What is the probability that, in an organism with a haploid number of 12, a sperm will be formed that contains all 12 chromosomes whose centromeres were derived from maternal homologs?

Having 2 chromosomes that are divided will give you a chance of getting one of them of 50%. Calculation of the probability as follows:

Probability = 0.5^12
Probability = 0.00024
So, you have a chance of 1 in 4167. Hope this answers the question.

Many archeologists and anthropologists disagree with dr. thorne's view.  thorne strongly believes that what many calls "homo erectus"  was in fact  homo sapiens,  and that they migrated out of africa almost 2 million years ago and dispersed throughout europe and asia. that's way different  from what scientists have always believed about the evolution of the species.