Class Notes (836,370)
Canada (509,757)
Biology (6,816)
Biology 1001A (1,727)
Tom Haffie (1,170)
Lecture 16

Lecture 16.docx

3 Pages
72 Views
Unlock Document

Department
Biology
Course
Biology 1001A
Professor
Tom Haffie
Semester
Fall

Description
Biology Chapter 18.2 and 18.7 (Lecture 16) Defining Species • Morphological • Biological • Phylogenetic Speciation (The process of species formation) • Isolation • Divergence • Secondary Contact Why does it matter whether two populations are one species or two? • Morphologically different • Different ecological niche • Endangered or not (legislation) 1. Morphological Species Concept • The concept that all individuals of a species share measurable traits that distinguish them from individuals of other species • Identify species by morphological similarity • Distinct clusters in phenotypic space • Problems with MSC o A lot of variation in phenotypes of a population o Very little variation between populations 2. Biological Species Concept • The definition of species based on the ability of populations to interbreed and produce fertile offspring • Group of actually or potentially interbreeding organisms, reproductively isolated from other such groups • More explanatory power than MSC (shared gene pool) • More objectively testable than MSC (when members of population A encounter population B in the wild. What happens?) • PREZYGOTIC ISOLATING MECHANISMS a reproductive isolating mechanism that acts prior to the production of a zygote or fertilized egg. o Can be isolated in terms of habitat, behaviour (courtship displayed not attractive), mechanical (different shaped penis’) • POSTZYGOTIC ISOLATING MECHANISMS a reproductive isolating mechanism that acts after zygote formation o Hybrid inviability; Hybrid has a low probability of survival to reproductive age (born dead) o Hybrid Sterility; Hybrid cannot form functional gametes o Hybrid Breakdown; Hybrids are capable of reproducing, but their offspring have reduced fertility or reduced viability. (i.e. low fitness) • Problems with BSC o Hard to tell if populations that are geographically separated (Allopatric) would interbreed if in close range o Asexual organisms don’t interbreed o Cannot tell what extinct organisms would inte
More Less

Related notes for Biology 1001A

Log In


OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit