Variation and selection

Topics

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Sample objectives

What this unit covers

• Variation: Explain how variation refers to the differences observed among individuals of the same species.
• Variation: Indicate that continuous variation leads to a spectrum of phenotypes between two extremes, such as body length and mass.
• Adaptive features: Explain an adaptive feature as a trait passed down that aids an organism's survival and reproduction in its habitat.
• Adaptive features: Analyze images or data regarding a species to identify and explain its adaptive traits.
• Selection: Explain natural selection by discussing: (a) genetic diversity within groups (b) the generation of numerous offspring (c) the competition for survival, including resource competition (d) the increased likelihood of reproduction for individuals that are more suited to their environment (e) how these individuals transmit their alleles to future generations
• Selection: Explain selective breeding by discussing: (a) how humans choose individuals with favorable traits (b) the mating of these individuals to create the next generation (c) the selection of offspring that exhibit the desired traits