Ch. 8 - Evolution Flashcards
Microevolution: changes in ____ that occur over time within a ____ (due to mutation, selection, gene flow & drift)
____
allele frequencies
population
Macroevolution: patterns of changes in ____ over broad periods of geologic time. Patterns determine ____ (evolutionary relationships among species and groups of species).
groups of related species
phylogeny
Lamarck theory:
- Use and disuse: ____ can develop with increased usage, unused parts are weakened (____ in athletes).
- Inheritance of acquired characteristics: body features acquired during lifetime can be ____ (____, since only changes in genetic material of cells can be passed to offspring).
- Natural transformation of species: organisms produced offspring with changes, transforming each later generation ____ (no ____ or splits into more species) => ____.
- Natural selection: survival of the fittest (Darwinism) => now called ____ (synthetic theory of evolution).
body parts
correct
passed down to offsprings
incorrect
slightly more complex
extinction
incorrect
neo-Darwinism
EVIDENCE FOR EVOLUTION:
1. Paleontology: ____ reveal prehistoric existence of extinct species; often found in sediment layers (deepest fossils
represent oldest specimens). (____ produce new species)(fos types: actual remains, petrification, imprints, molds, casts)
fossils
large, rapid changes
EVIDENCE FOR EVOLUTION:
2. Biogeography: geography to describe ____; unrelated species in different regions of world look alike
when found in ____.
____ – supercontinent Pangea slowly broke apart to 7 continents
distribution of species
similar environments
continental drift
- EVIDENCE FOR EVOLUTION:
Embryology: similar stages of development (____) among related species => establish evolutionary relationships
(____). Gill slits and tails are found in fish, chicken, pig, and human embryos.
“ontogeny recapitulates phylogeny” – this specific recapitulation theory is considered ____, basically said that embryological stages represent our past evolutionary ancestors .
ontogeny
phylogeny
defunct
EVIDENCE FOR EVOLUTION:
4. Comparative anatomy: describes two kind of structures that contribute to identification of ____.
a. Homologous structure: body parts that resemble one another in ____ species from ____.
b. Analogous structure: body parts that resemble one another in ____ species because they evolved
____ as adaptation to their ____.
evolutionary relationship
different
common ancestor
different
independently
environments
EVIDENCE FOR EVOLUTION:
5. Molecular biology: examines nucleotide and amino acid sequences of DNA and proteins from different species. More
than 98% of nucleotide sequences in humans and chimpanzees are identical. AA’s in ____ often compared.
cytochrome c
EVIDENCE FOR EVOLUTION:
6. Comparative biochemistry: Organisms w/ common ancestor = common ____
biochemical pathways
B. Natural Selection: responsible for producing adaptations (____ ) that increase individual’s fitness (____ )
- Populations possess an enormous reproductive potential: if all offspring produced and survived.
- Population size remain stable: populations generally fluctuate around a constant size.
- Resources are limited: resources do not increase as population grow larger.
- Individuals compete for survival: growing pop will exceed available resources => compete.
- There is variation among individuals in a population: such as skin color (very pale to very dark).
- Much variation is heritable: DNA passed down.
- Only the most fit individuals survive: survival of the fittest.
- Evolution occurs as favorable traits accumulate in the population: best adapted individuals => best adapted offspring leave most offspring.
superior inherited traits
ability to survive, leave offspring
Stabilizing selection: bell curve (average height in human is in middle), favors an ____(all selections shown)
intermediate
Directional selection: favors traits that are at ____ of a range of traits. Traits at opposite extremes are ____.
After many generations => changes in allele frequencies (such as ____).
- Industrial melanism: selection of ____ (melanic) varieties in various species of moths (peppered moth) as a result of ____.
one extreme
selected against
insecticide resistance
industrial pollution
____: occurs when environment favors extreme or unusual traits while selecting against common traits. Short and tall are favored while average is selected against.
