, on to more counterpoints.

First and foremost?

What's heritable is a tendency, nothing more. And, while 40 percent (if correct, and that number is nothing more than a guesstimate) is significant, it's still less than half of 100 percent. There are a number of traits we know of, that a genetic tendency toward which has a 40-percent basis. And, I'm sure that 40 percent is high. If we take the five-type personality profile, as an example, and insist that the composite of all five types has a 40 percent heritability factor, each individual factor would have to be more than 80 percent heritable, if we're using the basic "and" conjunctiveness. (Do the math yourself.) Even if we allow for some looseness of overlap, and not a strict "and," still, for all five types to be 40 percent heritable as a chunk, the individual ones would still have to be at least 65 percent heritable, and NO human trait is that heritable.

Even if I re-read Mooney's reading of Hibbing to claim that each factor individually is 40 percent heritable, I'm still skeptical. Read the next few paragraphs for details.

Related to that is the fact that the five-type test, while perhaps better than the MMPI, is not the be-all and end-all of psychological research on personality types.

Related to that? None of the studies in either of the books Mooney reviews appear to make any allowance for epigenetics. None. In the case of neuroticism, a large part of which is anxiety-related, we know from lab animal experiments that there's an epigenetic, as well as a genetic, component to heritability of anxiety.

Indeed, that's an issue with twin studies, which are supposed to be the gold standard. Identical twins (setting aside chimera issues) not only share the same genes, but, vis-a-vis even fraternal twins, depending on the date of twin division of the original single egg, identicals may share a more similar womb environment, if it includes a single placenta or single amniotic sac. (Identicals, depending on date of division, may have separate amniotic sacs and placentas, one sac but separate placentas, or share both.)

Related to that? Even on the genetic side, we're still in the Neolithic, or at best, the Early Bronze, on pairing specific sets of genes (no single-gene claims for personality factors need apply) to heritability of personality factors.

This is a big failure of proponents of personality testing in general. It's another reason why, while I say that the five-type personality spectrum is better than the MMPI, it's not the be-all and end-all. It's probably not that on how it divides personality and what it considers as the most important aspects of personality. It's certainly not that on its explanation of how these differences arise. Wikipedia's article on the Big Five, while not exhaustive, is a good starting point. It notes, outside the "criticisms" section, that the five factors appear to not be total cultural universals, despite implications otherwise on Mooney's story.

Mooney does caveat the evolutionary angle, to be sure:

Moreover, in evolution, some things happen for an explicitly Darwinian “reason”—traits become more prevalent or fixed in populations because they advanced organisms’ chances of survival and reproduction in a particular environment—while others happen more accidentally. Some complex social traits may emerge, for instance, because they are a fortuitous by-product of other, more fundamental traits laid down by Darwinian evolution.  

He notes religion as a good "spandrel" example.

However, Hibbing then claims conservativism is probably the "default." Why? Because Hobbes, and life is "nasty, brutish and short."

It was 5000 BCE, after the invention of agriculture, to be sure. But, not to read too much into "The Gods Must Be Crazy," maybe it was NOT so in, say, 25,000 BCE. That's a failure of Hibbing more than Mooney, but it's also a failure of Mooney for not making this observation himself.

He then goes on to Tuschman's book. Problems are to be found here, some of which Mooney notes. The biggest is that Tuschman may be advocating group selection as a partial explainer. As an educated layperson, I'm not dead against the idea, and think some evolutionary biologists who are, are likely wrong. But, it's still controversial. But, Mooney notes it's not clear that he does advocate this.

Mooney does say:

In the end, Tuschman’s book attempts a feat that those of us monitoring the emerging science of politics have long been waiting for—explaining the now well-documented psychological, biological, and genetic differences between liberals and conservatives with reference to human evolution and the differential strategies of mate choice and resource allocation that have been forced on us by the pressures of surviving and reproducing on a quite dangerous planet. It may or may not stand the test of time, but it certainly forces the issue.

