Quiz 1 notes Flashcards
evidence of first life seen around … bya
… and … of the atmosphere around 3 bya
followed by presence of … around 2.7 bya
at around 2.5 bya there was the … event where O2 levels in rocks started to rise
at about <500 mya, … showed up followed by … and then ….
4; photosynthesis; oxygenation; eukaryotes; great oxygenation; land plants; dinosaurs; humans
at around the time when earliest evidence of life came to be, earth was … than at the beginning, but still hot; the atmosphere lacked …, and there was no existing …
cooler; O2; land mass
logic behind LUCA: all known life exhibits: ... similar machinery of ... and ... same basic ...
genetic code (DNA); replication; protein synthesis; metabolic rxns
in fossil record, the organisms appear in this order (1 being earliest):
1: …
2: ..
3: …
4: …
5: …
6: …
arthropods fish amphibians reptiles mammals birds
Mesozoic era: 250-65 million ya:
… climate
no … present yet
warm; polar ice caps
Mesozoic includes …, …, and … periods and is defined by … at beginning and end of period
Triassic; Jurassic; cretaceous; mass extinctions
the mass extinction of the Mesozoic era that preceded dinosaurs has a cause that is still unknown: killed … life
may have been …, .., or … due to release of methane
marine; meteor; volcanoes; climate change
K-Pg boundary extinction killed …: 65 mya
…. (K)- … (Pg)
sudden mass extinction of about … of plant and animal species on Earth
dinosaurs; cretaceous; Paleogene; 3/4
K-Pg boundary extinction caused by either a massive … or …: proven bc a crater was found, … brought about by this–> stopped photosynthesis and reduced O2 levels, 6-9 mi wide crater
comet; asteroid; impact winter
def of mass extinction is one that eliminates at least ...% of all species. there have been five mass extinctions: ..-.. ... ...-... ..-... ...-...
O-S (Ordovician-Silurian) late D (late Devonian) P-Tr (Permian-Triassic) Tr-J (Triassic-Jurassic) k-pg (cretaceous-Paleogene)
…% of all species that have ever lived have gone extinct
99
background (natural) extinction rate: estimated by looking at the fossil record: on average, a species lasts about …-… million yrs before going extinct/evolving into a new species
with about 10M species, can predict 1-10 extinct/yr (rate = 0.0001%-0.00001% per year)
1-10
current observed extinction rate: for birds and mammals = …% per year. in other words, we would have predicted only 1 species of bird/mammal to go extinct over a period of 100 years but 1850-1950, we saw 100 species lost. so …% of extinctions due to human activities
.01; 99
…: age of the mammals –> 65 mya- today
cenozoic
Precambrian period: lasted from the formation of the planet (about 4.6 bya) until the start of the … period (about 540 mya)
represents about … of earth’s history
end of Precambrian period marked by the …- the sudden diversification of multicellular life
Cambrian; 7/8; Cambrian explosion
all living organisms: are ..., ... structures made up of 1 or more cells respond to ... in the environment ... ... and ... ... maintain ... (hemostasis = steady state) process ... for ... activities
organized; ordered; stimuli reproduce grow and develop regulate internal functions internal energy; metabolic
causes for Cambrian explosion:
possibly bc of …/… changes
possibly that O2 temporarily crossed … leading to an arms race of predator vs. prey, allowing carnivores and their prey to evolve, diversifying organisms
adaptations; environmental; ecological thresholds
not all organisms are equally likely to be preserved as fossils: organism’s … contributes
the organism has to be buried before it has the chance to …–> must be in location w/ a lot of …, typically near bodies of water, organism must lie in that area for long enough time and with enough …
high … and high … increase rate of decomposition, which is why there aren’t many organisms in tropical areas that are preserved as fossils
anatomy; decay; sediments; pressure; humidity; temperatures
…. is a fatal fungal disease for hibernating bats. bats roost in colonies of 100-1000 individuals
white nose syndrome
… science: “pure science”; seeks to expand knowledge regardless o the short term application of that knowledge
… science: aimed to solve real world problems
basic; applied
… hypotheses both hypothesize some effect, whereas a … hypothesis hypothesizes no difference
alternative; null
descriptive statistics relates to … and ….
