Hypothetical sisterkiller

It was premature of Hurst in his News and Views article I to accept Haig’s claim2 that a hypothetical meiotic drive element, SisterKiller, can lead to evolution from one-step to multi-step meiosis. The basis of Haig’s claim is that a SisterKiller allele that causes a gamete to kill its sister gamete can invade and go to fixation in a population using one-step meiosis, whereas in a population using multi-step meiosis, Sister Killer cannot invade. Hurst concludes that SisterKiller could have caused the evolution of multi-step meiosis. The conditions under which this is true are more restrictive than Haig suggests.