Download presentation
Presentation is loading. Please wait.
1
V. The Process of Speciation
Speciation – formation of a new species. Species – a group of organisms that can breed with one another & produce fertile offspring. *Members of a species can lose the ability to interbreed due to isolation. Isolation – anything preventing two groups within a species from interbreeding.
2
A. Isolating Mechanisms
*As new species evolve, populations become reproductively isolated from each other. Reproductive isolation – loss of two groups’ ability to interbreed & produce fertile offspring. -Reproductive isolation can develop through : 1. Behavioral isolation – when two populations are capable of interbreeding but have differences in courtship rituals/other reproductive strategies that involve behavior, ex : Eastern & Western meadowlarks.
3
Geographic Isolation 2. Geographic isolation – when two populations are separated by geographic barriers such as rivers, mountains, or bodies of water, ex : Abert squirrel & Kaibab squirrel.
4
Temporal Isolation 3. Temporal isolation – when two or more species reproduce at different times, ex : rainforest orchids.
5
Processes of Change *Species can also go through
the following processes of change : 1. Divergent Evolution 2. Convergent Evolution 3. Coevolution 1. Divergent evolution – when isolated populations of a species evolve independently. -Happens because of geographic barriers or when a small group leaves an original population to colonize a new area. Ex : Brown vs. Polar bears.
6
Convergent Evolution 2. Convergent evolution – when natural selection produces analogous (similar) adaptations in response to similar environments, ex : Serval cat (Africa) & Maned wolf (SA) - long ears/legs & the same prey.
7
Coevolution 3. Coevolution – when two or more populations that closely interact over an extended period of time evolve together, ex : flowers & bees.
8
B. Adaptive Radiation Adaptive radiation – evolution of many diverse
species from 1 common ancestor, ex : Darwin’s finches- spread.
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.