Joined: Dec. 2002
To answer these points of AFDave's directly:
|(1) No one to my knowledge has ever proposed a stepwise solution of HOW the 2A and 2B chimp chromosomes joined. This appears to be a HUGE obstacle.|
(2) The join was 'head-to-head'. If my understanding is true (stated below) that chromosomes are read in only one direction, then this would be a SECOND HUGE OBSTACLE.
1. Chromosome fusions happen all the time. A colleague of mine specializes in following them in microbial evolution: they are a ubiquitous response to selective pressure.
2. Chromosomes have no polarity. The "head-to-head" directionality is arbitrary.