Inbreeding

I've seen a few people asking if they can breed offspring with parents or siblings, so I decided to make a post on the topic, as my lectures are currently covering inbreeding.
It seems to be mention in a lot of places, but there doesn't seem to be a topic solely on it (please correct me if I'm wrong about this)
Some of this is my opinion, and I completely respect your right to your own opinion.

Inbreeding is defined as the breeding of individuals with alleles identical by decent.
This means that they can/do have the same alleles for some traits, which may be deleterious. Which means that if they have the same recessive allele, their offspring are more likely to have this gene.
Domesticated animals tend to be a lot more inbred than wild populations (unless of course the wild population is small), because we like to breed animals for specific traits.

Which can be a very bad thing.
Even in animals where breeding records are kept, this still happens.
While these animals may be pretty, it can have severe effects on their health, making them more prone to disease, have a genetic predisposition to developing some health problems (eg; cancer, heart problems) and deformations.
In inbred populations the rates of stillborn (dead) young, deformation, and heightened environmental sensitivity are increased.

You could breed them.
Axies don't appear to care who they breed with (some species will stubbornly refuse to breed with anyone who is related to them because they can detect who is genetically similar), which could suggest that it hasn't been an issue for them in their evolutionary history.
Inbreeding can cause some novel traits, such as new/variations in colour.
Albinism, for example, is recessive, and appears more frequently in inbred populations.
Because they are kept as pets, genetic variation in regards to survival [as a species] in the future is not really a concern- as long as they are kept as pets they probably would not need a lot of genetic diversity, as they will not really experience much environmental change, which would affect their survival.
Individuals are most likely related anyway, and I doubt that breeding closely related individuals would 'muddy' their genetics more. It's already pretty muddy looking to me.
But it will increase the rates of bad mutations

That said you probably shouldn't. The population is already inbred, and knowingly breeding directly related individuals won't really help this. You'll probably end up with less successful eggs, young that are sickly, or carry mutations that could affect their survival and shorten their lifespan.
Adding less related stock can increase the genetic diversity, which can reduce the rates of stillborn and deformed offspring.


Ultimately it's up to you to make your own decision on whether or not you should breed them.
Feel free to add your own arguments to this.

Just out of interest does anybody know how big the lakes are that they originally came from and ideas of rough population numbers before man started to interfere? My guess is that an isolated population like that probably had a fair amount of inbreeding anyway. I personally don't think inbreeding is such a bad thing as long as it's not repeated over many generations. Just a thought.


Regards Neil

No idea, I'd say it did as well.
Evidently at one point there was a genetic mutation that was advantageous for them, which allowed them to stay in a neotenic state. And in lakes you've got a pretty limited population, especially if there isn't any migration between lakes.

Inbreeding is crossing two closely related animals - siblings, parent and child. This doesn't mean that they have identical alleles although it might. Usually, inbreeding results in nothing more than very similar offspring - which is the desired result. However, if the particular family you are inbreeding (looking to isolate a particular gene for some reason, for instance) also carriers an allele for some undesirable characteristic, that trait will also become more prevalent in the population. There are a lot of examples of this. One such example is all of the problems that English Bulldogs have and Labrador Retrievers also have hip issues because of their constant inbreeding to create the various color lines.

The lakes in Mexico where these animals originated were, at one time, quite large. They are now nearly non-existent.