Natural Selection and Evolution
What is the term for small changes in allele frequency within a population over time?
Microevolution
What is the definition of speciation?
The process by which new species arise.
What is a trophic level?
A step in a food chain or web representing an organism's feeding position.
What are the three domains of life?
Bacteria, Archaea, and Eukarya
How can drought influence natural selection in Galápagos finches?
It can favor finches with larger beaks that can crack harder seeds.
Which mechanism of natural selection favors individuals at both extremes of a phenotype?
Disruptive Selection
What is the biological species concept?
It defines a species as a group of populations whose members can interbreed and produce viable, fertile offspring.
Define mutualism and provide an example.
A symbiotic relationship where both species benefit, such as bees and flowering plants.
Name two major characteristics of eukaryotes.
They have a nucleus and membrane-bound organelles.
What is the bottleneck effect?
A drastic reduction in population size that changes the genetic structure.
Explain how environmental changes, like pollution, influenced the survival of the peppered moth.
Pollution darkened tree bark, making dark moths less visible to predators, leading to an increase in their population.
What are the two main types of speciation?
Allopatric speciation and sympatric speciation
What is a keystone species?
A species that has a disproportionately large effect on its ecosystem's structure and function.
What is taxonomy?
The science of classifying organisms.
Explain gene flow and give an example.
The movement of alleles between populations, such as pollen dispersal in plants.
Name the five conditions required for Hardy-Weinberg equilibrium.
No mutations, random mating, no natural selection, extremely large population size, and no gene flow.
What is adaptive radiation? Provide an example.
Adaptive radiation is the diversification of a species into multiple forms filling different ecological niches, such as Darwin's finches.
Describe the nitrogen cycle.
It is the process of nitrogen moving through the atmosphere, soil, and living organisms, involving nitrogen fixation, nitrification, and denitrification.
What is a cladogram?
A diagram that shows evolutionary relationships among organisms based on shared traits.
What are vestigial structures? Provide an example.
Structures that have lost their original function, like the human appendix or pelvic bones in whales.
Describe the founder effect and give an example.
The founder effect occurs when a small group of individuals establishes a new population with a different gene pool, like the Afrikaner population in South Africa.
Explain the difference between autopolyploidy and allopolyploidy.
Autopolyploidy occurs when a species doubles its own chromosomes, while allopolyploidy occurs when two species hybridize and form a new species.
What is biomagnification?
The increasing concentration of toxins in organisms at higher trophic levels in a food chain.
Define monophyletic, paraphyletic, and polyphyletic groups.
Monophyletic includes an ancestor and all descendants, paraphyletic includes an ancestor but not all descendants, and polyphyletic groups include organisms without a common recent ancestor.
Describe how tectonic plate movements influence evolution.
They alter the distribution of organisms, leading to speciation, as seen in the Proteaceae plant family reflecting Gondwana's breakup.