Recurrent patterns of natural selection in a population of Darwin's finches
Recurrent patterns of natural selection in a population of Darwin's finches
复制标题
达尔文雀种群中自然选择的循环模式
作者：
T. Price;P. Grant;H. Gibbs;P. Boag
形态特征的适应性意义可以通过测量和识别作用于它们的选择力量来评估。 Boag 和 Grant1 于 1977 年记录了加拉帕戈斯群岛 Daphne Major 上一小群达尔文中地雀 (Geospiza fortis) 的定向选择。在食物供应减少和成年死亡率高的时期，大喙和体型受到青睐。我们在此表明，在随后的两个中度至高成人死亡率时期（1980 年和 1982 年），人口受到相同的选择。我们使用了最近开发的技术2来确定直接选择的目标。在所有三个死亡时期，喙深度和体重通常直接选择增加，但令人惊讶的是，喙宽度直接选择减少。这些结果对我们理解达尔文雀形态特征的进化变化具有重要意义3-6。
The adaptive significance of morphological traits can be assessed by measuring and identifying the forces of selection acting on them. Boag and Grant1 documented directional selection in a small population of Darwin's medium ground finches, Geospiza fortis, on I. Daphne Major, Galápagos, in 1977. Large beak and body size were favoured at a time of diminishing food supply and high adult mortality. We show here that in two subsequent periods of moderate to high adult mortality (1980 and 1982), the population was subject to the same selection. We have used a recently developed technique2 to ascertain the targets of direct selection. Beak depth and body weight were commonly under direct selection to increase but, surprisingly, beak width was directly selected to decrease, over all three periods of mortality. The results have implications for our understanding of evolutionary change in morphological traits of Darwin's finches3–6.