What is sex? How did it originate? Why does it persist?

什么是性？

• 批准号: 341399-2007
• 负责人: Gorelick, Root
• 金额: $ 1.54万
• 依托单位: Carleton University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2007
• 资助国家: 加拿大
• 起止时间: 2007-01-01 至 2008-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=362372
• 关键词: What; sex; How; did; originate

I examine the definition, origin, and ubiquity of sex.  Perspectives change when fundamental assumptions are questioned.  Does self fertilization count as sex?  Why is genetic mixing considered the primary function of sex, despite the need to invoke group selection?  My goal is to write a definitive evolutionary history of sex.My working hypothesis is that production of gametes and fertilization both rejuvenate an organism.  I posit that sex is not primarily a genetic phenomenon, but rather an epigenetic one.  More specifically, sex slows down evolution by resetting molecules responsible for development, resetting them to their state in previous generations.  This provides a direct benefit to the individual organism insofar as development would eventually go awry without production of gametes and fertilization.  This working hypothesis may explain the origin of sex and why sex still persists.  Compare this with the current and long-lived paradigm for the ubiquity of sex, in which sex increases genetic variation amongst all descendants, thereby speeding up evolution, but is not necessarily advantageous to any individual.Our research entails devising theory, building mathematical models, and conducting empirical tests.  The theoretical work takes two tacks.  First, we try to explain why reset of developmental signals is associated with gamete formation and fertilization.  Why should this reset be inextricably tied to halving the number of chromosomes?  Second, we consider the term 'gene' to include signals that control development, even if these developmental signals may not be directly coded for by DNA.  We build mathematical models of how such generalized genes evolve, which we use to test whether presence of sex provides an advantage to populations and hence possibly explain why sex has persisted.  We empirically test whether reset of those molecular signals that regulate development are exclusively associated with meiosis and fertilization.

我研究了性的定义、起源和普遍性。当基本假设受到质疑时，观点会发生变化。自我受精算不算性？ 为什么遗传混合被认为是性别的主要功能，尽管需要援引群体选择？ 我的目标是写一部关于性的明确的进化史。我的工作假设是，配子的产生和受精都能使生物体恢复活力。我认为性主要不是一种遗传现象，而是一种表观遗传现象。更具体地说，性通过重置负责发育的分子来减缓进化，将它们重置到前几代的状态。这对个体生物体提供了直接的好处，因为发育最终会在没有配子和受精的情况下出错。这个工作假设可以解释性的起源和为什么性仍然存在。将此与性普遍存在的当前和长期范式进行比较，其中性增加了所有后代的遗传变异，从而加速进化，但不一定对任何个体有利。我们的研究需要设计理论，建立数学模型，并进行实证测试。理论工作需要两个方面。首先，我们试图解释为什么发育信号的重置与配子的形成和受精有关。2为什么这种重置与染色体数量减半有着千丝万缕的联系？ 其次，我们认为“基因”一词包括控制发育的信号，即使这些发育信号可能不是由DNA直接编码的。我们建立了这些广义基因如何进化的数学模型，我们用它来测试性的存在是否为种群提供了优势，从而可能解释为什么性一直存在。只与减数分裂和受精有关。