Lecture 31: Origin of Life & Humans

Question 1

How old is the universe?

Answer 1

13.8 Billion years ols

Question 2

Define acceration disk

Answer 2

Gravitational condensation of matter at center of black hole or galaxy

Question 3

Define plastessimals

Answer 3

objects formed from the coalescing of matter in condensing accretion disk

Question 4

What is the Miller experiment?

Answer 4

It generated organic molecules from inorganic compounds with electrical energy.

Question 5

What are the 3 domains of life?

Answer 5

• Bateria
• Archaea
• Eucarya

Question 6

How is it believed the eukaryotic genome was formed?

Answer 6

Fusion of a bacterium with an archaean (genes for rRNAs & ribosomal proteins)

Question 7

Eukaryotic ‘infroamtion’ genes (genetic code) are more similar to…?

Answer 7

Archaeal genes

Question 8

Eukaryotic ‘metabolic’ genes (glycolysis, etc) are more similar to..?

Answer 8

Bacterial genes

Question 9

What is superposition?

Answer 9

(older below, younger above)

Question 10

What is faunal succession?

Answer 10

based on the observation that sedimentary rock strata contain fossilized flora and fauna, and that these fossils succeed each other vertically in a specific, reliable order that can be identified over wide horizontal distances.based on the observation that sedimentary rock strata contain fossilized flora and fauna, and that these fossils succeed each other vertically in a specific, reliable order that can be identified over wide horizontal distances.

(turnover or fossil composition)

Question 11

What is the Cambrian Explosion?

Answer 11

There is major diversification of body plans

Question 12

What is known about the invert-vert split?

Answer 12

The genetic distances between vertebrate and invertebrate taxa predict an early divergence date for the split (much earlier than Cambrian explosion).

Question 13

What is the Burgess Shale?

Answer 13

A sedimentation at base of marine “cliff” by marine mudslides, contains 540 million year old sediments.

Sediments accumulate at sea floor, mudslide captures.

Question 14

What is fine-grained sedimentation?

Answer 14

Deposition occurs at the scale of a few centimeters

Little or no bioturbation

Question 15

Define bioturbation.

Answer 15

the disturbance of sedimentary deposits by living organisms.

Question 16

What is the African replacement model?

Answer 16

• African origin of H. sapiens
• different migration waves
• Displaces H. erectus and Neandethals

Question 17

What is the Hybridization model?

Answer 17

• Like replacement model

- Involves hybridization between H. sapiens and others

Question 18

What is the Multiregional model?

Answer 18

• Parallel origin of H. sapiens in different regions

- Requires gene flow (to and from)

Question 19

What is greater encephalization?

Answer 19

A defining character of the genus homo.

• an evolutionary increase in the complexity or relative size of the brain, involving a shift of function from noncortical parts of the brain to the cortex.