Hoffmann Richard J
Department of Zoology, Iowa State University, Ames, IA, 50011.
Mount Desert Island Biological Laboratory, Salsbury Cove, ME, 04672.
Evolution. 1986 Mar;40(2):357-365. doi: 10.1111/j.1558-5646.1986.tb00477.x.
Northeastern North American populations of the sea anemone Metridium senile show marked differences in levels of genotypic diversity. Comparisons with expectations generated by computer simulation show that some populations are genotypically as diverse as expected for sexually reproducing populations with free recombination, whereas others are significantly less diverse than expected, despite efforts to avoid collecting clonemates. These reductions in diversity are not attributable to the Wahlund effect; they probably result from extensive clonal reproduction. Reduced genotypic diversity may be produced by low rates of recruitment of planktonic larvae, followed by asexual proliferation. The resulting founder effect may account for previously documented random allele-frequency variation between adjacent populations. It is presently uncertain whether the few genotypes found in some populations are particularly well-adapted to local conditions.
北美东北部海域的海葵（Metridium senile）种群在基因型多样性水平上存在显著差异。与计算机模拟产生的预期结果进行比较表明，一些种群在基因型上与具有自由重组的有性繁殖种群预期的一样多样，而另一些种群的多样性则明显低于预期，尽管已尽力避免收集克隆体。这些多样性的降低并非归因于瓦伦德效应；它们可能是广泛的克隆繁殖导致的。基因型多样性的降低可能是由于浮游幼虫的低补充率，随后是无性增殖。由此产生的奠基者效应可能解释了先前记录的相邻种群之间随机等位基因频率的变化。目前尚不确定在一些种群中发现的少数基因型是否特别适应当地条件。
