Egbert G. Leigh

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The high alpha-diversity of tropical forests has been amply documented, but beta-diversity-how species composition changes with distance-has seldom been studied. We present quantitative estimates of beta-diversity for tropical trees by comparing species composition of plots in lowland terra firme forest in Panama, Ecuador, and Peru. We compare observations(More)
To represent species turnover in tropical rain forest, we use a neutral model where a tree's fate is not affected by what species it belongs to, seeds disperse a limited distance from their parents, and speciation is in equilibrium with random extinction. We calculate the similarity function, the probability F(r) that two trees separated by a distance r(More)
Understanding why there are so many kinds of tropical trees requires learning, not only how tree species coexist, but what factors drive tree speciation and what governs a tree clade’s diversification rate. Many report that hybrid sterility evolves very slowly between separated tree populations. If so, tree species rarely originate by splitting of large(More)
Like altruism, mutualism, cooperation between species, evolves only by enhancing all participants' inclusive fitness. Mutualism evolves most readily between members of different kingdoms, which pool complementary abilities for mutual benefit: some of these mutualisms represent major evolutionary innovations. Mutualism cannot persist if cheating annihilates(More)
Many thought Darwinian natural selection could not explain altruism. This error led Wynne-Edwards to explain sustainable exploitation in animals by selection against overexploiting groups. Williams riposted that selection among groups rarely overrides within-group selection. Hamilton showed that altruism can evolve through kin selection. How strongly does(More)
We describe the analogy between the theory of natural selection on sex ratio in newborn gonochores (which will not change sex), and on the age of sex change in sequential hermaphrodites (which are all born into one sex and change to the other later on). We also discuss the conditions under which natural selection favors sequential hermaphrodites over(More)
To resolve a panselectionist paradox, the population geneticist Kimura invented a neutral theory, where each gene is equally likely to enter the next generation whatever its allelic type. To learn what could be explained without invoking Darwinian adaptive divergence, Hubbell devised a similar neutral theory for forest ecology, assuming each tree is equally(More)