JoVE Lab Manual
Lab Bio
Lab Bio
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Artificial Selection
Artificial Selection
Learning Objectives
At the end of this lab, students should know...
What is natural selection?
Natural selection describes the process where variations in traits differentially affect survival and reproductive success between individuals in natural settings.
What is required for natural selection to occur?
For natural selection to occur, phenotypes in a population must be variable, heritable, and result in variation in fitness of organisms.
How does natural selection lead to evolution?
Populations of a species contain genetic variations that are passed down among generations. These differences allow certain individuals to fare better in survival and/or reproduction.
What is artificial selection?
By adapting the concept of natural selection, humans have created a variety of domesticated plants and animals by selecting favorable traits.
How have we benefited from artificial selection?
Many of the crops and domesticated animals we keep today are an outcome of artificial selection. Artificial selection has enabled us to produce crops and animals more efficiently.
List of Materials
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Large Pocket Magnifier Double Lens (3x-6X)5
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Pollination Wands5
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Glue stick5
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Sharpie Markers5
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Dissecting probes/Mall probe and seeker5
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Brassica rapa seedsDependent on the lab size
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Peat pots (2 ¼ inches)Dependent on the lab size
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Potting soilDependent on the lab size
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Fertilizer pellets/plant fertilizerDependent on the lab size
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Toothpicks flatDependent on the lab size
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Sterile transfer pipettesDependent on the lab size
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Plant growth cart/access to sunlightDependent on the lab size
Lab Prep
- Observing Artificial Selection in Plants
- Two weeks before beginning the pollination experiments, collect a sufficient amount of small pots with a drainage hole in the bottom of each pot.
- Fill each pot about halfway with moist potting soil. NOTE: It is recommended to use a minimum of 50 plants for generation one. It is standard practice to list the species name and date of planting on each individual pot, although this is not necessary to label the generation one plants.
- Add a fertilizer pellet to the surface of the soil and then add more soil to the pot, enough to cover the pellet.
- Use a dissecting probe to make a shallow ¼ inch depression in the surface of the soil.
- Then, touch a toothpick tip to a glue stick. Use the sticky end of the toothpick to pick up one of the Brassica seeds and place the seed into the depression in the soil. NOTE: The dissecting probe can be used to knock the seed off the toothpick as needed.
- Lightly cover the seed with a thin later of soil. Then, repeat steps 3 – 6 for each pot.
- Place the pots in a brightly lit area, such as near a south-facing window or under a grow light. NOTE: Ensure the light is uniformly distributed across the group of plans. If this is not possible, rotate the plants every few days to ensure equal exposure.
- Water the plants with a plastic dropper until a small amount drains out of the pot. Do this as frequently as necessary to keep the soil moist.
