I cannot figure out how the first member of such a new species breeds. I can think of only three possibilities: i. it breeds with an unrelated partner with exactly the same changes in their chromosomes, which is highly unlikely, ii. it breeds with a sibling with similar chromosome makeup, iii. it breeds with a partner with different number of chromosomes, but somehow produces fertile offspring with similar chromosome makeup as the former. For example, did the first hominid with 46 chromosomes find a mate among those with 48 chromosomes, or one with 46 chromosomes as well?