That said, Mooney seems to want this to "force the issue." I've documented that above well enough, I think. It's part of his history.

Beyond that, "liberal" and "conservative" in the US exclude libertarians. Arguably, Mooney's reasoning does in other countries as well. Germany's Free Democrats, and possibly Britain's Liberal Democrats, would reject being put in either half of Mooney's dichotomy. 

And, that's not all. On to a few other points, with briefer discussion.

Another part of his history is to want to wrong-foot conservatives on this issue. Specifically on some subpoints, like this:

Being defensive, risk aversive, hierarchical, and tribal makes sense when the threats around you are very real and immediate.

So, our second point? Liberals are arguably just as tribal as conservatives. The "social justice warrior" movement, especially as illustrated by a group like Atheism Plusers, is Example No. 1 of this, with phrases like "mansplaining" and online actions like the Twitter add-on of the Block Bot, all while blaming only "the other," often very broadly defined, for the problems and actions involved. Since Mooney has recently moved the online location of the Point of Inquiry podcast because of said tribalism, he knows this full well. He refuses to discuss or admit this, but it's true. Indeed, what I call his "wrong-footing" is itself a tribal action.

In their book "Blindspot: Hidden Biases of Good People," authors Mahzarin Banaji and Tony Greenwald show, with social-psychology research, how self-professed liberals can exhibit, unconsciously, "tribal" behavior toward people of other racial groups, the opposite sex, the elderly and people of different sexual orientation.

Related to that? Again,the Big Five factors don't totally translate within the developed world. Even less do "conservative" and "liberal. In the non-WEIRD portions of our world, say, a New Guinean tribal chief, he'd scratch his head over this discussion.

Third? "Conservative" and "liberal" aren't "conservative" and "liberal."

Let's get back to this quote:

Being defensive, risk aversive, hierarchical, and tribal makes sense when the threats around you are very real and immediate.

Behavioral psychologists like Daniel Kahnemann and Amos Tversky have shown that we're ALL risk-aversive in many ways, like fearing a small financial loss more than salivating over a possible big gain.

Mooney knows this, too, I'm sure, even if he doesn't want to tie it in with his discussions.

Fourth? As I've indicated above, and on previous posts about Mooney, and occasionally about personality psychology in general, the Big Five is NOT the be-all and end-all of personal psychology study. I'm afraid that a number of people, including Mooney, obviously, are making it into a new MMPI, though. In reality, approaching vs. avoiding temperaments, people driven by intrinsic vs. extrinsic motivation (which partially overlaps Jung's old introvert and extravert) and other takes on personality reveal things the Big Five doesn't.

And fifth? Along the lines of David Hume, is does not equal ought. People do change political and social allegiances, just like religious affiliation.

In short, while it's not quite Pop Ev Psych, it's in the neighborhood. And, while it's not the worst example of scientism I've seen, it is an example.

On personality profiles and related areas of psychology, Mooney either doesn't know that much about all the science issues that are at stake, or else he's cherry-picking. I'm sure the latter is part of it, based on his previous writing on political differences. But, I don't think that's all of it.

He's good on things like climate change, but on psychology in general and personality psychology in particular, I think there are some understanding deficits, too.

And, the more he writes on this, the worse he gets. I've written a lot about him on this issue; click the "pulling a Chris Mooney" tag (not totally about him, but primarily so) for more. There's no other way to put it, other than to say that "worse" is, in my opinion, a tribalism-based "worse."

DNA not for genes only

Epigenetics has been in the news more and more recently, with new claims that a propensity to suffer from anxiety, even anxiety over exposure to a specific smell, can be passed on from generation to generation, at least in mice.

Then came David Dobbs' new article about gene plasticity and expression, which starts with this:

At the front of the room, a bug-obsessed neuroscientist named Steve Rogers was describing these two creatures — one elegant, modest, and well-mannered, the other a soccer hooligan.

