exam 1 Flashcards
Bottleneck (genetic drift)
the rapid decrease in population size due to environmental changes
What are some examples of bottleneck genetic drift
natural disasters, exploitation, human activities
Founders Effect (genetic drift)
result of when few individuals from a large population establish a new population
What is an example of a founder effect
The Amish in America have grown from few people and and tend to marry within the same community
Gene Flow
when breeding individuals migrate and increase genetic variability
What is an example of gene flow?
If one classroom population mates with one another while another classroom also mates with each other and then someone in both classrooms mate with each other
What is genetic drift?
Random changes in allele frequency that decrease genetic variation but increase genetic differences
What are the 2 types of genetic drift?
Bottleneck and Founders effect
What is a population?
Individuals of the same species reproducing/living in an area
What is microevolution?
small evolutionary change in allele frequency from generation to generation
What are the 5 microevolutionary processes
nonrandom mating, mutation, genetic drift, gene flow, natural selection
What is a gene pool
The combination of all the genes and alleles present in a population that can reproduce
Who is Charles Darwin
He proposed the theory of evolution by natural selection.
What year did Linnaues find modern taxonomy
1700s
Who is Carolus Linnaues
He founded the idea of modern taxonomy which grouped species into groups based on shared features
Who created the binomial nomenclature
Linnaeus
Name the 8 categories of the Linaneun classification systems
Domain, Kingdom, Phyla, class, order, family, genus, species
Which structure is the most inclusive and exclusive
Domain is The most inclusive because it groups all forms of life based on cell structure and is the most broad. The most exclusive is the species because it has the most narrow classification.
What is the Binomial system
The first part is genus and the second part designates the species
What is sexual selection
You are choosing a mate on colors or some other characteristic.
What are the 3 domains recognized
Bacteria, archaea, and eukarya
what is monophyletic
a clade or group of organisms that share a common ancestor and all descendants
What are the 3 types of taxonomic relationships
monophyletic, paraphyletic, and polyphyletic
What is a homologous structure
a body part or organ that shares a common ancestor but serves different functions
What is an example of a homologous structure
The arm structure of a human compared to a horse
What is an analogous structure
a feature found in different species that have similar functions but different origins
What is an example of an analogous structure
the fins of dolphins and shark
What is a hybrid zone
an overlap between recently diverged populations where interbreeding occurs to make hybrids
What are the 3 types of hybrid zones
reinforcement, fusion, and stability
What is a reinforcement zone
the hybrids are less fit than the parents then the species diverge til there is no more hybridization
What is a fusion zone
two species become one due to weakened reproductive barriers
What is a stability zone
fit hybrids continue to be produced
What are pre and post-zygotic barriers
they prevent gene flow
What is a prezygotic barrier
prevents zygote from forming and prevents mating and reproduction
What are the 5 prezygotic barriers
temporal isolation
habitat isolation
behavioral isolation
mechanical isolation
gametic isolation
What is temporal isolation
2 groups reproduce at different times of the day, season, or year
Give me an example of temporal isolation
wood frogs and leopard frogs live in the same area but mate at different times of the year
What is habitat isolation
organisms that are geographically close to each other but breed in a specific habitat in that area
What is an example of habitat isolation
Flycatcher birds have overlapping ranges but stay in their specific part of the tree
What is behavioral isolation
don’t reproduce with eachother because of behaviors like mating signals
What is an example of behavioral isolation
different species of fireflies use different light patterns to attract female mates
What is mechanical isolation?
structural differences prevent mating, parts don’t fit together
What is an example of mechanical isolation?
certain bees can’t fit in certain flowers to pollinate them
What is gametic isolation
there is molecular or chemical difference and the egg and sperm are incompatible due to different protein receptors
What is an example of gametic isolation
different species of sponges releasing gametes at the same time
What is a postzygotic barrier
barrier that forms after the zygote has already formed and reduces the fitness of offspring/hybrids
What is an example of a post-zygotic barrier
mules are horses and donkeys and are sterile
What is allopatric speciation
when geographic isolation occurs and evolves by natural selection or genetic drift
What is speciation
the evolution of a new species
what are the types of speciation
allopatric and sympatric
What is sympatric speciation
speciation occurs from ancestral species while in the same geographic location
what is an example of allopatric speciation
squirrels on the opposite sides of the Grand Canyon are evolving differently on each side
what is an example of sympatric speciation
plants
What is reproductive fitness
more reproduction and the ability to produce viable offspring
What is macroevolution
large-scale population change at the species level or higher
What is artificial selection
human intervention in animal or plant reproduction or survival to allow any individuals with desired traits to produce
What is genetic variation
the differences in DNA sequences between individuals within a species
what are the types of genetic variation
Genetic polymorphism
Heterozygote advantage
Geographic variation
What is genetic polymorphism
Differences in nucleotide sequences among a population may or may not lead to different phenotypes.
what do genetic polymorphisms tell us
The greater the differences, the further back in time two species may share a common ancestor
What is heterozygote advantage?
Natural selection maintains alleles that are unfavorable in the homozygous state when the heterozygote Aa has a higher degree of fitness than either homozygote AA or aa
what is geographic variation
genetic differences among different populations within the same species