Disruptive selection
____: differential mating of males (or females) in a population. Female chooses superior males => increase fitness of offspring; they invest greater energy so they maximize ____. Males increase fitness of offspring by maximizing ____.
Male competition: leads to fights; mating opportunities awarded to strongest male, favors traits like musculature,
horns, large stature, etc.
Female choice: leads to traits/behaviors in males that are favorable to female, favors traits like colorful plumage or elaborate mating behavior. Result often leads to ____ (differences in appearance of males and females) => becomes a form of ____.
sexual selection quality quantity sexual dimorphism disruptive selection
Artificial selection: a form of ____ carried out by humans when they breed favorable traits (not natural selection).
directional selection
SOURCE OF VARIATION
Diploidy: presence of two copies of each chromosome. In heterozygous conditions, ____ is stored for later generations => more variations is maintained in gene pool.
recessive allele
SOURCE OF VARIATION
Outbreeding: mating with ____ partners => mixing different alleles => new allele combinations.
unrelated
SOURCE OF VARIATION
Balanced polymorphism: maintenance of different ____ in population (one is usually best and increased in allele
frequency). However, polymorphisms (coexistence or ____) can exist and be maintained:
a. Heterozygote advantage: heterozygous condition bears ____ than either homozygous conditions. Sickle cell (AA, AS, SS). AS is 14% in Africa because it has ____.
b. Hybrid vigor (____): superior quality of offspring resulting from crosses between ____ strains
of plants => hybrid superior quality results from reduction of loci with ____ conditions and increase in ____.
c. Frequency-dependent selection (minority advantage): least common phenotypes have a selective advantage. Common phenotypes are selected against. Rare will ____ and will be selected against and repeat. Predators (search image of common phenotypes) => rare escapes; rare eventually becomes common, cycle repeats.
phenotypes
two/more different phenotypes
greater advantage
heterosis
two different inbred
deletion of recessive homozygous conditions
heterozygous advantage
increase in frequency
SOURCE OF VARIATION
____ – variation w/out selective value (e.g. ____ in humans)
neutral variation
fingerprints
SOURCE OF VARIATION
Geographic variation – variation of a species dependent on ____ or ____. A graded variation of a phenotype due to this is known as a ____; variation from north/south environments is a north-south cline
climate
geographic conditions
cline
Causes of Changes in Allele Frequencies:
- Natural selection: increase/decrease of allele frequencies due to ____.
- Gene flow: introduction/removal of alleles from population when individuals ____ or ____.
- Genetic drift: random increase/decrease of allele by ____. Small population => larger effect.
- ____: allele frequencies in group of migrating individuals are (by chance) not the same as that of their population origin.
- ____: occurs when population undergoes a dramatic decrease in size (natural catastrophe, etc) => vulnerable to genetic drift. - Nonrandom mating: individuals choose mates based upon their ____ (mates choose nearby individuals).
- Inbreeding: individuals mate with relatives.
- Sexual selection: females choose males based on superior traits. - Mutations
environment
leave (emigrate)
enter population
chance
founder effect
bottleneck
particular traits
Genetic Equilibrium (Hardy-Weinberg eq.): allele frequencies remain constant from generation to generation => no ____
- Require the following conditions: no ____, all traits are ____ (no natural selection), population must be isolated (no ____), large population (no ____), mating is ____, no net ____.
evolution
mutation neutral gene flow genetic drift random migration
____ for each allele (p, q)
allele frequencies
____ of homozygous (p^2, q^2)
____ of Heterozygous (pq + pq = 2pq)
frequency
frequency
Allopatric speciation: population is divided by ____ => interbreeding between two resulting populations is prevented => gene frequencies in two population can diverge due to natural selection, mutation, genetic drift. If gene pool is sufficiently diverge => will not ____ when barrier is removed => ____ formed. This form of speciation can
be through ____ (group is isolated by being physically removed from the original location of the larger group) or ____ (group is isolated by a geographic barrier but in the same overall location of the larger group).
geographic barrier interbreed new species is dispersal vicariance
Sympatric speciation: formation of new species ____ presence of geographic barrier.
