# Trying to connect behavior to evolution **URL:** \ **Category:** In My Humble Opinion\ **Created:** [April 3, 2025, 1:02pm UTC](https://boards.straightdope.com/t/trying-to-connect-behavior-to-evolution/1016566 "2025-04-03T13:02:03Z")\ **Posts on this page:** 20\ **Page:** 4
**Author:** ![scudsucker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/scudsucker/32/14101_2.png) [@scudsucker](https://boards.straightdope.com/u/scudsucker)\ **Post date:** [April 6, 2025, 2:25pm UTC](https://boards.straightdope.com/t/trying-to-connect-behavior-to-evolution/1016566/61 "2025-04-06T14:25:17Z")
> [@Czarcasm](#): > > but with a sample size that small not even correlation is implied. You appear to have not understood my scientific method. To unwrap, I studied a bunch of scientific literature that strongly correlated child gender with time of impregnation. I’ve not published a peer reviewed article yet, because.. it is not my field. I used that study to choose the day of impregnation. (As stated above) I did not just voice this as a statistical possibility) - I simply provided the appropriate gametes on an appropriately statistically chosen day. Everything else was beyond my control. But Math is Math. Oh… except romance. ---
**Author:** ![Czarcasm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/czarcasm/32/4050_2.png) [@Czarcasm](https://boards.straightdope.com/u/Czarcasm)\ **Post date:** [April 6, 2025, 2:28pm UTC](https://boards.straightdope.com/t/trying-to-connect-behavior-to-evolution/1016566/62 "2025-04-06T14:28:06Z")
And a sample size of one is no different than flipping a coin. ---
**Author:** ![scudsucker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/scudsucker/32/14101_2.png) [@scudsucker](https://boards.straightdope.com/u/scudsucker)\ **Post date:** [April 6, 2025, 2:42pm UTC](https://boards.straightdope.com/t/trying-to-connect-behavior-to-evolution/1016566/63 "2025-04-06T14:42:31Z")
@Czarcasm, medical research places the three to five days worth of sperm fecundity inside a woman into the realms of science. If you know any pre-menopausal women, you can ask them. Hell, please do. To be honest, unless @Czarcasm chooses to make a new thread about how and why two men are arguing about reproductive health in women, I am going to drop out. The Pit is the appropriate place, though I would venture to suggest “there is no appropriate place”. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [April 6, 2025, 4:04pm UTC](https://boards.straightdope.com/t/trying-to-connect-behavior-to-evolution/1016566/64 "2025-04-06T16:04:12Z")
@Czarcasm they seem to be referencing “the Shettle’s method” and it [seems to work at least roughly half the time](https://pmc.ncbi.nlm.nih.gov/articles/PMC4877388/) … It is not crazy to think that maternal factors can impact which sex zygote gets created and survives. But solid evidence that timing of intercourse impacts that is lacking. It is also not crazy to think that experience can impact the genes that get passed on - again see those links on epigenetics - but the mechanisms suggested in the OP do not make any physiological sense. ---
**Author:** ![HoneyBadgerDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/honeybadgerdc/32/1033_2.png) [@HoneyBadgerDC](https://boards.straightdope.com/u/HoneyBadgerDC)\ **Post date:** [April 6, 2025, 4:19pm UTC](https://boards.straightdope.com/t/trying-to-connect-behavior-to-evolution/1016566/65 "2025-04-06T16:19:14Z")
> [@DSeid](#): > > It is also not crazy to think that experience can impact the genes that get passed on - again see those links on epigenetics - but the mechanisms suggested in the OP do not make any physiological sense. I don’t pretend to know anything at all about this field. I am just a casual reader of trivia and there are several things about this topic that I was hoping I could throw out there and watch the xperts discuss it. Some of the things that lead me to believe or at least worth investigating I feel point to a possible link between the brain and sperm development. (some of my words may be off but I hope you get the drift) # 1. It takes about 74 days to manufacture a sperm. That is really a long time for something so simple. 