The grasshopper, he noted, sports long legs and wings, walks low and slow, and dines discreetly in solitude. The locust scurries hurriedly and hoggishly on short, crooked legs and joins hungrily with others to form swarms that darken the sky and descend to chew the farmer’s fields bare.

Related, yes, just as grasshoppers and crickets are. But even someone as insect-ignorant as I could see that the hopper and the locust were radically different animals — different species, doubtless, possibly different genera. So I was quite amazed when Rogers told us that grasshopper and locust are in fact the same species, even the same animal, and that, as Jekyll is Hyde, one can morph into the other at alarmingly short notice.

Dobbs goes on to note that two animals with the same DNA can express it in radically different ways, and goes further, with these rhetorical questions:

This raises a question: if merely reading a genome differently can change organisms so wildly, why bother rewriting the genome to evolve? How vital, really, are actual changes in the genetic code? Do we always need DNA changes to adapt to new environments? Are there other ways to get the job done? Is the importance of the gene as the driver of evolution being overplayed?

He doesn't reject the importance of genes, but suggests, as I understand, their "centrality" should be reduced from 98 percent to, say, 78 percent, on average. But, I'm giving a brief summary of a long article.

Some old-line geneticists poo-pooh reading too much into epigenetics, or even Dobbs' article. That would be you, Jerry Coyne.

P.Z. Myers is a cautious one on epigenetics, though not as tight as Coyne. And, while admitting he's in the minority of a selective sampling of his peers, he sees nothing wrong with Dobbs' piece:

I am saying that understanding genes is fundamental, important, and productive, but it is not sufficient to explain evolution, development, or cell biology. ...

I will also rudely tell you that we don’t understand the process (of gene expression) yet. Knowing the genes is not enough.

It’s as if we’re looking at a single point on a hologram and describing it in detail, and making guesses about its contribution to the whole, but failing to signify the importance of the diffraction patterns at every point in the image to our perception of the whole. And further, we wave off any criticism that demands a more holistic perspective by saying that those other points? They’re just like the point I’m studying. Once I understand this one, we’ll know what’s going on with the others. ...

We forget that our theories are purely human constructs designed to help us simplify and make sense of a complex universe, and most seriously we fail to see how our theories shape our interpretation of the data…and they shape what data we look for! That’s my objection to the model of evolution in The Selfish Gene: it sure is useful, too useful, and there are looming barriers to our understanding of biology that are going to require another Dawkins to disseminate.

Let me try to explain with a metaphor — always a dangerous thing, but especially dangerous because I’m going to use a computer metaphor, and those things always grip people’s brains a little bit too hard.

In the early days of home computing, we had these boxes where the input to memory was direct: you’d manually step through the addresses, and then there was a set of switches on the front that you’d use to toggle the bits at that location on and off. When a program was running, you’d see the lights blinking on and off as the processor stepped through each instruction. ...

That’s where we’re at in biology right now, staring at the blinking lights of the genome. 

P.Z.'s Gnu Atheism? Totally disagree. But, he has some solid evolutionary biology insights. Also, vis-a-vis Coyne, he's not a hard-core determinist on free will, which I think is driving Coyne's thoughts on evolutionary genetics, too.

And now, the newest applecart upsetter of the "genetic dogma" of Francis Crick and James Watson is this — the idea that there may be two codes in our DNA, one for coding for proteins (i.e., genes) and another for epigenetic-like modulation:

“For over 40 years we have assumed that DNA changes affecting the genetic code solely impact how proteins are made,” said Dr. James Stamatoyannopoulos, who led the UW team. “Now we know that this basic assumption about reading the human genome missed half of the picture. These new findings highlight that DNA is an incredibly powerful information storage device, which nature has fully exploited in unexpected ways.”

The researchers discovered that some codons, part of the 64-letter alphabet which makes up the genetic code, can have two meanings – one related to protein sequence and another related to gene control.

These duons apparently evolved together, researchers said, and the gene control instructions appear to stabilize beneficial features of proteins and how they’re made.

