Evolutionary Ecology

Species Numbers - 2012

What’s missing?

A new phylogeny – without prokaryotes

From Wilson,1992

Bird Adaptations

Evolution

• Evolution simply means change and biological evolution can be defined as changes in any attribute of a population over time

• Evolutionary changes that lead to adaptation must involve a change in the frequency of individual genes in a population from generation to generation

Adaptation – process which leads to survival and reproduction of characteristics beneficial to an organism in a particular environment

Parus caeruleus

Perfect Adaptation? Hmm…

Charles DarwinAge 46

Alfred RusselWallace – in his 70’s

Evolution by Natural Selection

1. Individuals in a population of a species are not identical.2. At least some of this variation is heritable.3. All populations have very high reproductive potential, but

they seldom achieve it. Mortality and less than maximum reproductive rate keeps them from taking over the earth - e.g. oysters

4. Different individuals leave different numbers of descendents. - this is where idea of fitness comes in

5. The number of descendents an individual has, depends on the interaction between the characteristics of the individual and its environment.

Two major points about natural selection

1. Variation among individuals arises due to chance mutations.

2. Individuals survive in today's environment because it is similar to their ancestors environment - adaptation is not planned or purposeful

What is selected?

The individual is selected.

Some of Bumpus’s survival data

Peppered Moth – Biston betularia – white and melanistic formson lichen covered and sooty trees

Distribution of Peppered Moths in BritainLeft map shows distribution in 1956, right map shows distribution in 1996; Dark part of circle shows proportion of dark form, light part of circle shows proportion of light form

Life stages of Coho salmon –top to bottom –Eggs, fry, oceanicSilverfish,Hooknose male,and female

Coat Color Mutation in Florida Beach Mouse – Peromyscus polionotus

Normal, dark mainland mouse on right; lightermutated island beach mouse on left; mutation due

to a change in a single nucleotide

Coat Color Mutation in Florida Beach Mouse – Peromyscus polionotus

Gene Flow in Walleye

Walleye sampling sites

Walleye relatedness tree

Chimpanzee Hands And Feet

Drought Cycles in Iran

Phylogenetic Constraint – Egg Size and Brood Patch in Penguins

Environmental or Genetic Variation in Yarrow?

Local adaptation in bentgrass Agrostis stolonifera

Trinidad Guppies - Poecilia reticulata

Two males

Male and Female

Adaptation and natural selection in guppy populations

John Endler