Studied by 2 peopleEvolve
Change
Microevolution
Any change in allele frequency in the gene pool of a population
Macroevolution
An accumulation of many small genetic changes that result in the formation of a new species from a pre-exsiting species
What are the two theories to how Earth formed?
Intelligent design/ creationism (God created)
The Big Bang Theory
What is The Big Bang Theory?
All matter in entire universe condensed in one location
Explodes, everything/particles goes flying
Gases and reactions following explosion forms galaxies, planets, suns, ect.
Earth was super hot from explosion and cooled to form a crust
Earth has solid iron core and has magma under crust
When does The Big Bang Theory say Earth was formed?
4.5 billion years ago
When does intelligent design say Earth was formed?
12,000 - 200,000 years ago
Where does Oparin’s Hypothesis say CHNO (part of SCHNOP) came from?
Simple gas molecules
Where does Oparin’s Hypothesis say carbon (C) came from?
Methane gas (CH4)
Where does Oparin’s Hypothesis say hydrogen (H) came from?
Hydrogen gas (H2)
Where does Oparin’s Hypothesis say nitrogen (N) came from?
Ammonia gas (NH2)
Where does Oparin’s Hypothesis say oxygen (O) came from?
Water vapor (H2O)
What is Oparin’s Hypothesis?
Methane gas, hydrogen gas, ammonia gas, and water vapor collided and reacted with each other because of all the energy present where eventually organic molecules formed
They rained down into the seas (“Organic soup”) while continuing reacting with each other
Lots of time passes then 1st cells are made
What are examples of energy present that caused organic molecules to form?
Heat
Light
Radiation
Lightning
Volcanic eruptions
What is Miller’s test?
Tested Oparin’s hypothesis
Uses distillation apparatus (made of glass tubing)
Created water cycle
Let experiment run for 24 hours
What were the results of Miller’s test?
Second time run: 2 amino acids (Glycine & Alanine)
How many years ago is Earth said to have been created according to the Big Bang Theory?
4.5 billion years ago
How many years ago were the 1st cells said to have been created according to the Oparin’s hypothesis?
3.5 billion years ago
How many years ago were the 1st cyanobacteria said to have been created?
2.5 billion years ago
Why is the appearance of the 1st cyanobacteria important?
They photosynthesize and bring oxygen into the air
How many years ago were the 1st eukaryote cells said to have been created?
1.5 billion years ago (took 2 billion years to develop)
What are the first cells according to Oparin’s hypothesis?
Cell membrane
Cytoplasm
RNA
Ribosomes
What are the traits of the first cells according to Oparin’s hypothesis?
Anaerobic (no oxygen in air)
Aquatic (formed in water)
Glycolysis (1st respiration process)
Smaller
Divided A-sexually by fission
Heterotrophs (ate each other)
Chemosynthesis (ate inorganic food)
Did not photosynthesize
What are fossils?
Remains of past life
What are the different kinds of fossils?
Could be an imprint (perfect impression)
Could be cast (stone replica)
What can be learned from fossils?
How the organism died, what lived with it (past life)
What are the methods of fossilization?
Tar pits
Ice caves
Amber
Volcanic ash
Peat bog
Sedimentary rock
What is amber?
Crystalized tree sap
What does amber fossilize?
Small animals/insects
What is a peat bog?
Muddy swamp like quicksand that is acidic
What is the most common method of fossiliztion?
Sedimentary rock
What is relative dating?
Comparing the age of fossils by observing how deep they are in the rock layer
What is absolute dating?
Using radioactive isotopes to find age
Is it better to have long or short half life for absolute dating?
Longer
What is half life?
The time it takes for half of radioactive material to decay
How do you use absolute dating?
Guess the measurement of grams of radioactive isotope at death
Calculate grams to half life of radioactive isotope till get 1 gram
Why isn’t absolute dating perfect or always accurate?
Number of grams is only an estimate
Measured assuming constant half life rate
What is the geologic time scale?
The entire history of Earth (includes history of life)
What is the geologic time scale divided up into?
Four eras of time
What are eras divided up into?
Periods
What are periods divided up into?
Epoch
What are the four eras of time?
Precambrian
Paleozoic
Mesozoic
Cenozoic
When was the Precambrian era?
4600-543 years ago (4 billion years long)
When was the Paleozoic era?
543-245 years ago (250 million years long)
When was the Mesozoic era?
245-65 million years ago (180 million years long)
What is considered to be the age of dinosaurs?
Triassic, Jurassic and Cretaceous periods in the Mesozoic era
What is our current era?
The Cenozoic era
When was the Cenozoic era?
65 million years ago - current time
What is the trend that ends an era?
Mass extinction of life (though some survive)
Why are eras getting shorter?
Change is happening faster
What should be seen in the fossil record?
Lots of gradualism, small steady changes over time to get to modern species
Why isn’t the fossil record not perfect evidence of macroevolution?
