1. APES – Chapter 7 - Biodiversity

2. Definition The diversity of life forms in the environment The diversity of life forms in the environment 3 scales within a region 3 scales within a region A) ecosystem A) ecosystem B) species B) species C) genetic C) genetic

3. Species diversity varies among ecosystems

4. How many species live on Earth? 2 million named to date 2 million named to date Current estimates = 5 to 100 million, but most say 10 million Current estimates = 5 to 100 million, but most say 10 million Challenges? Challenges? active only at night active only at night Live in inaccessible locations Live in inaccessible locations Require a microscope to be seen Require a microscope to be seen

5. Measuring species at a local or regional scale Species richness and species evenness Species richness and species evenness Number of species in a given area vs relative proportion of individuals within the different species Number of species in a given area vs relative proportion of individuals within the different species High species evenness – if its species are all represented by similar numbers of individuals High species evenness – if its species are all represented by similar numbers of individuals Which community is considered more diverse? Which community is considered more diverse? Both may decline after a human disturbance Both may decline after a human disturbance Measurement of these 2 indicators gives environmentalists a baseline to evaluate change Measurement of these 2 indicators gives environmentalists a baseline to evaluate change Community 1Community 2 Species A – 25%Species A – 70% Species B – 25%Species B – 10% Species C – 25%Species C – 10% Species D – 25%Species D – 10%

6. Shannon’s index of diversity Example 1 Imagine a community of 100 individuals that are evenly divided among four species, so that the proportions(pi) of the species all equal 0.25. Calculate H for this community. Example 2 Now imagine another community of 100 individuals that also contains four species, but in which one species is represented by 94 individuals and the other three species are each represented by 2 individuals. Calculate H for this community.

7. Evolution is the mechanism underlying biodiversity Change in genetic composition of a population over time. Change in genetic composition of a population over time. Microevolution – evolution on a small scale Microevolution – evolution on a small scale Macroevolution – genetic changes that give rise to new species or new genera etc. Macroevolution – genetic changes that give rise to new species or new genera etc. Evolution depends on genetic diversity Evolution depends on genetic diversity

8. Creating genetic diversity Genes Genes Genotype Genotype Mutation and recombination – change in DNA and crossing over Mutation and recombination – change in DNA and crossing over Mutations can be detrimental or improve an organism’s chance of survival Mutations can be detrimental or improve an organism’s chance of survival Ex) dusky-headed conure vs mosquito Ex) dusky-headed conure vs mosquito

9. Genotype vs Phenotype Actual set of traits expressed in that individual Actual set of traits expressed in that individual Determined by genes or a combination of genes and environment Determined by genes or a combination of genes and environment Ex) eye color vs gender in some turtle and crocodile species or morphology in daphnia Ex) eye color vs gender in some turtle and crocodile species or morphology in daphnia

10. Evolution by Artificial Selection Plants and animals bred for traits we desire Plants and animals bred for traits we desire Can produce unintended results – selection for herbicide resistance in weeds or selection for drug- resistant bacteria Can produce unintended results – selection for herbicide resistance in weeds or selection for drug- resistant bacteria

11. Evolution by Natural Selection Determined by the environment, not humans Determined by the environment, not humans Both require that individuals vary in their traits and that these variations are capable of being passed on to the next generation Both require that individuals vary in their traits and that these variations are capable of being passed on to the next generation N.S. favors any combination of traits that improves an individual’s fitness (its ability to survive and reproduce) N.S. favors any combination of traits that improves an individual’s fitness (its ability to survive and reproduce) Traits that improve an individual’s fitness are called adaptations Traits that improve an individual’s fitness are called adaptations N.S. can favor multiple solutions to a particular environmental challenge N.S. can favor multiple solutions to a particular environmental challenge

12. Evolution by Random Processes Mutation, genetic drift, bottleneck effect, and founder effect Mutation, genetic drift, bottleneck effect, and founder effect

13. Speciation and Extinction Determine Biodiversity Allopatric vs Sympatric Speciation Allopatric vs Sympatric Speciation

