What is the difference between a hypothesis, theory and law
A hypothesis is an explanation for an event, and hasn't been tested
or confirmed enough to become a
Theory - a confirmed and tested
explanation that is commonly accepted by the scientific community
(relativity, evolution) which differs from a
Law - Usually a
math equation, a law is used to predict other events. A law is
confirmed to be true under it's circumstances. (The Law of Gravity)
Steps of Scientific Method
Observation
Ask a
question
Hypothesis
Prediction
Experiment
Analyze
(and possibly repeat)
Report
Inductive vs deductive reasoning
inductive is specific to general and uses related observations to
arrive at a conclusion
deductive: specific to general - using data to arrive at a prediction
What does it mean for a hypothesis to be falsifiable, give an example.
It means that the hypothesis can be proven wrong
(give an example)
What is the definition of Evolution
Change in allele frequency over time
Who are the influential scientist who developed the theory of natural selection, what are their contributions.
Charles Darwin - origin of species / galapagos
A. R. Wallace - 'Wallace's Line' /malaysia
Three Requirements for Natural Selection to Take Place
Traits Vary
Traits are heritable
Differential reproduction
Sexual Selection vs Natural Selection
Sexual selection is selection for traits other than survival (mating
rituals etc)
Natural Selection is selection for traits for survival /
surviving to mate
Selective Pressure?
Drivers for Sexual Selection?
Selective Pressure - external factors that impact an organism's
ability to survive/pass on it's genes
The two drivers for sexual selection are competition for mates
and mate choice.
Give an example of natural selection in action
(provide an example)
What were some of the issues with Darwin's work and how were they resolved by modern science?
Did not understand mutation (Modern genetics)
Did not understand the mechanism of heredity (Gametes / meiosis)
Believed in 'blending' (mendel's peas and allele frequency
showed that many traits could be inherited from either parent)
What is Modern Synthesis
The blending of natural selection and modern genetics
What is population genetics?
What is a gene pool?
population genetics - study of how selective pressures change allele
frequency over time
pool - all of the alleles in a populatio
Besides natural selection, what are some other mechanisms of evolution
mutation
genetic drift
gene flow
What is the ultimate source of all genetic variation.
mutatio
How can gene flow both cause and prevent speciation
Gene flow can prevent population isolation, which would inhibit
speciation.
Genes flowing OUT of the population, may remove traits from the
pool, and cause specialization in those traits, leading to speciation.
What are some of the different causes of genetic drift
mortality, fertilization events, bottle neck, founder effect
Hardy-Weinberg equations and meanings
p+q=1 (dominant allele frequency + recessive allele frequency = 1 )
p^2 + 2pq + q^2 = 1 ( RR + Rr + rr = 1 )
What are causes of evolution/violations of hardy weinberg
Natural Selection
Mutation
Genetic Drift (AKA having a
small population)
Migration
Sexual Selection
Describe the 5 patterns of Selection, provide an example
Stabilizing (Selecting for the intermediate trait rather than
extremes, normal bellcurve)
Directional (selecting for one of
the extreme traits, pushing the bellcurve to the left or right)
Diversifying (Selecting for both of the extremes, pushing to two
humps in the bellcurve)
Frequency dependent - dependent on other
frequencies (see lizard example from lecture slides)
Sexual
selection Intrasex (males fight for access to females) intersex
(mating dances and rituals for female to choose mates)
What are some misconceptions about evolution
'just a theory'
populations evolve, not individuals
NOT the
origin of life
Environment doesn't cause evolution
Mutations
occur, whether they pass on or not is a result of selection
Homologous vs Analogous structures
Homologous structures look different but come from the same common
source
(bird wings vs human arms)
Analogous structures look the same but come from different
sources (bat wings vs bee wings)
divergent vs convergent evolution
divergent : related species split or 'diverge'
convergent : different species evolve the same or similar traits
they CONVERGE on it.
Examples of Evolution (same question twice)
Provide examples ie: antibiotic resistant bacteria, the finches in the galapagos etc etc
what are the main bodies of evidence for evolution
fossils, anatomy, embryology, molecular biology, biogeography
Biological definition of species
a population that can reproduce with one another
two schools of thought on speed of speciation
graduated (slow, over time) - like dinosaurs to birds
punctuated (quickly) - like the birds on galapagos
Sympatric vs Allopatric speciation
Sympatric - SAME HOME - something other than geography drove this speciation
Allopatric - different home - geography or natural disaster
split a species and caused the speciation.
prezygotic vs postzygotic barriers
Pre-z: mechanical (genitals), temporal (time of year/day), ecological
(habitat), behavioral (mating rituals), gametic (incompatible sex
cells)
post-z: reduced fitness for the zygote to survive, zygotic
failure, and sterility
Adaptive Radiation
A single founder species with multiple species branching. island chains and dispersal are a good example (Like birds or lizards)
Drivers of sympatric speciation
disruptive selection, assortive mating
drivers of allopatric speciation
mutation
natural selection
enough genetic and physical
variance
vicariance
geological barriers
Systemics vs Taxonomy
Systemics is the study of organisms to determine their relatives
taxonomy is the science of naming and grouping species
What is the most inclusive level of classification, what is the least inclusive?
DOMAIN > SPECIES
D / K / P / C / O / F / G / S
Why are shared ancestral traits unhelpful for sorting species?
What are Pleisiomorphies Synamorphies
Shared ancestral traits are seen across a large number of organisms
are more generic than they are specific
plesiomorphies - Primitive or ancestral trait
synamorphies
- Shared/Derived traits
Maximum Parsimony?
Fewest events = most likely
What types of genes would you use to look for differences between domains? Between Genera?
Domain : Slow evolving as they would be least likely to have changed recently
Genera: quick evolving, and the recentness will assist in sorting
Monophyletic vs Paraphyletic vs Polyphyletic
(Use the prefix to help you mono =1 para=next to poly=many)
monophyletic is an ancestor species and all
descendants
paraphyletic is an ancestor species and SOME
descendants but not all
polyphyletics includes distant relative
but NOT ancestor
Three assumptions of cladistics
related through a common ancestor
speciation makes 2 at a
time
traits change overtime and assume polarity
How does morphology help to build phylogeny
determining a shared or absent trait to organize organisms into can help track changes and assess relatedness
On a phylogenetic tree, how do you determine relatedness
things with fewer nodes between them are more closely related, things with more nodes between them are more distantly related
How do you write in binomial nomenclature
All in italics, capitalize 1st word, lowercase 2nd
Silly goose
Basis for classification of Domains
rRNA and structure. Archaea are extremophiles and exist where nothing else can, bacteria do have a nucleus (PROkaryotic) vs Eukaria which DO have a nucleus