0 having a single set of chromosomes (= structures containing chemical patterns that control what a plant or animal is like) that comes from one parent only: --
In order to test for ' dominance ', crosses were made between haploids derived from a single heterozygous mutant strain.
In our study, chromosome gain was only apparent in the haploid strains.
Let us now consider an infinite population of haploids, or diploids without dominance, which experience mutation and selection, but no recombination.
In this experiment, the aim was to measure growth rate of diploids in conditions as similar as possible to that used for haploids.
This might be expected when haploids are compared with heterozygotes, but not necessarily expected when haploids are compared with homozygous mutant diploids.
The same will be true if the ratchet has advanced sufficiently far that a substantial proportion of loci are fixed within haploid sets.
This is done below and it is found that the kind of epistasis also strongly influences the (haploid) error threshold.
If selection occurs during the haploid phase, haploid selfing leads to the same population-level consequences as haploid apomixis.
