Biodiversity bio life diversity variety Biodiversity biodiversity the

Biodiversity bio = life diversity = variety

Biodiversity biodiversity: the sum total of the genetically based variety of all organisms in the biosphere species biodiversity: number of different species in an ecosystem or the biosphere itself

Biodiversity Key Concept: biodiversity • is a great natural resource • many species provide us with foods and medicines • painkillers, antibiotics, anticancer drugs, etc • if biodiversity is lost, so are potential cures to diseases Periwinkle plant: • native to Madagascar • drugs derived from plant to treat certain cancers

Biodiversity Threats to Biodiversity • habitat destruction • pollution with toxic chemicals • hunting to extinction • introducing non-native species

Biodiversity Threats to Biodiversity • habitat destruction • destruction of habitat = loss of the number of species in that area = loss of biodiversity

Biodiversity Threats to Biodiversity • pollution with toxic chemicals • biomagnification – concentrations of harmful substances increase in organisms at higher trophic levels DDT: A Pesticide - kills agricultural pests - remains in env. for long time - is NOT metabolized by biological organisms! - stays in their biomass - passed on to consumers up food chain - results in top level carnivores being most at risk - banned in 1970 s

dioxin: a carcinogenic compound produced, among other ways, during trash incineration

Biodiversity Threats to Biodiversity • introducing non-native species • also known as invasive species • organisms that are NOT native to an ecosystem • reproduce quickly because new habitat lacks parasites and predators that control their population Example: nutri - native to South America - now a pest in SE USA - destroys water plants - destroys habitat of other species

Human Population Growth List some density-dependent factors that will limit human population growth?

Human Population Growth What type of population growth demonstrated here?

Human Population Growth Factors affecting human population growth: • advancements in agriculture • industrial revolution • advancements in medical and other technologies

Human Population Growth Population Demographics: the physical characteristics of a population Age-structure diagrams: predict future growth based on age composition of the population

Human Population Growth Predict how the following populations will grow or shrink over in the next 50 years…

Human Population Growth Predict how the following populations will grow or shrink over in the next 50 years…

Human Population Growth Predict how the following populations will grow or shrink over in the next 50 years…

Human Population Growth Societal issues affect population growth: • increased education and a raised standard of living leads to families having less children • hence, more modernized societies tend to grow more slowly