ANTH 200Lg 2-4-09

ANTH 200Lg 2-4-09 - ANTH200Lg 2409 Speciation

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

View Full Document Right Arrow Icon
ANTH 200Lg 2-4-09 Speciation the evolutionary process by which new biological species arise o Allopatric speciation A population splits into two geographically isolated allopatric  populations. The isolated populations then undergo genotypic and/or  phenotypic divergence as they (a) become subjected to  dissimilar selective pressures or (b) they independently undergo  genetic drift.  When the populations come back into contact, they have  evolved such that they are reproductively isolated and are no  longer capable of exchanging genes. o Parapatric speciation The zones of two diverging populations are separate but do  overlap.  There is only partial separation afforded by geography, so  individuals of each species may come in contact or cross the  barrier from time to time, but reduced fitness of the heterozygote  leads to selection for behaviors or mechanisms which prevent 
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 04/22/2009 for the course ANTH 200Lg taught by Professor Yamashita during the Spring '07 term at USC.

Page1 / 4

ANTH 200Lg 2-4-09 - ANTH200Lg 2409 Speciation

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