Question

Discuss the logical fallacy of codominance as an explanation for zebra stripes...

Answer 1

The coloration of zebras shown is rare. However, a certain myth has it that both white and black zebras should be common (myth of codominance & variegation).

Discuss the logical fallacy of codominance as an explanation for zebra stripes and list the possible alternative explanatins for the rare coloration. You may use punnet square to illustrate the argument.

Answer 2

I'm not really sure how to answer this, but I'm thinking that codominance is referring to exhibition of both parental phenotypes, hence, that means that it is heterozygote. But, given that zebras exhibit black and white stripes as the "wild-type" phenotype, then codominance can't be logical.

Could a possible argument be that this is due to a mutant allele which codes for the pigmentation of zebra that causes this. Not sure how to use a punnet square to argue this. though..

Answer 3

@thomaster

Answer 4

i'm not sure i'm familiar with what the "logical fallacy of codominance" is..but since codominance is the display of two distinct phenotypes, we can speculate:

lets say you had black (BB) horse, and a white (WW) horse, if the alleles that coded for skin/fur pigments were able to recombine, then if you cross these, you will get a heterozygote displaying both the white and the black phenotypes.



not sure how these would form stripes and not blotches (like cows) though.

Answer 5

Well, i think it's asking to explain why codominance may not be the case for this since zebras as naturally black and white stripes. But the zebra above is white and brown. and another zebra photo from the problem was an all black zebra with one white stripe. Lol. what a loser, zebra, huh?

Answer 6

@nincompoop

Answer 7

haha one stripe. i'm gonna read into it, i'll come back if i can find an argument.

Answer 8

ps i think it might be due to the influence of multiple alleles and their hierarchy in the outcome of the organism's phenotypic expression.

Answer 9

OMG. Genius. You're right. By hierarchy, are you referring to the order in which they are on the chromosome? Like 1st, 2nd, 3rd?? length wise.?

Answer 10

it's due to evolutionary adaptation - defense from tsetse and/or tabanid (horse fles). though but there hasn't been very strong explanation as to why horseflies are less attractive to stripes (very least) than full bodied color (black - most attractive, brown - more attractive or white least ) other than due to brightness and polarization. the attractiveness of horseflies showed in experiments that it decreases relative to the stripe width.
source to check - Egri, Ádám, et al. "Polarotactic Tabanids Find Striped Patterns with Brightness and/or Polarization Modulation Least Attractive: An Advantage of Zebra Stripes." The Journal of Experimental Biology 215.5 (2012): 736-45. Print.

Answer 11

hm idk if it would be necessarily in terms of spatial distribution but more of gene interactions. Like some genes' products affect other proteins, these interactions would have a combined effect. i think the term is epistasis

Answer 12

I wish there were more conversations on openstudy like this. Then maybe I could justify the existence of this site.