Announcements

Urban Forestry project starts this week. Go through protocol.

We'll be sending you off on your own. Please act responsibly.

Peer review of work. You will trade your results with a different lab group at the end and they will attempt to identify and use the data that you gave them. They will provide a score, calculated based on their ranking of various parts of the assignment.

BIOGEOGRAPHY

‘the geographic distribution of species'

Research focuses on geological and genetic evidence and develops theories to explain them.

Climate changed dramatically during the recent ice ages and the end of the last ice age was roughly 12,000 years ago.

BIOGEOGRAPHY

Humans have imposed an incredible transformation on the natural world.

This process is very recent.

Science magazine had a special section on Population.

PHYLOGENETICS

reconstruction of the historical relationships among organisms.

What is a phylogenetic tree?

Cladogram vs. phylogram

PHYLOGENETICS

Parsimony - the simplest explanation is the best.

many different algorithms to test for ‘optimality’

Maximum Likelihood (ML) based primarily on molecular modelsBayesian analysis – prior probabilities are used to generate null modelsCoalescent theory – probabilistic approach based on time to coalescence.

PHYLOGENETIC DATA

Homology – characters are identical by descent.

Binary traits – morphology and DNA

How is 'parsimony' measured?

PHYLOGENETIC UNCERTAINTY

All trees are just hypotheses.

Species trees vs. Gene trees.

Ancestral polymorphism.

Interspecific introgression.

MORPHOLOGICAL DATA

Phenotype can be strongly affected by environment and disease.

Good taxonomic characters should be linked to genetic traits that drive species diversification.

Convergent evolution.

INDEPENDENT CONTRASTS

Each evolutionary event should be independent.

Good for testing character associations to see if they are significant from an evolutionary standpoint.

MOLECULAR DATA

Phytochemistry - liquid chromatography

Allozymes – electromorphs of various proteins

DNA – DNA sequence