TABLE 1

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

Null recombinationLow recombination
N = 1000N = 500N = 1000N = 500
bClicksRunsClicksRunsClicksRunsClicksRuns
0.000239.420a12.910b
0.00033.130c0.50109.9510b
0.00040.49507.420b0.03101.3410
0.00050.12301.8610c0100.5510
0.00060.01300.62100.2210
0.00070100.34100.1310
0.00080.15100.0210
0.00090.1710
• 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.

• a 105 generations.

• b 2 × 105 generations.

• c 5 × 105 generations.