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[Lancensis]

For the record, the perceived stubbornness of animals like mules, donkeys, and oxen, is actually nothing more complex than the animals being smart enough to understand self-preservation. A horse will work itself to death if you keep telling it to go. A mule will stop when it's nearly exhausted. An ox will stop if it SEES dangerous terrain in front of it. (First-hand experience: a pair of oxen refused to walk onto a poorly-maintained boardwalk that was visibly pitted and rotten. The horse team they were following didn't hesitate.)

So basically a horse uses two extra chromosomes to make itself bigger, and more prepared to kill itself than a donkey?

[Kaelem Gaen]

I think that sorta sums it up yes.

[Arrkhal]

Yeah, horses vs. donkeys is a little bit like dogs vs. cats, though not quite as pronounced.

Another big differences is that if horses see something that they recognize as dangerous, like a snake or a wolf or something, they'll usually immediately panic and run, unless they're specifically trained not to.  Donkeys and mules will stop and evaluate the situation, before deciding what to do.  Which is usually charge and attack.

That reminds me, it'd be pretty cool if smaller races could use goats for mounts.  A large billy goat (the bigger breeds can be 300+ pounds) with knives strapped to his horns would be an absolutely devastating war mount.

[Noble Digger]

It seems like the kennels could one day be set up for advanced animal husbandry ("make mules" "improve dog breed" "launch pregnant cats out of ballistae"). Here's a tidbit you may enjoy. A female mule is called a 'jenny' and a male called a "jack".

From wikipedia:

Horses and donkeys are different species, with different numbers of chromosomes. Of the two F1 hybrids between these two species, a mule is easier to obtain than a hinny (the offspring of a male horse and a female donkey). All male mules and most female mules are infertile.

So you can get a progressively more donkey-based mule if you successfully breed female mules with donkeys across several generations? Could this eventually result in a mule strain with most of the positive donkey traits which is capable of breeding with horses? Like..

Code: [Select]

h+D H+d
 |   |
M+d M+d
 |   |
 Mutant+Mutant
  |
 Stable and beneficial mutation, likes horse dick


[Arrkhal]

Unfortunately, impossible.  There have been fewer than 100 fertile mules in the last 500+ years, so it's very unlikely to happen.  Also, fertile mules usually pass on their maternal genes without any recombination, thus a mule will breed like a horse, and a hinny will breed like a donkey.  I.e., stallion + fertile mule = normal horse, jack + fertile mule = normal mule, stallion + fertile hinny = normal hinny, jack + fertile hinny = normal donkey.

I've heard of 2 documented cases of a mule producing a 3/4 offspring, though.  One was a ton of years ago, where a mule produced a foal that looked like it was 3/4 horse, but they didn't know anything about genetics back then.  The other is the more recent "dragon foal" that actually is genetically 3/4 donkey.

So you're probably looking at a million-to-1 shot to produce a fertile mule/hinny in the first place, then a 50-to-1 for whether its eggs' DNA gets recombined.

Genetics is harder than it looks (also, Mendel was essentially barking up the wrong tree, as only a very small percentage of genes actually follow the dominant/recessive model; most are codominant).

[Lancensis]

Genetics is harder than it looks (also, Mendel was essentially barking up the wrong tree, as only a very small percentage of genes actually follow the dominant/recessive model; most are codominant).

Is that due to characteristics being affected by several different genes (like eye colour has been found to be - I hear) or for some other reason?

[Arrkhal]

There is that, but the majority of "wild-type" alleles are dominant to vastly varying degrees, anywhere from complete dominance to an even 50-50 split.  ABO blood types would be one of the simpler examples; I^A and I^B are each completely dominant over i, but co-dominant with each other.  But most genes aren't nearly so clear-cut as that, and allele pairs can sometimes interact in pretty crazy ways.  A better example might be human skin color, which is pretty obviously a continuum with no distinct phenotypes; otherwise, humans would only come in a couple dozen colors at most.  Not only are there more than one gene, and more than a couple alleles for each one, but each allele interacts differently with every other one.

You could think of it sort of like each gene is a portion of a recipe, and each allele specifies a different amount of a particular ingredient (and some of the crazy ones even use a different ingredient, or even say to take something out).  So one allele pair that says 2 tsp of salt + 1 tsp of sugar would result in something a little different than one that says 2 tsp salt + 1.5 tsp sugar, and would be completely different from 2 tsp of salt + 1 tsp of garlic.

Very few traits, compared to all the things that make each member of a species distinct, can be traced to a single dominant/recessive gene.

Most common deleterious alleles (and those are the ones you tend to hear the most about) are recessive, which makes sense.  A recessive deleterious allele will not affect any of the offspring if a heterozygous carrier mates with a homozygous wild-type (barring spontaneous mutation), while a co-dominant one would affect half of them on average, under the same conditions.  So that bias towards researching genetic diseases can make it seem as though genetics in general is mostly Mendelian.

Mendelian genetics are sort of like Newtonian physics.  They're all you learn outside of 200 or 300-level college courses, and they only tell you just enough to get you into trouble.