2. What are possible mechanisms? The nerves and blood are tightly blocked from where sperm are manufactured. The only thing that it does share some of its environment with is the brain. Neurotransmitter’s have very short alf lives so it is not likely they are picking up on them but when the neurotransmitter decays it leaves a wide variety and combinations of varieties af amino acids that will linger for an extended period of time. Could this possibly be interpeted by developing sperm cells? It seems to be the only exposure they would have to what we experience in life. It would be extremely difficult to find or prove in a human but something like mice it may be possible over a 20 year period. If the conversation progressed far enough, the topic I would be most interested in discussing were the tests that could be set up to force the desired changes. ---
**Author:** ![GIGObuster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gigobuster/32/421_2.png) [@GIGObuster](https://boards.straightdope.com/u/GIGObuster)\ **Post date:** [April 6, 2025, 4:34pm UTC](https://boards.straightdope.com/t/trying-to-connect-behavior-to-evolution/1016566/66 "2025-04-06T16:34:48Z")
> [@HoneyBadgerDC](#): > > I don’t pretend to know anything at all about this field. I am just a casual reader of trivia and there are several things about this topic that I was hoping I could throw out there and watch the xperts discuss it. Some of the things that lead me to believe or at least worth investigating I feel point to a possible link between the brain and sperm development. (some of my words may be off but I hope you get the drift) # 1. It takes about 74 days to manufacture a sperm. That is really a long time for something so simple. You lost me already, things like that are not simple. [Uncovering the protein complex critical to male fertility - ResOU](https://resou.osaka-u.ac.jp/en/research/2025/20250304_1#:~:text=Sperm%20formation%20is%20a%20highly%20complex%20process,result%20in%20nonfunctional%20sperm%20and%20male%20infertility). > Sperm formation is a highly complex process that involves many changes to the cell structure, such as shrinking of the nucleus, generation of a sperm tail, and remodeling of the sperm head\*.\* Disrupting this process at any point can result in nonfunctional sperm and male infertility. ---
**Author:** ![HoneyBadgerDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/honeybadgerdc/32/1033_2.png) [@HoneyBadgerDC](https://boards.straightdope.com/u/HoneyBadgerDC)\ **Post date:** [April 6, 2025, 4:42pm UTC](https://boards.straightdope.com/t/trying-to-connect-behavior-to-evolution/1016566/67 "2025-04-06T16:42:07Z")
> [@GIGObuster](#): > > You lost me already, things like that are not simple. I picked up on that as soon as I typed it and meant to go back and change the word to small. ---
**Author:** ![GIGObuster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gigobuster/32/421_2.png) [@GIGObuster](https://boards.straightdope.com/u/GIGObuster)\ **Post date:** [April 6, 2025, 4:46pm UTC](https://boards.straightdope.com/t/trying-to-connect-behavior-to-evolution/1016566/68 "2025-04-06T16:46:22Z")
> [@HoneyBadgerDC](#): > > I picked up on that as soon as I typed it and meant to go back and change the word to small. It does not make your line better, for starters, how the nucleus is **shrank** from the original size/setup shows that your line here is very underwhelming. It does not mean what you think. ---
**Author:** ![HoneyBadgerDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/honeybadgerdc/32/1033_2.png) [@HoneyBadgerDC](https://boards.straightdope.com/u/HoneyBadgerDC)\ **Post date:** [April 6, 2025, 4:49pm UTC](https://boards.straightdope.com/t/trying-to-connect-behavior-to-evolution/1016566/69 "2025-04-06T16:49:12Z")
If I were to interview 1000 scientists all actively involved in this field what percentage would tell me that brain activity had some kind of influence on sperm. ---
**Author:** ![GIGObuster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gigobuster/32/421_2.png) [@GIGObuster](https://boards.straightdope.com/u/GIGObuster)\ **Post date:** [April 6, 2025, 4:51pm UTC](https://boards.straightdope.com/t/trying-to-connect-behavior-to-evolution/1016566/70 "2025-04-06T16:51:51Z")
It is your line, not mine. You should investigate that, As others pointed out, demanding that a very iffy connection should be there just because one says so, does not force others to go against evidence or consensus. ---
