Inheritance
Understand inheritance in natural selection for Grade 8 evolution science. Students learn that traits pass from parent to offspring during reproduction, and that the traits of future populations depend entirely on which individuals survive and reproduce today.
Key Concepts
Organisms do not build their genes from scratch; they inherit them from their parents during reproduction.
This is why the survival of parents matters. If only the high poison newts survive today, they pass their "high poison genes" to the babies of tomorrow. The traits of the future population are determined by who reproduces today.
Common Questions
What is inheritance and why does it matter in natural selection?
Inheritance means organisms receive their genes from their parents, not from the environment. In natural selection, only surviving individuals reproduce, so only their genes pass to the next generation. The future population's traits depend on who survives today.
How does inheritance drive population change over generations?
If high-poison newts survive predation and reproduce while low-poison newts do not, the next generation inherits more high-poison genes. Over many generations, this inherited advantage accumulates, shifting the whole population toward the adaptive trait.
Can individual organisms change their traits through effort or environment?
No—individual organisms cannot change their inherited genetic traits during their lifetime through effort or will. Only the population changes over generations, not individuals. This is why natural selection requires many generations to produce noticeable population-level shifts.