Two roads to two sexes: unifying gamete competition and gamete limitation in a single model of anisogamy evolution
Two roads to two sexes: unifying gamete competition and gamete limitation in a single model of anisogamy evolution
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DOI：
10.1007/s00265-010-1116-8
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发表时间：
2011-03-01
影响因子：
2.3
通讯作者：
Kokko, Hanna
中科院分区：
文献类型：
--
作者：
Lehtonen, Jussi;Kokko, Hanna
最近的研究揭示了自我一致性在进化模型中的重要性，特别是在男女互动的背景下。这一点在祖先性别分化的模型中基本上被忽视了，即，异配生殖的进化在这里，我们模拟异配生殖的进化在费舍尔一致的背景下，明确考虑到在一个典型的生殖群体中的相互作用的个人的数量。我们揭示了当地交配组中的成年个体的数量和选择压力之间的相互作用，负责性别的分歧。同样的基础模型可以以两种不同的方式产生异配生殖。当配子相对容易找到彼此时，配子竞争可以导致异配生殖，但是当这更困难并且没有配子竞争时，配子限制可以为异配生殖的进化提供另一条途径。与早期的模型一致，生物体的复杂性倾向于异配生殖。我们认为，早期的贡献，卡尔穆斯和斯库多，主要是驳回组选择，在一定条件下是有效的。将他们的工作与帕克的贡献联系起来，有助于解释为什么雄性会产生比后代更多的精子：精子可以进化为提供受精卵，但这对所需的努力几乎没有什么好处，因为精子必须具备提供能力，才能知道哪些精子会进入受精阶段。这一见解在不确定的父系关系下（在这种情况下，当一些投资永远不会带来遗传利益时，再次选择投资）和配子大小进化之间建立了逻辑联系。
Recent studies have revealed the importance of self-consistency in evolutionary models, particularly in the context of male-female interactions. This has been largely ignored in models of the ancestral divergence of the sexes, i.e., the evolution of anisogamy. Here, we model the evolution of anisogamy in a Fisher-consistent context, explicitly taking into account the number of interacting individuals in a typical reproductive group. We reveal an interaction between the number of adult individuals in the local mating group and the selection pressures responsible for the divergence of the sexes. The same underlying model can produce anisogamy in two different ways. Gamete competition can lead to anisogamy when it is relatively easy for gametes to find each other, but when this is more difficult and gamete competition is absent, gamete limitation can provide another route for anisogamy to evolve. In line with earlier models, organismal complexity favors anisogamy. We argue that the early contributions of Kalmus and Scudo, largely dismissed as group selectionist, are valid under certain conditions. Linking their work with the contributions of Parker helps to explain why precisely males keep producing more sperm than can ever lead to offspring: sperm could evolve to provision zygotes but this brings little profit for the effort required, because sperm would have to be equipped with provisioning ability before it is known which sperm will make it to the fertilization stage. This insight creates a logical link between paternal care under uncertain paternity (where again investment is selected against when some investment never brings about genetic benefits) and gamete size evolution.