Lecture 10: Evolutionary Conservation Biology

Hendry!

Components of evolutionary conservation biology

1. Preserving for evolutionary history/ diversity

2. Preventing Inbreeding Depression

3. Incorporating Contemporary (rapid) Evolution

Components of Preserving for Evolutionary History/ Diversity

• EDGE species

• ESUs

• Phylogenetic diversity

Evolutionarily Distinct Globally Endangered (EDGE) Species

Very evolutionarily distinct species considered a greater loss because of the history lost

Evolutionarily Significant Units (ESUs)

• Established by the US Endangered Species Act

• Intraspecific diversity is very in some populations

• Looks at important populations within a species

Phylogenetic diversity

• Prioritizing areas with high/ unique phylogenetic diversity

Preventing Inbreeding Depression

• Increase population size

• Inbreeding avoidance

• “Genetic Rescue” (ex. Florida panthers)

Why can’t evolution just save them?

• Evolution is too slow - perceived wisdom

• The problems are too complex

Rapid evolution as a “foe”

1. Antiviral resistance

2. Antibiotic resistance

3. Chemotherapy resistance

4. Pesticide resistance

5. Herbicide resistance

Conceptualizing adaptation

• With an abrupt shift in optimum, the phenotype will eventually readjust

• With gradual changes, the phenotype “chases” the optimum

How can organisms change their phenotype to match the optimum?

1. Plasticity - genetic or otherwise, migration

2. Evolution

Phenotypic change - natural variation

• Daphne Major - beak size changes based on El Niño/ drought

Phenotypic change - global warming

• Red squirrels are breeding 15 days earlier, working off environmental cues

• Estimated “genetic breeding date” shifts

Phenotypic change - trophy hunting

• Smaller horns in bighorn sheep

Phenotypic change - fish harvesting

Atlantic cod fishery collapsed, closed in 1992

Fish mature earlier at a smaller size

• This hampers the recovery process because smaller fish have fewer eggs

Evolutionary rescue 

• In some scenarios, evolution allows recovery

• Ex. Trinidadian guppies