DISSERTATION RESEARCH: Temperature gradients along latitude and elevation: Effects on dispersal

热带高地总是比低地冷;温度不会像温带高地那样随季节变化。因此，热带山地生物可能适应狭窄的温度范围，因此在生理上无法上下移动。相比之下，温带山地生物可能适应更广泛的温度范围，由于季节循环，使他们更有可能在海拔之间移动。这一预测被称为Janzen效应，解释了为什么在热带地区不同的海拔拥有不同的物种，而在温带地区，一个特定的物种可以生活在不同的海拔高度。很少有关于Janzen效应的测试。这项研究将确定Janzen效应是否发生在安第斯青蛙物种中。换句话说，热带安第斯山脉的蛙类是否比温带安第斯山脉的蛙类更少地在山上或山上移动？将利用遗传技术估计迁移率。这项研究将有助于了解热带动物多样化的机制。该项目的意义延伸到所有的外温动物（“冷血动物”），因为它们的生理直接受到外部环境的影响。这项研究将预测某些生物种群是否对全球变暖导致的山地气候变化更具适应力。来自安第斯山脉小城镇的学生将积极参加与共同伙伴的科学讨论，讨论他们自己的安第斯植物群和动物群的起源和多样化，并将直接接触分子进化方面的现有实地技术和程序。

Tropical-zone highlands are always colder than lowlands; temperatures do not change across seasons the way they do in temperate-zone highlands. As a result, tropical montane organisms may be adapted to narrow temperature ranges and thus physiologically incapable of moving up or down mountains. In contrast temperate montane organisms are probably adapted to wider temperature ranges due to seasonal cycles, making them more likely to move between elevations. This prediction, called the Janzen Effect, explains why in tropical regions different elevations hold different species whereas in temperate regions a given species can live at a range of altitudes. Very few tests of the Janzen Effect exist. This research will determine if the Janzen Effect occurs in Andean frog species. In other words, do frog species in the tropical Andes move up or down the mountains less often than species in the temperate Andes? Movement rates will be estimated using genetic techniques. This study will help to understand the mechanisms of diversification of tropical animals.The implications of this project extend to all ectotherms ("cold blooded animals"), because their physiology is directly affected by the external environment. This study will produce predictions about whether some populations of organisms might be more resilient to montane climate variation resulting from global warming. Students from small towns in the Andes will actively participate in scientific discussions with the Co-PI about the origin and diversification of their own Andean flora and fauna and will have direct contact with current field techniques and procedures in molecular evolution.