Talk:Gene–environment interaction

Untitled
rated by T0mpr1c3 (talk) 10:16, 28 August 2008 (UTC)

Psychology bias
This entry is way too psychology-biased at the moment. I'm fairly certain that gene-environment interactions were talked about in biology several decades earlier than the article currently says of psychology (1990s; biology: 1950s? I'm thinking Waddington). - Samsara 16:03, 13 January 2006 (UTC)

I would have guessed JBS Haldane... Pete.Hurd 06:01, 28 January 2006 (UTC)

Merge?
While we're at it, could this page not be merged/redirected to heritability or nature versus nurture? it's really short, and I'm not sure where it's intended to go that would cover ground not properly covered on those pages. Pete.Hurd 06:01, 28 January 2006 (UTC)

Example to add
Francis et al 2003, Nature Neuroscience 6:445-446.

Pre- and post-natal
I wonder if there isn't a way to make a few remarks on the distinction of pre-natal and post-natal environments. Either one clearly falls in the category "environment", but I think many readers will tend to forget about pre-natal environment as a entering into the interactional quality of development. Maybe some reference to the Francis, et al. paper that you sent me, Pete.Hurd (Epigentetic sources of behaviral differences in mice), which was interesting in considering both environments along with gene strains. Lulu of the Lotus-Eaters 21:24, 31 January 2006 (UTC)


 * Yeah, I'll put some thought into some text, I don't have time to make a nifty graphical description of the Francis paper, but I think it would be super-useful to triple underline the idea that "born that way" does not equal "genetics" due to the importance of uterine environment effects. Maybe some mention of how MZ twins that share a single amniotic sac are more similar than MZ twins that each had their own... I'll see if I can find that reference too. Pete.Hurd 23:01, 31 January 2006 (UTC)


 * Pete, I'd say that twin studies with information on chorionicity have generally been too small to draw any firm conclusions about postnatal similarity, but it is true that monochorionic twin pairs have higher rates of perinatal complications T0mpr1c3 (talk) 00:45, 31 July 2008 (UTC)

T0mpr1c3's recent comment on this old thread made me want to add some general description of pre-/post-natal distinction. I was trying to squeeze in a link to "epigenetics", but I couldn't quite get it in the flow. I certainly welcome any improvements on my addition. LotLE × talk 01:04, 31 July 2008 (UTC)
 * Hey Lulu, I was thinking that "prenatal" environmental influences are seen in oviparous species. For example maternal effects, such as differential deposition of hormones into the egg, in birds and lizards.  Birds have been known to alter hormone concentrations in the egg across the clutch, increasing or decreasing testosterone with laying order.  A recent paper (IIRC) showed the sex ratio of the other eggs in experimentally assembled clutches of lizard eggs influenced adult morphology... Pete.Hurd (talk) 03:48, 31 July 2008 (UTC)


 * I added a sentence on oviparous species. Does it look sensible to you?  LotLE × talk  04:02, 31 July 2008 (UTC)


 * Pete and Lulu, it seems to me that the ideas you are bringing up relate to mechanistic interaction between genes and environments rather than the statistical interactions. Perhaps this distinction could be clarified. T0mpr1c3 (talk 09:42, 31 July 2008 (UTC)


 * Tom, shouldn't mechanistic interaction automatically lead to statistical interaction? And isn't statistical interaction uninteresting in and of itself unless it indicates mechanistic interaction? After all, statistics should be just a tool to get to the underlying mechanisms. --Crusio (talk) 10:27, 31 July 2008 (UTC)


 * Yes, I agree in principle. But GxE can be defined either way and the entry probably needs to make that clear. T0mpr1c3 (talk) 06:47, 2 August 2008 (UTC)

Heritability
The concept of heritability really needs working in, somewhere in the first paragraph. Pete.Hurd 05:13, 3 February 2006 (UTC)

removed chart
I removed the chart, even though it is a really nice picture, because it does no necessarily give a correct description of GxE interaction. An interaction would occur if the same environmental manipulation has differential effects on individuals (plants in this case) with different genotypes. If the environmental effect is the same regardless of genotype, we have si,ple additivity of genotype and environment. As an example, take two genotypes G1 and G2 and two environments E1 and E2. Additivity would occur if, for example, we have the following case:


