ANSC 313 Lecture Notes - Lecture 6: Ocellated Turkey, Wild Turkey, Reproductive Isolation
LECTURE 13!
!
Turkey Ancestors!
wild turkey!•
ocellated turkey !•
Date: 3000 BP!•
!
turkey domestication!
Mexican turkey hopes found in Guatemala, dating to 2000 BC!•
Mexican turkey outside its natural range there = domestication!◦
found male, female and juveniles with morphological characteristics of reduced flight!◦
pueblo indians in the southwest US raised turkeys in captivity by 1200-1300!•
evidence is turkey dung and feathers inside pueblo rooms at Bandolier, new Mexico and ◦
other sites!
turkey feathers were woven into yucca strands for blankets and clothing!◦
beloved that the turkey is the only animal domesticated in north america!•
!
!
Speciation!
species: a discrete, reproductively defined systems of populations with a common evolution!
!
breed~ race!
a population distinguishable from another of the same species by !
frequency of genes!•
chromosomal variation!•
hereditary phenotypic characteristic!•
NOTE:!
a breed is subject ti certain criteria by law!•
i.e. breed standard, "registration"!•
!
Process of speciation!
some event physically separates part if the population from the rest!•
those isolated start to respond differently to a different selection pressure!•
genetic drift may exacerbate this because of small population size!•
if/ when the isolates rejoin the larger population later, they may no longer be reproductively •
compatible!
!
reproductive isolating mechanisms!
presygotic= no mating occurs!•
ecological ( glaciers)!◦
temporal ( heats at different times of year in sheep)!◦
behavioural ( courtship rituals differ)!◦
mechanical ( genitalia have changed)!◦
gametic ( sperm can't penetrate ova)!◦
Postzygotic!•
hybrid inviability ( abortion, week and young)!◦
hybrid sterility (both sexes are sterile, mules)!◦
hybrid breakdown ( one sterile. usually heterogametic, i.e. male mammals & female birds)!◦
!
phylogeny- evolutionary relationships from ancient to recent!
