Wikipedia:Reference desk/Archives/Science/2022 April 15

= April 15 =

Cats with the same or similar fur pattern
How probable is it that there are two or more cats (of either sex) anywhere with the identical or very similar fur color pattern (not only twins)? 212.180.235.46 (talk) 18:21, 15 April 2022 (UTC)
 * Black cats all look pretty similar to me! However, I guess their mothers can tell them apart.... Mike Turnbull (talk) 19:27, 15 April 2022 (UTC)
 * Seal point Siamese cats, while not monochrome, have very similar coats. The European shorthair has a distinctive stripe pattern, but it is not hard to find a pair that is difficult to tell apart. For calico cats it is hard to find a really similar pair; assigning a probability (which would have to be done experimentally) requires a workable operationalized definition that draws a line between "very similar" and "not very similar". See how many similar-looking couples you can spot here – but be aware that some photos show the same cat in different poses. If n is large enough and you find s very similar pairs, the probability is roughly 2s/n2. --Lambiam 22:31, 15 April 2022 (UTC)
 * All white Persian breeds have the same (lack of) pattern. Van cats are especially similar down to skull shape and eye color. 97.82.165.112 (talk) 00:29, 16 April 2022 (UTC)
 * While the validity of Lambiam's caveat (regarding a firmer metric of what constitutes 'similar') cannot be questioned, I can nevertheless tell you with some certainty that the probabilities are actually extremely high, if we are talking about Felis catus. I've done a lot of domestic, feral, and wild cat rescue over the course of my life and have had an opportunity to observe how Mendelian inheritance plays out in coat pattern expression/phenotypes of various breeds, and I can tell you that I have many times seen nearly identical cats be spit out by the same breeding group, sometimes as siblings, and sometimes generations apart.  Indeed, in a given breeding pool, even when you do not get near-identical pairs, you will often see numerous cats sharing a large number of idiosyncrasies in the expression of patterns in their fur.  On the converse side, however, remember also that expression of the genes controlling appearance can be heavily influenced by epigenetic factors, both in utero and during juvenile development: even genetic twins will sometimes end up looking quite differently after variant environmental factors and diet.  I realize this isn't the most empirical or precise of data to answer your inquiry with, but rather an impressionistic answer to your question, but let me put it to you this way: if you were to raise 30-40 cats from one maternal line across 3-4 generations, I would bet you would end up with at least two or three pairs that you would probably be able to tell apart easily enough, but who would confuse the hell out of anyone not super familiar with them. SnowRise let's rap 15:26, 16 April 2022 (UTC)
 * The definition of "twin" in a species that produces litters can be problematic. Most cats are fraternal twins inasmuch as they come with other kittens from a single pregnancy, but the kittens may only be half-sibs.  A queen on heat will mate with multiple toms, given the opportunity, and so some of the fraternal twins are only half-twins! Martin of Sheffield (talk) 16:46, 16 April 2022 (UTC)
 * Well, arguably I used nomenclature that was too imprecise, in an effort to keep the info accessible to the OP, but I was specifically talking about monozygotic twins: even these can end up having markedly different coats as they develop, which is a surprise to many people, as it feels unintuitive to their experience/understanding of the largely identical nature of most human monozygotic twins. Of course the truth is is much more complex than that with humans as well, but that's the common perception. Sn<b style="color:#99d5fe;">o</b><b style="color:#b2dffe;">w</b><b style="color:#B27EB2;">Rise</b><b style="color:#d4143a"> let's rap</b> 20:28, 17 April 2022 (UTC)