**Author:** ![HoneyBadgerDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/honeybadgerdc/32/1033_2.png) [@HoneyBadgerDC](https://boards.straightdope.com/u/HoneyBadgerDC)\ **Post date:** [April 6, 2025, 4:58pm UTC](https://boards.straightdope.com/t/trying-to-connect-behavior-to-evolution/1016566/71 "2025-04-06T16:58:26Z")
> [@GIGObuster](#): > > iffy connection should be there just because one says so, does not force others to go against evidence or consensus. Your post has nothing to do with anything I said. You are attempting to twist the conversation. I isimply feel for those inclined it might be an interesting discussion. ---
**Author:** ![GIGObuster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gigobuster/32/421_2.png) [@GIGObuster](https://boards.straightdope.com/u/GIGObuster)\ **Post date:** [April 6, 2025, 5:07pm UTC](https://boards.straightdope.com/t/trying-to-connect-behavior-to-evolution/1016566/72 "2025-04-06T17:07:55Z")
It would be interesting if there was a moment to reflect that, well, there are things that in reality are not simple or so small. And the consensus with experts is that Lamarckism is still bananas, even [**Epigenetics** does not directly support Lamarckism.](https://platofootnote.wordpress.com/2017/09/19/one-more-time-no-epigenetics-is-not-lamarckism/) ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [April 6, 2025, 6:47pm UTC](https://boards.straightdope.com/t/trying-to-connect-behavior-to-evolution/1016566/73 "2025-04-06T18:47:14Z")
> [@HoneyBadgerDC](#): > > The only thing that it does share some of its environment with is the brain Huh? No sperm does not share environment with the brain other than being in the same body. The brain communicates to the testes by way of the neuroendocrine system, but that is from a relative distance. The breakdown products of neurotransmitters in the brain are not near the testes and are resorbed and reused or excreted far away from there. So > [@HoneyBadgerDC](#): > > Could this possibly be interpeted by developing sperm cells? No. > [@HoneyBadgerDC](#): > > It seems to be the only exposure they would have to what we experience in life. Again they aren’t getting to the sperm, but no. Other things do. We create stress hormones, we get exposed to toxins, microplastics, we simply age … there are lots of things we do in life that expose the developing sperm to things. > [@HoneyBadgerDC](#): > > If I were to interview 1000 scientists all actively involved in this field what percentage would tell me that brain activity had some kind of influence on sperm. Almost all would explain about the neuroendocrine axis and how through it the brain controls sperm production and testosterone levels. Pretty sure not a one would say the brain impacts sperm in the way you are suggesting or anything at all similar to that. Zero. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [April 6, 2025, 6:57pm UTC](https://boards.straightdope.com/t/trying-to-connect-behavior-to-evolution/1016566/74 "2025-04-06T18:57:13Z")
It looks like the article linked talks about a blood-testis barrier, and Bing just decided two plus two equals jellyfish. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [April 6, 2025, 6:59pm UTC](https://boards.straightdope.com/t/trying-to-connect-behavior-to-evolution/1016566/75 "2025-04-06T18:59:48Z")
What _observed phenomenon_ are you trying to fit with a hypothesis? ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [April 6, 2025, 7:24pm UTC](https://boards.straightdope.com/t/trying-to-connect-behavior-to-evolution/1016566/76 "2025-04-06T19:24:23Z")
