Animal Inbreeding - A genetic discussion

[Eli]

Gah.. Don't you hate it when you type a huge long post and the thread gets deleted while typing?

Anyway, I'd like to continue the discussion we were having in the later posts of the other thread.

I guess it can't be about humans, though. What about with other animals?

How would it work? How does it work, with endangered species and such? Would the chance for survival completely depend on how the animals happened to re-create the population?

Obviously when trying to save an endangered species, we can inject our knowledge into the mix and keep things as genetically diverse as possible.

But what about wild populations? I know that it's a problem with, for example, urban populations of ferral cats.

Is there anyone here that studies this sort've stuff? Are there computer models? How exactly does inbreeding with no outside contact shape the way a species evolves?

It couldn't possibly always end in failure...

 

[alkemyst]

first many don't understand what in/line breeding are. They think it's nailing your cousin and having a three-eyed child.

It's mostly illegal only because it magnifies problems as well as pluses...however, the bad is very bad sometimes. This is why the law was made...it was causing problems.

People choose their mates on subjective things, breeders breed objectively. They study the pluses and minuses and plan a probable progeny. They aren't usually making random crosses with random results.

Some historical families at one point only inbred. Hemophilia is one outcome shared by some of that lineage.

 

[Eli]

Originally posted by: alkemyst
first many don't understand what in/line breeding are. They think it's nailing your cousin and having a three-eyed child.

It's mostly illegal only because it magnifies problems as well as pluses...however, the bad is very bad sometimes. This is why the law was made...it was causing problems.

People choose their mates on subjective things, breeders breed objectively. They study the pluses and minuses and plan a probable progeny. They aren't usually making random crosses with random results.

Some historical families at one point only inbred. Hemophilia is one outcome shared by some of that lineage.

Yeah.. I guess you must've missed the other thread. It had turned into a discussion of whether it would actually be technically possible for two siblings to re-create the human population.

Let's say you start with two cats, brother and sister... put them together, and watch. What would happen? Maybe we don't even really know, but we should have a pretty good idea. There's gotta be people that study this stuff, if not specifically. Wonder if there have been computer models run simulating things like this...

My guess is that the first few generations would be OK, and then it would start going downhill. More and more of the population would become defective and diseased. That wouldn't necessarily spell the end of them though, would it? It would be an uphill battle.. and it might even take a little bit of what you may call "luck".. Just the right circumstances... for the species to pull through?

It's hard to think about it after the first few generations, it gets quite complex...

 

[alkemyst]

Providing no birth fatal conditions, no reproductive system conditions, and no conditions that prevent one from reaching reproductive maturity there should be no problems with keeping a viable lineage.

However, there may be complications along the way.

 

[thomsbrain]

we already have a real-life "model." it's called kentucky.

 

[Vegito]

Goldfish goes to centuries of inbreeding and a lot of guppies also... the breeder inbreed to get the features they want..

when i had guppies, they definite inbreed w/o a second thought

 

[Nitemare]

Originally posted by: alkemyst
first many don't understand what in/line breeding are. They think it's nailing your cousin and having a three-eyed child.

It's mostly illegal only because it magnifies problems as well as pluses...however, the bad is very bad sometimes. This is why the law was made...it was causing problems.

People choose their mates on subjective things, breeders breed objectively. They study the pluses and minuses and plan a probable progeny. They aren't usually making random crosses with random results.

Some historical families at one point only inbred. Hemophilia is one outcome shared by some of that lineage.

<Joe Dirt>You're my sister! You're my sister!

 

[rahvin]

One example that could be used as justification for certain theories is the cheeta. Sometime during the last ice age the cheeta population was decimated, it's believed that at most one breeding pair survived. Genetically all the Cheetas are very very similar, DNA analysis reveals them all to be related on the level that human DNA would show if you and a very close relative were checked. This lack of diversity has two impacts on the species, the lack of diversity could lead to a future problem where a disease wipes out the entire population because there isn't enough genetic diversity to resist disease and a high propensity for genetic defects as a result of duplicate genes from the imbreeding.