inferential statistics involves …
central tendency; variability; t-test
… measures how far a set of random numbers are spread out from their mean
variance
…: quantifies the amount of variation or dispersion of a set of data values
standard deviation
…: serves as a baseline to compare your experimental results to. the one that “gets” the treatment. this group helps us figure out what … the independent variable had on the results
control group; kind of effect
we select a … from the population and then … from this group to the population
sample; generalize conclusions
a … will tell u whether or not sample means are significantly different
t-test
p-value: calculated from the data and is the probability that the set of events …
occurred by chance
p value is the probability that our … is true and that our … are the same
null hypothesis; two distributions
levels of organization:
… to … to … to … to … to individual
biosphere; biome; ecosystem; community; population
…: all individuals of a species in a specific location
population
…: number of individuals
…: area (quantity and/or location) of where they are found
size; range
… yrs to reach 1 billion people but then … yrs to reach 7 billion people
200,000; 200
which factors influence the size of a population: … (+) … (-) … (+) … (-)
births
deaths
immigration
emigration
how do populations change over time?
…
r = (delta N/ delta t) / N1
r = …
delta N = change in …
delta t = change in …
N1 = …
intrinsic growth rate; population size; time; original population size
…: even when per capita growth rate remains constant
as population size increases, number of new individuals added per time unit …
all populations have the potential for …
exponential growth; increases; explosive growth
why do we care about population growth? ...availability … … … … … … …
water hunger disease pollution carbon emissions extinctions of other species poverty equity
on average, the human population growth rate is … but yet, the population is still …
decreasing; growing exponentially
factors that influence human birth rates:
…
…
access to … (including …)
education
equality for women
health care; reproductive health care
dN/dt = rN –> …
real populations cannot maintain … for long
biotic potential; exponential growth
K = number of individuals of any particular species that can be supported in an environment …
indefinitely
K = …
carrying capacity
logistic growth:
dN/dt = rN
growth stops when …
N = K
logistic growth can be modeled by adding a term for carrying capacity to the exponential growth equation:
…
this term is called …
(K - N)/K; environmental resistance
…: all alleles present in all individuals in a species
gene pool
geological time scale: … –> … –> …
eras; periods; epics
… = number of individuals with a genotype/ total number of individuals in a population
genotype frequency
phenotypic variation can either be environmental or genetic
environmental takes place on the … and is …
genetic variation is …
individual; not heritable; heritable
(sources of genetic variation)
… ( in sexual reproduction): the process of making haploid gametes in which the combination of alleles that are placed into a given gamete could be any combination of those possessed by the diploid parent
random assortment
(sources of genetic variation)
… lead to variation
mutations
(sources of genetic variation) types of mutation:
… mutations:
subcategories of this: … substitution and … mutations
point; base; frameshift
(sources of genetic variation) mutations can lead to a faulty protein –> … mutation
it can lead to an incomplete protein with an early stop codon –> … mutation
there can be mutations with no effect –> … mutation
and normal proteins are called …
missense; nonsense; silent; wild type
mutations lead to phenotypic variation through changes in …, which can result in changes to … and changes to …
gene expression; physical characteristics; gene regulation
somatic mutations: occur in … tissues and cannot be … germline mutations: present in … or … can be … cause cancer family syndrome
nongermline; inherited; egg; sperm; inherited
every time human DNA is passed from one generation to the next it accumulates … - … new mutations
for humans at birth (germline for parents), about one mutation occurs for every … base pairs –> about … base pairs, which means about …. mutations per person
100; 200; 30 million base pairs; 3 billion; 100
(sources of genetic variation) ..: during meiosis, pairs of homologous chromosomes (one from each parent) can exchange DNA in a process called …
recombination; crossing over
recombination shuffles mutations to produce new
sequences
gene flow = …
migration
evolution is change in … of biological populations over successive generations
heritable traits
evolution = change … of a population over time
allele frequencies
…: population is not evolving
hardy Weinberg equilibrium
assumptions of hardy Weinberg: no … no … no … … …
selection mutation migration large population random mating
mutation increases … and generates … for other evolutionary processes (e.g. natural selection, drift)
genetic diversity; raw material
where do mutations come from?
