Chapter 6 Concept Questions Why is species diversity so important? “ All the domesticated animals and plants that human beings depend on today were once wild, and we continue to need the genetic diversity that exists in wild populations-that diversity is still life ’ s major defense against changing conditions. ” (pg ) Is Human extinction possible? “ Scientists have identified five major extinction crises over the past 500 million years, in which at least 65 percent of all species known in the fossil record of the time disappeared. ” (pg )

What if species are lost? Loss of species means loss of genes Biodiversity represents the sum of all genomes of all organisms on earth Losing genetic information from threatened or endangered species we lose unique genetic libraries within those species

Extinction How is it related to biodiversity?

Extinction Biodiversity: the variety of life on Earth. Evolutionary survival strategy Biodiversity has suffered some major setbacks during the past 500 million years.

History of Extinction SB Pg.216 Dinos 175 MY Humans 1 MY Extinction Due To: 1.Climate Change 2. Volcanic Eruption 3. Meteor Impact

Biodiversity Recovery Process takes millions of years Recovery involves new species evolving and replacing old ones.

Background Extinction Rates Normal Background Extinction Rate: species/year Current rate (SB p ) 50,000/year 137/day 6/hour

Rivet Hypothesis Decreasing Biodiversity Little by Little

Rainforest video Spread of Hanta Virus in the southwest Rains increase Pinion pine nuts increase Deer Mice feed on pinion pine nuts Deer mice population increases Increase in deer mice fecal matter Inhaled by individuals Deadly version of Hanta virus appears 70% mortality rate How can invading “new” areas of the rainforest render us susceptible to “new” viruses? International travel

Cute Cuddlies vs. Stinky Uglies

Importance of Preserving Ecosystems Trophic Pyramid What can happen if the top is damaged? What can happen if the bottom is damaged?

Sacred Balance p. 217 “We are fortunate to have evolved when biological diversity has been at the greatest level ever achieved. Succeeding human generations will not be as fortunate: the current extinction crisis is without precedent— never before has a single species been responsible for such a massive loss of diversity” Relationship between population and resources

Resources Demo Next Generations?

Man vs. Nature Ikei Island Industrialization of Japan causes its coast to become polluted. Fish migrate to Ikei Island to cleaner waters Dolphins follow fish Fish prices increase because there is a decrease in the coastal fish population due to pollution. Fishermen compete with eachother employing new technologies (hand held lines vs. gill nets) because fish prices increase further decreasing fish population (overfishing) Fishermen compete with dolphins for fish. Blame dolphins for low catch rates instead of pollution and overfishing caused by humans. Herd and kill dolphins to thin their numbers.