Ecology Population Ecology Part 2

1. Ecology Population Ecology Part 2

2. Predicting Populations Sex and the Single Guppy

3. Natural Selection • This includes describing how organisms respond to the environment and how organisms are distributed. • Events that occur in the framework of ecological time (minutes, months, years) translate into effects over the longer scale of evolutionary time (decades, centuries, millennia, and longer).

4. Natural Selection

5. Natural Processes

6. Finch Beak Size or Shape

7. Modes of Selection http://gregladen.com/blog/2007/01/the-modes-of-natural-selection/

8. Modes of Selection Disruptive- produces a bi-modal curve as the extreme traits are favored Stabilizing-reduces variance over time as the traits move closer to the mean Directional-favors a phenotypic trait (selected by the environment)

9. Scenario These photographs show the same location on Captiva Island following Hurricane Charley. What would happen to a population of birds who derive their diets from the tree tops? The population had a wide range of beak sizes. What would happen to the population gene pool over time if the new environment favored smaller beaks? Over time, which beak would be most represented in the population of birds?

10. Selection Diagrams A B C

11. Beak Selection After Hurricane

12. Species absent because Yes Yes Dispersallimitsdistribution? Yes No No No Biogeography & Distribution of Species • Serves as a starting point to understanding limits on distribution of species

13. Species absent because Area inaccessible or insufficient time Yes Yes Dispersallimitsdistribution? Yes Behaviorlimitsdistribution? No No No Biogeography & Distribution of Species • Serves as a starting point to understanding limits on distribution of species

14. Species absent because Area inaccessible or insufficient time Yes Yes Dispersallimitsdistribution? Habitat selection Yes Behaviorlimitsdistribution? Biotic factors(other species)limitdistribution? No No No Biogeography & Distribution of Species • Serves as a starting point to understanding limits on distribution of species

15. Species absent because Area inaccessible or insufficient time Yes Yes Dispersallimitsdistribution? Habitat selection Yes Predation, parasitism,competition, disease Behaviorlimitsdistribution? Biotic factors(other species)limitdistribution? No No Abiotic factorslimitdistribution? No Biogeography & Distribution of Species • Serves as a starting point to understanding limits on distribution of species

16. Species absent because Area inaccessible or insufficient time Yes Yes Dispersallimitsdistribution? Habitat selection Yes Predation, parasitism,competition, disease Chemical factors Behaviorlimitsdistribution? Biotic factors(other species)limitdistribution? No WaterOxygen Salinity pHSoil nutrients, etc. No Abiotic factorslimitdistribution? No TemperatureLight Soil structure FireMoisture, etc. Physical factors Biogeography & Distribution of Species • Serves as a starting point to understanding limits on distribution of species

17. Hydrangea Flower Color Hydrangea react to the environment and ultimately display their phenotype based on the pH of their soil. Hydrangea flower color is affected by light and soil pH. Soil pH exerts the main influence on which color a hydrangea plant will display.

18. Fish And Maintaining Homeostasis In Various Water Conditions Fish and other aquatic animals deal with changing environments in part due to nature and in part due to human interactions. Pressure- their bladder fills with gas to equalize internal pressure

19. Biogeographic Realms

20. Introduced Species • What’s the big deal? • These species are free from predators, parasites and pathogens that limit their populations in their native habitats. • These transplanted species disrupt their new community by preying on native organisms or outcompeting them for resources.

21. Guam: Brown Tree Snake • The brown tree snake was accidentally introduced to Guam as a stowaway in military cargo from other parts of the South Pacific after World War II. • Since then, 12 species of birds and 6 species of lizards the snakes ate have become extinct. • Guam had no native snakes. Dispersal of Brown Tree Snake

22. Southern U.S.: Kudzu Vine • The Asian plant Kudzu was introduced by the U.S. Dept. of Agriculture with good intentions. • It was introduced from Japanese pavilion in the 1876 Centennial Exposition in Philadelphia. • It was to help control erosion but has taken over large areas of the landscape in the Southern U.S.

23. Introduced Species

24. New York: European Starling • From the New York Times, 1990 The year was 1890 when an eccentric drug manufacturer named Eugene Schieffelin entered New York City's Central Park and released some 60 European starlings he had imported from England. In 1891 he loosed 40 more. Schieffelin's motives were as romantic as they were ill fated: he hoped to introduce into North America every bird mentioned by Shakespeare. Skylarks and song thrushes failed to thrive, but the enormity of his success with starlings continues to haunt us. This centennial year is worth observing as an object lesson in how even noble intentions can lead to disaster when humanity meddles with nature.