Also, there have been changes to expression shown in the grandchildren of people studied, so even though it doesn't alter the DNA sequence, epigenetic expression has been shown to be heritable.
We can agree to disagree.
![Smile :)](./images/smilies/icon_e_smile.gif)
The word 'gene' has been in use for a little more than a hundred years. Lineage has been used for more than six-hundred years and refers to decendancy from a common progenitor.
- "She Has Her Mother's Laugh: The Powers, Perversions, and Potential of Heredity." - Carl Zimmer...you might be shocked to discover just how much skepticism there is in scientific circles about transgenerational epigenetic inheritance...
While it's true that the methylation pattern in cells can change during people's lifetimes, it's not at all clear that those changes can be inherited.
The trouble with this hypothesis is that it doesn't fit what we know about fertilization. A sperm carries its own payload of DNA, which has its own distinct epigenome as well. For example, sperm have to tightly wind their DNA in order to fit it inside their tiny confines. During fertilization, the sperm's genes enter the egg, where they encounter proteins that attack the father's epigenome. As the embryo starts to grow, the epigenetic drama continues. The totipotent cells strip away much of the remaining methylation on their DNA. And then they reverse course and start putting a fresh batch of methyl groups back on.
This new methylation helps cells in an embryo take on new identities. Some cells commit to becoming the placenta. Others start giving rise to the three germ layers. And when the embryo is around three weeks old, a tiny wedge of cells receives a set of signals that tell them that they have been picked for immortality. They will become germ cells. The newly formed primordial germ cells alter their epigenome yet again. They strip of much of the methylation from their DNA.
Many scientists doubt that inherited epigenetic marks can survive all of this stripping and resetting. If heredity is a kind of memory, methylation suffers radical amnesia in every genertion.
I agree. However, I would also note that in groups as small as two individuals, and certainly in those as large as 5, in addition to the tendency to become more alike, there is the tendency to assume complementary or contrasting roles which need not apply in other contexts. Simple examples would be never becoming very good at handling money, because your spouse always handled that task, or reverting to babyish behavior when you find yourself back in context of youngest in sibling group. This is one of the most interesting things I learned in therapy; modeling preferred behavior is often much less effective than creating an attractive vacuum for the behavior you prefer.jennypenny wrote:I would think that five great-yet-diverse influencers would be better than five great-but-almost-exactly-the-same influencers. No proof, just a hunch.
+17Wannabe5 wrote: ↑Sun May 05, 2019 4:51 pmreverting to babyish behavior when you find yourself back in context of youngest in sibling group. This is one of the most interesting things I learned in therapy; modeling preferred behavior is often much less effective than creating an attractive vacuum for the behavior you prefer.
Along the same lines, we know of a post-menopausal woman who began teaching a class of rambunctious middle school girls and was shocked when her cycle restarted.In our newly published research, my colleagues and I identified the neural circuits and signaling processes behind the physiological effects, including rapid aging, that occur when Drosophila encounter their dead. Because other animals also experience physiological effects in the presence of their dead, identifying how this process works in fruit flies could shed light on how it operates in other species, including in people.
It may be a similar phenomena as to why menstrual cycles synchronise when women are in close proximity to one another.
Hopefully it happened between periods.Ego wrote: ↑Sun Jul 02, 2023 3:51 pmhttps://theconversation.com/seeing-dead ... ble-207283
Along the same lines, we know of a post-menopausal woman who began teaching a class of rambunctious middle school girls and was shocked when her cycle restarted.
This has actually been debunked. (One example of a scientific article: https://pubmed.ncbi.nlm.nih.gov/26181612/)
There seems to be conflicting research on this, although my ovaries seem to like being team players anyway.DutchGirl wrote: ↑Mon Jul 03, 2023 11:51 amThis has actually been debunked. (One example of a scientific article: https://pubmed.ncbi.nlm.nih.gov/26181612/)