2. We need to start with Evolutionary Theory!  What is evolution?  Change over time (in our case referring to living things)  Change in allele frequencies in a population over time  What is theory?  Well supported testable explanation  Lots of things change over time. Can you think of any?

3. Two Types of Evolution  Microevolution  Small subtle genetic variations that result in a new subspecies  For example, insects developing resistance to pesticides

4. Microevolution

5. Macroevolution  Macroevolution  Large scale evolution occurring over a lot of time that results in new species  This is usually the type of evolution you here people argue about  An example would be dinosaurs to birds

6. Evolution at a glance

7. Charles Darwin  Englishman who proposed the theory of evolution  Darwin looked at fossils and compared them to animals he saw today  He observed natural variation  Differences among individuals of a species. Why?  Genetics, DNA  Look around the room we are all a little bit different. That is natural variation.  He realized there is a struggle for existence  Members of each species compete regularly to obtain food, living space, and other necessities of life

8. Charles Darwin  Darwin’s observations led him to propose something called the survival of the fittest.  Also known as natural selection  Individuals that are better suited for their environment survive and reproduce most successfully  Only fittest individuals pass on their genes  There traits increase in the population over time  Leading to change over time or evolution

9. Gene Pools  Combined genetic information of all members of a particular population  Within each gene pool there is genetic variation. Why?  Different alleles for genes  When specific traits in the gene pool are selected as advantageous, then they tend to increase in the population.

10. Sources of Genetic Variation  Mutations  Any change in the DNA sequence  Gene shuffling during meiosis  All genes segregate independently during meiosis  8.4 million different combinations of genes  Crossing over during meiosis

11. Crossing over and Independent Assortment

12. Populations, Natural Selection, and Gene Frequencies  What is a bell curve?  Well, it’s a graph that’s line is shaped like a bell.  It has many uses. The follow graph shows the range of IQ in the population.

13. Directional Selection  You can use bell curves to look at the number of individuals in a population with a specific trait. Furthermore, you can look at how the trait will change in the population over time.  In directional selection individuals at one end of the curve are more likely to survive, reproduce, and pass on their advantagous trait.

14. Stabilizing Selection  Individuals at the center of the bell curve are most likely to survive.

15. Disruptive Selection  Individuals at either end of the curve are most likely to survive.

16. An example

17. Hardy-Weinberg Principle  Allele (Form of gene or trait) frequencies in populations will remain constant unless one or more factors cause the frequencies to change  In other words, the bell curve for different traits will not shift. It will remain the same.  Five conditions to maintain genetic equilibrium  random mating  large population  no movement of individuals in or out of the population  no mutations  no natural selection

18. Ecology Scientific study of interactions among organisms and between organisms and their environment  In ecology living things (biotic) and nonliving things (abiotic) interact

19. Biosphere  All the parts of the planet where life exists  Land  Water  Air  Interactions among organisms and their environment occur in the biosphere (see Ecology)  Ecological level of Organization  Biosphere  Biome  Ecosystem  Community  Population  Individuals

20. Biomes  Biomes are climatically and geographically defined areas of ecologically similar climatic conditions such as communities of plants, animals, and soil organisms.  Examples of biomes:  Tropical Rainforest  Desert  Tundra  Boreal Forest - Taiga  Temperate Deciduous forest  Savannah  Temperate Grassland

21. Biomes

22. Ecosystems, communities, and poplulations  Ecosystems are a dynamic complex of plant, animal and micro-organism communities and their non-living environment, interacting as a functional unit.  Communities are multiple populations living in the same area.  Populations are organisms of the same species living in a defined area.

23. Ecosystems

24. Life needs energy to sustain itself  Energy flows through the environment  The sunlight is the main source of energy for the environment (photosynthesis in plants)  Other organisms use inorganic chemicals for energy (bacteria on the ocean floor, volcanic vents, and hot springs, these are the only organisms that do not rely on the sun)  Autotrophs make their own food from sunlight or inorganic chemicals  Heterotrophs rely on other organisms for their energy supply

25. Heterotrophs Herbivores – eat plantsCarnivores – eat animals

26. Heterotrophs Omnivores – eat plants and animals Detritivores– animals that eat dead or decaying organic matter (do not break it down into simpler compounds)

27. Decomposer – fungi or bacteria that break down decaying organic matter into simple compounds

28. Food Chains and Food Webs  Energy moves through the ecosystem in one direction, from the sun or inorganic compounds to autotrophs and then to heterotrophs  The food chain is a series of steps in which organisms transfer energy by eating and being eaten.  A food web is the network of complex interactions formed by the feeding relationships among the various organisms in an ecosystem  A food web links all the food chains together

29. Food Chain and Biomass Pyramid

30. Food Chain (The Quaternary Consumer is the Top Consumer)

31. Important facts about the food chain  A trophic level is a step in the food chain. For example, the plant in the previous slide is the 1 st trophic level, the insect is the 2 nd, the mouse is the 3 rd, etc.  Only 10% of the original energy is passed on from one trophic level to the next. The rest is lost in heat and waste.  The ultimate source for 99.9% of food chains is the sun.

32. Food Webs

33. Matter Flow  Energy flows in a one way direction through the ecosystem and matter (water, carbon, nitrogen, etc) is recycled between ecosystems.  We are going to look at three matter cycles  Water  Carbon  Nitrogen

34. Water Cycle

35.  http://www.biology.ualberta.ca/facilities/mult imedia/uploads/alberta/watercycle.html. http://www.biology.ualberta.ca/facilities/mult imedia/uploads/alberta/watercycle.html  http://earthguide.ucsd.edu/earthguide/diagra ms/watercycle/. http://earthguide.ucsd.edu/earthguide/diagra ms/watercycle/

36. The Carbon Cycle

37.  http://www.biology.ualberta.ca/facilities/mult imedia/uploads/alberta/CarbonCycle.html. http://www.biology.ualberta.ca/facilities/mult imedia/uploads/alberta/CarbonCycle.html

38. Detailed Carbon Cycle

39. Nitrogen Cycle

40.  http://www.biology.ualberta.ca/facilities/mult imedia/uploads/ecology/ncycle.html. http://www.biology.ualberta.ca/facilities/mult imedia/uploads/ecology/ncycle.html