Term
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Definition
Major mechanism of change over time - Darwin's theory of evolution
There is variation among phenotypes - genetic mutations play a role in increasing variation
Competition for resources results in differential survival, w/ individuals w/ the most favorable traits surviving to reproduce offspring
An adaptation is a genetic variation that is favored by selection and is manifested as a trait that provides an advantage to an organism in a particular environment
Fitness is the ability to survive and reproduce |
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Term
| Hardy-Weinberg Equilibrium |
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Definition
A mathematical model used to
calculate changes in allele frequency,
providing evidence
for the occurence of evolution in a popluation. |
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Term
Hardy-Weinberg Equilibrium
5 conditions must be met for a population to be in H-W equilibrium - conditions are seldom met |
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Definition
- Large population
- no migration
- no mutations
- random mating
- no natural selection
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Term
Hardy-Weinberg Equilibrium
Equations |
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Definition
p=frequency of dominant alleles in a population
q=frequency of recessive alleles in a population
p2=frequency of homozygous dominant individuals in a population
q2=frequency of homozygous recessive individuals in a population
2pq=frequency of heterozygous individuals in a population
p + q = 1
p2 + 2pq + q2 = 1 |
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Term
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Definition
| An evolutionary process by which 2 or more species arise from 1 species and 2 new species can no longer breed and reproduce successfully |
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Term
Speciation can occur by many mechanisms
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Definition
Geographic isolation: species separated by physical barrier
Reproductive isolation:
- different behaviors limit mating
- different habitats limit mating
- different mating seasons limit mating
- different anatomical structures limit mating |
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Term
| Speciation can take place... |
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Definition
... over millions of years
OR
rapidly (after extinction events, etc.) |
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Term
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Definition
Fossils can be dated by a variety of methods that provide evidence for evolution.
- age of the rocks where a fossil is found
- rate of decay of isotopes including carbon-14
- relationships w/in phylogenetic trees
- mathematical calculations that take into account information from chemical properties and/or geographical data
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Term
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Definition
Morphological homologies represent features shared by common ancestry.
Vestigial structures are remnants of functional structures, which can be compared to fossils and provide evidence for evolution. |
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Term
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Definition
| Biochemical and genetic similarities, in particular DNA nucleotide and protein sequences, provide evidence for evolution and ancestry. |
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Term
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Definition
| Primitive Earth provided inorganic precursors from which organic molecules could have been synthesized due to the presense of available free energy and the absence of a significant quantity of oxygen. |
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Term
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Definition
| Chemical experiments have shown that it is possible to form complex organic molecules from inorganic molecules in the absence of life. |
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Term
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Definition
| The complex reaction sets could have occurred in solution (organic soup model) or as reactions on solid reactive surfaces. |
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Term
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Definition
| The RNA World hypothesis proposes that RNA could have been the earliest genetic material. |
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Term
| Phylogenetic Trees and cladograms... |
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Definition
... can represent traits that are either derived or lost due to evolution.
... illustrate speciation that has occured, in that relatedness of any two groups on the tree is shown by how recently two groups had a common ancestor.
... can be constructed from morphological similarities of living or fossil species, and from DNA and protein sequence similarities.
... are dynamic, constantly changing due to current and emerging knowledge. |
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