Krause, the mule.

[Annatto]

sorry if im in the wrong topic thing, but i need some help. the mule krause, she has 63 chromosomes, so how many chromosomes are in each of her egg cells? and her mothers? and what would be unusual about the meiotic proces in krause? any answer would be greatly appreciated thanks

[army]

with 63 chromosomes, the mule fails to proceed meiosis for each of its generative cells. That's why mule is infertile. She can not produce ovum.
there will be a better answer from the expert, of course. I could not explain for more detail, I'm sorry.

[Annatto]

thanks, but for some reason this mule had 2 offspring, thats why im confused with the chromosomes.

[sorrels]

Hi, I have anecdotal evidence about fertile mules. A certain mule breeder used Percheron mares and Spanish jacks to produce good working mules. He also maintained separate hers of the donkeys and horses for breeding and marketing. One of his mule foals was female. She was quite obviously of mixed blood as I saw her. This mule gave bith to a female foal through a Spanish jack she had been with. The jack was remarkable for his markings and was the only potential sire of the foal.

This is not totally unknown. There is a chromosomal difference between donkeys and horses and usually, mules are infertile but it can happen and has been reported in several places. I would suggest that in such cases, the 63 chromosomes of the mule divide unevenly and make it possible for such a mating to occur.

That seems possible given the fact that in humans we have evidence of XYY males and XXX females. The frequency of such mismatches ir low in humans and there are far fewer mules than humans and for that reason I suspect the occasional fertility of a mule goes unobserved.

Theoretically, an XYY male is impossible but it does happen. Richard Speck, the murderer is the most prominent example that comes to mind but there have perhaps been many others who never achieved the same level of noteriety.

An uneven division of chromosomes is one potential source of speciation. It is a rare enough event but should two individuals with the same tendency mate, one could have a new species rather quickly.

Examining cases of Down's Syndrome, one finds a mismatch at the level of the chromosome. Down's Syndrome is actually rather common and suggests that there may be other cases that may not be as obvious. How many of us have had a chromosomal examination? The technology is limited at present. Perhaps furture advances will permit greater knowledge of speciation in humans and animals.