Very weird science question--fish breeding vs. human reproduction

Ms.Bubbles

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Sep 26, 2005
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I was looking at my endlers recently and thinking about breeding them, when suddenly it occurred to me--fish mate with their own 'family' members. I mean, you put a male and female of a species together and they reproduce, then their offspring reproduce with each other, etc. Seems normal.

Now look at human beings--if we reproduce with our own family gene pool, we get all kinds of mutations and weaknesses and problems. So besides being a real social taboo, family interbreeding is a genetic no-no.

What's up here???? Can all animals (lions, elephants, dogs, birds, etc.) safely interbreed with their own 'family'? What about monkeys and chimpanzees-- humananity's closest "ancestors"?

Are humans the only species on this entire planet that cannot safely reproduce within their "family"? And if so, what does this mean?
 
I seem to remember a breeder posting soemthing about this a few weeks ago that said she could go 5 or generations of interbreeding before problems started to arise. I think for mammals it shouldn't be done at all. If I remember my biology, the more complex the organism the more danger there is with interbreeding. In the wild there are migrations and very few bodies of water are absolutely isolated with only a single breeding pair, so there is genetic intermingling there along with the "fincest" I would guess :)
 
Fincest...so poetic.

So what about, say, lions in the wild. Do they recognize members of their own "family" and avoid breeding with them? How come we never hear about animal mutations from interbreeding?
 
I think because in the wild, such as with lions, if there is a mutation, the mother of the newborn will reject it automaticaly if mutated enough for recognition, thus ending up with the infant dying from exposure, starvation, predators, etc. This is the same with say houses cats.... the multi-toed ones, the one a few weeks ago with 2 faces.... that sort of thing.

Graphic, for your post, that is priceless, hehehe
 
Different animals have different was of avoiding interbreeding.

Animals that live in very loose but large social groups do not need to worry much about interbreeding because they have so many potential mates. The chances of successive generations breeding with colse relatives is slim. This works for herding animals and many types of fish including livebearers. Remember that in the wild enders (and relatives) have more space to cover and more fish to interact with.

Animals that live in more structured social societies have a few different options.

1. All members of one sex in the group many get kicked out at sexual maturity. This is the case with many mammals. The obvious example would be a loin tribe. The females stick together in a family group and the males roam around trying to fight their way into a new group.
2. The females may simple prefer outside males. This doesn’t mean they never mate with males from their own group, but it incenses genetic diversity. Many primate groups (like baboons) operate this way. If any watches Meercat Manor this happens with those furry critters too.
3. When the group reaches a certain size the young are encouraged to leave. This happens in large wolf packs. The young may even be encourage to go a certain way. For example beaver young typically look for a new home going down stream, or to another river. This way they do not run into past generations.
4. Only the dominate pair breeds. This can go along with other mentioned examples. It just controls who mates.

Animals that live solitary (or usefully solitary ) lives have options too.

1. Many animals simple remember their mothers and siblings (litter mates). They do not mate with them.
2. Again if every one is spread out the chances of you mating with your next of kin is rare.
3. Mother animals can kick young out of her territory when the mature. If they have to go find and fight for a territory of their own the young may have to travel far and wide. This hopefully puts them in contact with distant relatives.
4. Natural wonder lust and migration can accomplish this as well.
5. Many animals die after breeding. This way parents and children/grandchildren ever inter breed.


I am sure there are other examples as well this is just what I could think of.

* There is evidence that people naturally do not want to mate with siblings. Studies of unrelated children raised in group homes and similar situations rarely ever become romantic with the children they were raised with. Of course there are exceptions to this, and it is hard to tell if it is instinctual or a cultural thing.
 
jennypenny said:
* There is evidence that people naturally do not want to mate with siblings. Studies of unrelated children raised in group homes and similar situations rarely ever become romantic with the children they were raised with. Of course there are exceptions to this, and it is hard to tell if it is instinctual or a cultural thing.
That's right. I saw a TV study on dating not long ago which involved several blindfolded women being were asked to sniff the T-shirts of many different men (a cruel fate, but anyway...) Every single woman rejected the smell of their (unknown at the time) brother's T-shirts, citing the scent as "unattractive" (been there lol), whereas they found other guy's T-shirts a turn-on.

I guess if I do end up ever breeding the endlers, I will make a point of separating the sexes of the offspring when they're young, so interbreeding never occurs. It's not hard to tell male and female endlers apart.
 
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