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. 196-202)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 216-225)

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

ExtinctionHow is it related to

biodiversity?

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

History of Extinction SB Pg.216

Dinos175 MY

Humans1 MY

Extinction Due To:1.Climate Change2. Volcanic Eruption3. Meteor Impact

Biodiversity RecoveryProcess takes millions of yearsRecovery involves new species evolving and replacing old ones.

Background Extinction Rates

Normal Background Extinction Rate: 10-25 species/yearCurrent rate (SB p.217-218)

50,000/year137/day6/hour

Rivet HypothesisDecreasing Biodiversity Little

by Little

Rainforest videoSpread of Hanta Virus in the southwest

Rains increasePinion pine nuts increaseDeer Mice feed on pinion pine nutsDeer mice population increasesIncrease in deer mice fecal matterInhaled by individualsDeadly 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 PyramidWhat 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 DemoNext Generations?

Man vs. NatureIkei Island

Industrialization of Japan causes its coast to become polluted.Fish migrate to Ikei Island to cleaner watersDolphins follow fishFish 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.