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What is Comparative and Evolutionary Physiology? 

P
hysiology is the area of biology concerned with the study of the normal function of living organisms, their organ systems, tissues, and cells. Comparative and Evolutionary Physiology is specifically concerned with the study of how different physiological processes change or adapt over evolutionary time and in response to fluctuating or extreme environmental conditions. 

Comparative physiologists seek answers to questions of physiological function such as how and why a rainbow trout can breathe water, a bar-headed goose can fly over Mt. Everest, a kangaroo rat doesn't need to drink any water during its postnatal lifetime, an elephant seal can dive 1000 meters for many minutes, or how a wood frog can survive 40% of its body water freezing. 

Evolutionary physiologists may seek answers to questions about how physiological processes have or have not changed over evolutionary time. These changes may be on a macroevolutionary scale, such as the why, when, and how of the evolution of warm-bloodedness (endothermy) in vertebrates, of the four-chambered heart, or of air-breathing. They might also be on a microevolutionary scale and include how physiological systems, like the cardiorespiratory system, change over generations in response to selection pressures such as oxygen and water availability or temperature extremes.


Our laboratory specifically addresses questions related to the function and evolution of the vertebrate cardiorespiratory system, particularly in ectotherms.

The vertebrate cardiorespiratory system is comprised of the heart, blood, the gas exchange organs (e.g. lung, gills or skin), and the metabolic processes involved with energy production found in all living cells. The function of these components is affected by the animal's body temperature. Most animals on Earth are ectothermic, which means that the principal source of heat determining body temperature comes from the environment. In contrast, endothermic animals, such as ourselves, rely mainly on the heat derived from the chemical bonds in the food we consume. Although endothermy can be found among some fishes and possibly some reptiles, it is principally a trait of birds and mammals. Our research is directed at understanding the function and evolution of the cardiorespiratory system of pond turtles, ectotherms that can tolerate a wide range of temperatures and oxygen availability.
 
For information about our present research projects, click here.