Transcript Class Overview

Evolution, Ecology & Biodiversity
This course covers:
- Population Genetics
- Evolution
- Diversity of life
- Ecology
- major theme of the course is evolution
What do you think is the best definition of
evolution (for a biologist)?:
a) Origination of species by development
from earlier forms
b) Change in allele frequencies in a population
over generations
c) Descent with modification
d) The survival of the fittest
e) Gradual process in which something changes
into a more complex or better form
Population Genetics necessary to understand evolution
Evolution is relevant to understanding virtually
everything about living things!
Why are there millions of species on this planet?
What are they?
What can we learn from this diversity?
How do these species interact with each other & their
environment?
Evolutionary thinking
Evolutionary biology credited to Darwin (1859)
- not first to think of evolution…
Georges-Louis Leclerc (Comte de Buffon) - 1707-1788
- believed in long history of earth, change in organisms,
noted vestigial organs
Erasmus Darwin - 1731-1802
- believed that life had evolved from simple origins
- wrote poetry…
Organic life beneath the shoreless waves
Was born and nurs'd in ocean's pearly caves;
First forms minute, unseen by spheric glass,
Move on the mud, or pierce the watery mass;
These, as successive generations bloom,
New powers acquire and larger limbs assume;
Whence countless groups of vegetation spring,
And breathing realms of fin and feet and wing.
- Etienne Geoffroy Saint Hilaire (1772-1844)
- variations on single body plan, homologies
The best known ‘pre-Darwinian’ evolutionist
was….?
His theory made what well-known argument?:
a) the environment directly modifies organisms
b) individuals with greater fitness would pass
on their traits
c) changes in a trait arise by chance
d) traits improved by frequent use would be
passed on to offspring
e) many past species went extinct
Jean Baptiste de Lamarck (1744-1829)
- best known evolutionist pre-Darwin
- believed species change AND suggested mechanisms
by which it might happen
- tendency to increase in size
- perception of needs
- use and disuse, inheritance of
acquired characters
Charles Darwin - the man…
- first to accumulate sufficient evidence to convince
people that evolution had occurred
- first to develop a logical, coherent mechanism to
explain how & why evolution happens
- keen naturalist, traveled around world on The Beagle
(1832-36)
Where in the world are armadillos found?
a) Americas only
b) Americas and Africa
c) Americas and Asia
d) Americas & Australia
e) World-wide
- fossils in South America, birds in Galapagos islands,
etc. led him to question species fixity
Glyptodon
Large Hairy Armadillo
4 spp. of
mockingbirds
from
Galapagos