Fitness — Science definition
Defined in 2 courses:
- Reproductive contribution — surviving offspring left — rather than strength or health. (Life Science & Scientific Inquiry)
- A measure of an individual's reproductive success — the number of surviving, fertile offspring it leaves relative to others in the population, not its strength or size. (Life Science: Biology)
Where it is taught
- Natural Selection, Adaptation & Population Change — Evolution, Evidence & Life History, Life Science & Scientific Inquiry, Grade 7
- Natural Selection — Evolution, Ancestry & Biodiversity, Life Science: Biology, Grade 10
In use
Fitness in biology means reproductive contribution — how many surviving offspring an individual leaves — not strength or health, and a slower, weaker individual that leaves more offspring has higher fitness.
Natural Selection, Adaptation & Population Change
In biology, fitness does not mean strong, fast, or aggressive — it means reproductively successful.
Natural Selection
Questions using fitness
Problem 1
- physical strength
- body size
- lifespan
- number of surviving, fertile offspring
Answer and explanation
number of surviving, fertile offspring
Fitness means reproductive success — how many surviving, fertile offspring an individual leaves relative to others — not strength, size, or longevity.
Problem 2
Hints
Resistance can also spread through gene transfer; the scenario alone does not specify every mechanism.
Answer and explanation
No. Fitness is environment-dependent; the advantage may change elsewhere.
Problem 3
- physical strength
- lifespan alone
- reproductive success in its environment
- body size
Answer and explanation
reproductive success in its environment
Fitness is measured by surviving offspring contributed to the next generation, which may have little to do with strength or size.