extra material ch 29 Flashcards
the rate of current extinction
x1000 times faster in the last 50 years
- at least 322 species of terrestrial vertebrate have gone extinct
- decline of 25%
MYA of major extinction events
End-Permian ~252 mya w/ loss of trilobites
End-Cretaceous ~66 mya w/ loss of dinos
End-Devonian ~359 mya w/ major marine life collapse
effect of arthopocene
At leat 50% ice-free terrestrial ecosystems converted to cropland and pasture
Cities cover ~3% terrestrial Earth surface
3 levels of organization of biodiversity
Genetic diversity
Species diversity
Ecosystem diversity
Luke Gibsons study and discovery of the Malayan Rate suggests what about invasive species and habitat fragmentation
Invasive species can exploit fragmented habitats, accelerating native species decline.
TSD and jackydragons
TSD adaptively matches sex to conditions that maximize fitness:
TSD-temeprature dependent sex determination
female and male jackydragons temp
Females: Produced at low (23–26°C) or high (30–33°C) =[more favourable] temperatures.
- more eggs with bigger body produced at higher temperatures
Males: Produced at intermediate (27–29°C) temperatures.
who questioned Erwins hypothesis of the 30 million unknown species and suggested the number be tweaked to 100 million instead?
NIGEL STORK
PVA
POPULATION VIABILITY ANALYSIS (PVA): estimates how large a pop. must be to increase the likelihood of its long-term survival
COSEWIC looks at
Popn trends
Habitat availability
Geographic range
Threats → Eg: pollution, climate change
Effective popn size (breeding adults)
charismatic megafauna (another term)
flagship species
what is beta diversity
species diversity across community boundaries
what can u infer about IUCN
likely underestimating the number of species at risk of extinction
