Chromosomal Crossover Puns

I was reading about chromosomal crossover in The Selfish Gene. According to Dawkins, when chromosomal crossover happens, gene boundaries are not respected: "But crossing-over does not respect boundaries between cistrons. Splits may occur within cistrons as well as between them."

So I guess that genes often get destroyed or 'blended'. But if I am right then how does evolution even work? It sounds like genes are too volatile for the process to work.

This gets much more complicated after this. The way we pass on genes requires a Y-Chromosome from the man being passed down from a father to a son, which he got from his father (the paternal grandfather of this hypothetical child).

Does this mean that a man is less related to his mother's father, who only gave her an X chromosome which he may have gotten a piece of?

Is a new X-Chromosome always 50/50 of it's two sources of genetic material? Or is it a bell curve and you could end up with an X-Chromosome which is almost entirely from one source or the other, making you less related?

The Star Trek episode Up The Long Ladder, they talk about a group of colonists who crashed with just 5 survivors. They knew this wasn't a sufficient gene pool so turned to cloning instead. But what would be a sufficient gene pool?

Let's start by looking at 4 people, 2 men, 2 women. How many descendants could they have without any inbreeding. Let's assume they skip monogamy and each pairing produces a girl and a boy.

I've deliberately named them like this so you can see who the parents were, this makes it easier to spot genetic overlap aka inbreeding. For example, Girl1A can't have kids with Boy2A or Boy1B because they're both her half-brothers. The only viable partner for Girl1A is Boy2B. So the third generation comes from the diagonal joins of the second generation.

At this point everyone has all four original people as their grandparents, all four of the original initials just in different orders. No one can reproduce with anyone without it being inbreeding and any inbreeding now would be a mess. Lets say Girl1A2B wants to have kids with Boy2B1A, they share ALL FOUR grandparents. A normal person has 8 great-grandparents, cousin marriage gives 6 great-grandparents, this situation (Which wiki calls double-first-cousins) gives only 4 great grandparents. The risks of genetic issues from inbreeding at this stage would be severe.

In theory this colony could decide to stop there and switch to cloning. They have 20 different people rather than the 4 they started with. Man1, Man2, WomanA, WomanB, Woman1A, Man1A, Woman1B, Man1B, Woman2A, Man2A, Woman2B, Man2B, Woman1A2B, Man2A2B, Woman1B2A, Man1B2A, Woman2A1B, Man2A1, Woman2B1A and Man2B1A. Most of these people are genetically cousins, uncles, siblings and children of each other so there'd be a LOT of family resemblances and visual similarities between them. As Groove Armada taught us in 1999, if everybody looked the same, we'd get tired of looking at each other. If 5% of people looked the same then it's better but still not great.

(Note there is also a cross-generational pairing where Man1 could have children with the two daughters of Man2 when they're old enough, but this makes the diagram messier. It adds 16 additional unique i

As I understand it you have 23 pairs of chromosomes, each made up of one half from your mother and one half from your father. When you have a child only one of these halves are passed on. How does the body decide which one? Is there and equal amount from each parent or is it possible you pass on 100% of your fathers chromosome-halves and 0% of your mothers? Will it be the same each time, or is it randomly selected every time a sperm/egg cell is produced?

Thanks

I want to create a crossover operator for a genetic algorithm, such that exactly N genes are active in each of the offspring (exactly N genes would be active in each parent as well). Say that I have two parents, the characteristics of which are represented by bit strings of boolean values, e.g. :

[1,0,0,0,1,1,1,0,0,1] and [1,1,1,0,0,0,1,0,1,0]

Five genes are "on" in each parent; I need the offspring to also have exactly five genes (bits in the bit string) on or active. Choosing a cut point and swapping sections won't work, nor will iterating over the positions in the chromosome and assigning a bit from either parent based on probability (both of these approaches could result in more or less than five positions being active).

The alternative I can think of would be to combine all the ON genes from both parents in a pool, and randomly select five from that pool (if a gene is active in both parents, double the probability of it being selected). Is this a good solution, or am I overlooking something really obvious?

It seems like it sucks a bit, as with most other crossover schemes I've seen, if a gene is active in both parents it's guaranteed to be active in the child. Unless I coded this behaviour into the probabilistic selection (i.e. select all genes that are in both parents as mandatory "on", then select the remaining positions randomly from the pool from both parents?).

