BIOL 3040 Chapter Notes - Chapter 20: Path Dependence, Pleiotropy, Senescence
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List and distinguish among the four types of answers that can be given to why questions in biology: proximate: immediate mechanisms, developmental: over a life time, evolutionary: natural selection and other evolutionary forces, phylogenetic: evolutionary history. 20. 2 fever: describe the proposed costs and benefits of fever in animals, beneficial. May up-regulate some immune defenses and increase rate these cells proliferate and act. Trigger expression of heat shock proteins: harmful. Especially when it comes to responding to infectious disease: its better to be too cautious and catch a disease than to be too relaxed and miss one. 20. 3 coevolutionary arms races between pathogens and hosts: explain why it appears that pathogens are winning the arms race, hosts are at a disadvantage. Most pathogens have rapid generation times; most hosts have longer generation times. Selection acts much faster on pathogens: describe the immune strategies used to fight off pathogens, detecting characteristic components of pathogens. Pathogen-associated molecular patterns (pamps: finding infected cells.