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

论文研究：沿纬度和海拔的温度梯度：对扩散的影响

• 批准号: 0910313
• 负责人: David Cannatella
• 金额: $ 1.5万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-15 至 2011-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0910313&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Temperature; gradients; along

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.

热带地区的高地总是比低地更冷。温度在整个季节中不会像温带地区的高地那样改变。结果，热带山地生物可以适应狭窄的温度范围，从而在生理上无能力向上或向下移动。相比之下，温带山地生物可能会由于季节性周期而适应更大的温度范围，从而使它们更有可能在海拔之间移动。该预测称为Janzen效应，解释了为什么在热带地区，不同的海拔物种不同，而在温带地区，给定物种可以居住在一系列高度。很少有Janzen效应的测试。这项研究将确定在安第斯山蛙种类中是否发生了Janzen效应。换句话说，热带安第斯山脉的青蛙物种在山上或向下移动的频率比温带安第斯山脉中的物种要少吗？运动率将使用遗传技术估算。这项研究将有助于理解热带动物多样化的机制。该项目的含义扩展到所有调热（“冷血动物”），因为它们的生理学直接受到外部环境的影响。这项研究将对某些生物种群是否可能对全球变暖导致的山地气候变化更具弹性产生预测。来自安第斯山脉小镇的学生将积极参与与Co-Pi的科学讨论，内容涉及自己的安第斯山脉和动物群的起源和多样化，并将直接与当前的野外技术和分子进化过程接触。