11. Great Dying

Question 1

What percentage of marine species died out in the Permian mass extinction?

Answer 1

90-95%

Question 2

When did the Permian extinction occur?

Answer 2

End of the permian

Question 3

What was diversity of terrestrial life like before the Permian extinction?

Answer 3

High diversity, esp of insects, amphibians, reptiles and mammal-like reptiles

Question 4

What was diversity of land plants like before the Permian extinction?

Answer 4

Very diverse, but arranged in characteristic belts based on lattitude

Question 5

What were the 6 main types of marine life in the late permian?

Answer 5

Attached, burrowing, hiding, crawling, swimming, predating

Question 6

What marine life type was characteristic of the permian?

Answer 6

Shelly fauna

Question 7

What is the Triassic fossil record like?

Answer 7

Very poor

Question 8

What types of species are seen in the Triassic fossil record?

Answer 8

Very limited number of species, all very abundant and environmentally tolerant

Question 9

Why are few specialist species seen in the Triassic fossil record?

Answer 9

Specialists were wiped out by the Permian Extinction

Question 10

What factor has overwhelming support as the cause of the Permian extinction?

Answer 10

Global warming

Question 11

What temp difference is seen prior to the Permian extinction?

Answer 11

Rise of approx 6° at the equator, but higher at higher latitudes

Question 12

What main systems sustains our ocean circulation?

Answer 12

Pole-to-equator temperature gradient

Question 13

How did uneven temperature rise affect the oceans in the Permian?

Answer 13

Reduce temp gradient and reduce or stop ocean circulation

Question 14

How would a reduction in ocean circulation lead to mass extinction?

Answer 14

• Dead organisms settle rather than being carried away
• Oxygen used up for decay
• Leads to cold, anoxic water which is hard for organisms to survive
• Pos feedback loop where more organisms dying amplifies the effects

Question 15

What are some possibilities for the cause of the warming pre Permian extinction?

Answer 15

• Oxidation of uplifted coals at the South pole releasing CO2 into atmosphere
• Siberian traps releasing CO2 and greenhouse gases
• Methane hydrates

Question 16

What data makes the Siberian traps an unlikely main cause for the heating?

Answer 16

Lots of Carbon-13 at the surface, too light to be explained by Siberian Traps

Question 17

Describe the suggested warming cycle of the permian.

Answer 17

1 Siberian traps cause CO2 warming
2 Melted Methane hydrates cause negative C13 excursions
3 Methane Warming

Question 18

Why is warming questionable as the only reason the Permian extinction was so severe?

Answer 18

Because similar heating has taken place in other periods without such dire consequences, 6° at the equator is not that severe

Question 19

Why did the heating of the Permian have such a severe affect?

Answer 19

Permian geography? Land masses and ocean environments were connected - stuff in one affects them all

Question 20

How does our current level of global warming compare to that of the Permian?

Answer 20

We have experienced a 3° rise in temp in about 100 years, while the Permian was 6° in 100,000-1 million years.
Half the rise but in <0.1% of the time

Question 21

Why might the Permian extinction have been far less severe if the world then looked like now?

Answer 21

Ocean anoxia in one sea might not affect anoxia specialists in unconnected seas

Question 22

Why is it concerning for us now that global mixing had such a large impact on the Permian extinction’s severity?

Answer 22

We (humans) are increasing global mixing at rates higher than any other in history

Question 23

How do humans accelerate global mixing?

Answer 23

Transport of cargo, direct movement of species, forcing species from natural habitats

Question 24

What groups of life are the most common biological invaders?

Answer 24

Plants, then fish, then birds

Question 25

How do biological invaders affect disease?

Answer 25

Invaders often propagate diseases that are fatal to native species

Question 26

Which environmental processes do invaders commonly impact?

Answer 26

Productivity, decomposition, hydrology, geomorphology, nutrient cycle etc

Question 27

Which invaders affect frequency of fires ?(and thus largely impact landscape and ecosystems)

Answer 27

Plants and grasses