exam 1 Flashcards
alfred wallace posed his hypothesis related to evolution around the same time as charles darwin was synthesizing his idea of natural selection (T/F)
true
who first described uniformitarianism?
James Hutton
what is false in relation to charles darwin and his 5-year journey aboard the HMS beagle?
most of his time was spent surveying and studying the plants and animals of the northern hemisphere above the artic circle where little exploration had occurred at the time he set sail
(T/F) none of the naturalists and zoologists of the early 1800s (including darwin) believed in the fixity of species
false
darwin’s natural selection hypothesis was based on heritable traits, competition for finite resources, genetic fitness, and…
adaptation
what evidence disproves the misconception:
evolution is just a theory
hundreds of hypotheses linked with evolution have been posed and supported by scientific experimentation
what evidence disproves the misconception:
individuals in a population evolve
evolution may occur via natural selection on an entire population of organisms exposed to persistent environmental pressures
what evidence disproves the misconception:
lack of transitional fossils for most organisms disproves evolution
paleontologists recognize that many organisms that fill-in evolutionary gaps will not be identified, but molecular bio helps refine many phylogenies relationships
what evidence disproves the misconception:
organisms intentionally evolve to survive
the ability to “evolve” already exists in a population of genetically diverse organisms for which natural selection may apply selective pressure
what evidence disproves the misconception:
random chance alone guides evolution
evolution may occur through selective pressure placed on a series of genetic mutations that accrue over multiple generations within a population of organisms
what are examples of sympatric speciation?
- one fruit maggot fly species lays eggs on apples while another lays eggs on blueberry in the same area
- reproduction of species A occurs in fall while species B occurs in winter
- successful mate selection of species A and species B depends on elaborate mating calls and displays of mates
- (?) mating between species A and species B is initiated by the reproductive strictures do not align properly
what variable represents the genotypic frequency of homozygous dominant individuals in the Hardy-weinberg equation?
p2
what are some things considered as prezygotic barriers?
- sexual selection of males by female birds
- copulatory structures of males do not align with females
- northern flying squirrels reproduce in late spring while southern reproduce in early fall
what is the hardy-weinberg equation?
p2 + 2pq + q2 = 1.0
sample = 25 fish
B = .4
b = .6
what is the genotypic frequency of bb?
0.36
the most likely source of genetic variation in prokaryotes is linked to higher rates of _____ repro, whereas eukaryotic organisms increase genetic variation during ____ and fertilization
asexual; meiosis
what is balancing selection?
The frequency of right-versus left-mouthed, scale-eating cichlids fluctuates around 50% as the prey population responds to increases of either mouth orientation.
what is disruptive selection?
The coloration of pepped moths responds to selective pressures by favoring two distinct color morphs on opposing, extreme ends of the normal coloration spectrum.
what is stabilizing selection?
The density of spines within a cactus population settles on an intermediate number instead of low or high density spine distribution.
what is directional selection?
The coloration of field mouse fur transitions into a darker morph which is better suited for camouflage compared to an intermediate or light-colored morph.
what is sexual selection?
The male lions actively guards a pride of lionesses against subordinate males.
the “supergroup” category fits btwn __________
domain and kingdom
considered homologous traits:
- The bones of vertebrate forelimbs all have the same structural components like a humorous, ulna, and radius.
- The conservation of nucleotides in the genes that code for cytochrome-c used by all eukaryotic cells for aerobic respiration.
what are plesiomorphies?
shared ancestral traits
what is am example of a polyphyletic grouping?
birds and mammals
what is am example of a monophyletic grouping?
reptiles and birds
what is the correct way to state binomial nomenclature?
Channa argus (italicized)
(T/F) by definition, all cells lack a cell wall including calcium producing species
true
which plane will perfectly bisect a bilateral organism into two equal halves?
midsagittal plane
what organisms are included in the supergroup ophisthokonta with animals?
fungi and choanoflagellates
between phylum and class
superclass
between class and order
subclass
which organisms have a body cavity derived from the mesoderm?
eucoelomate
what time period occurred immediately after cretaceous?
paleocene
approximately how long ago did the cambrian explosion occur?
500,000,000
what is not a common feature of animals?
autotrophic
way to describe the back of a bilateral organism?
dorsal surface
(T/F) the coelom is derived from the endoderm during embryonic development in animals
false
the age of _____ occurred during the mesozoic era
reptiles
during what time epoch did the ice age megafauna dominate life on earth?
pleistocene
what is the worst mass extinction event in earth’s history when 90% of all life vanished?
permian
(T/F) endosymbiotic theory is used to describe the evolution of the first multicellular organism
false
characteristics of protosome animals
- spiral cleavage pattern
- blastopore develops into mouth
tiktaalik is an example of a ____ fossil that helped bridge the gap between lobe-finned fishes and the first tetrapods
transitional
(T/F) darwin did not originally know that the birds he observed on the galápagos islands were all species of ground finches until a college identified them later
true
(T/F) humans evolved from chimpanzees
false
which is false about the species concept?
the biological definition is best applied to species that undergo asexual reproduction
what is true about the species concept?
- while we focused on the biological definition of species, other definitions exist and depends on field of study
- biological species concept stipulates that all individuals of the same kind may naturally interbreed while members of two different kinds may not interbreed
- the base deviation of the word is latin meaning “kind” or “appearance”
- the species epithet is the most exclusive taxonomic hierarchy of life
(T/F) hybrid zones my become stable through time because hybrid individuals are routinely observed under natural conditions
true
(T/F) an example of genetic drift would include a volcanic eruption that randomly removes individuals from a population and is not linked to any perceived selective advantage for any phenotype
true
genetic drift…
- is more severe for small populations
- is often associated with higher year-to-year variation in allelic frequency of a population
- often leads to less genetic variation overall within the population
- may lead to harmful alleles becoming fixed in the population and make the bottle neck effect worse
______ speciation occurs as a result of geographic isolation of the original population; an example would include distinct changes in body depth among ______ resulting from the presence or absence of a predator in two separate ponds.
allopatric; mosquitofish
What is the allelic frequency of the recessive allele if the genotypic frequency of homozygous recessive individuals is 0.4356 in a population of peppered moths?
0.66
(T/F) while one trait may be adaptive for a particular need in a species, it may be maladaptive or of limited usefulness in other circumstances which highlights that adaptions are often compromises in terms of natural selection
true
____ traits are often referred to as “advanced” and may be shared a trait or ______ among all organisms in the group relative to a more ancestral taxon. For example, vertebrates have a vertebral column compared to invertebrates that lack the same structure.
ancestral; plesiomorphy
(T/F) the use of the word “clade” infers that the grouping is considered paraphyletic by definition
false
(T/F) the most parsimonious phylogenetic tree will include the maximum number of traits to explain the relationships in the cladogram
false
phylogenic trees…
are useful to show the relative progression of traits in a specific order from more ancestral to derived
(T/F) the allelic frequency of both recessive and dominant alleles remains fixed and does not naturally fluctuate
false
what is false as written if hardy-weinberg equilibrium is observed within a given population?
mating of organisms is not random
HW equilibrium is true IF…
- No mutations (change in allele at DNA level)
- No migration (individuals may leave or enter the population)
- Large gene pool (the population as a whole is very large)
- Random mating (individuals pair/mate by chance)
- No selection (phenotype favored over another)
during which epoch did the large 60+ foot mega-toothed shark called carcharocles megalodon dominate the seas as an apex predator?
pliocene
