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BAKER'S LAW REVISITED: REPRODUCTIVE ASSURANCE IN A METAPOPULATION
Author(s) -
Pannell John R.,
Barrett Spencer C. H.
Publication year - 1998
Publication title -
evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.84
H-Index - 199
eISSN - 1558-5646
pISSN - 0014-3820
DOI - 10.1111/j.1558-5646.1998.tb03691.x
Subject(s) - metapopulation , biology , biological dispersal , ecology , context (archaeology) , obligate , evolutionary biology , demography , population , sociology , paleontology
Baker's Law states that it is more likely for self‐compatible than for self‐incompatible individuals to establish sexually reproducing colonies after long‐distance dispersal, because only the former can do so with a single individual. This hypothesis, proposed by H. G. Baker 40 years ago is based largely on the observation that self‐compatibility is particularly frequent among colonists of oceanic islands. Here we argue that the principle of Baker's Law applies equally in the context of a metapopulation in which frequent local extinction is balanced by recolonization of sites by seed dispersal: metapopulation dynamics will select for an ability to self‐fertilize. We review several studies that support this hypothesis and present a metapopulation model in which the seed productivity required by obligate outcrossers for their maintenance in a metapopulation is compared with that of selfers. Our model also estimates the reduction in the advantage of reproductive assurance to selfers as a result of perenniality and seed dormancy. In general, selection for reproductive assurance is greatest when the colony occupancy rate, p , is low and is much reduced when p approaches its maximum. This provides an explanation for the observation that many highly successful colonizers, in which p is often high, are self‐incompatible. The basic model we present also lends itself to comparisons of metapopulation effects between unisexuality and cosexuality and between different modes of self‐incompatibility.