BIOL 121 Lecture Notes - Lecture 4: Survivorship Curve, Fecundity, Natural Selection

• School: UBC
• Department: Biology
• Course: BIOL 121
• Professor: Lynn Norman

Document Summary

Two factors preventing infinite pop . growth and / or permanent stabilization at k: density - independent rates regardless of pop . size factors : affects per capita growth. Often abiotic ex . hurricanes, cold snaps , volcanic eruption: density - dependent factors : effect on per capita growth rates depends on pop. size. Often biotic ex . disease , competition for resources , predation. Refers to stages an organism goes through in its lifetime birth growth reproduction death survivorship curve : snows probability of survival tends to change w/ age. Organisms broadly classified under 3 types of survivorship curves expected to maximize total lifetime relationship between life history traits. Natural selection favours individuals w/ high fitness (cid:8869) max fitness = high birth rate & high survival rate. Organisms can"t maximize all life traits (cid:8869) energy & resources are limited. Fecundity : potential ability of an organism to produce eggs / children.