Class Notes (1,100,000)
CA (620,000)
UOttawa (30,000)
BIO (3,000)
BIO 1130 (700)
Lecture 21

BIO 1130 Lecture Notes - Lecture 21: Probability Distribution, Himalayas, Reproductive Isolation

Course Code
BIO 1130
Jon Houseman

This preview shows half of the first page. to view the full 3 pages of the document.
Organismal Biology BIO1130
Lecture 21: Chapter 7, Geographic Variation and Speciation Continued
Origin of Species
· Morphological species concept is the most practical approximation of biological
species concept
· Biological species concept makes most scientific sense, but sometimes we do not
have the sufficient data to classify biological species (cannot create data in lab; must
be observed in nature)
· So, when we don’t have data from nature, we classify using morphological
species concept instead
· Phyletic speciation (anagenesis): Gradual evolution or “linear” succession of
species in a way that the changing species shows different phenotypes through time
o Anagenesis does occur, but does not explain biodiversity
· Multiplication of species (cladogenesis): creation of species by establishing a
reproductive barrier between them
o From one species, you create 2
o Double the amount of species through 1 speciation event
o Only mechanism responsible for the creation of biodiversity
· Evolution of a primate
o There was anagenesis in the species at first, and then there was
cladogenesis (2 species formed; we know this because there were 2
species present at the same time period)
Models of Speciation (Cladogenesis)
· From a genetic standpoint, a premise for the multiplication of species / the
establishment of a reproductive barrier is the interruption of migration or gene flow
between populations
o At one point, there must have been a stop in the gene flow
· Models of speciation (cladogenesis) shows how the gene flow can be interrupted;
2 types
· (1) Allopatric Speciation
find more resources at
find more resources at
You're Reading a Preview

Unlock to view full version