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In lecture two of a four part series, evolutionary biologist David Kingsley discusses how just a few small genetic changes can have a big effect on morphology, using examples from maize, dog breeding, and stickleback fish.
This lecture is available from Howard Hughes' BioInteractive website.
Howard Hughes Medical Institute
Though originally developed for high school students, this lecture will also be useful for college students.
Correspondence to the Next Generation Science Standards is indicated in parentheses after each relevant concept. See our conceptual framework for details.
- Artificial selection provides a model for natural selection.
- People selectively breed domesticated plants and animals to produce offspring with preferred characteristics.
- Evolution results from natural selection acting upon genetic variation within a population.
- Complex structures may be produced incrementally by the accumulation of smaller advantageous mutations.
- Speciation is the splitting of one ancestral lineage into two or more descendent lineages.
- Occupying new environments can provide new selection pressures and new opportunities, leading to speciation.
- As with other scientific disciplines, evolutionary biology has applications that factor into everyday life, for example in agriculture, biodiversity and conservation biology, and medicine and health.
- Scientists use multiple lines of evidence (including morphological, developmental, and molecular evidence) to infer the relatedness of taxa.
- Scientists use experimental evidence to study evolutionary processes.
- Scientists use artificial selection as a model to learn about natural selection.