1. Ecosystems and Living Organisms

2. Changes in Living Systems – Evolution
- Microevolution – changes in frequencies of genes in a population over time
- how often a certain gene is expressed in the population
NOT: Change of an individual
Driving Force of Evolution = Natural Selection (Survival of the Fittest)
Relationship to Environmental Science: The environment establishes the abiotic factors that living organisms must cope with in order to survive. Those organisms best suited to that environment will live to reproduce.

3. Principles of Natural Selection
1. Overproduction of Young: produce more, some will survive
2. Variation: Since most species are diploid and reproduce through sexual recombination, the offspring will be a mixture of genetic content of the parents

4. - benefit of variation in offspring: slight changes may make the crucial difference in allowing one organism to survive over another
Ex: Disease – if all the individuals of a population are genetically identical, then a single type of disease could make them all die – slight variations in the immune system could play an important role in developing a defense and while immune systems in humans are unique (even in identical twins), greater variation will provide greater probability that some organisms will survive.

5. 3. Limited Resources: food, water, shelter, nutrients, light
– results in competition – those that are better at obtaining the resources and defend them (fittest) are going to have the opportunity to survive
“Survive” – have genetically viable offspring

6. 4. Reproductive Success: those that have more genetically viable offspring are more successful – their genes have passed on – the more an individual’s genes are in the population the more likely they will be passed on to the next generation

7. Result of Natural Selection
1. Species that Fit their Environments
Thus those genes which give the individual a better chance at living to the age where it can reproduce will be passed to the next generation. Thus the traits of the resulting population will be “selected” by the conditions in which they exist. In the end, the population will be adapted for that environment.

8. 2. With enough change, a population can diverge into different species and given enough time (theoretically) into completely different forms.
Species = group of populations whose members have the potential to interbreed with one another in nature to produce viable, fertile offspring, but who cannot produce viable, fertile offspring with members of others species

9. Population Interaction and Change:
Changes in Communities Over Time: Succession
- the sequence of community changes after a disturbance.
Primary succession begins in a lifeless area where soil has not yet formed
Ex volcanic island or the moraine left behind as a glacier retreats.

11. STEPS: 1.only autotrophic prokaryotes may be present.
2.mosses and lichens colonize and cause the development of soil.
3. grasses, shrubs, and trees sprout from seeds blown or carried in from nearby areas.

13. Secondary succession occurs where an existing community has been removed by a disturbance such as a clear-cut or fire, while the soil is left intact.
STEPS: 1.Herbaceous species grow first, from wind-blown or animal-borne seeds.
2. Woody shrubs replace the herbaceous species
3. Forest trees.

15.
FROM:

16. Succession of a Pond

17. Interspecific Interactions and Community Structure:
- between different species
Methods of Interaction:
- symbolized by the positive (+) or negative (−) effects of the interaction on the individual populations or as (0) which means no effect through interaction

18. A. competition: competition for resources is usually harmful to one or both species (-/-) because even the winner must expend energy and may lead to the elimination of another species
- causes the competitive exclusion principle, which states that two species with similar needs for the same limiting resources cannot coexist in the same place (niche)
- therefore each species occupies its own unique place in the environment called its NICHE – includes both abiotic and biotic components

20. - causes the competitive exclusion principle, which states that two species with similar needs for the same limiting resources cannot coexist in the same place
- therefore each species occupies its own unique place in the environment called its NICHE – includes both abiotic and biotic components

22. When Connell removed Balanus from the lower strata, the Chthamalus population spread into that area.
The spread of Chthamalus when Balanus was removed indicates that competitive exclusion makes the realized niche of Chthamalus much smaller than its fundamental niche.
RESULTS
CONCLUSION
Ocean
Ecologist Joseph Connell studied two barnacle speciesBalanus balanoides and Chthamalus stellatus that have a stratified distribution on rocks along the coast of Scotland.
EXPERIMENT
In nature, Balanus fails to survive high on the rocks because it is unable to resist desiccation (drying out) during low tides. Its realized niche is therefore similar to its fundamental niche. In contrast, Chthamalus is usually concentrated on the upper strata of rocks. To determine the fundamental of niche of Chthamalus, Connell removed Balanus from the lower strata.
Low tide
High tide
Chthamalus fundamental niche
Chthamalus realized niche
Chthamalus
Balanus realized niche
Balanus

