140 likes | 254 Views
Population Biology. Under ideal conditions, populations will continue to grow at an increasing rate. The highest rate for any species is called its biotic potential. Classic examples : rabbits, yeast have a high biotic potential. What has a low biotic potential?.
E N D
Under ideal conditions, populations will continue to grow at an increasing rate. • The highest rate for any species is called its biotic potential.
Classic examples: rabbits, yeast have a high biotic potential What has a low biotic potential?
This assumes . . . • Unlimited food • Unlimited space • NO predation • NO competition • NO disease • NO environmental disruptions • NO crowding
However, population growth is usually restricted by limiting factors.
abiotic limiting factors • nutrients • temperature • storms • floods • drought
biotic limiting factors • competition • occurs when two organisms • occupy the same niche. • disease • parasitism
When a population is limited by biotic and abiotic factors, it will not grow out of control.
Carrying capacity is the number of organisms of one species that an environment can support. It will grow until it reaches carrying capacity.
A population curve that grows until it reaches carrying capacity will be s-shaped.
Populations at carrying capacity will fluctuate in number. But, overall, birth rate will equal the death rate. (immigration = emigration)
This stable state will remain until some environmental factor changes.
The interaction of predator and prey result in a predator-prey cycle.