BISC 100 - Lecture 28, 29, 30: Evolution

WHAT IS BIOLOGICAL EVOLUTON?

Historical development of evolutionary thought

LAMARCK’S TRANSFORMATION THEORY

FATHERS OF THEORY OF
NATURAL SELECTION

Charles Lyell

The Voyage of the Beagle

Descent with Modification

REMEMBER…….

Darwin based his theory of natural selection on
two key observations...

WHAT IS ADAPTATION?

Fossils

The chronological order of which different
vertebrate groups appear in fossil records

Biogeography

Comparative anatomy

Homology vs Analogy

Comparative anatomy – Divergent evolution

Comparative anatomy – Convergent evolution

Analogous Structures

Comparative anatomy: Adaptive radiation

Comparative anatomy

______ & _______ bones evident in ancient whale fossils

Comparative Embryology

Molecular Biology

Darwin: Evolutionary trees

Darwin's theory and the modern synthesis

A population is a...

Garter snake evolution in response
to predators:
Remember spotted vs stripes

WHAT IS MICROEVOLUTION?

Genotype frequency

Allele frequency:

Microevolution is the changes in allele frequencies that
occur over time within a population, due to

Five factors which cause populations
to evolve are

Sources of genetic variation

Genetic drift is a

Gene flow

Natural selection IN TERMS OF MICROEVOLUTION*

Three general outcomes of natural selection

Sexual dimorphism

Sexual selection

The origin of species

The biological species concept defines a species as

Prezygotic barriers

The species concept is based on

Reproductive barriers between species

Postzygotic barriers

Reduced Hybrid Viability

Reproductive
barriers between
closely related
species

Mechanisms of speciation

Allopatric speciation of antelope squirrels

Sympatric speciation

Sympatric speciation: Polyploidy