Evolutionary Ecology

An interdisciplinary field - incorperates ecology and evolutionary biology

Studies how interaction of species with biotic/abiotic environment is shaped by their evolutionary histories

Used to understand how ecology influences speciation and vice versa

Speciation - formation of one or more species from ancestral species

Occurs when populations of ancestral species become reproductively isolated

Types of speciation:

• Allopatric - two+ populations become geographically isolated (common)
• Peripatric - small groups of individuals break off from the rest of the species' geographic range (common)
• Parapatric - populations not seperated by geographical barrier, but colonisation of new habitat type/nice occurs
• Sympatric - no geographic or habitat barier to gene flow between populations

Cryptic species - individuals that are morphologically identical but are different species

Sister species - two species most closely related to each other

Phylogenetic tree used to represent evolutionary relationships between species - use morphological characters, genetic characters or both. Extinct species also added to phylogenetic trees using morphological characters. 

Synapomorphies - characters shared between most recent common ancestor and all descendants

Clade - group of organisms comprising of all descendants of most recent common ancestor 

Phylogeography - study of historical processes influencing modern distributions of a species using molecular tools. Understands process of genetic population divergence and speciation

Phylogeographic break - location where 2 + clades come into contact

Example - Mexacanthina lugubris sea snail

• Can be split into 2 genetically distinct clades 
• Diverged ~500-420 tya - Pleistocene seaway along California present
• Closed ~400tya - not enough time for new species to form
• Shape of shells slightly different and some genetic differences
• Evidence of seaway seen in morphological differences in terrestrial and marine species e.g. lizards, shrimps