 * G1E1 = 10
 * G1E2 = 15
 * G2E1 = 20
 * G2E2 = 25

(E2 increases the studied character with the same amount in each genotype). An interaction occurs in this example:


 * G1E1 = 10
 * G1E2 = 11
 * G2E1 = 20
 * G2E2 = 30

(E2 increases the character in each genotype, but much more so in G2 than in G1). Or, in the case of Tryon's rats:


 * G1E1 = 10
 * G1E2 = 20
 * G2E1 = 20
 * G2E2 = 20

(G1 and G2 differ in E1 but not in E2). --Crusio 16:59, 21 September 2007 (UTC)


 * Huh? Obviously the chart doesn't illustrate every possible norm of reaction. But the effect of environmental change is still, of course, differential across genotype.  The point of the chart isn't that "all gene/environment interaction is exactly this", but rather "interaction can be in a manner that contradicts stereotypes about the meaning of heritability".  That's a point worth adding... I'll improve the caption.  LotLE × talk  17:42, 21 September 2007 (UTC)
 * The chart still is not correct. My point is that the chart could simply indicate a situation where plants in the right hand environment grow, say, 10 cm less tall than in the left hand environment, whatever their genotype. That is not genotype x environment interaction, but additivity of genotype and environment (my first numerical example above). GxE is when different genotypes react differently after a particular environmental change. Such as Tryon's rats, where the Bright line was the same, whether they were reared in an enriched or an impoverished environment, but where the Dull line changed its behavior dramatically when the environment changed. That is interaction. Under both additivity and interaction can you have a situation where heritability (within an environment) is 100% and different environments produce different phenotypes. With additivity this would always be the case. With interaction, you could have examples where heritability in one environment is 100% and 0 in another. Hope this clarifies, I realize this is getting rather technical.
 * I leave the chart for the moment, I don't want to start an edit war :-) but I think it should be taken out as it does not give a correct illustration of what GxE interaction is. --Crusio 19:24, 21 September 2007 (UTC)
 * So, if the chart were changed to identify different genotypes within each treatment, and then show that the effect of the environmental variation was different across the environmental change, then we'd be ahead. (?). First glance I took at the figure, I assumed we were supposed to think that the leftmost plant was the same genotype, etc... Pete.Hurd 19:33, 21 September 2007 (UTC)

I did not create the chart, so am not certain what it's creator intended. But my reading was that each pot illustrated seven different genotypes, arranged in the same order in the left and right pots. The response to the changed soil is not identical across genotypes: for example, the tallest plant on the left does not match the position/genotype of the tallest one on the right. The point in the graphic caption is that within each pot, all the variation is genetic (since the environmental conditions are identical within a pot. Between pots an environmental effect changes expression of the group (and only environmental, since the same genotypic range occurs in each pot).  LotLE × talk  19:52, 21 September 2007 (UTC)
 * In order to demonstrate that the variation between plants within treatments is entirely genetic there will have to be replicates showing that different individuals of the same genotype have identical heights (under the same environmental conditions). Pete.Hurd 19:56, 21 September 2007 (UTC)


 * It depends what we're trying to show, doesn't it? If genotype A in environment 1 has variation in expression... well, I guess that still means <100% heritability, right? Do you think expanding the box caption can clarify it well enough, Pete.Hurd?


