Unit 9: Population Genetics Flashcards
Acquired inheritance
a theory proposed by Lamarck that an organism will develop a trait by using it; for example, a giraffe’s neck will get longer because of stretching to reach leaves high in a tree
Acquired traits
traits an organism develops within its lifetime, such as strong muscles
Adaptation
any function, structure, or behavior that allows an organism to be successful in their environment so they survive and reproduce
Adaptive radiation
the process by which a single species evolved into many new species to fill available niches
Allele frequency
how often an allele occurs in a gene pool relative to the other alleles for that gene
Allopactric speciation
new species form when a geographic barrier, such as a canyon or river,
separates a population
Analogous structures
structures that are similar in unrelated organisms because the structures perform the same job, but they are not inherited from a common ancestor
Artificial selection
breeding done by humans to select certain traits or characteristics in the plant or animal
Behavioral isolation
a type of reproductive isolation that prevents organisms from reproducing due to the presence or absence of certain behaviors (such as mating rituals)
Biogeography
the study of the distribution of organisms, species, ecosystems, and biomes around the world
Bottleneck effect
a type of genetic drift that occurs when a population suddenly gets smaller due to a natural disaster
Camouflage
species has an appearance (color, shape, or pattern) that help blend into the background
Charles Darwin
an English naturalist who developed the theory of evolution
Comparative anatomy (morphology)
the study of the similarities and differences in the structures of
different species
Comparative embryology
the study of similarities and differences in the embryos of different species
Directional stabilization
selection occurs when one of the two extreme phenotypes is selected, so the majority of the population’s characteristics shift towards that end
Disruptive selection
selection that occurs when phenotypes in the middle of the range are selected against, so two different phenotypes develop
Evolution
a change in gene frequencies within a population
Fitness
an organism’s ability to survive and produce fertile offspring
Fossil
the remains, impression, or trace of a living thing of a former geologic age, and can include pieces of bone, impressions pressed into rocks, or insects trapped in tree resin
Fossil record
the information about Earth’s history that can be gathered from fossils
Founder effect
a type of genetic drift that occurs if a few individuals start (or ‘found’) a new
population (for example move to a new island or new area
Gene flow
occurs when individuals move into or out of a population
Gene pool
the combination of all of the genes present in a given population
Genetic drift
a random change in allele frequencies that occur in small populations
Geographic isolation
prevents organisms from reproducing due to being separated by geographic
barriers (such as mountains or rivers)
Homologous structure
structures that are similar in related organisms because they were inherited from a common ancestor; they may or may not have similar functions, but they have the same basic pattern of bones
Inherited traits
features/characteristics that are passed from one generation to the next
Invasive species
plants and animals that are brought to a new habitat and ‘bully’ the native species
to the point where many cannot survive
Jean Baptiste
French naturalist that proposed the theory of acquired characteristics (an organism will develop a trait by using it; for example, a giraffe’s neck will get longer because of stretching to reach leaves high in a tree)
Lyell (Charles)
English geologist that published book Principles of Geology that explained geological processes have shaped the Earth’s surface, so the Earth must be very old
Macroevolution
large scale evolutionary change over geologic time and results from microevolution taking place over many generations
Malthus (Thomas)
English economist that argued human populations grow faster than resources so famine and disease break out, which keeps populations in check
Microevolution
the study of changes in the gene pool of a species’ population over time
Mimicry
an adaptation in which a species uses appearances to copy, or mimic, another species (example - a nonpoisonous frog may evolve to look like a poisonous frog)
Natural selection
beneficial traits (like camouflage) produce more offspring than others, and results in a population that has more of those traits
Naturalist
a person who studies nature, especially a zoologist (studies animals) or botanist (studies
plants); similar to an environmental biologist
Paleontologist
scientists who study fossils
Population genetics
the science that focuses on evolution within populations
Postzygotic barrier
a reproductive barrier that reduces the viability (reproductive capacity) of hybrid offspring; a mule is an example - a horse and donkey produce a mule which is not fertile
Prezygotic barrier
anything that prevents mating and fertilization; habitat isolation, behavioral isolation, temporal isolation, and mechanical isolation are examples
Reproductive barrier
barriers that prevent members of a species from mating and producing
offspring; three types (temporal, geographic, and behavioral)
Speciation
the process by which a new species evolves
Species
a group of organisms that can breed and produce fertile offspring
Stabilizing selection
average phenotypes become more common as selection occurs when
phenotypes at both extremes are selected against
Sympatric speciation
new species form from some type of reproductive barrier (either prezgotic or postzygotic
Temporal isolation
prevents organisms from reproducing due to differences in the time of breeding schedules
Theory of evolution
the change in a species over time due to natural selection
Vestigial structures
structures that no longer serve a purpose in an organism; examples are human appendix, human tailbone, and pelvic bone in whales
