Origins of Life and The Single Cell Planet

Question 1

Oldest rock

Answer 1

Castonites

Question 2

Describe castonites

Answer 2

Contain zircon-93

Question 3

Describe Zircon-93

Answer 3

Half life 1.5bn years

Question 4

Phanerozoic Eon

Answer 4

• Eon of visible life
• last 550M years

Question 5

Which era is the Cambrian epoch in?

Answer 5

Paleozoic

Question 6

Chert

Answer 6

• SiO2 toentophysalis fossilised

Question 7

Stromatolites

Answer 7

• Trace fossils of bacteria
• 3500Mya
• Paleoproterozoic

Question 8

What carbon isotope does carbon dating use?

Answer 8

C14

Question 9

Why are archaea and bacteria hard to distinguish paleontologically?

Answer 9

Extremeophiles don’t preserve well

Question 10

Multicellularity did not evolve in a

Answer 10

Single clade

Question 11

Darwin’s dilemma arises from the fact that

Answer 11

Soft-bodied organisms decay after death (unless preserved in sediments and fossilised)

Question 12

VSM

Answer 12

Vase-shaped microfossils

Question 13

Describe tubular fossils

Answer 13

• Claudina; Namacalathus
• polykete worms
• Cnidarian-grade
• complex skeletal structures
• Namibia, 550Mya

Question 14

Describe the Ediacaran biota (Tarhan et Al, 2017)

Answer 14

• complex
• macroscopic
• terminal Ediacaran rocks
• preserved in sandstones

Question 15

Describe Rangiomorphs

Answer 15

• fractal (maximises SA)
• below photic zone

Question 16

Cholesteroids

Answer 16

Animal-exclusive signature

Question 17

The Cambrian explosion is the

Answer 17

Origin of modern phyla

Question 18

How long has there been life on Earth?

Answer 18

~4.5bn years

Question 19

What are the 3 Eons?

Answer 19

1. Archaean
2. Proterozoic
3. Phanerozoic

Question 20

Name the eras

Answer 20

1. Paleoproterozoic
2. Mesoproterozoic
3. Neoproterozoic
4. Palaeozoic
5. Mesozoic
6. Cenozoic

Question 21

Describe trilobites

Answer 21

Paléozoïque

Question 22

Describe diNoSauRs

Answer 22

• Mesozoic

Question 23

Describe ammonite

Answer 23

• Mesozoic

Question 24

All the fossils we know come from the

Answer 24

• Phanerozoic
• last 550My

Question 25

Which is the oldest fossil to be assigned bacteria

Answer 25

- Eoentophysalis - Cyanobacteria - 2000Mya - Belcher subgroup - Hudson Bay, Canada

Question 26

What entombed early organisms?

Answer 26

Silica (concentrated in oceans)

Question 27

What are the 5 major groups of eukaryotes ?

Answer 27

- SAR - Plants - Excavates - Amoebozoa - Opishokonts

Question 28

Describe the oldest eukaryotes (Adam et al, 2017)

Answer 28

- global occurrence - 1600-1400Mya - end of Mesoproterozoic - large size (50μm) - complex wall ultra structure - complex ornamentation

Question 29

Give an example of one of the oldest eukaryotes (Butterfield, 2015)

Answer 29

- Bangiomorpha pubescens - red alga - 1045Mya - Hunting formation, Canada

Question 30

Describe the Lantian Biota (Yuan et al, 2011)

Answer 30

- 600Mya - China

Question 31

Describe how the molecular clock works (Erwin et al, 2011)

Answer 31

1) assess similarity of DNA of modern organisms 2) estimate evolutionary rate 3) calculate divergence times

Question 32

Describe sponges

Answer 32

- one germ layer - multicellularity

Question 33

Cnidara

Answer 33

- two germ layers

Question 34

Bilateria

Answer 34

- three germ layers - bilateral symmetry - separate mouth and Anus

Question 35

Protostomes

Answer 35

- eight-cell stage - spiral cleavage - gastrulation - mouth forms first

Question 36

Deuterostomes

Answer 36

- radial cleave - mouth forms second