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Fig. 6. | BMC Biology

Fig. 6.

From: Biological function in the twilight zone of sequence conservation

Fig. 6.

Variation in selection efficiency. Purifying selection is increasingly inefficient for alleles of small selection coefficient s within species of relatively small effective population sizes N e , leading to an increasing rate of accumulation of deleterious changes. The graph shows the probability of fixation of a new variant relative to the neutral expectation (Y-axis) as a function of N e s for s = −10−5 (modified from [10]). For larger values, such as N e  = 105, the probability of fixation relative to the neutral expectation is small at approximately 7%. Nevertheless, in a population with a tenfold smaller N e this probability rises to 81%

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