TABLE 1.

The speed of Muller's ratchet on a null- or low-recombining chromosome

	Null recombination				Low recombination
N = 1000		N = 500		N = 1000		N = 500
b	Clicks	Runs	Clicks	Runs	Clicks	Runs	Clicks	Runs
0.0002	39.4	20a		—	12.9	10b		—
0.0003	3.1	30c		—	0.50	10	9.95	10b
0.0004	0.49	50	7.4	20b	0.03	10	1.34	10
0.0005	0.12	30	1.86	10c	0	10	0.55	10
0.0006	0.01	30	0.62	10			0.22	10
0.0007	0	10	0.34	10			0.13	10
0.0008			0.15	10			0.02	10
0.0009			0.17	10

The average number of clicks per 10⁵ generations is shown, assuming a constant rate of element fixation, with the recombination rate on the fourth chromosome either 0 (null recombination) or 10⁻⁵ between insertion sites (low recombination). The remaining parameters are u = 0.01, v = 0, a = 0.001.

All simulations are run for 10⁶ generations, except where indicated. — denotes simulations where element fixation was so rapid that the computing power was insufficient to run the simulation for 10⁵ generations.

^a10⁵ generations.

^b2 × 10⁵ generations.

^c5 × 10⁵ generations.