Spatial dynamics of adaptive sex ratios

: Ranta E, Lummaa V, Kaitala V, Merila J

Publisher: BLACKWELL SCIENCE LTD

: 2000

: Ecology Letters

: ECOLOGY LETTERS

: ECOL LETT

: 3

: 1

: 30

: 34

: 5

: 1461-023X

DOI: https://doi.org/10.1046/j.1461-0248.2000.00112.x

According to Fisherian seu allocation theory, parents that can adjust their offspring sex ratio in response to skews in population sex ratio will maximize their fitness over parents lacking this ability. There is good evidence that adaptive sex ratio adjustment occurs in many natural populations, but deviations from theoretical predictions have also been observed. These anomalies may be more apparent than real. When the spatial dimension of sex ratio variation is ignored, then a mismatch between empirical data and theoretical predictions based on panmictic mating is to be expected. We illustrate this with data on human ses ratio variation in 21 preindustrial populations, and with a cellular automaton model built re, obey Fisherian sex allocation rules. The results from the model generally match with the data. When information about the ambient sea ratio is limited, then the ses allocation decisions may appear locally maladaptive. In general, the results indicate that Fisher's ses-ratio theory may have greater explanatory power than previously thought.