The role of sexual signal evolution in speciation and species coexistence

没有什么地方比动物相互交流时所使用的各种颜色和声音更能体现生命的多样性了。与人类的语言相似，动物使用信号来识别亲戚、保卫领地和吸引配偶。然而，个体使用的信号类型在不同物种之间可能会有很大差异。例如，雄性孔雀用它们色彩鲜艳的尾羽吸引雌性孔雀，而红翼黑鸟则用带有黄色条纹的红色翅膀斑点来赢得配偶。但这种壮观的多样性为什么会存在，它是如何产生的呢？最重要的是，数百万年来新信号的进化可能会导致相关种群之间的沟通中断，因此预计会以不同的沟通方式促进新物种的形成。几个世纪以来，包括查尔斯·达尔文在内的进化生物学家一直质疑为什么动物使用这么多不同的信号进行交流，以及新信号的进化是否会导致新物种的形成。然而，尽管这种兴趣由来已久，回答这些基本问题仍然是一个重大挑战。现在，第一次有可能使用包括紫外线数字摄影和录音在内的新技术来测量数千种动物物种通信信号的多样性。鸟类以其引人注目的羽毛颜色和歌声而闻名，它们拥有近10,000个不同的物种，为在全球范围内检验这些想法提供了一个独特的机会。鸟类感知世界的方式与人类和其他动物截然不同，因为它们的眼睛对紫外线很敏感，这让它们能够看到人眼看不到的颜色。我将生成新的数据集，捕捉所有鸟类的视觉和声音信号的全光谱多样性。我的方法的力量在于，我将能够重建鸟类自己是如何听到歌声和看到羽毛颜色的--这是鸟类相互交流的两种主要方式。我将使用这些新的数据集来比较不同物种的信号，以了解信号如何以及为什么随着时间的推移而变化，以及新的信号是否与新物种的起源相一致。我将结合对地球上生物多样性最丰富的地区之一喜马拉雅地区自然鸟类种群的详细观察。这将使研究通信信号变化对物种之间相互作用的当代后果以及促进生物多样性的因素成为可能。此外，我的研究将通过探索信号如何以及为什么在数百万年内跨物种变化，以及这种变化对新物种的起源和维持的后果，来阐明尚未解决的进化问题。我的研究将极大地促进我们对动物通讯信号进化过程的了解，并最终了解这些信号在促进和维持地球上生命多样性方面所起的作用。

Nowhere is the diversity of life more apparent than in the astonishing array of colours and sounds animals use to communicate with each other. Similar to human language, animals use signals to identify relatives, defend territories and attract mates. However, the types of signals used by individuals can be very different from one species to the next. For example, male peacocks attract females using their technicoloured tail feathers, whereas the redwing blackbird displays a red wing spot with a yellow stripe to win mates. But why does this spectacular diversity exist and how did it arise? On top of this, the evolution of new signals over millions of years can lead to the breakdown of communication between related populations, and is therefore predicted to promote the formation of new species with different ways of communicating. For centuries, evolutionary biologists including Charles Darwin have questioned why animals use so many different signals to communicate, and whether the evolution of new signals leads to the formation of new species. Yet, despite this long-standing interest, answering these fundamental questions still remains a major challenge.For the first time, it is now possible to measure the diversity of communication signals across thousands of animal species using new technologies, including ultraviolet digital photography and sound recording. Birds are famous for their striking plumage colour and song, and with almost 10,000 different species, they provide a unique opportunity to test these ideas on a global scale. Birds perceive the world in a very different way to humans and other animals, as their eyes are sensitive to ultraviolet light, allowing them to see colours invisible to the human eye. I will generate novel datasets capturing the full spectrum of diversity in visual and acoustic signals across all birds. The power of my approach lies in the fact that I will be able to reconstruct how birds themselves hear songs and see plumage colour-the two main ways that birds communicate with each other. I will use these novel datasets to compare signals across species in order to understand how and why signals change over time, and whether new signals coincide with the origin of new species. I will combine this with detailed observations of natural bird populations in one of the most biodiverse regions on Earth, the Himalayas. This will make it possible to study the present-day consequences of changes in communication signals for interactions among species and the factors promoting biodiversity.Together, my research will shed light on unresolved evolutionary questions by exploring how and why signals change over millions of years across species, and the consequences of this for the origin and maintenance of new species. My research will significantly advance our knowledge of the processes underlying the evolution of animal communication signals and ultimately the role that such signals play in promoting and maintaining the diversity of life on Earth.