14. Factors determining the pace of evolution For each of the following factors, create a line graph that depicts the ability of a species to adapt to change- lesser  greater on x axis For each of the following factors, create a line graph that depicts the ability of a species to adapt to change- lesser  greater on x axis Rate of environmental change(slow vs fast – on y axis) Rate of environmental change(slow vs fast – on y axis) Genetic variation(less vs more – on y axis) Genetic variation(less vs more – on y axis) Population size(small vs large – on y axis) Population size(small vs large – on y axis) Generation time(long vs short – on y axis) Generation time(long vs short – on y axis)

15. Genetically Modified Organisms

16. Evolution shapes ecological niches and determines species distributions

17. Fundamental vs Realized Niche Biotic factors can also limit the physical location of organisms Biotic factors can also limit the physical location of organisms Such as.... Such as.... Presence of competitors Presence of competitors Presence of predators Presence of predators Presence of disease Presence of disease Result is the organism’s realized niche Result is the organism’s realized niche

18. Niche generalists vs specialists Example – an insect that feeds on a wide variety of plants versus one that feeds on a single variety of plant Example – an insect that feeds on a wide variety of plants versus one that feeds on a single variety of plant Which do you think would be more vulnerable to extinction if conditions in their environment were to change? Which do you think would be more vulnerable to extinction if conditions in their environment were to change?

19. Environmental Change and Species Distribution

20. Environmental Change and Species Extinctions Species cannot adapt to changes or move to a more favorable environment Species cannot adapt to changes or move to a more favorable environment -- no favorable environment that is geographically close enough to move to -- no favorable environment that is geographically close enough to move to -- alternative favorable environment may already be occupied by other species -- alternative favorable environment may already be occupied by other species -- environmental change may occur so rapidly that the species does not have time to evolve new adaptations -- environmental change may occur so rapidly that the species does not have time to evolve new adaptations

21. The Five Global Mass Extinctions

22. The Sixth Mass Extinction

23. Arguments in favor of conserving Earth’s biodiversity

24. Medicinal Plants Dung of the Devil – H1N1 Dung of the Devil – H1N1 Salicylic Acid – Willow tree Salicylic Acid – Willow tree Drugs to treat childhood leukemia and Hodgkin’s disease – Rosy periwinkle Drugs to treat childhood leukemia and Hodgkin’s disease – Rosy periwinkle Antiviral and anticancer drugs – Mayapple Antiviral and anticancer drugs – Mayapple Anti-inflammatory and anti-tumor drugs – invertebrates found in coral reefs Anti-inflammatory and anti-tumor drugs – invertebrates found in coral reefs

25. Working Toward Sustainability The Nature Conservancy – uses grants and private donations to purchase privately owned natural areas or to buy development rights to those areas The Nature Conservancy – uses grants and private donations to purchase privately owned natural areas or to buy development rights to those areas Declines in the populations of many fish and shellfish has steered their focus to coastal ecosystems Declines in the populations of many fish and shellfish has steered their focus to coastal ecosystems They have purchased harvesting and exploitation rights and use them as a conservation tool They have purchased harvesting and exploitation rights and use them as a conservation tool

26. Legislation 1. CITES – Convention On International Trade in Endangered Species of Wild Flora and Fauna(1973) – no living specimen or “wildlife product” could be traded if it came from an endangered or threatened species 1. CITES – Convention On International Trade in Endangered Species of Wild Flora and Fauna(1973) – no living specimen or “wildlife product” could be traded if it came from an endangered or threatened species 2. Endangered Species Act of 1973 – Identifies threatened and endangered species in the US, and puts their protection ahead of economic considerations 2. Endangered Species Act of 1973 – Identifies threatened and endangered species in the US, and puts their protection ahead of economic considerations 3. Marine Mammals Protection Act of 1972 – protects marine mammals from falling below their optimum sustainable population levels 3. Marine Mammals Protection Act of 1972 – protects marine mammals from falling below their optimum sustainable population levels