Maybe this will finally break the slavish devotion some people have to Richard Dawkins' The Selfish Gene. I know Myers feels at least a bit that way.

Of course, really, Stanley Prusiner's fingering of prions as causing mad cow disease long ago upset the central dogma of Crick and Watson. That's why so many biologists were so strident against Prusiner getting a Nobel. It's also why the one he got was in chemistry, and not physiology or medicine.

And, it's also why John Horgan is wrong with a book called "The End of Science." We're not even close to that.

Gay? It’s in the epigenetics as well as the genes — no #gaygene, no #popevpsych

This new research and meta-research, summarized here, indicating that tendencies toward being gay or lesbian are a matter of epigenetics more than genetics in general, and ruling out the idea of a “gay gene,” makes a lot of sense to me.

The idea that it has at least a fair amount to do with epigenetic issues in the womb makes HUGE sense to me, as statistical studies show consecutive male births (no intervening females) increase the likelihood of each successive male being gay:

Here’s the key info:

Writing in The Quarterly Review of Biology, researchers William Rice, a professor at the University of California, Santa Barbara, and Urban Friberg, a professor at Uppsala University in Sweden, believe that homosexuality can be explained by the presence of epi-marks — temporary switches that control how our genes are expressed during gestation and after we're born.

Specifically, the researchers discovered sex-specific epi-marks which, unlike most genetic switches, get passed down from father to daughter or mother to son. Most epi-marks don't normally pass between generations and are essentially "erased." Rice and Friberg say this explains why homosexuality appears to run in families, yet has no real genetic underpinning.

Epigenetic mechanisms can be seen as an added layer of information that clings to our DNA. Epi-marks regulate the expression of genes according to the strength of external cues. Genes are basically the instruction book, while epi-marks direct how those instructions get carried out. For example, they can determine when, where, and how much of a gene gets expressed.

Moreover, epi-marks are usually produced from scratch with each generation — but new evidence is showing that they can sometimes carryover from parent to child. It's this phenomenon that gives the impression of having shared genes with relatives.

That said, at the same time, the io9 story looks like a bit of oversell, past the headline. I wouldn't go so far as to say homosexuality is not genetic; I would certainly say it's not solely genetic, and might say it's not primarily genetic.

And, just because you rule in epigenetic influences, you can’t rule out genetic ones by fiat.

At the same time, this theory is hugely explanatory for why a trait that reduces evolutionary fitness continues to perpetuate, too.

And, it also relates to other issues, such as gender identity problems.

Epigenetics in general also undercuts the ideas of Pop Evolutionary Psychology, especially its vaunted Enivironment of Evolutionary Adaptedness.

That’s because epigenetic influences are themselves subject to outside environmental influences. And, as the io9 story notes, and as we’ve seen in other issues like obesity, epigenetic influences can be passed on from generation to generation.

So between heredity of nongenetic factors that are environmentally determined, and such factors rapidly shifting, the EEA is all wet, again.

Identical twins aren't so identical, not even their brains

That's been known to be true for some time. Depending on when the single fertilized egg divided, identical twins can have separarate amniotic sacs, umbilical cords and placentas, the same sac, the same cord as well, or even the same placenta.

And now, we're learning that identical twins may not have entirely the same genetic makeup, not even in brain cells. (And, perhaps this is due to chimera issues, which got new light in late 2013?)  As a result, twin studies for illnesses, behavior, etc., may be called into a bit of question, and future twin studies more carefully controlled for subjects.

At the same time, the authors occasionally slip into quasi-teleological language while wondering why evolution "allows" this. Their proposed answer as to why this may happen is interesting, but could serve to have that language nuanced better. Also, even if you allow for the teleological/personifying language, that may not be the reason why this happens; maybe epigenetic events are at least partially involved, even with identicals. After all, they don't share 100 percent the same environment.

