Lecture 3 - Evolution and natural selection

Question 1

What does LUCA stand for?

Answer 1

Last universal common ancestor

Question 2

When was the last LUCA?

Answer 2

3.5-3.8 billion years ago

Question 3

How are the 3 major divisions or domains of life identified?

Answer 3

Based on comparison of ribosomal RNA

Question 4

How did W. Doolittle revise the ‘web of life’?

Answer 4

Domains of life are based on horizontal gene transfer

Through the sharing of genes

A community rather than a single origin

Question 5

In what ways are eukaryotes similar to archaea?

Answer 5

1. Proteins involved in cytokinesis
2. Cell shape determination
3. Protein recycling
4. Membrane remodelling (cellular compartmentalisation)

Question 6

What was previously understood about similarities between archaea and eukaryotes?

Answer 6

Features used to be unique to eukaryotes ONLY

Question 7

What is the most modern view of the ‘tree of life’?

Answer 7

Based upon the sequences of 16 ribosomal proteins, extensive mapping

Eukaryotes are group that has arisen from archaea

Question 8

When was Einstein’s Theory of General relativity?

Answer 8

1915

Question 9

What is the general relativity theory?

Answer 9

Gives the simplest description of eolution that is consistent with all known experimental and observational data

Consistent across all known data

Question 10

Why is Einstein’s work under scrutiny?

Answer 10

Echoes of gravitational waves when black holes fuse

Suggests there is a structure to the event horizon of a black hole

(Einstein suggest nothing should be found there)

Question 11

What is the movement of information to understanding science starting with Mythos and then Logos?

Answer 11

Mythos: stories of gods and heros
Logos: dominated by rational thinking
- lack of evidence for claims

1. Science is performed in a naturalistic framework

Question 12

What are the fundamental principles of science?

Answer 12

1. Science is performed in a naturalistic framework
2. Experimental/ observational support is required
3. Proceed with the simplest explanation consistent with all the data
4. Inductive reasoning allows you to draw conclusions
5. Compile and disseminate your knowledge
6. Accept uncertainty

Question 13

What is Occam’s razor?

Answer 13

Take the simplest possible view that aligns with data

Supported by Einstein - make simple but no simpler

Question 14

What is the principle of Parsimony?

Answer 14

Theories should explain and predict with the fewest assumptions

Question 15

What percentage of papers are rejected?

Answer 15

80%

Question 16

What must happen before work is published?

Answer 16

Scientists describe their approaches, observation and conclusions in sufficient detail allowing others to extend or repeat them

Question 16

What must happen before work is published?

Answer 16

1. Scientists describe their approaches, observation and conclusions in sufficient detail allowing others to extend or repeat them
2. Papers are submitted to journal
3. Papers returned for improvement

Question 17

What is the idea of falsification with science?

Answer 17

Science is a set of ideas about how the universe works

Science has an in-built self correcting mechanisms

We can never be certain that new data will not change out ideas - all science is theory

Question 18

What is evolution?

Answer 18

The genetic content of a population changes over time

Question 19

What is microevolution?

Answer 19

Changes in allele frequencies in a population of a species over time

Question 20

What are the 3 main mechanisms of microevolution?

Answer 20

Natural selection

Genetic drift

Gene flow

Question 21

What is macroevolution?

Answer 21

Changes at or above the level of the species

Question 22

What was the second voyage of HMS Beagle?

Answer 22

5 year journey but 3 years on land

Darwin - Galapagos Islands

Question 23

What ideas influenced Darwin?

Answer 23

Economic population (population growth and food supply)

Naturalistic framework

Observations and prior knowledge

Combination of all factors contributes to natural selection