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

Grade 9th Grade · Science · 60 min

What's Included

Learning Objective

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

Warm-Up Video

Ecotasia · 7:06

Protecting Genetic Diversity: Conservation and Evolution Explained

Guided Notes

3 key concepts

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.

Practice Questions

12 questions · Multiple choice & Short answer

Exit Ticket

Quick comprehension check

“Explain how genetic diversity helps a species survive when its environment changes.”

Complete Lesson Package

Get all 3 ready-to-use resources:

Teacher GuideComplete lesson plan

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Why Genetic Diversity Matters

What's Included

Learning Objective

Warm-Up Video

Guided Notes

Practice Questions

Exit Ticket

Complete Lesson Package

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