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86 Cards in this Set
- Front
- Back
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What were the 5 major theories of Darwinism according to Ernst Mayr?
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1) perpetual change
2) common descent 3) multiplication of species 4) gradualism 5) natural selection |
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What is the basic Darwinian theory on which the other 4 are based?
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perpetual change
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What is theory of perpetual change?
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the living world is steadily changing
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What does the theory of common descent state?
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all life descended from a common ancestor through a branching of lineages
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What is common descent a basis for?
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taxonomy
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What is the branching tree of life referred to as?
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a phylogeny
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What does the theory of multiplication of species state?
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the evolutionary process produces new species by the splitting and transformation of older ones
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What is a species?
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a group of interbreeding natural populations which are reproductively isolated from other populations
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What occurs in allopatric speciation?
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populations occupy separate geographical areas and cannot interbreed because of separation
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What two actions may follow if the reproduction barrier falls in allopatric speciation?
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the populations may intermix if genetic divergence is insignificant
-OR- the populations may continue to diverge if genetic divergence is significant |
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In which two ways can allopatric speciation occur?
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vicariant speciation or a founder event
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What occurs in vicariant speciation?
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a climatic or geological event fragments a population
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What occurs in a founder event?
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a small number of individuals from a population are separated by long distance
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What occurs in nonallopatric speciation?
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populations of a species divide even though they occupy the same geographical region and there are no obvious reproductive barriers
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What is an example of a species that exhibits nonallopatric speciation?
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cichlid fish
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What even has been used as the cause for nonallopatric speciation?
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sympiatric speciation
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What occurs in sympiatric speciation?
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populations of species divide because they are living in different levels of the same environment
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What does the theory of gradualism state?
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evolutionary change is a result of gradual changes in populations over long periods of time
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What is the nature of most genetic changes that produce major effects?
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harmful
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What does gradualism fail to explain?
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all structural differences in species
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left-phyletic gradualism
right-punctuated equilibrium |
Which two patterns of evolutionary change are portrayed by the graph?
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What are the two types of gradualism?
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population and phenotypic
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What occurs in population gradualism?
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new genetic variants are established in a population by increasing their frequencies across generations incrementally
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What is the pattern of population gradualism?
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it occurs first in only a few individuals and eventually characterizes a majority of the population
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What occurs in phenotypic gradualism?
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new traits evolve by a long series of small, incremental steps
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Which type of gradualism is controversial and which is not controversial?
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population-not controversial
phenotypic-controversial |
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Who proposed the theory of punctuated equilibrium?
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Eldridge and Gould
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What occurs in punctuated equilibrium?
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phenotypic evolution is concentrated in brief speciation events followed by long periods of evolutionary stasis
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What is the duration of speciation?
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10,000 to 100,000 years
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How long may a species survive?
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5 to 10 million years
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How much of a species' life span does speciation make up?
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<1%
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Which 4 types of traits does the theory of natural selection apply to?
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developmental, behavioral, anatomical, and physiological
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How many observations and inferences does the theory of natural selection consist of?
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5 observations and 3 inferences
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What is observation 1 of natural selection?
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Species have great fertility. They make more offspring than can grow to adulthood.
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What is observation 2 of natural selection?
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Populations remain roughly the same size, with modest fluctuations.
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What is observation 3 of natural selection?
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Food resources are limited, but are relatively constant most of the time. From these three observations it may be inferred that in such an environment there will be a struggle for survival among individuals.
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What is observation 4 of natural selection?
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In sexually reproducing species, generally no two individuals are identical. Variation is rampant.
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What is observation 5 of natural selection?
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Variation is heritable.
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What is inference 1 of natural selection?
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a struggle for existence occurs among organisms in a population
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What is inference 2 of natural selection?
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varying organisms show differential survival and reproduction, favoring advantageous traits
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What is inference 3 of natural selection?
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natural selection, acting over many generations, gradually produces new adaptations and new species
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Which mechanism did Darwin not know of?
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inheritance
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What did Darwin view inheritance as?
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a blending of parental traits
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According to Darwin, how could an organism alter its heredity?
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through the use and disuse of parts
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What is polymorphism?
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different allelic forms of a gene
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What is evolution in the studies of microevolution?
