1. Evolution and Biodiversity
APES
Mr. Hudson

3. Biodiversity Includes several factors: Species diversity
Ecosystem diversity
Genetic diversity
Functional diversity
Processes of matter cycling, energy flow w/in food chains/webs

4. Importance? Vital to maintaining life on earth
Supplies life with all form of natural capital
Preserves water/air quality
Keeps soils fertile

5. How so biodiverse? Evolution and natural selection
Natural selection- individs. with certain traits enhance their ability to reproduce
Increases likelihood of passing on these favorable traits
*Natural selection drives evolution**

6. Fossils Most of our knowledge of evolution comes from fossils
Only represent 1% of all species that ever lived

7. Populations can change over time
Mutations—random DNA errors, favorable mutations passed down
Adaptations—inheritable trait that allows organism to survive and reproduce more than others

8. Example Natural selection “fast” Bacteria exposed to an antibiotic
Some will naturally be genetically resistant
The resistant will pass on traits to offspring– resistant strain will replace non resistant strain

9. MRSA (Methicillin-Resistant Staphlyococcus aureus?

10. Geology affects nat. sel.
Movement of earth’s continents have allowed animals to move from each other
Speciation- form new species through natural selection from one species

11. Geographic isolation
Groups of same species are isolated for long periods of time

13. Reproductive isolation
Long term geographic isolation causes a shift in the gene pools through natural selection
New species ultimately formed

14. Arctic fox
Gray fox

15. Climate Sometimes climate changes too quickly, animals cannot adapt
Go extinct

17. Extinction
Eradication of entire species…………… forever

18. Species diversity
Healthy, sustainable, productive ecosystems are diverse
SPECIES DIVERSITY
Species richness- # of diff. species
Species evenness- # of individs. of a given species

19. Rainforest High species richness—many diff. species
Low species evenness– only a few of each

21. Canada
Canadian wilderness may have only a few types of trees (low richness), but thousands of them (high evenness)
Fir, dogwood, cedar, pine, oak

22. Aspen Grove-- Canada

23. Species Richness is GOOODD!!!
Think about it…..more species, for example—plants, will be more resilient as a community
Less affected by drought
More resistant to invasion by new insects
Exploit resources differently
Some plants short roots, others long
Some bloom early, some bloom late

24. What roles do species play in an ecosys?
Niche– species “role” or way of life
Includes everything that affects survival/reproduction, resource needs, space it requires, temps it can tolerate.
It is a pattern of living

25. Generalists vs. Specialists
Generalists– LARGE NICHE
cockroach
Specialist– small
i.e. pandas– only eat bamboo

26. Native/invasive (alien, exotic)
Native—evolved with a specific ecosystem
Invasive—introduced deliberately/accidentally

27. Invasives
Purple loose strife

28. Indicator Species Provide early warning signs to damage
i.e. dolphins– only clean in healthy clean water
“canary in the cage”

29. Keystone species
Have a large affect on abundance and types of other species in ecosystem
Loss of a keystone can lead to population crashes/extinctions of other species

30. Example American alligator
Large amount if habitat destroyed in 1950s
Providing nesting mounds, feeding sites for other animals
As numbers of alligators diminished, #’s of other species began diminishing

31. American Alligator
Top predator– helps controls pop of all other species

32. Foundation species
Shapes communities by creating/enhancing habitats for other species
i.e. elephants knock over trees—creates openings for grasses/shrubs
Gives smaller grazers food

33. Beavers
Dam rivers—create ponds/wetlands for other species

34. Difference btw. Keystone/foundation species
Foundation– help create species habitat
Keystone—(can be foundational), but actively maintain ecosystem and help serve other species living there