23. Fundamental Niche – potential space the organism can occupy
Realized Niche – actual space occupied
- if the niches of two species vary even slightly, they can coexist in the same community by RESOURCE PARTITIONING –
EX: different types of warblers (birds) will live in different sections of trees and therefore not have to compete with one another for habitat
- the whole tree is a fundamental niche for the birds but the actual layer they inhabit is the realized niche

24. B. predation (+/-): Predator/Prey
B. predation (+/-): Predator/Prey Predator Adaptations: sight, smell, strength, teeth/beak shape, claw shape, poisons, camouflage (ambush)
Mimicry: predator simulate the prey of their prey – alligator snapping turtle
Killer Whale Beach Hunting
Killer Whales Team Work
Golden Eagle Video

25. Prey Adaptations
Behavioral defenses include fleeing, hiding, and self-defense.

26. Alarm calls

27. Mobbing the predator Injury Feigning Displays

28. Mechanical defense: claws, teeth, spines, shells
Chemical defense: poison, odors, taste

29. often show Aposematic coloration (WARNING)

30. Adaptive coloration Camouflage or cryptic coloration

44. Octopus Camouflage
Octopus and Coconut

45. Mimicry
Batesian mimicry a harmless, palatable species mimics a harmful, unpalatable model.
Müllerian mimicry, two or more unpalatable species resemble each other.

46. Batesian Mimicry

47. Müllerian Mimicry

48. Monarch and the Viceroy

49. Herbivory (+/-):herbivore eats parts of a plant or alga.
Herbivores adaptations.
- herbivorous insects have chemical sensors on their feet to recognize appropriate food plants.
- Mammalian herbivores have specialized dentition and digestive systems to process vegetation.
Plant Defenses:
chemical toxins: caffeine, nicotine, alkaloids, poison ivy
spines, thorns and prickles

50. Parasitism (+/-): parasite derives its nourishment from a host, which is harmed in the process.
Endoparasites live within the body of the host Botfly
Ectoparasites live and feed on the external surface of the host.
Parasitoidism is a special type of parasitism in which an insect
(usually a wasp) lays eggs on or in living hosts.
- larvae feed on the body of the
Zombie Snails

51. guinea worm: http://www.youtube.com/watch?v=yEhujLgu7wM
intestinal worms (not sure what kind): 
Jump to the 2:00 mark, watch for awhile and then to about 5:12. OH MY WORD

52. Disease: Pathogens are disease-causing agents that have deleterious effects on their hosts (+/−)
Pathogens are typically bacteria, viruses, or protists.
Fungi and prions can also be pathogenic.
Parasites are generally large, multicellular organisms, while most pathogens are microscopic.

53. Mutualism (+/+): Mutualism is an interspecific symbiosis in which two species benefit from their interaction
EX: nitrogen fixation by bacteria in the root nodules of legumes
digestion of cellulose by microorganisms in the guts of ruminant mammals
exchange of nutrients in mycorrhizae, the association of fungi and plant roots.

54. Commensalism. interaction that benefits one species but neither harms nor helps the other (+/0).
Commensal interactions are difficult to document in nature because any close association between species likely affects both species, if only slightly.

55. End Result Abiotic + Biotic + Interaction = Species Richness
Increased by: Decreased by:
More niches - geographic isolation
Heterogeneous area - homogeneity
Proximity to other areas - Stress on Env.
Ecotone/edge effect - species dominence
- loss of keystone spe.

56. Impact of Invasive/Exotic Species
Species not normally part of an ecosystem
Lack natural predators
Move into unoccupied niches
Out compete native species
Reduce species richness and biodiversity
Examples:
Kudzu, zebra mussel, gypsy moth, Starling, Lithrum (purple loosestrife) Asian Carp, Leafy Spurge