evolution Flashcards
(16 cards)
Natural selection is a _____ mechanism behind descent with modification and results in the organism being adapted to their environment over time. For natural selection to occur a trait must be ______, ________, ________
Natural selection is a non-random mechanism behind descent with modification and results in organism being adapted to their environment over time. For natural selection to occur a trait must be:
heredity
have variation
variation must result in differential reproduction
sources of variation comes from:
1.
2.
3.
mutation (new version of the gene)
sex
gene flow (movement of the gene)
fitness refers to the ____ of an organism to pass on its _____ to future generations. It includes _____, finding a mate, mating, and ____. Ultimately the more ______ the fitter the organism.
Fitness refers to the successfulness of an organism to pass on its genetic material to future generations. It includes surviving, finding a mate, mating, and reproducing. Ultimately the more viable young produced the fitter the organism.
artificial selection
human manipulate fitness, increase the fitness of individuals with desirable trait
natural selection for natural plants:
the individual with _____ pass on genes causes ____ over time with changes in the environment
natural selection for natural plants:
the individual with advantageous traits pass on genes causes changes over time with changes in the environment
Constraints of natural selection( conditional requirements reality of species) :
_______ must occur
Developmental constraints
_______ are deleterious
______ traits must have strong selective advantage
Constraints of natural selection( conditional requirements reality of species) :
mutation must occur
Developmental constraints
More mutations are deleterious
Advantageous traits must have strong selective advantage
allele frequency is the ____ of particular ____ among all ___ of a gene in a population’s _____
allele frequency is the proportion of particular alleles among all allele copies of a gene in a population’s gene pool
the gene pool is
gene pool is all sets of genes present in a population
Factors that increase likelihood of drift
small population size
Founder effect
Bottleneck
Founder effect
a new population is established by a very small number of individuals from a larger population
Bottleneck
Bottleneck - population is greatly reduced in size for one or more generations(population can grow to be larger) bear come and eat half of the beehive
can larger population has genetic drift?
Larger population can have genetic drift because of the founder effect or bottleneck
genetic drift can _____ alleles from population leaving only one (___ fixation)
genetic drift can eliminate alleles from population leaving only one (allele fixation)
a sudden change in environment that drastically reduce the size of the population, bottleneck effect-certain allies may be ______ while others ________
bottleneck effect-certain allies may be overrepresented while others underrepresented
example of natural selection:
Rock pocket mouse — color blends in perfectly(advantageous trait), dark color appears because of mutation(random event, variation), heredity(their parents DNA), different reproduction (reproduce a large amount)
Rock pocket mouse — color blends in perfectly(advantageous trait), dark color appears because of mutation(random event, variation), heredity(their parents DNA), different reproduction (reproduce a large amount)
________- is a change in allele frequency in a population due to random sampling.______t may occur more quickly and more drastically in populations of _______. Even large populations may have reduced genetic variation due to past _____ effects and ______
genetic drift is a change in allele frequency in a population due to random sampling.Genetic drift may occur more quickly and more drastically in populations of small size. Even large populations may have reduced genetic variation due to past founder effects and bottlenecks
