Lecture 17 - Bio 121 Lecture 17 origin of species A....

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Bio 121 Lecture 17 – origin of species A. Defining species a. Biological species concept – genetically distinctive group of natural populations that share a common gene pool and are reproductively isolated from other such groups under natural conditions b. Limitations b.i. Since it assumes interbreeding, it does not apply to asexual organisms b.ii. Since fossils don’t interbreed, it doesn’t work well with extint species b.iii. Species that interbreed in labs, but not in nature B. Mechanisms of speciation (splitting 2 populations that are interbreeding into different populations that are not interbreeding) a. Allopatric – other homeland a.i. A population to form a new species while its geographically isolated from the parent population (mountain, ocean, river) a.ii. When a species becomes allopatric, there is chance of speciation a.iii. Favorable conditions for allopatric speciation a.iii.1. Population is usually small and usually occurs at edge of population so it may already be a little different a.iii.2. Founder effect, initially a difference
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 03/12/2012 for the course BIO 121 taught by Professor Minchella during the Fall '10 term at Purdue University.

Page1 / 2

Lecture 17 - Bio 121 Lecture 17 origin of species A....

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online