I.2 Haploid inheritance
单倍体也有短暂的二倍体时期：
Meiosis：减数分裂
依据图示信息，同时基因型A的频率是p，基因型a的频率是（1-p）：
建立Hardy-Weinberg proportions：（即组成相应二倍体的概率）
在经过短暂的二倍体事件后，通过减数分裂变成单倍体，所以接下来计算单倍体内不同基因型的频率：
所以，就单倍体而言，每一世代的基因型频率相同（又因为无性生殖每一世代的基因型频率相同）所以，haploids as exactly equivalent to asexuals
tips：许多问题可能应该以单倍体角度考虑
问题：该如何理解？？？It has been implicitly assumed that, even if there is a mating type system as in yeast, where two alleles, a and α determine the mating types, that the genotype frequencies are the same among both a and α haploids, so that we need not take mating types into account.