 * Btw, I modified the image to make explicit my reading about the seven same genotypes in each pot. I created a PNG version because the format is more appropriate, but it also means the JPEG is not modified.  LotLE × talk  20:22, 21 September 2007 (UTC)
 * Given the subject matter of the article, I think we might as well make the figure illustrate a nice GxE interaction. The figure makes no distinction between noise and genetics, I like its potential, but I think the figure itself will have to be changed before it makes a worthwhile pedagogical payoff. Pete.Hurd 20:51, 21 September 2007 (UTC)
 * I agree with Pete. In fact, I think that the current figure is too complicated. The point that within a certain environment all differences between individuals can be 100% heritable, but that despite that a change in environment can still modify the phenotype of these individuals is a valid one, but does not belong here. It would be better at its place in the article on heritability. There it should be modified also, to show that heritabilities are population and environment specific. To get back to Tryon's rats, under normal circumstances the trait "learning ability" is highly heritable, but under enriched conditions the heritability is essentially zero. --Crusio 14:15, 22 September 2007 (UTC)

If it's the shared opinion of Crusio and Pete.Hurd that this isn't the right chart for this article, I bow to that consensus. I realize it's not a "fully general" illustration of the concept. Maybe if Pete or Crusio has an idea of what a better illustration would be, you could write to the creator of the first chart to see if he could do it. I like the style of the plants of different heights, in any case: it just feels friendlier for this than a completely abstract bar chart or line  chart. LotLE × talk 18:23, 22 September 2007 (UTC)


 * I agree that it's a much friendlier chart, and with tweaks it will work great to illustrate the topic. I'll look more into it's creator, and drop some suggestions and see if we can coax further labour from them. Pete.Hurd 19:45, 22 September 2007 (UTC)

Norm of Reaction
"Heritable phenotypic variation among individuals of a single genotype, elicited by variation in environmental conditions" (Keller, EF, and Lloyd, EA (1992). Keywords in Evolutionary Biology, p.256.) I tried to paraphrase, evidently not to everybody's satisfaction. Also I think we probably need some further discussion of how reaction norms relate to the concept of GxE, maybe along the lines of http://plato.stanford.edu/entries/heredity/ Any offers? T0mpr1c3 (talk) 10:08, 1 September 2008 (UTC)
 * Well, evidently NoR is broader than GxE, because even in the absence of the latter, you can study the NoR (it will just be the same over all environments). I am not sure that the definition of Keller and Lloyd is correct, I always thought that NoR was the distribution of phenotypes that a particular genotype would give over different environments (meaning, including the variation within one genotype and one environment). I may be wrong about this, though. When I get back to the lab, I'll look this up in some older genetics textbooks, which generally are better for checking definitions (given the unfortunate drift of the meaaning of many definitions nowadays). --Crusio (talk) 10:22, 1 September 2008 (UTC)

Recent edit to lead
I have moved this edit from the article to here:
 * There is still much discussion about how genes and the environment interact to influence complex behavioral traits and susceptibility to diseases. These issues were recently debated at Genes & Environment 2010.

The text is not sufficiently helpful to be warranted, and certainly should not be in the WP:LEAD (because that is a summary of the article). Further, we do not embed external links in articles; instead, links which satisfy WP:EL should be in an "External links" section. Ideally, someone would find some useful information from the site and use it as a reference for material added to the article. Johnuniq (talk) 03:39, 8 December 2010 (UTC)

Citations list useful for updating this article and related articles
You may find it helpful while reading or editing articles to look at a bibliography of Biology and Genetics Citations, posted for the use of all Wikipedians who have occasion to edit articles on human genetics and related issues. I happen to have circulating access to a huge academic research library system at a university with an active research program in these issues (and to other academic libraries in the same large metropolitan area) and have been researching these issues sporadically since 1989. You are welcome to use these citations for your own research. You can help other Wikipedians by suggesting new sources through comments on that page. It will be extremely helpful for articles on human genetics to edit them according to the Wikipedia standards for reliable sources for medicine-related articles, as it is important to get these issues as well verified as possible. -- WeijiBaikeBianji (talk, how I edit) 20:17, 30 October 2013 (UTC)

Please update with: "Different environmental variables predict body and brain size evolution in Homo"
I think it would be good to add some short info about this study's findings to the article and/or other relevant articles (like human height and brain size). It's currently featured in 2021 in science like so:

Scientists report that in the past – with little relevance to future evolution – lower temperatures were associated with larger Homo body sizes and that long-term variability in precipitation was correlated with brain size.

--Prototyperspective (talk) 14:59, 23 August 2021 (UTC)