And, it may turn out that on a statistical average, such transposition isn't favorable or unfavorable, and that we're talking about a ramped-up genetic drift. Or maybe more modest transposition was more favorable, and now, the degree of favorability has lessened. From what little I know, genetic studies like this are kind of like studying individual frames, or at best, snippets, from a movie, when the backdrop for the movie may have been radically different at another point.

Update, May 2, 2021: Fascinating Smithsonian piece here. If you're familiar with what chimeras are, namely a human fetus that has absorbed another in the womb, the discovery that moms can become chimeras from their fetuses is ... fascinating.

Pop Ev Psych vs. depression

Popular Evolutionary Psychology is well-known for its just-so stories about how all sorts of human conditions MUST have some sort of evolutionary advantage.

Well, this New York Times column expertly deflates that claim vis-a-vis depression. Besides presenting evidence that the ruminating thought style of depression is of little advantage if any, it notes that ... cancer has zero evolutionary advantage.

Even if depression is “natural” and evolved from an emotional state that might once have given us some advantage, that doesn’t make it any more desirable than other maladies. Nature offers us cancer, infections and heart disease, which we happily avoid and do our best to treat. Depression is no different.

Game, set, match.

Meanwhile, the more we learn about epigenetics, the more we realize that, not only does it TOTALLY upset the Pop Ev Psych applecart, it's even leading more and more biologists to consider "Lamarckianism lite" as a valid extension on traditional evolutionary biology.

But with the skyrocketing prevalence of conditions such as obesity, diabetes, and autism, which have no clear genetic etiology in the majority of cases, as Brunet pointed out, “It seems that all complex processes are affected by epigenetics.”

A whole new ballgame, in this case, to extend the metaphor.

It's all in your RNA

No, it's not all in your genes, unless, per this story on the latest RNA findings, we expand what we define as a "gene." And, this isn't about epigenetic controls on DNA, it's about what previously might have been called "junk RNA." So, it may not "all" be in your RNA, but more of "it" may be there than previously thought.

Only now have scientists begun identifying the previously invisible contractors who make sure that materials get where they are supposed to be and in the right order to build a human being or any other creature. Some of these little-known workers belong to a class of molecules called long intergenic noncoding RNAs.

Scientists used to think that these “linc­RNAs” were worthless. As their name suggests, these molecules — at least 200 chemical letters long — do not encode information that the body’s manufacturing machinery can use to cobble together proteins. And the lincRNAs originate in what scientists used to view as barren wastelands between protein-coding genes. But new research is showing that these formerly underappreciated workers have important roles in projects both large and microscopic.

“They regulate every process under the sun,” says John Rinn, an RNA researcher at Harvard Medical School.

It seems this lincRNA works in a way similar to epigenetic markers on DNA, but more closely connected with "coding" RNA than epigenetic markers are with genes.

To me, this says even more. It raises in more depth the question about what the "original replicator" was, just how "alive" we should consider viruses to be and more. Per the late Lynn Margulis, we may have hints of a new, lower level of co-evolution or symbiosis than she demonstrated with the eukaryotic cell.

Was there some evolutionary competition as well as co-evolution? Etc., etc.

And, do we need to worry about RNA mutations as well as DNA mutations, more than previously thought? Per the story, probably so.

Meanwhile, another story on noncoding RNA is just out, too, from Public Library of Science. This one says that noncoding RNA might be one of the factors that accelerated human brain development beyond other primates. It's at the eye-glazing level of microbiology for me, much more so than a story about string theory (absent too, too much math) would be. And, it sounds a bit speculative, per comments about it on Google+. But, the fact that noncoding RNA is being tentatively linked to specific evolutionary development reinforces the possibility of some of the ideas I draw from the Science News story.

The flip side? If genes, environmentally-influenced epigenetics, other environmental factors, and noncoding RNA all have roles to play in human development, things like a "cure for cancer" just faded further into the distance, and on similar lines, the idea of "genetic medicine" both got more complex and of less immediate potential. Somebody alert Ray Kurzweil and other futurists.

