Chapter 22
True/False: Traits are favored depending on environmental conditions
True/False: Much phenotypic variation is due to genetic variation in a population
True
True/False: There must be gene flow for speciation to occur
False, no gene flow
Sedimentary rocks are deposited into layers called ______ - richest source of fossils
Strata
____________ is a unit at a particular level.
Taxon
_____________ is the process by which humans choose individual organisms with certain phenotypic trait values for breeding.
Artificial selection
____________ is the ultimate source of new alleles.
Mutation
A ____________ is a group of populations whose members have the potential to interbreed in nature and produce viable, fertile offspring
Species
The fossil record is biased in favor of species that:
Existed for a (short/long) time
Were (few/abundant) and widespread
Had (hard/soft) parts that could fossilize
Long, abundant, hard
___________ is naming and classifying organisms, while __________ is the evolutionary history of a species.
Taxonomy, Phylogeny
Similar structures due to common ancestry but may have different function are called ___________
Explain why mutation rates are fast in prokaryotes and viruses.
Mutation Rates are low in all organisms
Consider generation time:
FAST in prokaryotes & viruses
SLOW in plants and animals
Habitat differention is a mechanism for __________ speciation.
sympatric
What are stromatolites?
The oldest known fossils are stromatolites, rock-like structures composed of many layers of bacteria and sediment; date back 3.5 billion years ago
Name the three domains.
Eukarya, Bacteria, and Archaea
Explain what an endemic species is.
Species found only in one certain place.
These island species are closely related to species on the mainland, where colonizers must have come from
Once islands were colonized, species diverged into endemics seen today
Name and explain the three mechanisms contributing to shuffling.
Crossing over: homologous chromosomes trading segments
Independent assortment: random assignment of parent chromosomes to gamete
Fertilization: random gamete combinations
What is speciation? Name and explain the two types.
When one species splits into two or more species and generates biodiversity.
ALLOPATRIC: geographic separation (more common)
SYMPATRIC: no geographic separation
What was likely the initial source of oxygen in our ecosystem?
aquatic photosynthetic bacteria
What were Darwin's two inferences?
Individuals whose inherited traits give them a higher probability of surviving and reproducing in a given environment tend to leave more offspring than others.
This unequal ability of individuals to survive and reproduce will lead to the accumulation of favorable traits in a population over generations.
Name the five causes/mechanisms of evolution.
-Natural selection
-Genetic drift
-Migration
-Non-random mating
-Mutation
Name the seven reproductive barriers. Which ones are pre/postzygotic?
Prezygotic:
Spatial
Temporal
Behavioral
Mechanical
Gametic
Postzygotic:
Hybrid Viability
Hybrid Fertility
Hybrid Breakdown
Explain the theory of endosymbiosis.
The hypothesis of endosymbiosis proposes that mitochondria and chloroplasts were formerly small prokaryotes living within larger host cells
The endosymbiotic theory posits that some eukaryotic cell organelles, such as mitochondria and plastids, evolved from free-living prokaryotes. Available data indicate that the mitochondrial endosymbiosis initiated the evolution of the eukaryotic cell
EASY 500: Which domain do humans belong to?
Eukarya