Not seen in most species
Record is incomplete, can miss species
Not always interpreted correctly
No way to know if correct
Can’t always go off DNA or appearance
So much unknown
What are homologous structures?
Has similar bone/internal structure/pattern, don’t have same function
What is an explanation for homologous structures?
Common ancestor
What are vestigial structures?
Left over/extra reminate body parts no one of species uses
What is an explanation for vestigial structures?
Had a common ancestor that once used the body part
Can you live without a vestigial body part?
Yes
What are examples of vestigial structures?
Human coccyx (tailbone)
Human appendix
What are homologous vertebrate embryos?
When all vertebrate (backboned) at some point goes through stage when embryo
What are physical traits of being homologous vertebrate embryos?
Curved spine, ends at tail
Big eyes
4 limb buds
Gill slits
What is an explanation for homologous vertebrate embryos?
Common ancestor
What is the most important difference between species that beats all others?
Developmental (homologous vertebrate embryos)
What are homologous molecules?
2 main molecules compared between species: DNA gene sequence and proteins
What is an explanation for homologous molecules?
Common ancestor
What is Lamarck’s theory?
Inheritance of acquired characteristics (wrong- anything you inherit must come from DNA)
Vestigial organs go away if we decide we don’t need them anymore (wrong- not choice, though over time could possibly disappear)
Organisms have an innate desire to change (wrong- change isn’t a choice)
Who is Charles Darwin?
Considered the father of modern evolution
What is Darwin’s story on the Galapagos Islands?
Found 13 different kinds of finch (only 1 kind in Ecuador)
Guess original had children with different beak mutations, had to find new food
Kept alive because no predators, no competition
Don’t reproduce together by choice
What are Darwin’s observations?
There is variation within a population
More organisms are produced than the environment can support
Population size remains constant over time
The Earth is slowly but constantly changing
What is Darwin’s theory of macroevolution?
There is fierce competition for resources
Natural selection
What is considered fit to survive is constantly changing as environment is constantly changing
What is fitness?
Whatever helps you survive better
Lives long enough to pass fit trait, reproduce
Adaptations are fit traits
Eventually everyone in population will have fit trait, those without had died
What is natural selection?
Main mechanism for change
Nature/environment determines fitness
How much life has gone extinct? Why?
95%, couldn’t mutate and change with environment
What is speciation?
The making/forming of new species from a pre-existing species
What are species (only applies to animals)?
Must naturally mate/reproduce in wild
Offspring viable (they must be able to reproduce when they grow up)
Both criteria must be met to be determined as the same species
What is allopatric specation?
Geographic barrier causing split in species
Reproductive isolation
Each population gets different mutations till becoming different species
What is sympatric speciation?
In same location
A group gets mutation
Can still reproduce together
Mutated and normal group may choose to reproduce separately, eventually becoming a new species
What is adaptive radiation?
When one species enters a new territory and quicky radiates out into multiple species (all shares common ancestor)
Why is adaptive radiation possible?
No competition, no preators in new area
Can adapt to different environments predators to fill different niches in area
What is an example of adaptive radiation?
Darwin’s finches
What is convergent evolution?
Two different unrelated species in different locations evolve similarly, has similar adaptations
Why is convergent evolution possible?
They live in similar environments
Natural selection is similar
What is an example of convergent evolution?
Sugar glider (Australia) & flying squirrel (North America)
What are analogous structures?
Similar adaptations to different species
Looks similar outwardly
Has same function
Different origin
Different inside
Exact opposite of homologous structures
What is gradualism?
Small gradual changes in species over time (very rare)
What is equilibrium?
Species doesn’t change at all, living fossils (species millions of years old that still exist today: sharks)
What is punctuated equilibrium?
Short burst of rapid change (most common)
What could cause rapid change in punctuated equilibrium?
Big natural disasters
New species migrated
What are the 5 conditions of Hardy-Weinberg equilibrium (no change in allele frequency of a gene pool)?
No mutations (can’t create new allele or change allele)
No natural selection (everyone must be equally fit, has equal chance of survival)
No migration in or out
Large population size (couple losses won’t change allele frequency, smaller populations change faster as affected more by loss)
Random mating (no selectiveness, everyone is equal)
What was Hardy-Weinberg’s conclusion?
Can’t meet all 5 conditions for prolonged periods of time, therefore change in allele frequency is inevitable (must happen)
What are the equations to calculating allele frequencies?
p^2 + 2 pq + q^2 = 1
p+q=1
What does “p” represent?
Frequency of dominate allele (A)
What does “q” represent?
Frequency of recessive allele (a)
What does “q^2” represent?
Frequency of homozygous dominate genotype (AA)
What does “pq” represent?
Frequency of heterozygous genotype (Aa)
What does “p^2” represent?
Frequency of homozygous recessive genotype (aa)
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