adaptation and evolution Using human examples adaptation and evolution

What is the driving force for evolution? Variation Adaptation Natural selection What are some of most weird organisms that live on earth? Icefish – live in Antarctic ocean What traits does this fish need in order to survive in the extreme cold environment?

Making of the fittest – The birth and death of genes Answer How would a biologist explain how the antifreeze protein evolved in living icefish from ancestors that did not make the antifreeze protein? How would a biologist explain how a living icefish species without red blood cells evolved from an ancestral icefish species that made red blood cells?

Humans - Survival in high altitudes What are some physiological problems to survival in high altitudes? Headache Nausea Fatigue Dizziness Swelling of hands and feet Short of breath

Physiological adaptions or Evolutionary adaptation? What is the difference? Physiological – individual Evolutionary – population HIF gene maintains oxygen homeostasis in all aerobic organisms Induces RBC development Increase production of enzymes for glycolysis (why?) Variation in HIF-1α allows for endurance

How does EPO doping give athletes an unfair advantage? Erythropoietin – hormone controls?

What is unique to Highlanders? Lowlanders have Average SaO2 = 97% Average Hb concentration in adult males = 15.3g/dL What levels SaO2 and Hb would you expect to find in a Tibetan?

Tibetans -highlanders 89 15.8 Table 2: Oxygen saturation and hemoglobin concentration in lowlanders at sea level and Tibetans. Group Average SaO2 % Average Hb g/dL Lowlanders 97 15.3 Tibetans -highlanders 89 15.8 Source: Data in the table are from Beall, C. (2006). Andean, Tibetan, and Ethiopian patterns of adaptation to high-altitude hypoxia. Integrative and Comparative Biology, 46(1), 18–24.

Tibetan versus Han Chinese Birth Weights

Is it heritable? To tell if Tibetans have adjusted or adapted genetically to high altitudes? Set up a chart and answer Who or what is changing? Does the environment induce a change or is it caused by the individuals genes Is the change more or less permanent or potentially reversible? Discuss how you would design an experiment to show this