Extended Data Fig. 7: Parameter search for computer model of selection acting at level of cell fitness.

a, Fitting the three parameters (location, depth, and pitch) of the inverse sigmoid function resulted in the function shown. b, 3D scatter plot showing the 20,000 models we trained to fit the inverse sigmoid to our data. Each dot represents a model trained with a random combination of the three parameters, and the color indicates the log-transformed smoothed and combined mean squared error (see Methods for details) of the resulting fit to our observed data. The minimum MSE is indicated by a large gold-colored marker. c, A range of multinomial sample sizes per cell for simulating the heteroplasmy was tested, and 1000 was chosen. The boxplots represent a total of n = 20,000 models. The 500 box represents 5071 models, the 1000 represents 4979 models, the 2000 represents 4944 models, and the 4000 represents 5006 models. The boxes show the interquartile range, the line through the box shows the median, the whiskers show 1.5 * interquartile range. d, Plots showing the marginal 2D facets of the 3D plot in panel b. Each hexagon is colored based on the mean smoothed and combined MSE for models in that 2D bin. Red lines indicate the chosen optimal parameter combination.