How do we know
-scientific knowledge is (3)
-relation between confidence and evidence
probability is NOT _______
-expect _______ because of variation
-evidence based, testable, open to change
-as evidence increases, so does confidence
-uncertainty
-exceptions
Early Earth
-mainly had (5) but lacked _____
-it was in a ____ state. Prevented____
-how were these inorganic substances made into organic compounds?
-carbon dioxide, mathane, ammonia, hydrogen, and sulphide
-reduced state. oxidation
-energy from lightning
Urey Miller Experiment
-simulated ______ and tested what?
-__% of C was in ______
-early earth, chemical origin of life
-2, amino acids (13 of 22)
Ocean environment
-_____ may have been reducing and early life
-evidence (2)
-how did they make ATP
Vents
-sulfur bacteria, thermophiles habitat
-they were chemolithotrophs and used different inorganic food sources/ hydrogen sulfide as a electron donor
First prokaryotes
-many found in ______ where ______ form a biofilm that traps sediment
stromatolites, cyanobacteria
biofilm is a surface of water where it slowly sinks down
Archaean Period
-how did cyanobacteria obtain energy and was was produced as a byproduct
-what major event occurred here
-evidence for this (2)
-what was the period of photosynthesis without oxygen called
-photosynthesis, and released oxygen into the environment
-converted the reducing atmosphere into an oxidizing one which changed earth. Great oxygenation event
-Banded iron formation (oxygen reacted with iron and sulphur) declined because now oxygen readily reacts with iron to rust and minerals were oxidized now too
Cambrian explosion
-what was it
-____ ____ preservation and appearance of _______
-why was it an explosion of life? (4)
-rapid appearance of organisms
-soft body/shells and modern groups like heads legs, etc
-oxygen levels from algae, genetic diversity, new niches, calcium carbonate production in ocean for defense
Normal extinction vs mass extinction
-what are the rates compared to speciation
-why is mass important
normal is when speciation is greater than or equal to extinction while a mass extinction results in a short interval of the opposite
-they clear niches and create new opportunities
Biological diversity
Evolution
-4 levels we can study evolution on
-ongoing process of change
-change in allele frequencies (genes) in a population over time
1. genetics and inheritance
2. population and genetics
3. paleobiology (large scale changes)
4. morphology (development)
Erasmus Darwin
Patrick Matthew
Robert Chambers
-idea of one life form/spark
-idea of natural selection for best suiting to its conditions
-the organic creation is a progress, god didnt make it as 1 thing
Charles Darwin
- 4 main ideas that inspired him
(Cuvier Lyell Lamarck Mathius)
- What was he convinced of
- some species survive while others go extinct
- the earth is old and is changing gradually
- species themselves must change (transmutation)
- pressure to force adaptation to be the fittest
-life evolved over time, artificial selection and natural
Charles Darwin cont.
-what 3 parts did he consider
4 major conclusions
which idea was already known
-variation in traits, reproduction, and inheritance (NOT envrionment)
1. individuals vary
2. some variation is inherited
3. more offspring born than what can survive
4. survival is not random and related to phenotype
selection (artificial) and he began to think of natural selection
Describe Darwins case study
-adaptive radiation
-beak gene?
_____ can occur without ______, but ______ by natural selection cannot
galapagos islands all had different ecosystems and the finches all adapted differently to each one in terms of beak size
-process in which organisms diversify rapidly from 1 species into new forms
-yes and it was heritable.
-natural selection can occur without heritability (bc of environment), but evolution by natural selection cannot occur as this is when its passed down
Key concepts
-there is _____ in a trait and it is ______
-some survive and reproduce better and pass down variations
-theory
-scientific theory
variation, heritable (passed down)
-guess, opinion, hypothesis
-incorporates all laws, evidence, hypothesis, and subject to revision, holds true