- Balanced polymorphism: natural selection due to ____. Example: different color in insects, one color can
camouflage to different substrate, and the other that can’t will be eaten. Only insects with same color can mate (isolated from other subpopulations). - Polyploidy: possession of more than normal two sets of chromosomes (3n, 4n in plants two viable diploid gametes and two sterile gametes with no chromosomes => tetraploid 4n zygote formed => repeat with diploid gametes male/female => ____ with normal gametes).
- Hybridization: two different forms of a species (closely related species) mate and produce along a geographic boundary called ____ (more genetic variations => hybrid can live beyond range of either parents).
without
polymorphism
reproductive isolation
hybrid zone
SPECIATION
Adaptive radiation: ____ of many species from a ____ ancestor; occurs when ancestral species is introduced to an area where diverse geographic/ecological conditions are available for ____.
rapid evolution
single
colonization
MAINTAINING REPRODUCTIVE ISOLATION
Prezygotic Isolating mechanism: prevent ____ fertilization
1. ____ : species do not encounter.
- ____ : species mate/flower during different seasons/time.
- ____ : does not perform correct courtship rituals.
- Mechanical isolation: male/female genitalia are not ____ .
- ____ : male gametes do not survive in environment of female gametes. (gametes do not recognize others).
fertilization
habitat isolation temporal isolation behavioral isolation compatible gametic isolation
MAINTAINING REPRODUCTIVE ISOLATION
Postzygotic Isolating mechanism:
- ____: zygote fails to develop properly and dies before reaching reproductive maturity.
- Hybrid sterility: hybrids become functional adults but ____.
- ____: hybrids produce offspring that have reduced viability/fertility (hybrid’s children can’t reproduce!)
hybrid inviability
cannot reproduce
hybrid breakdown
Patterns of Evolution:
1. Divergent evolution: two/more species that originate from common ancestor and become increasingly ____ over
time (result of speciation).
different
Patterns of Evolution
2. Convergent evolution: two ____ species that share similar traits by ____ (____ traits).
unrelated
environment
analogous
Patterns of Evolution
3. Parallel evolution: two ____ species made similar evolutionary changes after their ____.
related
divergence from common ancestor
Patterns of Evolution
Coevolution: evolution of one species in response to ____ that appear in ____ (predator/prey)
new adaptations
another species
Macroevolution:
1. Phyletic gradualism: evolution occurs by ____; but unlikely to be valid because
____ are missing (no fossils); fossils only reveals major changes in groups of organisms.
- Punctuated equilibrium: evolutionary history consists of geologically long periods of ____ (stability) with ____ followed by geologically short periods of ____. ____ of fossils revealing intermediate stages of evolution is considered data that confirms ____.
gradual accumulation of small changes
intermediate stages of evolution
stasis little/no evolution rapid evolutions absence rapid evolutionary events
ORIGIN OF LIFE (1-4):
1. ____: through volcanoes (CH4, NH3, CO, CO2, H2, N2, H2O, S, HCl, HCN, ____ O2).
- Primordial seas ____: as earth cooled => gases ____ => sea with water and minerals.
- ____: formation of organic soup from inorganic, energy from UV, ____, heat, radiation => acetic acid, formaldehyde, and amino acids.
- Oparin & Haldane: organic soup theory; if there was O2 (very reactive), no ____ would have formed.
Operin’s hypothesis was that origin Earth environment was ____ (providing chemical requirements to produce complex molecules from simple building blocks. In an oxidizing environment you’d break complex molecules apart).
