Concepts of Biology-Ch.17
Terms
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- Stratification
- Layering of sedimentary rock; results from deposition of materials over time.
- Radiometric dating
- Method of determining the age of a fossil by comparing the relative proportions of parent and daughter radioisotopes in rock samples or fossils.
- Macroevolution
- Large-scale patterns, trends, and rates of change among higher taxa.
- Plate tectonics
- Idea that great slabs (plates) of the Earth’s outer layer float about slowly on the mantle beneath them and have rafted continents to new positions over time.
- Continental drift
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Idea that the continents were once joined and have “drifted†apart
Initially based on the shapes - Homologous structures
- Similar body part that occurs in different species as a result of descent from a common ancestor.
- Analogous structures
- Similar body parts in distantly related lineages that arise as a result of similar environmental pressures.
- Biological species concept
- The definition of a species is based on its reproductive isolation.
- Pre-zygotic isolation
- Mating or zygote formation is prevented
- Post-zygotic isolation
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Takes effect after hybrid zygotes form
Zygotes may die early, be weak, or be sterile - Allopatric speciation
- Divergences end in speciation after a physical barrier that arises between populations of a species stops gene flow between them.
- Sympatric speciation
- In the absence of a physical barrier, a new species arises within the home range of an existing species.
- Parapatric speciation
- Mode of speciation in which subpopulations of a species that are maintaining contact along a common border evolve into distinct species.
- Gradual model
- Speciation model in which species emerge through many small morphological changes that accumulate over a long time period
- Punctuation model
- Speciation model in which most changes in morphology are compressed into brief period near onset of divergence
- Adaptive radiation
- Burst of diversification from a single lineage; gives rise to new species adapted to specific environmental niches
- Extinction
- Irrevocable loss of a species.
- Domain
- Classification of all species into the domains Bacteria, Archaea, and Eukarya.
- Kingdoms
- Classification of all species into the kingdoms Bacteria, Archaea, Protista, Fungi, Plantae, and Animalia.
- Scientific name
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Binomial system of nomenclature
Devised by Carolus Linnaeus
Each species has a two-part Latin name
First part is generic (genus)
Second part is specific name (species) - Phylogeny
- Evolutionary relationships among species, starting with an ancestral form and including branches leading to descendants.