Genes and epigenetics, nature VIA nurture

If you haven't kept up with recent research on heredity, population genetics or anything similar, the new Time has a GREAT story on epigenetics. Look it up and read it. Then throw away any simplistic ideas you have about "genetic inheritance."

If you are familiar with the basic idea of epigenetics, some of the newest findings may still surprise you, such as the rate of influence, the depth of influence, and more. Giraffes' necks aside, maybe Lamarck wasn't so wrong. Certainly, Stan Prusiner looks ever more right on prions, in light of stuff like this.

Obviously, we are nowhere near the end of discovering what epigentic findings mean. But, I think we can put paid to a few of the more outlandishly positivistic ideas of late 20th-century genetics.

Individualized medicines? Not likely to happen, and certainly not any time soon. You'd have to check at least some epigenetic as well as genetic factors. The price for that and an even higher level of individualizing the medications, would seem to pretty much rule that out.

Insurance, insurance, privacy, snooping, pre-existing conditions? All in a new realm now.

Drug testing? Some lawyer will raise an epigenetic argument at some point, whether it's legit or a red herring.

Child abuse affects the child brain

More and more, through things such as human physiological research, specifically on suicide victims, and discussed more here, it’s clear that child abuse, especially to younger children, can change both the structure of the human brain and how it expresses itself.

The first study, albeit with very small numbers, focues on the hypothalamic-pituitary-adrenal (HPA) function, as this is one of the most important stress “pathways” in the body.

Results revealed that genes associated with the good functioning of this pathway had been modified extensively as opposed to those found in the other 24 bodies, which ruled out the possibility of suicide causing these changes.

“In humans, childhood abuse alters HPA stress responses and increases the risk of suicide,” Michael Meaney of McGill Univeristy says in the new paper published in a recent edition of the journal Nature Neuroscience.

A “known” thing, now getting initial research confirmation.

The more detailed review of Meaney’s work indicates that early child abuse changed the expression of a gene that is important for responding to stress. In other words, it resets a person’s “anxiety thermostat.”

Celebrating Darwin – looking for the ‘third wave’ in evolution

For the Darwin bicentennial, Seed magazine has an excellent collection of special articles.

One of the most seminal, to my mind, is Eva Jablonka’s call to integrate much more epigenetics into the modern neo-Darwinian synthesis.

Things like Lynn Margulis’ symbiosis have already been incorporated, as a big enough issue. But, as Jablonka notes herself, epigenetics would more directly challenge the integration of genetics into Darwinism that brought about the neo-Darwinian synthesis as the “second wave” of modern evolution.

After starting by noting the evidence is accumulating for more than just DNA being involved with evolution, Jablonka gives us a definition:

Epigenetics is a term that includes all the processes underlying developmental flexibility and stability, and epigenetic inheritance is part of this. Epigenetic inheritance is the transmission of developmental variations that have nothing to do with changes in DNA base sequences. In its broad sense, it covers the transmission of any differences that do not depend on gene differences, so it encompasses the cultural inheritance of different religious beliefs in humans and song dialects in birds. It even includes the developmental legacies that a young mammal may receive from its mother through her placenta or milk — transmitted antibodies, for example, or chemical traces that tell the youngsters what the mother has been eating and, therefore, what they should eat. But epigenetic inheritance is commonly associated with cellular heredity, in which differences that arise among genetically identical cells are transmitted to daughter cells.

She then notes that epigentics is connected to cell differentiation within an embryo, and even more, once differentiation starts, how kidney cells “reproduce true.”

Next, she notes that more and more evidence has accumulated for the transference of epigenetic traits between organisms.

From there, she goes to the mother lode of the need to go to a “third wave” of evolution:

Induced and heritable epigenetic change may guide genetic changes.

That’s one big reason I score down, and scorn, modern Pop Evolutionary Psychology, too. It takes no account of epigenetics.

Anyway, read the full story for an idea of where evolutionary research is headed, and where its main theorists need to be focused.