What is a genetic bottleneck, and how did it affect the Chatham Island black robin population?

A genetic bottleneck is when a population declines dramatically and recovers from only a few individuals. In the Chatham Island black robin population, it led to a lack of genetic diversity and the spread of a harmful gene.

Why is genetic diversity important for the long-term survival of a species?

Genetic diversity increases the chance that some individuals will have advantageous mutations that help them survive and reproduce in changing environments, allowing the species to evolve.

According to the video, what are the four drivers of evolution?

Selection, mutation, migration, and drift

Explain how the introduction of Nile perch into Lake Victoria led to the extinction of some cichlid species and altered the characteristics of others.

Nile perch preyed on native cichlids, driving some to extinction. The disappearance of detritivores led to eutrophication, decreased visibility, and new selection pressures, causing the surviving cichlids to develop larger eyes and gills.

Define genetic drift and explain how it can negatively impact small populations of endangered species.

Genetic drift is the random passing on or not passing on of genes from parents to offspring. In small populations, it can lead to the fixation of traits, even if those traits are not beneficial, potentially leading to extinction.

Why Genetic Diversity Matters Lesson Plan for Grade 9th Grade

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Learning Objective

I can explain how genetic diversity contributes to the survival of a species.

1
A genetic bottleneck occurs when a population declines dramatically and recovers from only a few individuals.
2
Genetic diversity is important because it increases the likelihood that some individuals will have a mutation that is advantageous when the environment changes.
3
Besides selection, the other drivers of evolution are mutation, migration, and genetic drift.

Why Genetic Diversity Matters

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Learning Objective

Warm-Up Video

Key Concepts

Practice Questions

Exit Ticket

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