Species are distributed unevenly across the surface of Earth. More species are found in the warm tropics than in cool temperate regions. This pattern was first recognized over two centuries ago by Alexander von Humboldt, with his observation “The nearer we approach the tropics, the greater the increase in the variety of structure, grace of form, and mixture of colors, as also in perpetual youth and vigor of organic life.”

中文翻译：

---

热带多样性梯度的解释植根于过去[进化]

物种在地球表面分布不均。在温暖的热带地区发现的物种比在凉爽的温带地区发现的更多。亚历山大·冯·洪堡（Alexander von Humboldt）在两个多世纪前首次认识到这种模式，他观察到“我们越接近热带地区，结构的多样性、形式的优雅和颜色的混合就越多，在永恒的青春和有机生命的活力。”