12 Evolution and Conservation Flashcards
How do human activities change the environment?
Habitat loss
Climate change
Pollution
Invasive species
What are the consequences of changes to the environment?
Reduced population sizes
Extinction of populations
Extinction of species
Loss of ecosystems
How have causes of extinction changed historically vs currently?
Human exploitation and introduced species lower
Habitat loss much higher
What are the correlates of extinction?
Are some species more likely to become extinct than others? - do they have some characteristics that cause this
Are species at threat randomly distributed?
Does this depend on their ecology?
Does this depend on where they live?
What is phylogenetic niche conservatism?
An important evolutionary outcome
- Species inherit their niches from ancestors
- Closely related species are ecologically similar and share similar life histories
- Results from low rates of adaptability and evolution
What are the consequences of phylogenetic niche conservatism?
- Closely related species share similar levels of threat as they are ecologically similar
- Low rates of adaptability - evolution can’t keep up with changes in environment -> evolution
- Lo rates of evolution
What is IUCN threat?
Measure of how likely populations are to become extinct in coming years
What correlates with extinction threat?
Geographic range size - strong relationship
If one species is threatened, it is likely that its relatives will be as well
How is phylogenetic conservatism measured?
By looking to see whether evolutionary distance correlates with differences in traits
Which traits show phylogenetic conservatism?
Body size
Gestation time
Trophic level
IUCN threat
Where is niche conservatism greatest?
In the tropics
- Slower evolution in the tropics leads to this - respond less quickly to changes in the environment
Why do we need to prioritise where to place conservation efforts?
Some areas and groups are more or less adaptable in the face of threats
Some areas contain more unique species than others
Phylogenies contain unequal distributions of species
Should aim to conserve as wide a range of phylogenetic diversity as possible - focus on evolutionarily distinct species
What is phylogenetic diversity?
The total amount of history shared by a group of species
- Total up all branch lengths that link the species together
- Higher phylogenetic diversity would have a longer total branch length
