1. Populations

2. Pop. Characteristics
Geographic Distribution – the areas inhabited by populations (where?)
Density - # of individuals per unit area
Ex people per sq. mile
Growth Rate – depends on
# of births
# of deaths
# of individuals entering or leaving a pop.

3. I vs. E IMMIGRATION – movement INTO a population
EMIGRATION – movement OUT OF a population (Exited)

5. Growth
Exponential – when individuals of a pop. reproduce at a constant rate.
Occurs under IDEAL conditions
J-curve plot
Logistic – growth slows or stops following exponential growth

7. Carrying Capacity…
The Maximum amount of individuals of a population that an environment can support.
Generally means birthrate = deathrate

8. “Starving Child and a Missionary” Famous Photos

9. Limiting Factor (LF)
 Limits the size of a population  causes decrease in numbers.
Density DEPENDENT (LF) – factor that limits larger populations
Ex. Competition, Predation, Parasitism, disease
Density INDEPENDENT (LF) – affects all populations regardless of size
Ex. Natural disasters, clear-cutting forests, etc.

10. Picture taken by Kevin Carter, March 1993 in Southern Sudan
Picture taken by Kevin Carter, March 1993 in Southern Sudan. Carter chased vulture off. Journalists were told not to touch famine victims to help prevent disease transmission. Carter won a Pultizer Prize for this photo but haunted by guilt of not picking up the child and not knowing her fate, he committed suicide just 3 months later

11. DISEASE as a Limiting Factor
…can disrupt an ecosystem’s balance
Humans: AIDS, INFLUENZA, Tuberculosis
OTHERS
-Dutch Elm Disease (fungal-but spread by beetles)
(Of the estimated 77 million elms in North America in 1930, over 75% had been lost by 1989)
-PFIESTERIA – The genus of heterotrophic dinoflagellates which can lead to algal blooms and fish kills. (ex. Chesapeake Bay and off NC coast in 1980s and early 1990s)

12. Fish kill due to Pfiesteria in New Bern, NC (Neuse river) -OCTOBER 2013

13. Good adaptations can lead to higher population numbers…
CLICK
-Costa Rican caterpillar

14. Human Population… Is increasing with time.
Really boomed in last 300 years
Demography – study of human populations
Demographic Transition – a dramatic change in birth rates…is complete when birth rate decreases to meet the death rate
In US and Japan growth has slowed as both have already completed their demographic transition
Worldwide population still grows exponentially.

17. World Population
Population counter and past date-specific data