Differential Survival
Understand differential survival in natural selection: individuals with adaptive traits survive and reproduce more than those with non-adaptive traits, causing the environment to filter the population over generations.
Key Concepts
Individuals with adaptive traits have a distinct advantage: they are more likely to survive long enough to reproduce.
Conversely, individuals with non adaptive traits are more likely to be eaten or die before they can have offspring. This process filters the population. The environment "selects" the survivors based on their traits.
Common Questions
What is differential survival in natural selection?
Differential survival means individuals with traits better suited to their environment survive to reproduce at higher rates. Individuals with non-adaptive traits are more likely to die before reproducing, filtering the population toward adaptive traits.
How does differential survival change a population over time?
Each generation, adaptive traits become more common because carriers reproduce more. Non-adaptive traits decline because carriers reproduce less. Over many generations, the population shifts significantly toward the adaptive trait distribution.
How do Grade 8 students study differential survival?
Students analyze real population data — such as stickleback fish armor levels across different lakes — to see how environmental pressures correlate with which traits are most common, providing direct evidence for differential survival.