7 October 2021

What is about behavioural and evolutionary ecology?

Evolution

"Nothing in biology makes sense except in the light of evolution”
/T. Dobzhansky, 1972/


Evolution

Evolution principles

EVOLUTION - a change in gene frequency within a population over time.

Image credit: the University of California Museum of Paleontology's Understanding Evolution (http://evolution.berkeley.edu).

Evolution - mechanisms

Evolution - genetic variation

Primary sources of genetic variation:

1 mutations

  • single mutation and/or accumulation of many
  • random or forced
  • neutral, beneficial, harmful
  • no change, small change, big change

2 gene flow - based on migration/dispersal movements

3 sex - gene combinations into a population

Natural selection


Critical assumptions:

  • variation in traits
  • differential survival/reproduction
  • heredity


Image credit: the University of California Museum of Paleontology's Understanding Evolution (http://evolution.berkeley.edu).

Natural selection in action

Natural selection - FITNESS

Fitness - ability to survive, find a mate, produce offspring — and ultimately leave its genes in the next generation.



Image credit: the University of California Museum of Paleontology's Understanding Evolution (http://evolution.berkeley.edu).

Natural selection - classification

Natural selection - classification

by effect on genetic diversity - negative/purifying selection
(source: https://en.wikipedia.org/wiki/Natural_selection)

Image credit: Van den Eynden J, Basu S, Larsson E (2016) Somatic Mutation Patterns in Hemizygous Genomic Regions Unveil Purifying Selection during Tumor Evolution. PLoS Genet 12:1–18.

Natural selection - classification

Natural selection - classification

Natural selection - classification

Natural selection - classification

References