Lecture 1-3 Flashcards
What does the lowest line on the tree of life represent?
Last Universal Common Ancestor
What does the next line represent?
The common ancestor of archaea and eukaryotes
What are the 3 domains?
bacteria, archaea, Eukaryotes
What is the relationship between humans and chimps?
Shared a common ancestor 6-7 million years ago.
What is the Impact Hypothesis and what supports it?
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
What influenced the distribution of organisms over time?
- movement of continents affect total amount of land area
-relative amounts of land in the tropics vs northern latitudes - nature of ocean current
What may be the reason for the challenges that we face?
- biggest brain on the planet
- complex society
- unparalleled capacity for cooperation
- ability to solve problems by reason, science, humanism, progress
ALL FROM ENLIGHTENMENT
What is the “Great Chain of Being”
Credited to Aristotle - lifeforms in a hierarchy with some ‘higher’ or ‘better’ than others with a claim that ranking was designed by the creator
What is ladder thinking?
- life = progressing
- higher and advanced forms replacing primitive ancestors
- going towards a greater goal… but no lifeforms can be considered more advanced than another
What is the limit of Goal Directedness when talking about evolution?
- very misleading
- what is the ‘goal’ to reach from evolution??
- very subjective
What is Deep time?
- 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
What two events happened in 1543? What did it mean?
- 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
What was germ theory?
- later half of 19th century
- one of the most important advances in medicine ever
- pathogens cause many diseases
What are viruses?
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”
What were medical schools important for?
developing the enlightenment idea that new knowledge could be obtained by measurement, careful description, and experiment.
how is branched evolution a better metaphor than ladder?
- 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
what is LUCA?
last universal, common ancestor…
- estimated to lived 3911 mya
What was the biggest extinction period?
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
who was the first person to grasp just how old earth is?
James Hutton
What were the major events of the precambrian?
life, photosynthesis, oxygen atmosphere
What were the major events of the Phanerozoic era?
-initial diversification of animals
- evolution
- early diversification of land plants and fungi
- movement of animals to land
- 5 mass extinctions during this time
Who was Antonie van Leeuwenhoek?
draper, taught himself to grind lenses to better assess quality of fabrics - first to see and report cells and sperm
What are the four components essential in cells?
- membranes - keep in and out separate
- metabolism - generate energy, synthesize new molecules, do the housekeeping
- a genome (set of genes which is encoded the info to build and run cell)
- the ability to produce a descendant by cell division
how is bacteria different from other kinds of bacteria?
- size varies
- shape varies
- mobility varies
what are membranes made out of?
- phospholipids
- naturally form liposomes in water - a cell shaped structure
- polar head, hydrophilic, water loving
- non-polar tail, hydrophobic, afraid of water
What are nanometers?
a billionth of a meter, smaller than microns
What can get through the bilayer or not?
- small non polar molecules
- small, uncharged polar molecules
CANT
- large, uncharged polar molecules (big)
- ions (charged)
