Fossil Records

Question 1

What is a fossil?

Answer 1

preserved remains or any preserved trace of a once living org

Question 2

What are the four conditions for fossilisation?

Answer 2

1. Bone or hard structures.
2. Rapid burial
3. Anoxic conditions
4. Chemistry doesn’t dissolve organisms (alkaline)

Question 3

How are fossils dated?

Answer 3

1. Relative dating:
   
   • Stratigraphy
   • Index fossils
2. Absolute dating:
   
   • Radiometric dating methods
   • C14 –> N14 (Only up to 70,000)

Question 4

What are the major evolutionary transitions?

Answer 4

Note: changes in the way info is stored and transmitted.
1. multicellularity
2. the genome
3. division of labour
4. development of more complex units

Question 5

How did multicellularity occur?

Answer 5

• Evolved over multiple times - through endosymbiosis, etc

Question 6

List the evolutionary events:

Answer 6

• first animal most similar to sponge
• biomarkers suggest support the fossil evidence and suggest that animals have evolved approx 635 mya.
  around 575 mya larger and more diverse animals appear.

Question 7

Explain the process of origination and extinction:

Answer 7

1. Origination: new species evolve
2. extinction = species di out.
   The rate of origination and extinction determine the diversity of a species.

Question 8

Explain adaptive radiation (ask elise):

Answer 8

• evolutionary lineages undergo exceptionally rapid diversification into a variety of lifestyles or ecological niche
• involve a new environmental niche v absence of completion

Question 9

Explain what mass extinction is:

Answer 9

• a statistically significant departure from background extinction rates that results in substantial loss of diversity
• may occur because of:
  
  • climate
  • habitat loss
  • competition
  • predation
• mass extinctions may be local, global, taxonomically/broad, occur over different time scales.

Question 10

List the 5 big extinctions:

Answer 10

• Ordovician
• Devonian
• Permian
• Triassic
• Cretaceous

Question 11

Explain the End-Ordovician:

Answer 11

Look at notes

Question 12

Explain the end-Triassic:

Answer 12

Look at notes

Question 13

What are human-driven extinctions?

Answer 13

• Dodo bird were native to Maricious but humans hunted them and introduced rats to eat Dodo bird eggs –> led to their extinction.
• Tasmanian tiger declared extinct in 1936, hunted to extinction.

Question 14

Human causes of extinction:

Answer 14

1. Habitat loss
2. species introctions
3. pollination
4. overpopulation
5. climate change
6. disease

Question 15

Explain the impact of habitat loss in contributing to human-caused extinction:

Answer 15

• Occurs due to deforestation, urban development.
• Case study = ohahu wetlands

Question 16

Explain the impact of climate change on human-caused extinction;

Answer 16

• Atmospheric CO2 increase (highest levels in past 800,000 years).
• temp increases:
  
  • glaciers = melting
  • planted animal ranges have shifted
  • loss of sea ice
  • heat waves
  • seawater rising
  • artic predicted to be ice-free in this century
  • CO2 dissolves into ocean making it more acidic (8.21–> 7.8.10)
  • affect marine life.