Class Notes (903,575)
CA (538,023)
UTSC (32,632)
BIOA02H3 (532)
Lecture

Chapter 23

2 Pages
88 Views

Department
Biological Sciences
Course Code
BIOA02H3
Professor
Kamini Persaud

This preview shows half of the first page. Sign up to view the full 2 pages of the document.
The morphological species concept is classifying organisms based on their
appearance.
Speciation is the process by which one species splits into two or more daughter
species, which thereafter evolve as distinct lineages.
Reproductive isolation is when individuals in a population can mate with each other
but not with those of another population.
Biological species concept states that species are groups of actually or potentially
interbreeding natural populations which are reproductively isolated from other
groups.
Not all evolutionary change results in new species; however, if a species becomes
isolated into two different populations. These two populations over a certain amount
of time will encounter a change in allele and genotype frequencies as a result of
evolutionary mechanisms and then the 2 populations may no longer be able to
exchange genes.
Speciation requires gene flow within a population that has formally exchanged genes
to be interrupted.
Allopatric speciation is when a population is divided by a physical barrier. It can
occur via a Vicariant event in which no individuals disperse and they are separated
by a physical barrier, or via Dispersal which is when a few individuals somehow
cross the physical barrier and then 2 different populations evolve
Sympatric speciation does not require physical separation however uses ecological
isolation (different resources or different riches). Sympatric speciation usually occurs
by polyploidy which is the duplication of whole set of chromosomes.
Chromosome duplication in a single species is called autopolyploidy
Allopolyploidy is the combining of chromosomes from two species and can arise if two
closely related species mate or hybridize. Allopolyploids are often fertile.
Prezygotic reproductive barriers operate before fertilization occurs
Habitat isolation is when individuals of different species select different habitats
and therefore never come in contact
Temporal isolation : If the mating periods of two species do not overlap they will be
reproductively isolated by time
www.notesolution.com

Loved by over 2.2 million students

Over 90% improved by at least one letter grade.

Leah — University of Toronto

OneClass has been such a huge help in my studies at UofT especially since I am a transfer student. OneClass is the study buddy I never had before and definitely gives me the extra push to get from a B to an A!

Leah — University of Toronto
Saarim — University of Michigan

Balancing social life With academics can be difficult, that is why I'm so glad that OneClass is out there where I can find the top notes for all of my classes. Now I can be the all-star student I want to be.

Saarim — University of Michigan
Jenna — University of Wisconsin

As a college student living on a college budget, I love how easy it is to earn gift cards just by submitting my notes.

Jenna — University of Wisconsin
Anne — University of California

OneClass has allowed me to catch up with my most difficult course! #lifesaver

Anne — University of California
Description
The morphological species concept is classifying organisms based on their appearance. Speciation is the process by which one species splits into two or more daughter species, which thereafter evolve as distinct lineages. Reproductive isolation is when individuals in a population can mate with each other but not with those of another population. Biological species concept states that species are groups of actually or potentially interbreeding natural populations which are reproductively isolated from other groups. Not all evolutionary change results in new species; however, if a species becomes isolated into two different populations. These two populations over a certain amount of time will encounter a change in allele and genotype frequencies as a result of evolutionary mechanisms and then the 2 populations may no longer be able to exchange genes. Speciation requires gene flow within a population that has formally exchanged genes to be interrupted. Allopatric speciation is when a population is divided by a physical barrier. It can
More Less
Unlock Document


Only half of the first page are available for preview. Some parts have been intentionally blurred.

Unlock Document
You're Reading a Preview

Unlock to view full version

Unlock Document

Log In


OR

Don't have an account?

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