I feel like I've solved this problem before, but it's been a while since I've played with a GA; thanks in advance for suggestions/comments!

TIL that Common eland, and other spicies of Bovidae, have Y-autosome translocation, and I wondered whether this would cause problems during the meiotic crossover?

I don't want to step on anybody's toes here, but the amount of non-dad jokes here in this subreddit really annoys me. First of all, dad jokes CAN be NSFW, it clearly says so in the sub rules. Secondly, it doesn't automatically make it a dad joke if it's from a conversation between you and your child. Most importantly, the jokes that your CHILDREN tell YOU are not dad jokes. The point of a dad joke is that it's so cheesy only a dad who's trying to be funny would make such a joke. That's it. They are stupid plays on words, lame puns and so on. There has to be a clever pun or wordplay for it to be considered a dad joke.

Again, to all the fellow dads, I apologise if I'm sounding too harsh. But I just needed to get it off my chest.

So this is an idea that came to me recently and is still very much in its infancy but the more I think about it the more it makes sense to me. One theory behind gender dysphoria is that it is caused by cross sex anatomical differences in the brain. So my line of questioning is that if we accept that gender dysphoria is a genuine mental health condition and we accept that brain anatomy can differ between the sexes, why do we always automatically assume that they are linked? What if these two concepts are entirely unrrelated to one another?

There is a wealth of evidence to suggest that males and females typically have slightly different brain function on a biological level. While behaviour and thought patterns can be heavily culturally influenced there is also literature that records some cross sex differences in behaviour as being observable from birth, suggesting that on some level male and female brains differ anatomically. As a "soft" source for this claim there is an interesting Norwegian documentary that explores these concepts. That's not to mention the fact that cross culturally and throughout history men and women have exhibited consistent trends of behaviour in many aspects that heavily suggest that there are influential factors at work that go beyond the scope of culture.

As with any variance, or mutation if we're going that far, it is possible that these anatomical neural differences may manifest in cross sex bodies due to congenital birth variances/defects. What's not clear however is how much of an impact, if any, this may have on behaviour and more importantly on an internal sense of gender identity or comfort within one's assigned birth sex.

Brain scan studies typically show that male and female homosexuals exhibit similarities in brain activity to their cross sex heterosexual counterparts. Homosexuals also exhibit social behaviours, interests and patterns similar to their cross sex heterosexual counterparts at a much higher rate than same sex heterosexuals, suggesting that to at least some extent "brain sex" can be linked with interests and behaviour. If cross sex brain differences had a significant impact on gender identity and discomfort then a strong predictor of gender dysphoria in an individual should be homosexuality.

This is not the case

The significant vast majority of homosexuals, including and in spite of those that display traits suggesting a degree of anatomical cross sex

Do your worst!

I'm surprised it hasn't decade.

For context I'm a Refuse Driver (Garbage man) & today I was on food waste. After I'd tipped I was checking the wagon for any defects when I spotted a lone pea balanced on the lifts.

I said "hey look, an escaPEA"

No one near me but it didn't half make me laugh for a good hour or so!

Edit: I can't believe how much this has blown up. Thank you everyone I've had a blast reading through the replies 😂

It really does, I swear!

They’re on standbi

Buenosdillas

Pilot on me!!

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Dad jokes are supposed to be jokes you can tell a kid and they will understand it and find it funny.

This sub is mostly just NSFW puns now.

If it needs a NSFW tag it's not a dad joke. There should just be a NSFW puns subreddit for that.

Edit* I'm not replying any longer and turning off notifications but to all those that say "no one cares", there sure are a lot of you arguing about it. Maybe I'm wrong but you people don't need to be rude about it. If you really don't care, don't comment.

When I got home, they were still there.

What did 0 say to 8 ?

" Nice Belt "

So What did 3 say to 8 ?

" Hey, you two stop making out "

I won't be doing that today!

[Removed]

You take away their little brooms

This morning, my 4 year old daughter.

Daughter: I'm hungry

Me: nerves building, smile widening

Me: Hi hungry, I'm dad.

She had no idea what was going on but I finally did it.

Thank you all for listening.

There hasn't been a post all year!