Lecture 1-3

Question 1

What does the lowest line on the tree of life represent?

Answer 1

Last Universal Common Ancestor

Question 2

What does the next line represent?

Answer 2

The common ancestor of archaea and eukaryotes

Question 3

What are the 3 domains?

Answer 3

bacteria, archaea, Eukaryotes

Question 4

What is the relationship between humans and chimps?

Answer 4

Shared a common ancestor 6-7 million years ago.

Question 5

What is the Impact Hypothesis and what supports it?

Answer 5

Theory that an asteroid struck earth and caused the cretaceous extinction.

Evidence =
- spike of iridium in 66 million year old rocks worldwide (abundant in asteroids)
- spike of shocked quartz in 66 million year old rocks worldwide (formed only under really high pressures)
- Spike of micro tektites in 66 million year old rocks in Gulf of Mexico (only form under really high templates and pressures)
- Huge 66 million year old crater discovered off coast of Mexico (very wide, impact would have far reaching effects

Question 6

What influenced the distribution of organisms over time?

Answer 6

• movement of continents affect total amount of land area
  -relative amounts of land in the tropics vs northern latitudes
• nature of ocean current

Question 7

What may be the reason for the challenges that we face?

Answer 7

• biggest brain on the planet
• complex society
• unparalleled capacity for cooperation
• ability to solve problems by reason, science, humanism, progress

ALL FROM ENLIGHTENMENT

Question 8

What is the “Great Chain of Being”

Answer 8

Credited to Aristotle - lifeforms in a hierarchy with some ‘higher’ or ‘better’ than others with a claim that ranking was designed by the creator

Question 9

What is ladder thinking?

Answer 9

• life = progressing
• higher and advanced forms replacing primitive ancestors
• going towards a greater goal… but no lifeforms can be considered more advanced than another

Question 10

What is the limit of Goal Directedness when talking about evolution?

Answer 10

• very misleading
• what is the ‘goal’ to reach from evolution??
• very subjective

Question 11

What is Deep time?

Answer 11

• Earth is very very old
• solar system 4-5 billion years ago
• Earth and moon soon after
• lifeforms been present on planet almost since start
• earth constantly changing since this time

Question 12

What two events happened in 1543? What did it mean?

Answer 12

• Vesalius printed book of drawings of human body (practical usefulness)
• Copernicus argued Earth revolved around the sun (conceptualization of universe)
• Symbolized launch of modern science

Question 13

What was germ theory?

Answer 13

• later half of 19th century
• one of the most important advances in medicine ever
• pathogens cause many diseases

Question 14

What are viruses?

Answer 14

Viruses are tiny, have molecular shells with a minimal set of genetic instructions and when injected into a cell, instructions take over the cell’s inner machinery and use it to make more viruses, destroying the cell. Not sure if its “alive”

Question 15

What were medical schools important for?

Answer 15

developing the enlightenment idea that new knowledge could be obtained by measurement, careful description, and experiment.

Question 16

how is branched evolution a better metaphor than ladder?

Answer 16

• each species have it’s own evolutionary past and each with different history with different circumstances
• any two lifeforms must share a branch point somewhere on the tree

Question 17

what is LUCA?

Answer 17

last universal, common ancestor…
- estimated to lived 3911 mya

Question 18

What was the biggest extinction period?

Answer 18

Permian period 225 mya
- one we know more about is cretaceous period 65 mya = demise of dinosaurs and other creatures
- we didn’t survive because we are better than dinosaurs, we were just able to

Question 19

who was the first person to grasp just how old earth is?

Answer 19

James Hutton

Question 20

What were the major events of the precambrian?

Answer 20

life, photosynthesis, oxygen atmosphere

Question 21

What were the major events of the Phanerozoic era?

Answer 21

-initial diversification of animals
- evolution
- early diversification of land plants and fungi
- movement of animals to land
- 5 mass extinctions during this time

Question 22

Who was Antonie van Leeuwenhoek?

Answer 22

draper, taught himself to grind lenses to better assess quality of fabrics - first to see and report cells and sperm

Question 23

What are the four components essential in cells?

Answer 23

1. membranes - keep in and out separate
2. metabolism - generate energy, synthesize new molecules, do the housekeeping
3. a genome (set of genes which is encoded the info to build and run cell)
4. the ability to produce a descendant by cell division

Question 24

how is bacteria different from other kinds of bacteria?

Answer 24

• size varies
• shape varies
• mobility varies

Question 25

what are membranes made out of?

Answer 25

• phospholipids
• naturally form liposomes in water - a cell shaped structure
• polar head, hydrophilic, water loving
• non-polar tail, hydrophobic, afraid of water

Question 26

What are nanometers?

Answer 26

a billionth of a meter, smaller than microns

Question 27

What can get through the bilayer or not?

Answer 27

• small non polar molecules
• small, uncharged polar molecules

CANT
- large, uncharged polar molecules (big)
- ions (charged)