1. POPULATIONS Kraj

2. What is a Population?
All the members of a species living in the same place at the same time.
Examples: Palm trees on an island, a school of specific fish, daisies in a field in Ohio.

3. Properties of Populations
Population Density-the number of individuals per unit area or volume
Example: the number of small mouth bass per cubic meter of water in a lake.

4. Properties of Populations
Dispersion- the relative distribution or arrangement of its individuals within a given amount of space.
Descriptions of dispersion-
Even Random Clumped

5. POPULATION DISPERSION

6. How Does a Population Grow?
Growth Rate-the birth rate minus the death rate of a population.
Change in population size = Births - Deaths

7. How Fast Can a Population Grow?
Biotic Potential:
The fastest rate at which its potential population can grow.

8. How Fast Can A Population Grow?
Reproductive Potential:
The maximum number of offspring that each member of the population can produce.

9. Reproductive Potential
If perfect conditions, it would take a pair of elephants 750 years to produce 19 million descendents.

10. Reproductive Potential-Exponential
A bacteria cell could produce 19 million new cells in a few days or weeks.

11. BACTERIA REPRODUCTION-GROWTH

12. LIMITS TO POPULATION GROWTH
Carrying Potential is the maximum population that the ecosystem can support indefinitely.

13. RESOURCE LIMITS
All organisms require resources to grow and increase in population.
Natural resources (water, food, shelter, etc.) are limited.
This helps determine the carrying capacity of an ecosystem.
Competitions within a population.
Members of a species use the same resources.

14. RESOURCE LIMITS Each must compete with each other for those resources.
Some species have territories-areas that are defended by one or more individuals against others.
Example: Leopards have a large area of land they hunt. They will attack any other leopards that hunt in that area.
Honey Bees

15. TWO TYPES OF POPULATION REGULATION
DENSITY DEPENDENT REGULATION
Deaths occur more quickly in a crowded population than in a sparse population.
Reasons for deaths-
Competition
Predation
Disease

16. TWO TYPES OF POPULATION REGULATION
Density Independent Regulation
When certain portions of the population die regardless of how dense the population is.
Reasons for deaths:
Weather
Natural disasters
Human actions (deforestation, damming a river, hunting, etc.)

17. HOW SPECIES INTERACT An Organism’s Niche Niche: the unique role of a
species in an ecosystem
It includes the species’:
Physical home
Environmental factors needed for survival.
All interactions with other organisms.
Its functional role.
An organism’s pattern of use of its habitat.

18. Example of a Niche KANGAROOS
Kangaroos occupy Australia’s niche of large grazing (feeding on grasses) herbivores

19. 5 Major Ways Species Interact
Competition
Adaptation to competition
Predation
Symbiosis
Coevolution

20. COMPETITION
Different individuals or populations attempt to use the same limited resources.

21. ADAPTATIONS TO COMPETITIONS
Species have adapted to competition in their ecosystems when niches overlap.
Populations are lower
If one species is removed, the one that remains expands to fill the niche.

22. PREDATION Predator- an organism that feeds on another organism
Prey- an organism that is fed upon
Some predators feed only on one species and its population adjusts to that prey population.
Others have adapted to eating many different species, allows for a more stable population due to varied resources.

23. SYMBIOSIS A close, long term association between 2 or more species.
There are 3 types:
Parasitism-organism feeds on a host organism.
They rarely kill their host-mosquitoes, lice, ticks.
Mutualism-All participating species benefit.
Lichens are examples-photosynthesis, nutrients
e.coli-in humans-bacteria helps digest, bacteria secretes vitamin K
3. Commensalism-One species benefits and the other is unaffected. Whales and barnacles

24. EXAMPLES OF SYMBIOSIS

25. COEVOLUTION Two or more species evolve in response to each other.
Examples:
Bees and Flowers-
Pollen in flowers are sticky
Attaches to bees and the bee travels to another flower fertilizing it.
Bees can’t see red and most flowers that bees use for pollination are blue and/or yellow.
*Madagascar Orchid and Hawk Moth