 

[Eli]

Originally posted by: alkemyst
Providing no birth fatal conditions, no reproductive system conditions, and no conditions that prevent one from reaching reproductive maturity there should be no problems with keeping a viable lineage.

However, there may be complications along the way.

Yeah. I guess that's a lot of IFs.

Originally posted by: rahvin
One example that could be used as justification for certain theories is the cheeta. Sometime during the last ice age the cheeta population was decimated, it's believed that at most one breeding pair survived. Genetically all the Cheetas are very very similar, DNA analysis reveals them all to be related on the level that human DNA would show if you and a very close relative were checked. This lack of diversity has two impacts on the species, the lack of diversity could lead to a future problem where a disease wipes out the entire population because there isn't enough genetic diversity to resist disease and a high propensity for genetic defects as a result of duplicate genes from the imbreeding.

Hmm.. Yes..

So while biologically undesirable, it wouldn't necessarily condemn the species to certain death... It would just make the road much harder, potentially much.

How do recessive(not sure if that's the right term) genes work?

Let's say two animal siblings have babies. A few of the babies are exactly like mom & dad. However, one of the babies is nothing like them. It's showing genes from perhaps some distant, completely different lineage. Wouldn't that count for something?

Don't we all have those genes in us, they just may not be dominant or prevalent.. because, what? They just didn't happen to be arranged like that as you were being "put together"?

 

[ruffilb]

Well, the problem is that over a long enough line, while genetic differences increase due to mutation, meosis, etc, only rarely does a mutation make a difference in the actual phenotype of an organism, and when it does, it's not always desireable.

The way recessive traits work, as long as the couple doesn't have similar recessive (harmful or not) traits, there's almost no chance for them to come out.

If two mammals with similar recessive traits produced offspring, say, 10 or so lived past childbirth (they'd really be going at it), there'd be a much greater chance for them to die later on of possible recessive diseases/invaluable traits. (I don't exactly know how to do this probability, I don't think it's a punnet square due to the sexual aspect of the reproduction. Help me out?)

I guess the question is: Would the species last long enough to gain genetic diversity without first dying out from shared recessive problems?

Edit: BTW, I know what thread you're talking about... I brought it up, if I'm not mistaken

 

[Rastus]

Inbreeding is very common in the animal world.

Most purebred dogs are inbred by unethical breeders running puppy mills.

When a rancher wants to change the breed of cattle he is raising, he just buys one bull. About three or four generations later on his ranch all of his cattle are that breed. That's done with inbreeding.

The American Bison (Buffalo) got so depleted about 100 years ago, all buffalo have the same DNA.

 

[JulesMaximus]

Animals shanimals...who cares...as long as you're not fvcking your sister.

 

[sandmanwake]

I'd like to see controlled breeding of humans myself. Just like they did in Dune.

 

[Eli]

Originally posted by: JulesMaximus
Animals shanimals...who cares...as long as you're not fvcking your sister.

 

[sandmanwake]

Originally posted by: JulesMaximus
Animals shanimals...who cares...as long as you're not fvcking your sister.

Edited by request:
Whatever, it's your thread. I don't see anything wrong with what I posted though.

 

[Eli]

Originally posted by: sandmanwake

Originally posted by: JulesMaximus
Animals shanimals...who cares...as long as you're not fvcking your sister.

<snip>

Shhhhh!!!! Edit your post please.

It's probably this kinda discussion that got the other thread deleted.

 

[JulesMaximus]

Originally posted by: Eli

Originally posted by: sandmanwake

Originally posted by: JulesMaximus
Animals shanimals...who cares...as long as you're not fvcking your sister.

<snip>

Shhhhh!!!! Edit your post please.

It's probably this kinda discussion that got the other thread deleted.

Ya think? :Q

 

[alkemyst]

it's not always recessive genes that are the bad ones.

However, the way a recessive gene works is that it requires it to be present in both parents...a dominant can be in either or both. Now this is a simple statement, there is a lot more to it at times.

Sometimes you are breeding for recessive traits. A lot of times these are the traits that bring the bigger bucks from collectors/exhibitors.

In my opinion, birth defects aside, I would not see a problem personally knowing someone who was dating/married to a relative. If someone is making someone else happy and not causing another any side effects I am all for it.