Extincitions

Question 1

What are extinctions/mass extinctions and why do they matter?

Answer 1

Extinctions occur when the last individual of a species dies out

A mass extinction is a rapid loss of species over a large area

Functional extinctions occur when individuals remain but the odds of sustainable reproduction are low

Question 2

Why do extinctions occur?

Answer 2

when the environment of a species changes faster than the species can
adapt

volcanic activity
climate change
asteroids

Question 3

general trend of animal diversity over time

Answer 3

Overall: Diversity increases over time, with fluctuations caused by mass extinctions and recoveries.

Question 4

Evidence for the role of an impact at the end of the cretaceous (K-T event)

Answer 4

shock metamorphism (a shock wave caused by the impact altering the rocks-high temp and pressure)
has only been observed meteorite impact sites and nuclear test sites

scoot particles and charcoal found in boundary clay
suggest global wildfires associated with ignition of large amounts of plant matter on earth’s surface

Question 5

what is the hypothesis that links an iridium layer with asteroid extinction?

Answer 5

It proposes that a huge asteroid impact caused the mass extinction at the end of the Cretaceous

Evidence: a worldwide layer of iridium (rare on Earth but common in asteroids) found in sediments from that time.

Question 6

causes of end-permian extinction

Answer 6

Siberian Traps volcanism: Massive eruptions released CO₂, SO₂, and toxic gases, causing global warming, acid rain, and ocean acidification.

climate change
ocean chemistry disruption

Question 7

how may we avoid impact-induced extinction?

Answer 7

Detection & tracking: of near-Earth objects to identify potentially hazardous asteroids early.

Deflection strategies

Develop emergency plans and evacuation strategies for smaller impacts

Question 8

What is a multi-planet species and the concept behind this?

Answer 8

A multi-planet species is a species that lives on more than one planet or celestial body.

reduces risk of extinction

Question 9

why could a crater impact make non-avian dinosaurs go extinct?

Answer 9

-Large shockwaves and short-term heat
-dust and rock blocked sunlight
-long-term cooling