Sexual selection and speciation: from gametes to ornaments

130多年前，查尔斯·达尔文提出，一些植物和动物的特征可能有助于个体获得配偶，尽管这些特征对生存不利。他说，这样的“性选择”特征与自然选择产生的生存特征有很大不同。尽管这是一项重大的科学发现，但由于社会学和科学方面的原因，它在一个多世纪的时间里基本上被忽视了。然而，在过去的30年里，人们对性选择的兴趣大幅复苏，这既是因为做出各种有趣预测的复杂理论的发展，也是因为新的实验、分子和观察技术的发展，使我们能够彻底检验这些理论。我的研究重点是动物的交配前(交配吸引)和交配后(受精)特征，以测试和发展理论，帮助我们更好地解释由于性别选择而进化的动物的多样性。我们目前的研究解决了两个普遍的问题：(1)为什么鸟类内部和物种之间的颜色有如此大的差异？以及(2)为什么精子的大小、结构和行为在不同物种之间有如此大的差异？因此，我们试图了解不同颜色的鲜艳羽毛如何帮助雄性(较少是雌性)鸟类获得高质量的配偶。我们在鸟类着色方面的工作使人们更好地理解颜色视觉的本质，以及颜色在自然界中产生和展示的机制。我们对精子进化的研究也旨在帮助我们更多地了解动物结构和行为的多样性，但它们还有一些额外的水产养殖、农业和医学应用，帮助我们了解男性的状况如何影响他的精子质量和受精成功。越来越清楚的是，交配前和交配后的过程对物种的起源、多样性和维持都很重要，因此我们的工作对物种形成过程的研究做出了重要贡献。

More than 130 years ago, Charles Darwin suggested that some plant and animal features might help individuals to obtain mates, even though those traits were detrimental to survival. Such 'sexually selected' traits, he said, are thus very different from survival traits that resulted from natural selection. Even though this was a major scientific discovery, it was largely ignored for more than a century for both sociological and scientific reasons. The past 30 years, though, has seen a major resurgence of interest in sexual selection due to the development of both sophisticated theories that make a variety of interesting predictions and new experimental, molecular and observational techniques that allow us to thoroughly test those theories. My research focuses on both precopulatory (mate attraction) and postcopulatory (fertilization) characteristics of animals to test and develop theory that will help us to better explain the diversity of animals that have evolved as a result of sexual selection. Our current research addresses two general questions: (1) Why is there so much variation in colour within and among species of birds? and (2) Why does the size, structure and behaviour of sperm vary so much from species to species? Thus, we are trying to understand how bright plumage of different colours helps male (and less often female) birds obtain mates of high quality. Our work on bird coloration is leading to a better appreciation of the nature of colour vision and the mechanisms by which colours are produced and displayed in nature. Our studies of sperm evolution are also designed to help us understand more about the diversity of animal structure and behaviour but they have some additional aquacultural, agricultural and medical applications in helping us to understand how a male's condition influences his sperm quality and fertilization success. It is becoming increasingly clear that both pre- and postcopulatory processes are important to the origin, diversification and maintenance of species, so our work makes an important contribution to the study of the speciation process.