21–30 of 37 posts
Also, cuddle your kids: http://www.sciencealert.com/cuddling-babies-alters-their-gen...
The impact of epigenetics can be powerful. A neat example is sex, one of the most obvious and striking axes of biological variation. Unlike humans where the presence or absence of an entire chromosome (X or Y) determines sex, there are turtles and reptiles that determine their sex based on ambient temperature alone. The logical consequence is that a pair of female and male turtle twins can share exactly the same geno…
Epigenetics is heritable information that is not encoded in DNA base sequence. Common mechanisms include DNA methylation patterns, histone binding patterns, and histone modifications, all of which can be stably inherited from one cell division to the next, but not necessarily transgenerationally, from parent to offspring, through the germ line.
You are also confused about turtle sex determination. The master regulator of sex determination (which must respond directly to temperature) is unknown. The epigenetic regulator KDM6B is required to mediate the temperature signal for male development, but there is no evidence that it is the master regulator. Maybe you read a press release instead of the actual paper in Science.
Environmental sex determination is not that unusual, and need not depend on epigenetics or even transcription factors.
There should be a better distinction made between EPIgenetics and epiGENETICS. The former is more about regulatory mechanisms (methylation, histone modifications, polycomb-like mechanisms, etc) on top of our DNA. The latter is more about non-DNA inheritance of information across generation, which is not completely clear yet. I think people tend to conflate these two ideas.
Slippery slope here. Most people don't understand or accept evolution, even engineers. For example, anyone who accepts equitable distribution of attributes across genetic variances(a commonly accepted social narrative). Evolution is messy. Epigenetics makes it even messier. We have to be careful not to conflate the value of someone by anything genetic. Especially not epigenetics, which seems from this article to be r…
The impact of epigenetics can be powerful. A neat example is sex, one of the most obvious and striking axes of biological variation. Unlike humans where the presence or absence of an entire chromosome (X or Y) determines sex, there are turtles and reptiles that determine their sex based on ambient temperature alone. The logical consequence is that a pair of female and male turtle twins can share exactly the same geno…
Epigenetics is not "how the genome is read" -- you're describing the normal action of transcription factors. Epigenetics is heritable information that is not encoded in DNA base sequence. Common mechanisms include DNA methylation patterns, histone binding patterns, and histone modifications, all of which can be stably inherited from one cell division to the next, but not necessarily transgenerationally, from parent t…
To the best of my knowledge, DNA methylation patterns, histone binding patterns, and histone modifications all have causal biological impacts solely by their causal influence on "how the genome is read". Epigenetics is "how the genome is read", as well as more beyond that. But how the genome is read is substantial portion of epigenetics and, for better or worse, the aspect of epigenetics that receives the most attention when discussed with general audiences. I think it's inaccurate to deny the role of "various readings" of the genome in a definition of epigenetics.
I'm unsure how your citing of KDM6B is related to or addresses any confusion in my statement on temperature-dependent sex determination. From what I can understand, you point out that KDM6B histone demethylase acts epigenetically and that it regulates temperature-dependent sex-determination, both of which are consistent with what I said earlier...
Earlier quoted context omitted.
> For example, anyone who accepts equitable distribution of attributes across genetic variances(a commonly accepted social narrative). Can you give an example?
Don't feel the trolls. It's a racist dogwhistle.
If epigenetics is multi-generational then what of things like slavery and the ungodly number of atrocities littering our history, both race-based or otherwise. What things do we do now that are going to be harmful in such capacity, beyond the obvious prison system.
More importantly, I think we could potentially improve ourselves collectively by harnessing this power. I know my own family history is littered with trauma.
Earlier quoted context omitted.
Epigenetics is not "how the genome is read" -- you're describing the normal action of transcription factors. Epigenetics is heritable information that is not encoded in DNA base sequence. Common mechanisms include DNA methylation patterns, histone binding patterns, and histone modifications, all of which can be stably inherited from one cell division to the next, but not necessarily transgenerationally, from parent t…
"Epigenetics is heritable information that is not encoded in DNA base sequence." I agree with this. Combined with the observation that temperature-dependent sex determination occurs within a specific window of time, after which sex cannot be changed for the remainder of the organism's lifetime, I believe it follows logically that somatic cells (certainly those within the sexual organs) must be receiving heritable inf…
I'm not a molecular biologist, so take this all with a grain of salt. There are two things which get confused when discussing epigenetics. First, you have gene expression which is mediated by the environment. That is what you are talking about with your turtle example. This is pretty common. After all, being able to respond to environmental stimuli is useful.
But there is another phenomena that gets labelled as epigenetics: stuff in the environment which modifies the DNA of the germ line cells (eggs and sperm) of an organism. The part about it being germ line cells is important, because that means that the changes to DNA will be passed on to the offspring, whereas epigenetic changes in any of the other cells of the body will not. People are in love with this aspect of epigenetics because, frankly, there's a certain type of person who is enamored with the idea that this might "disprove" Darwinian evolution (OMG Lamarck was right!).
It's extremely frustrating because this second phenomena is, as far as we know, extremely uncommon. I mean, it almost has to be. Large organisms are like a house of cards; if you make too many changes, everything comes crashing down. So, if there were epigenetic changes to germ line DNA happening all the time, there would be unfeasible levels of mutation happening from one generation to the next. But the fact that it is extremely uncommon does not stop people from hearing about how this second meaning of epigenetics is a weird end-run around Darwinian evolution, then hearing about how common the first meaning of epigenetics is, and coming to the conclusion that Darwinian evolution is invalid.
Incidentally, these two meanings are the root cause of you and the person who responded to you misunderstanding each other.
Looks like the theory of evolution needs modifications due to epigenetics.
Not sure why this is being downvoted, but it's definitely the case that as we learn more about epigenetics, we will need to modify our understanding of evolution substantially, particularly the relationship between epigenetic expression and mutation, in which the latter can "lock in" the changes from the former and lead to more rapid speciation. Exciting stuff.
Earlier quoted context omitted.
The only thing I don't like about people who deny the strong influence of genes on the individual are they tend to shout racist at anyone trying to study this question. This shouting has made whole areas of human research impossible to study in practice. Does anyone know of anyone who became a racist because they looked at the scientific literature? My experience is people become racist for a variety of reasons and t…
>This shouting has made whole areas of human research impossible to study in practice. Maybe here in the West, but something tells me China isn't going to get caught up in either the ethical or political implications of such research. They'll just do it and quickly operationalize (or weaponize) whatever they discover as fast as possible.
Slippery slope here. Most people don't understand or accept evolution, even engineers. For example, anyone who accepts equitable distribution of attributes across genetic variances(a commonly accepted social narrative). Evolution is messy. Epigenetics makes it even messier. We have to be careful not to conflate the value of someone by anything genetic. Especially not epigenetics, which seems from this article to be r…
> people don't understand or accept evolution [...] For example, anyone who accepts equitable distribution of attributes across genetic variances Even if the straw-man "everybody is totally equal" can't stand up, I think there's a good argument for: "We have to assume everybody is equal by default,(A) because we are absolutely too ignorant and limited to determine the long-term value or trade-offs within a gene or ge…