Standard 15.13 Natural Selection:
You need to know the conditions required for natural selection to occur.
Natural Selection is based on four main principles:
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TUTORIAL #1 TUTORIAL #2 ________ 1. Bozeman Podcast: Coevolution 2. Bozeman Podcast: Genetic Drift 3. Bozeman Podcast: Microevolution 4. Stated Clearly - Natural Selection 5. Bozeman Podcast: Speciation/Extinction 6. Khan Academy 7. Edgenuity-15.13 8. Extended Learning Modules 15.13 __________ |
Natural selection of advantageous traits leads to a population dominated by organisms that are anatomically, behaviorally, and physiologically well suited to survive and reproduce in a specific environment.
Peppered Moth Variations: Notice the two colors of moths naturally occurring: light-colored, and dark-colored.
In this picture: Which moth do you think will have a better chance to hide from birds, and thus survive and reproduce? |
Here look at this light-colored peppered. Noticed how well adapted it is to its surrounding (the light colored tree).
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Galapagos Island's Finches Support the Theory of Natural Selection
On the Galápagos, finches evolved based on different food sources — long, pointed beaks are best suited to catch insects, while wide, blunt beaks work best for cracking seeds and nuts.
- On the Galápagos Islands, only large seeds are available during the drought.
- Small-beaked finches are not able to access this food supply, so they are more likely to starve.
- Many of the large-beaked finches are likely to die as well, but some will be able to live on a hard-seed diet.
- As these finches survive and produce offspring, the average beak depth increases.
Adaptive Radiation
The Galápagos' finches is also an example of adaptive radiation, an evolutionary process in which organisms diversify rapidly from an single common ancestor.
This phenomena particularly happens when new ecological niches become available for the taking. For examples after a massive extinction, or the appearance of a new volcanic island.
This phenomena particularly happens when new ecological niches become available for the taking. For examples after a massive extinction, or the appearance of a new volcanic island.
Evolution of Antibiotic- Resistance Bacteria
SC.912.L.15.15_Genetic Diversity
- Describe how mutations and genetic recombination increase genetic variations
Where do genetic diversity come from?
The main sources of genetic variation come from:
The main sources of genetic variation come from:
- Mutation.
- Artificial Genetic Recombination (through biotechnology)
- Natural Genetic Recombination:
- Meiosis: Independent assortment of the chromosomes and crossing over (or recombination) between chromatids of homologous chromosomes during meiosis (prophase I).
- Sexual Reproduction
- Random mating between organisms.
- Random fertilization.
- Gene flow (movement of genes from one population to another due to immigration and emigration)