01:119:116 Lecture Notes - Lecture 11: Adaptation, Osmoregulation, Homeostasis
12 Oct 2018
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Document Summary
Favors those variants in population that increase relative fitness. Adaptive evolution (better match between organisms and environment) Only mechanism that consistently causes adaptive evolution. All living things regulate internal conditions in some way. The steady state of physiological conditions in the body. 40. 8: stimulus response increases or decreases stimulus, stimulus: a fluctuation, response: triggered by stimulus, 2 types, positive feedback. In general, negative feedback much more common: examples of homeostasis. All organisms must regulate internal environment and exchange with internal environment. Organisms may need to maintain solute concentration. Organisms may need [solute}< or > environment. Chemical processes osmosis and diffusion across lipid bilayer. Pumps water out to maintain water balance. Adapted for terrestrial life, but still require water. All living ( and some nonliving) things have homeostasis. Mechanisms, requirements depend on environment and morphology. Dedicated transport tissues prevent desiccation,maintain ph, [solute] Water is denser and more viscous than air. Selection favors similar adaptations: complexity and organisms.
