lecture 9

• explains how species are different • if the species CANT reproduce and make an offspring -> different species • if the species CAN reproduce and make an offspring -> same species

• allopatric • sympatric

• there is a physical barrier between the species and they cant reproduce together • over time, even if the barrier is removed, if they cant reproduce together, they are new speices

• become different species in the same place

• happens after fertilization by either intrinsic or extrinsic

• prevents fertilization • geographical • populations are physically isolated • Temporal, behavioral • breeding season is changed • mechanical • difference in reproductive structure • cellular • sperm and egg are incompatible

• genes from mom and dad aren’t compatible • Problem comes from the individual not from the environment

• Individual has a phenotype that’s not good for the environment

• when one species evolves into many species example: darwins finches

-Come from one ancestor -The phenotypes are related to their environment -Finches with different beak size for different food -The trait that differ actually helps them survive or reproduce -Rapid speciation

• ecological opportunity - theres a new place with few competition - extinction • theres no competitors - key innovation • a new trait or feature that helps them exploit resources in a new way • high tendency for speciation - some organism form new species more than others

Adaptation to different environments causes populations to become different species