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changes in allele frequencies in populations of organisms over time
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What is the gene pool?
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all alleles that exist in a population
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What two facts does the theory of genetic equilibrium state?
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1) the dominance or recessiveness of a gene doesn't affect its frequency
2) dominant genes aren't superior to recessive genes |
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What does the Handy-Weinberg Equilibrium theory state?
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in a large, naturally occuring 2 parent population, allele frequencies tend to remain constant from generation to generation
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What are the 5 assumptions of the Handy-Weinberg Equilibrium theory?
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1) no mutations
2) no genetic drift 3) no migration 4) no natural selection 5) mating is random |
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What does the Handy-Weinberg Equilibrium theory account for?
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the persistence of rare traits
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What is the equation of the Handy-Weinberg Equilibrium theory and what do the variables stand for?
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p^2+2pq+q^2=1
p= frequency of dominant allele q= frequency of recessive allele p^2= frequency of homozygous dominant individuals q^2= frequency of homozygous recessive individuals 2pq= frequency of heterozygotes |
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In the Handy-Weinberg Equilibrium theory, what is it nearly impossible to eliminate?
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a recessive allele
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What is genetic drift?
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random change in allelic frequencies in a population occurring by chance
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How does the size of a population correlate with genetic drift?
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the smaller the population, the greater the effect of genetic drift
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If two alleles are equally frequent, what will occur if breeding is random?
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half of the population will be heterozygous and 1/4 will be homozygous for each allele
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Which type of frequencies does preferential mating alter?
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genotypic
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What occurs in positive assortive mating?
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individuals mate with others that are like themselves in some respect
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What is inbreeding?
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preferential mating among close relatives
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What does inbreeding increase?
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homozygosity
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What occurs in migration?
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individuals move into and out of populations
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What does migration prevent?
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different populations from diverging
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Which frequencies does natural selection change?
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allelic and genotypic
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What occurs in stabilizing selection?
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extreme forms of a phenotype are selected against
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What occurs in directional selection?
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phenotypic character of population as a whole shifts in one direction
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What occurs in disruptional selection?
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intermediate forms of a phenotype are selected against
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What are mutations?
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chemical or physical changes in genes resulting in alteration of the sequence of bases in DNA or RNA
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Which types of mutations does natural selection select against?
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harmful mutations
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Is a long gene or a short gene more likely to have a mutation?
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a long gene
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What promotes rapid evolution of a species?
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subdivision of the species into small populations
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Which two factors allow combinations of many genes to be tested?
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genetic drift and selection
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What does migration among populations allow?
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for favorable new genetic combinations to spread throughout the entire species
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Which kingdom does man belong to?
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Animalia
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Which phylum does man belong to?
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Chordata
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Which subphylum does man belong to?
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Vertebrata
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Which class does man belong to?
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Mammalia
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Which order does man belong to?
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primates
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Which suborder does man belong to?
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Anthropoidea
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Which superfamily does man belong to?
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Hominoidea
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Which family does man belong to?
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Hominidae
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Which genus does man belong to?
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Homo
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Which species does man belong to?
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Homo sapiens
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Which subspecies does man belong to?
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Homo sapiens sapiens
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Which 10 characteristics separate primates from all other animals?
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1) grasping fingers and toes with opposable thumbs
2) vision dominates sense of smell 3) large eyes with stereoscopic and color vision 4) increased ratio of brain to body size 5) specialized forelimbs and clavicles 6) increased sensitivity of touch receptors in hands 7) increased parental investment in offspring 8) complex social behavior 9) 5 digits with flat nails 10) body covered with hair |
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Which 7 characteristics separate hominoids from other animals?
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1) no tail
2) no cheek pouches 3) distinctive molar teeth with a 5 point crown 4) semi-erect posture 5) flexible arm and shoulder joints 6) ams longer than legs (except for humans) 7) large, complex brain |
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Which 8 characteristics separate hominids from other animals?
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1) bipedal
2) pelvis & feet restructured for weight-bearing 3) small incisor & canines; large molars 4) arms shorter than legs 5) no opposable toes 6) increased manual dexterity 7) increased brain size 8) decrease in musulature and bone mass of skull and flattening of muzzle area |
