Lecture 12 - evolution & conservation Flashcards
(21 cards)
What is conservation?
area of biology that looks at how species are affected by changes in the world. It goes on to explore how to protect these environments & species
What can threaten conservation?
- human activities change the environment
- habitat loss
- climate change
- pollution
- invasive species
What is the consequence of change to the environment?
The change in the environment can lead to the organisms in that area who are well-adapted to the first environment struggling in the new environment. This can lead to more predation or less reproduction and as a result can lead to reduced population sizes
- reduced population sizes
- extinction of populations
- extinction of species
- loss of ecosystems
How much has species declined?
World Wildlife Fund (WWF) found that there was 50-67% decline in species from sample of 4005 species by 2018 compared to 1970
What are examples of extinction due to a decrease in population?
- Dodo bird - flightless pigeon (extinct in the 17th century)
- Chinese river dolphin - suffered from pollution in river
- Great auk (penguin-like)
What was the biggest factor driving extinction?
loss of habitat
How can we identify correlates of extinction?
- are some species more likely to become extinct than others
- are species at threat randomly distributed
- does this depend on their ecology
- does this depend on where they live
Large, tasty, flightless animals more likely to be driven extinct
What is a phylogenetic niche conservatism?
- an imprint at evolutionary outcome
- species inherit their niches from ancestors
- closely related species are ecological similar
- share similar life-histories
What are examples of phylogenetic niche conservatism?
- old world leaf warblers
- very similar in appearance
- also similar in ecology
- insectivorous
- feed on trees
- short-lived
- many co-occur
As a result, loss of one species, likely to lead to the outer
What are the consequences of phylogenetic niche conservatism?
- closely related species share similar levels of threat, because they are ecologically similar
- low rates of adaptability - conservatism is a consequence of this
- low rates of evolution - also conservatism results from this
Describe phylogenetic niche conservatism & extinction in mammals
- IUCN threat - measure of how likely populations are to become extinct in coming years
- life history & ecological variables
- chosen carefully
- used statistical analysis to compare threats and these variables
What correlates with extinction threat?
- geographic range size
- body size
- gestation time
- age at sexual maturity
- tropic level
- population density
- human footprint
- human density
What is phylogenetic conservatism?
measured by looking to see whether evolutionary distance correlates with differences in traits
What is included when considering the level of phylogenetic conservatism?
- geographic range size - NO
- body size - YES
- gestation time - YES
- trophic level - YES
- IUCN threat - YES
Is phylogeny a good predictor of extinction threat?
moderately good - thus is a consequence of shared evolutionary history
Describe niche conservatism in mammals
- further analysis by Cooper
- measured & compared rates of evolution across groups & over the globe
- evolution is faster outside of the tropics
- Niche conservatism is greater in the tropics
What is phylodiversity?
- some areas & groups are more or less adaptable in the face of threats
- some areas contain more unique species than other
- phylogenies contain unequal distribution of species
- based on phylogenetic information can prioritise conservation
What is phylogenetic diversity?
total amount of history shared by a group of species
How can phylogenetic diversity information be used?
- record the species present in a set of areas
- generate a phylogeny for the species
- calculate phylogenetic diversity
- prioritise accordingly (when deciding what to conserve)
What is an example of how phylogenetic diversity information be used?
phylogenetic diversity & species richness in Australian Frogs
How important is phylogeny in prioritising species?
- phylogeny should be an important consideration in deciding which species to conserve
- conservation should aim to conserve as wide a range of phylogenetic diversity as possible
- focus away from species rich groups in which individual species are threatened
- focus on evolutionarily distinct species
- this is because phylogenetic diversity correlates with genetic & functional diversity
