Unit 1: Diversity of Living Things Lesson 1: Introduction to Biodiversity

Biological Diversity or Biodiversity The number and variety of species and ecosystems on Earth Ex: a rainforest has more biodiversity than the tundra

How do we measure biodiversity? Biodiversity is often understood as the number of types of plants, animals and microorganisms The fundamental unit of biodiversity is the SPECIES

What is a Species? All organisms capable of breeding freely with each other under natural conditions Ex: under natural conditions, lions breed with lions; robins breed with robins

AMBIGUOUS CASES FOR THE DEFINITION OF SPECIES: Mules – male donkey + female horse

Ambiguous Cases for the species con’t Plants of two different species hybridizing to form a cross between species

Ambiguous Cases for the Species: Organisms that reproduce asexually ex: dandelions; defined as a species based on its physical characteristics

What is Biodiversity Canadian Geographic Biodiversity Definition Summary Video

Other ways to consider biodiversity 1.Genetic Diversity:  The genetic variability among organisms; usually referring to individuals of the same species Ex: human genetic diversity are differences in hair, skin, and eye colour etc.

Other ways to consider biodiversity 2.Species Diversity:  A measure of diversity that takes into account the quantity of each species present, as well as the variety of different species present Ex: An ecosystem with 10 species each with 500 individuals is considered to be more biologically diverse than an ecosystem with 10 species each with 50 individuals. This is because the larger the population, the more biologically, diverse interactions. The greatest species diversity exists in ecosystems with many different species that each have large populations.

Other ways to consider biodiversity 3.Structural Diversity:  The range of physical shapes and sizes within a habitat. Structural diversity is critical for biodiversity because it creates microhabitats ie: An ecosystem with more structural diversity will have greater biodiversity. Ex: A flat ocean bed has less biodiversity than an irregular bottom with rocks, reefs, logs or even sunken ships. It is the diversity of habitats

So, how much biodiversity is there? The UN declared 2010 the International Year of Biodiversity In 2010, 1.75 million different species have been identified Scientists estimate that there are 13 million different species in the world, but that estimate has been known to vary from 3 million to 100 million

If there is so much biodiversity out there, why do we worry when species go extinct? Species extinction is a natural process Biologists estimate that a new species will, on average, become extinct after approximately 1 million years Human activity in speeding up the rate of extinction E.O. Wilson estimates that the current extinction rate is times as great as it would be without humans

Importance of Preserving our Biodiversity: Loss of biodiversity means: 1.Threatened food supply when an entire species and plant varieties are lost 2.Eliminates sources of natural medicines and potential new medicines (as well as other resources) 3.Significant economic impact on tourism and forestry when accompanied by habitat destruction 4.Has the potential to cause serious disruptions in biogeochemical cycles ex: normal carbon uptake by natural ecosystems

E O Wilson Full TED Talk Video (4 min) of E O WilsonMini Video (4 min) of E O Wilson

Homework: 1.Suggest three examples of species that clearly fit the definition of a species based on the biological species concept. Explain your choices. 2.Explain why some species must be defined based on their morphology rather than on reproductive behaviour. 3.Analyze some ways in which the loss of biodiversity might affect the following industries a) agriculture and forestryb) tourismc) healthcare 4.E.O. Wilson estimates that we are losing species per year. Based on this number, how long will it take for 1 million species to become extinct? 5.What are some of the primary human activities responsible for the increased rate of extinction? 6.Explain how climate change is affecting biodiversity in the Arctic. Why are changes in the Arctic ecosystems significant for the rest of the world?