> [@HoneyBadgerDC](#): > > but when the neurotransmitter decays it leaves a wide variety and combinations of varieties af amino acids that will linger for an extended period of time. You still do not seem to understand what neurotransmitters, proteins, or amino acids are. First, amino acids are a specific class of molecule. That chart of various types of neurotransmitters I posted? None of them are made up of amino acids and therefore none of them break down into amino acids. Second, for the neurotransmitters that are made up of chains of amino acids, they aren’t using a “wide variety” of amino acids, they are using 20 or 21 types. The same 20 or 21 types used for the tens of thousands of types of proteins used in the body. When those chains of amino acids are disassembled, they are still the same 20 or 21 types. There are not “neuron amino acids” that are different than other amino acids. There is absolutely no way for a sperm cell to know if a lysine it encounters came from a neuropeptide, from the tuna salad you had for lunch, or from the disassembled flagellum of an invading bacterium. Every single cell of the body contains amino acids, and contains the same amino acids. > **[Proteinogenic amino acid](https://en.wikipedia.org/wiki/Proteinogenic_amino_acid)** > > Proteinogenic amino acids are amino acids that are incorporated biosynthetically into proteins during translation from RNA. The word "proteinogenic" means "protein creating". Throughout known life, there are 22 genetically encoded (proteinogenic) amino acids, 20 in the standard genetic code and an additional 2 (selenocysteine and pyrrolysine) that can be incorporated by special translation mechanisms. > In contrast, non-proteinogenic amino acids are amino acids that are either not incorporated int... Also, _ **your balls are not in your brain** _. ---
**Author:** ![HoneyBadgerDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/honeybadgerdc/32/1033_2.png) [@HoneyBadgerDC](https://boards.straightdope.com/u/HoneyBadgerDC)\ **Post date:** [April 6, 2025, 7:25pm UTC](https://boards.straightdope.com/t/trying-to-connect-behavior-to-evolution/1016566/77 "2025-04-06T19:25:06Z")
> [@Mangetout](#): > > What _observed phenomenon_ are you trying to fit with a hypothesis? Just looking for another method for evolution besides natural selection. Here I was just suggesting a way that it might come from the brain. I guess not though. ---
**Author:** ![HoneyBadgerDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/honeybadgerdc/32/1033_2.png) [@HoneyBadgerDC](https://boards.straightdope.com/u/HoneyBadgerDC)\ **Post date:** [April 6, 2025, 7:29pm UTC](https://boards.straightdope.com/t/trying-to-connect-behavior-to-evolution/1016566/78 "2025-04-06T19:29:47Z")
> [@Darren\_Garrison](#): > > Second, for the neurotransmitters that are made up of chains of amino acids, they aren’t using a “wide variety” of amino acids, they are using 20 or 21 types. The same 20 or 21 types used for the tens of thousands of types of proteins used in the body. When those chains of amino acids are disassembled, they are still the same 20 or 21 types. There are not “neuron amino acids” that are different than other amino acids. There is absolutely no way for a sperm cell to know if a lysine it encounters came from a neuropeptide, from the tuna salad you had for lunch, or from the disassembled flagellum of an invading bacterium. Every single cell of the body contains amino acids, and contains the same amino acids. That was very helpful, could the ratios of these amino acids be of any relevance? ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [April 6, 2025, 7:33pm UTC](https://boards.straightdope.com/t/trying-to-connect-behavior-to-evolution/1016566/79 "2025-04-06T19:33:32Z")
> [@Darren\_Garrison](#): > > Also, _ **your balls are not in your brain** _. Although I do know some people who have them near each other? Their heads are up their ass and that ain’t far away! ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [April 6, 2025, 7:36pm UTC](https://boards.straightdope.com/t/trying-to-connect-behavior-to-evolution/1016566/80 "2025-04-06T19:36:23Z")
> [@HoneyBadgerDC](#): > > That was very helpful, could the ratios of these amino acids be of any relevance? The blood levels of amino acids are in constant flux, muscles and organs breaking proteins down and building up continuously, amino acids used for energy too, new ones added in by the foods we eat. So, no. [Previous page](https://boards.straightdope.com/t/trying-to-connect-behavior-to-evolution/1016566.md?page=3) [Next page](https://boards.straightdope.com/t/trying-to-connect-behavior-to-evolution/1016566.md?page=5)