What does “seed” mean in this context? They aren’t ‘manufactured’ from scratch.
From what I recall from high school biology, there’s a process called meiosis that results in sperm. It’s a particular type of cell division that, unlike mitosis, results in cells that carry half our chromosomes - with a mix of the contributions from both parents.
It’s true that not just any cells in our body can divide this way but sperm ultimately originate from some form of cell division, just like all our other cells.
No, a seed is an advanced stage, not an early one, so that’s a poor analogy. In seed-producing plants, a pollen grain is a whole plant that begins growing when it lands on the pistil of a compatable flower. The pollen grain produces sperm cells of its own.
It is called alternation of generations
The seed is the equivalent of the embryo inside an egg, not the producer of sperm.
It’s determined by anything that affects the survival rate of the fetus according to gender; genetic or not. More by the X chromosome than the Y in fact since the Xs are present in all humans not just males, so they have a competitive advantage. The Y chromosome in fact is degenerating and likely to vanish entirely in a few million years, something that has likely happened before as it periodically is completely suppressed by the Xs until a new version of the Y evolves.
Back in my dog breeding days we used to say the sperm determined the sex but the condition of the uterus determined which sperm were successful. If we were looking for males we bred on the first two days of the cycle, females the last 2 days and a mix we bred in the middle. It did seem to work too often to be just chance.
Did you do a thorough statistical analysis to determine what chance would be and how many standard deviations off chance was observed? Just a feeling is not sufficient.
Take a million people and have them all flip a coin 10 times. Don’t tell them anybody is doing it. You will find roughly 1000 of them should flip 10 heads in a row. Another 1000 will flip 10 tails in a row. That’s just the math (2^10 = 1024).
Now, if you took one of them aside, they may think they got trick coins or that they have some secret skill but out of a million people, it’s just a fact that about one in a thousand of them will flip 10 heads in a row.
Taking one seemingly rare event (a litter of all male puppies or flipping 10 heads in a row) and thinking there must be something special is confirmation bias. Have the same person (or dog breeder) try the same experiment 100 times. Are all the results the same, i.e. always controllable? Were the results properly recorded or “I just remember”.
Taking just one result and generalizing is a form of cognitive bias. Might as well buy this Tiger repelling rock I happen to have. I have yet to be attacked by a Tiger, after all.
Step one of the scientific process is to observe, then step two is to form a hypothesis to explain your observations. Don’t get the two mixed up.
If there is some sort of phenomenon you have observed which leads you to suspect the existence of some sort of genetic memory, consider sharing the underlying observation from the outset. Then people can provide a fresh perspective, or even hypotheses for you to research further in support of your developing theory. Such as the need for a larger sample size. If you’ve observed a correlation with the phase of the menstrual cycle and sex of the offspring, at a small scale with dogs, you may be interested in looking at data collected for natural family planning research, in humans. (Spoiler alert: very weak evidence, so far)
In particular, you shouldn’t be looking for a specific mechanism for neurotransmitter levels in cerebral fluids to affect genetic expression in the testes without first observing or inferring a correlation between the two.
The comment about the sex of the puppies had nothing to do with this post at all someone else had started talking about the sex of us bringing I made a simple comment of an experience I had nothing more to it it has nothing to do with this thread at all.
I will add something we do know about “carrying a record of our activities.” The mother’s immune system grants temporary immunity to diseases the child has never encountered, because the mother’s trained white blood cells are still circulating through the child for a little while after birth. I believe part of the reason we know this is because on rare occasions, the system backfires and Mom’s white blood cells think the baby is a disease, or vice versa, called Rh disease, and it causes serious problems, usually death without proper transfusions. But the ‘memory’ is ephemeral, it only lasts a short time (until Mom’s cells die out?) and doesn’t affect the genetic expression of cells in the child’s immune system.
That said, cells from the mother do end up in her children, and the other way around. In fact they are persistent enough that cells from a child can persist in the mother and end up in her later children.
As an aside, articles like that often mention “male cells” a lot because they are easier to distinguish from those of the mother, since they have a protein marker that female cells lack. Something that is suspected to contribute to autoimmune disease among women who have had sons.
Very interesting! I had not known how common fetal microchimerism was. Trying to read more it seems to go primarily fetus to mother and it is unclear if the net is positive or negative for either or both of them. It seems to always be one step more complicated than we currently think …
It might sound like eugenics, but… I used randomness to get my first child, a boy. But then..
I really wanted a daughter so I used a “track my period app” (I am male..) to calculate the ideal date for insemination, and a suprise romantic date was followed by calculated sex. Sure enough, a girl was the result.
Then I got a vasectomy, so that experiment is over.
Or, sure enough, the result was yet again random. Not only does correlation not imply causation, but with a sample size that small not even correlation is implied.