- Stanley Miller: tested theory of above and produced organic molecules. Miller & Urey used ammonia, methane,
water, and hydrogen sealed + simulated lightning saw several organic molecules, AA’s, starting materials, but no NAs! - Polymers and self-replication: monomers => polymer (____). ____ are abiotically produced
polypeptides
earth and atmosphere form
little/no O2
formation
condense
complex molecules were synthesized
lightning
organic molecules
reducing
dehydration condensation
proteinoids
ORIGIN OF LIFE (5-9):
5. Organic molecules were concentrated/isolated into protobionts: ____ (precursors of cells = like cells, metabolically active but unable to ____). ____ and ____ (spontaneously formed lipid or
protein bilayer bubbles) are experimentally (abiotically) produced protobionts that have some selective permeable qualities.
Note: we can also produce microsomes in the lab: vesicle-like artifacts from reformed pieces of the ER if cell is broken up in a lab
- Primitive heterotrophic prokaryotes: obtained materials by consuming other ____ (pathogenic bacteria).
- Primitive autotrophic prokaryotes: ____, heterotroph gained ability to produce its own food => ____.
- Oxygen and ozone layer + abiotic chemical evolution ____: by production of ____.
- UV light + Oxygen => ozone layer (absorbed latter UV light => blocking energy for abiotic synthesis of organic materials => termination of primitive cells. - Eukaryotes formed: endosymbiotic theory, eukaryotic cells originated mutually among prokaryotes (mitochondria, chloroplast establish resident inside another prokaryotes).
Evidence: Thylakoid membranes of chloroplasts resemble ____, mitochondria and chloroplasts have their own circ. DNA ____ wrapped with ____ (prokaryotic like), ribosomes of these organelles resemble those of bacteria, they reproduce independently via process similar to ____, two membranes.
protobionts
reproduce
microspheres/liposomes
coacervates
organic substances
mutation
cyanobacteria
ended
photosynthetic activity of autotrophs
photosynthetic membranes of cyanobacteria
not
histones
binary fission
____ – structures that appear to be useless but had ancestral function; ex humans (appendix and tail), horses (splints), python (leg s reduced to bones)
vestigial structures
____ - two or more harmful species that are not closely related, and share one or more common predators, have come to mimic each other’s
warning signals
mullerian mimicry
____ – deceptive; harmless species has evolved to imitate the warning signals of a harmful species directed at a common predator
batesian mimicry
____ - Continuous population but it doesn’t mate randomly: individuals more likely to mate with geographic neighbors, divergence may happen due to reduced gene flow since selection pressures vary across the population’s range (different niches, adjacent but not isolated). Environmental gradients?
parapatric speciation
____ - Very similar to allopatric speciation in that a population is isolated and prevented from exchanging genes from the “main” one (geographically), but one of the populations is much smaller than the other, so it is subject to accelerated genetic drift – along w/ differing selection pressures
peripatric speciation
____ – one species replaces another, straight path evolution
anagenesis/phyletic evolution
____ – New species branches out from parent species
cladogenesis/branching evolution
____ – a group of species that includes a common ancestor and all of its descendents (aka monophylum)
clade
____ – a particular stage of an ecosystem
sere
____ – an organic matter leaves an impression in rock or inorganic matter, later the organic matter decays and leaves a negative impression
mold
____ – a type of fossil formed when a mold is filled in
cast
____ – small local population (e.g. all the beavers along specific portion of a river)
deme
General Categories of living organisms: \_\_\_\_ (chemosynthetic bacteria), \_\_\_\_ (green plants, photoplankton), \_\_\_\_(yeast), \_\_\_\_ (amoebas, earthworms, humans)
autotrophic anaerbones
autotrophic aerobes
heterotrophic anaerobes
heterotrophic aerobes
Symbiosis – relationship between 2 species. Can be: ____(beneficial/beneficial), ____(beneficial/neutral), ____(beneficial/detrimental)
mutualism
commensalism
parasitism
____ – shared traits derived from an evolutionary ancestor common to all members of a group
synapomorphies
____ – similar characteristics resulting from convergent evolution, therefore not derived from a common ancestor
analogous traits
____ – Occam’s Razor, simplest explanation is most likely correct (phylogenetic trees: fewest number of changes w/ respect to synapomorphies is likely most correct representation of reality)
law of parsimony
