"DNA My Dog" misidentifies humans as dogs

[ikeOnABike]

@llamaspit

Does this look like an American Eskimo dog to you?

Well… no… but maybe it’s off season now for the Iditarod so they’re just, you know, trying out a new look?

[FSogol]

Well Sam, it looks like my gig is up. They’ve proved I’m not a dog. Thanks for all the tummy rubs, snacks, and walkies but I’ll be moving on.

[socialclimber]

@knappa

(You are half mom and dad, but your inheritance from your grandparents doesn’t have to be a quarter each and it often becomes more skewed when you look at smaller samples.)

I’m not sure what you mean by “You are half mom and dad”.

(Edited to add: And ignore everything after this, which is definitely wrong, as pointed out by bucanneer and knappa.)

Let’s ignore the genes on the X and Y chromosomes which introduce extra complications. For genes on every other chromosome, , you have an equal chance of inheriting each genetic parent’s allele. This does not mean you inherit exactly half of them from each parent.

If it was true that exactly half of any person’s genes come from each genetic parent (and it isn’t) then it would be true that exactly 1/4 would come from each genetic grandparent.

[bucaneer]

Um, that’s all wrong. We are diploid organisms, meaning our chromosomes come in pairs, and in each pair one chromosome is inherited from the mother and the other from the father. That also means that we have two alleles for every (autosomal) gene, one from each parent. The trick is that the child doesn’t simply get one chromosome from each of the parents’ chromosome pairs. Instead, each unpaired chromosome in the gametes - eggs and sperm - is produced by mixing up the contents of the pair. The mixing process (meiosis with crossover) is essentially random, so any given gamete will probably end up with unequal amounts of inherited genetic material. The unpaired set of chromosomes that a child inherits from a parent via a gamete represents a half of the parent’s genome, but the genetic contribution from each grandparent is unequal.

[knappa]

@socialclimber

If it was true that exactly half of any person’s genes come from each genetic parent (and it isn’t) then it would be true that exactly 1/4 would come from each genetic grandparent.

@bucaneer said it well. Here’s some educational material from the NIH for reference:

Diploid

Occasionally you can get trisomy, which would break the half-and-half structure, but that usually leads to conditions in the death/serious disease/infertility category. Plants seem to handle higher number of chromosomes better.