Fig. 1

The model life cycle. The life cycle consists of discrete steps of (1) mitochondrial mutation (wild-type (white) to mutant (red) mitochondria, represented by small circles), (2) selection between cells, (3) random mating with cell fusion, (4) mitochondrial mixing and (5) division with random mitochondrial segregation. The paternal gamete (yellow) contributes only πM out of its M mitochondria to the zygote, shown here as elimination of some paternal mitochondria. This loss is made up by amplification of the maternal gamete (brown) contribution to (2 − π)M mitochondria. Note that a variety of sampling procedures for both maternal and paternal contributions did not affect outcomes (Additional file 3: Figure S3). The amount of paternal leakage π is controlled by either the maternal (MTmat, blue square) or paternal (MTpat, purple square) mating type nuclear genotype