[quote=concretegurl;3369698]
Quote:
Originally Posted by Rhetts_mama  I did leave that out I'm sorry when I said Parti carrier then bred to Standard I meant to add Standard, a standard with 'no history' of carrying the recessive gene in the line.
...but then again my oh my...
...that's a genetics debate too...those whom carry the gene and have had it presented in their linage and those whom carry the gene and it has and always will remain dormant-which do you label as a carrier? Technically speaking all humans carry the recessive gene to have a tail-it is simply blocked by more dominant genes-yet on super rare occasions babies around the world are born with a slight abnormal protrusion similar to an appendage (a "tail"). No, I am not speaking of the similar occurrence of chromosomal anomaly that result in extra appendages- I am talking specifically about the "tail" gene and it presence.
Ye a HUGE debate in genetic science itself is whom to and to not label a "carrier"....but for this purpose I should have added that-sorry!  |
Say what? I have no idea how a vestigial tail in humans could possibly equate to a parti-carrier label on a yorkshire terrier. How about sticking to valid references that might contribute to the substance of this thread? Everyone is free to post any thought that pops into their head, but so much better if we list valid references that people can really use to make some sense of the subject at hand. There is no substantiative value to off-the-wall genetics anomalies that happen with such rarity as to be void of comparison. Not to mention a completely different genetic concept is the culprit.
All humans have tails (it is not the act of a recessive gene) during a part of their embryonic development. Most are absorbed by the immune system and only the coccyx (tailbone) remains. But VERY, VERY few (23 since 1884 --
over a hundred years) may have a vestigial tail which is not fully absorbed prior to birth. Not the same as white color occuring spontaneously or otherwise. No matter if you are speaking to the tailbone, the tail in embrionic development or the congenital birth defect of a tail structure..... it still is not a valid comparison. When a child is born with this tail structure it is because the normal inactivation has not occured. The white color showing up is due to the recessive gene in both dam and sire joining in the same pup. Not the same genetic action at all. References say this residual tail is NOT familial -- instead "the inheritance of the tail structure is unnecessary since the developmental system has been inherited but is normally inactivated in humans." In other words everyone inherits the tail -- some inactivation mechanism just do not work quite right -- but again -- happens so very seldom! There is no such "inactivation mechanism" to thwart the "white" in all yorkies. It just does not compare at all.