Review of Genetics, Evolution, and Tree of Life

bacteria, archaea, protista, animalia, fungi, and plantae

what are the six kingdoms?

bacteria, archaea, and eukaryotes

what are the three domains in the tree of life?

adaptations and evolution

broadly, where does biodiversity come from?

divergent evolution

two species evolve in different directions from a common ancestor species

convergent evolution

two very distantly related species independently evolve similar phenotypes

phenotype

physical/visual/observable characteristics

beak characteristics corresponded to feeding strategies

what were Darwin’s observations on the Galapagos finches?

provides record of the course of life throughout time and shows the waxing and waning of biological diversity

what does a fossil record show?

4 billion

how many years ago was the earliest life detected on Earth?

fossil, anatomical, adaptation to environment, and artificial selection

what are the different types of evidence of evolution?

homologous structures

structures with different appearances and functions that all derived from the same body part in a common ancestor; different functions, same structure

dewclaw in a dog vs. the thumb of a human

what is an example of a homologous structure?

true

T/F: all organisms are well adapted to their specific environment

artificial selection

breeding plants/animals with the desired traits to keep producing offspring that produce those traits and continually improve the chosen trait

vestigial structures

structures from a common ancestor that animals have but aren’t necessarily functional/useful to the animal

human muscles for wiggling ears or nonfunctional eyes in cavefish

give an example of a vestigial structure

population

a group of individuals within the same species

biological species concept

groups of actually or potentially interbreeding natural populations which are reproductively isolated from other such groups; species consist of populations whose members reproduce with each other and produce fertile offspring

temporal isolation

species reproduce in different seasons or times of day

ecological isolation

species live in the same area, but utilize different habitats and rarely meet

geographic isolation

species live in different areas, often separated by a physical barrier (e.g. river or mountain range)

behavioral isolation

species have different mating rituals (ex: blue footed booby mating dance)

mechanical isolation

physical/structural differences between the species preventing mating (ex: flower structure allows certain pollinators, but not others)

prevention of gamete fusion

gametes of two species do not function well together or reproductive tract prevents gametes from interacting

postzygotic isolation

hybrids of two species are not viable or adults are infertile

hybridization

mating between two different species with a zygote being formed

adults or fertile adults

what do things to hybrids often NOT develop into?

shift in allele frequencies

how do we know evolution is occurring?

evolution

change over long periods of time with shifts in allele frequencies as a result of natural selection

mutation, gene flow, nonrandom mating, genetic drift, and natural selection

what are the 5 agents of evolutionary change?

mutation

rare, but the ultimate source of genetic variation

gene flow

movement of alleles from other populations

nonrandom mating

preferentially reproduce with like or different individuals

natural selection

survival of the fittest

fitness

relative reproductive success; individuals with a phenotype have more surviving offspring than other individuals with an alternative phenotype

survival, mating success, number of offspring per mating that survive, and traits favored in a specific environment

what factors make up the “fitness” of an organism?

natural selection

environmental conditions determine which individuals in a population produce the most offspring

variation, variation leads to differences in the number of surviving offspring, and variation must be genetically inherited

what are the three conditions for natural selection to occur?

stabilizing selection

selection that favors an average phenotype

directional selection

selection that shifts the range of phenotypes

diversifying/disruptive selection

selection that selects against the average phenotype and favors the extreme phenotypes

sexual selection

selective pressures on males and females to obtain matings; can result in development of secondary sexual characteristics that do not benefit survival, but can maximize reproductive success

frequency-dependent selection

selection that favors phenotypes that are either common or rare

gradualism

slow, progressive evolutionary changes over a long time

punctuated

brief periods of evolutionary changes with long periods of stability after

adaptive radiation

closely related species that have recently evolved from a common ancestor by adapting to different parts of the environment; leads to species clusters

an environment with few other species and many resources

where does adaptive radiation generally occur?

sympatric speciation

speciation occurring within a parent species remaining in one location

fruit flies in the Hawaiian islands and Galapagos finches

what are some examples of adaptive radiation?