rarely from the ..
mostly from …
errors occur about every … copies
environment; DNA copy mistakes; 1 billion
gene flow (migration):
can increase genetic diversity in a population with …
can decrease genetic diversity in a population as …
new immigrants; emigrants leave
…: random change in allele frequencies –> … form of evolution
genetic drift; non adaptive
drift is less dramatic in … populations
large
genetic drift: changes in allele/genotype frequencies due to …
chance
…: an event that drastically reduces the size of a population
population bottleneck
examples of events causing a bottleneck:
…
…
…
natural disaster
overhunting
habitat destruction
…: a new colony or population is started by a subset of the original population
founder effect
genetic result TYPICALLY … variation and is a random process not operating on …
decreases; fitness
founder events and bottlenecks result in genetic drift because they end with a much smaller … and allele frequencies vary more … in small populations
population; rapidly
…: a characteristic that enhances the survival or reproduction of organisms that bear it
adaptation
if an … is advantageous for the individual in terms of … and/or …, it will become more common in the population over time by natural selection
allele; survival; reproduction
requirements for natural selection:
…
… (Survival and Repro)
traits must be …
variation
differential success
inherited
…: emphasizes genetic basis of evolution
modern synthesis
natural selection results in … fluctuations in allele frequencies
non random
deer mice:
Mc1r gene influences … via the production of …
dark hair produced by high levels of … ( a pigment). light hair has lower levels of this
2 alleles:
MR -wild type- … levels of eumelanin
Mc - mutant- … production of eumelanin
coat color; pigment; eumelanin; regular; reduced
…: measure to which an individual’s genotype is represented in the next generation
fitness
lava rocks in both Arizona and New Mexico
rock pocket mice show similar patterns of ..
selection
… selects against the extremes
… selects against one of the two extremes
… selects against the mean
stabilizing selection
directional selection
disruptive selection
bacteria:
…
single celled
… cell wall
virus:
small infectious agent
has … genome
packaged in a ..
prokaryotes; peptidoglycan; nucleic acid; protein coat
antibiotics simply become less effective when mutated (resistant) bacteria … and. ..
survive and reproduce
stronger antibiotics are needed to kill …
now resistant populations
mutations occur regardless; mutations persist when they confer a … in the face of antibiotics
selective advantage of resistance
when prescribed antibiotics, must take entire treatment otherwise can …
confer resistance
natural selection results in changes in … depending on whether the allele benefits or harms the survival and reproduction of an organism
allele frequency
types of selection: based on changes in allele frequency
…: increasing frequency of a beneficial allele (an allele that confers an increase in fitness to an individual that has it)
positive
types of selection:
…: decreasing frequency of a deleterious allele (an allele that results in a reduction in fitness to an individual that has it)
negative
types of selection:
…: maintains two or more alleles in a population
balancing
advantages of normal RBC: good at …
advantages of sickle cells: …
disadvantages of normal RBC: susceptible to …
disadvantages of sickle cells: …
carrying oxygen; resistant to malaria; malaria; blood clots
complete dominance:
… genotypes
… phenotypes
three; two
incomplete dominance:
… genotypes
… phenotypes
three; three
selection acts upon …, which are controlled y genes, so selection changes genotype and allele frequencies
phenotypes
fitness = … x …
importance of reproduction is … to survival in terms of selection
survival; reproduction; equal
…: special case of natural selection; it acts on an organism’s ability to obtain or successfully copulate with a mate
sexual selection
types of sexual selection: … and …
Intrasexual; intersexual
… (biological) = biological trait determined by specific sex chromosomes inherited from both parents
female: only … chromosomes (with some exceptions)
male: includes presence of a … chromosome (with some exceptions)
sex; X; Y
… = socially, culturally and personally defined –> exists on a continuum; not biologically defined
gender
… selection: competition among members of the same sex for reproductive access
Intrasexual
… selection: members of one sex choose members of the opposite sex to mate with based on traits
intersexual
what evolution isn’t:
…: animals evolve because they ‘want’ or ‘need to’ –> change in an individual’s lifetime
natural selection: survival of the …
Lamarckism; fittest
