Lecture 12 - evolution & conservation Flashcards
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
