Same design, steady numbers
Consistent copying keeps a population steady.
A pond of fish
A kind of fish lives in a pond. Each generation of fish looks like the last generation and uses the pond in the same way.
What helps each new generation keep the features that suit the pond?
What this lesson covers
The idea
Populations fill well-defined niches; consistent DNA copying maintains the body design features that suit the niche, so reproduction is linked to the stability of populations of species.
A pond of fish
A kind of fish lives in a pond. Each generation of fish looks like the last generation and uses the pond in the same way.
What helps each new generation keep the features that suit the pond?
- Copying the DNA consistently
- Changing the body design each time
- Moving to another pond
A place for the population
Open each tab.
Steady copying, steady population
A niche is a place in the ecosystem that a population fills. To keep using it, the organisms must keep the body design features that suit it. Consistent DNA copying does that. This is why reproduction is linked with the stability of species.
Populations fill well-defined niches. Consistent DNA copying maintains the body design features that suit the niche, so reproduction is linked to the stability of populations of species.
Notes
Populations fill niches. Consistent DNA copying keeps the body design that suits the niche, so reproduction is linked to the stability of populations.
Check yourself
In the book, a niche is …
What does consistent DNA copying maintain?
Reproduction is therefore linked to the stability of …
- a kind of cell that divides. Populations of organisms fill niches. A niche is a place in the ecosystem, not a cell.
- a well-defined place in the ecosystem that a population fills — correct. Yes!
- a mistake made while copying DNA. Variations are mistakes in copying. A niche is a well-defined place in the ecosystem.
- Brand new features in every generation. Consistent copying keeps the features that suit the niche, so the young look like their parents.
- The size of the niche. The niche is a place in the ecosystem. Consistent copying maintains body design features.
- The body design features that suit the niche — correct. Yes!
- populations of species — correct. Yes!
- the weather. The book links reproduction to the stability of populations of species, not to the weather.
- one individual's life. Reproduction is not necessary for an individual's life. The link is to populations of species.