Genetic Variation and Stickleback Evolution

The video discusses sticklebacks as a model for studying evolution, highlighting key terms like fitness and selective pressure. It explains the differences between saltwater and freshwater sticklebacks, focusing on how environmental factors influence their evolution. The video also covers the rapid changes in allele frequency and the role of regulatory genes in evolutionary changes. The importance of genetic variation for species survival is emphasized.

What is the definition of evolution in terms of allele frequency?

• A change in the allele frequency of a population over time

• The survival of the fittest individuals

• The mutation of genes over generations

• The adaptation of species to new environments

Which type of stickleback is more likely to have large pelvic spines?

• Freshwater sticklebacks

• Both freshwater and saltwater sticklebacks

• Neither type of stickleback

• Saltwater sticklebacks

Why do freshwater sticklebacks tend to have no spines?

• Because they have more predators in freshwater

• Because spines provide no advantage against dragonfly larvae

• Because they need to swim faster

• Because they have more hiding places

What does the chart in the video illustrate about sticklebacks?

• The slow evolution of sticklebacks over thousands of years

• The rapid change in allele frequency in a short period

• The constant population of spined sticklebacks

• The extinction of non-spined sticklebacks

What caused the rapid increase in spined sticklebacks in the lake?

• An opening to the ocean allowing saltwater sticklebacks in

• A mutation in freshwater sticklebacks

• A decrease in dragonfly larvae

• A change in water temperature

How did sticklebacks lose their spines according to the video?

• Through environmental adaptation

• Through mutations in protein-coding genes

• Through changes in regulatory genes

• Through natural selection favoring larger spines

What role do regulatory genes play in evolutionary changes?

• They are not involved in evolution

• They activate other genes, influencing traits

• They directly code for proteins

• They mutate frequently causing changes

Why is genetic variation crucial for species survival?

• It increases the lifespan of individual organisms

• It prevents mutations from occurring

• It ensures all members of a species are identical

• It allows species to adapt to environmental changes

How did genetic variation help sticklebacks during the glacier melt?

• It allowed them to develop new spines

• It enabled them to survive in both saltwater and freshwater

• It caused them to migrate to warmer areas

• It led to the extinction of less fit individuals

What is the relationship between genetic diversity and selective advantage?

• Higher genetic diversity increases the likelihood of a selective advantage

• Selective advantage is unrelated to genetic diversity

• Genetic diversity decreases the chance of a selective advantage

• Genetic diversity only affects physical traits