Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings PowerPoint® Lectures Lectures by Greg Podgorski, Utah State University Sustaining the Variety of Life Current Issues in Biology, Volume 4 Scientific American

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Concept Review Sustaining the Variety of Life Extinction is a natural process. The average lifetime of a species is roughly 1 million years. This means that at natural or background rates, one in 1 million species is expected to become extinct each year. Current rates of extinction are at least 100 times higher than this background rate

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Concept Review Sustaining the Variety of Life The elevated extinction rate is due to human activities that include habitat destruction introduction of exotic species overharvesting and in the future, global warming

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Concept Review Sustaining the Variety of Life Some species are much more vulnerable to extinction than others, and these species are geographically concentrated. To sustain the variety of life, special places rich in threatened species must be identified and protected. The intuitive notion that extinctions occur most often in areas where the most people live is wrong. Extinctions occur most frequently where fronts of habitat destruction, especially deforestation, overlap concentrations of vulnerable species.

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Concept Review Sustaining the Variety of Life Probably one-half of the world’s species live in 25 mostly forested, tropical areas where human actions have removed > 70% of the natural vegetation. These areas are hot spots for conservation efforts. The laws of biogeography explain how species are distributed across the world.

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Concept Review Sustaining the Variety of Life Laws of Biogeography Law 1. Most species’ ranges are very small; few are very large. Law 2. Species with small ranges are locally scarce. Law 3. The number of species found in a given area varies greatly and according to common factors. Law 4. Species with small ranges are often geographically concentrated.

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Concept Review Sustaining the Variety of Life The costs of sustaining biodiversity are large, but so are the benefits. The Millennium Ecosystems Assessment report has documented benefits that include food, water, fuel, climate regulation, and many other often undervalued services that are provided by healthy ecosystems. There are many possible solutions to conserving biodiversity. Ultimately, all solutions must benefit local human populations as well as endangered species.

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Concept Review Sustaining the Variety of Life How can biodiversity be conserved? By encouraging conservation groups to purchase logging leases for sensitive tropical wilderness forests. By providing economic alternatives to displaced poor people who now clear the majority of tropical forests. By connecting now-fragmented forests through forest bridges.

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Concept Review Sustaining the Variety of Life How can biodiversity be conserved? By promoting ecotourism to provide a cash incentive to local people to conserve the natural environment. By allowing preserved forest tracts to be used as capital in the Kyoto carbon-trading system. By promoting understanding of the economic benefits provided by intact ecosystems.

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Sustaining the Variety of Life Testing Your Comprehension At the background rate of extinction, one expects 1 in _________ species to become extinct each year. a) 10 b) 1,000 c) 10,000 d) 1,000,000

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Sustaining the Variety of Life Testing Your Comprehension At the background rate of extinction, one expects 1 in _________ species to become extinct each year. d) 1,000,000

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Sustaining the Variety of Life Testing Your Comprehension Probably of all species live in the world’s hot spots for biodiversity conservation. a) 1/10 b) 1/4 c) 1/2 d) 9/10

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Sustaining the Variety of Life Testing Your Comprehension Probably of all species live in the world’s hot spots for biodiversity conservation. c) 1/2

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Sustaining the Variety of Life Testing Your Comprehension The bulk of tropical forests are cleared by a) multinational logging companies b) nationally sponsored logging companies c) local logging companies d) displaced poor people

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Sustaining the Variety of Life Testing Your Comprehension The bulk of tropical forests are cleared by d) displaced poor people

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Sustaining the Variety of Life Testing Your Comprehension The Millennium Ecosystems Assessment report a) lists economic benefits provided by ecosystems b) focuses exclusively on ecotourism c) provides a plan for sustainable tropical forest logging d) argues against acceptance of the Kyoto Treaty

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Sustaining the Variety of Life Testing Your Comprehension The Millennium Ecosystems Assessment report a) lists economic benefits provided by ecosystems

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Sustaining the Variety of Life Biology and Society It is vitally important that we protect each and every species. Strongly Agree Strongly Disagree A. E. C. B. D.

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Sustaining the Variety of Life Biology and Society Since biodiversity is a global resource, binding decisions about biodiversity conservation must be made internationally. Strongly Agree Strongly Disagree A. E. C. B. D.

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Sustaining the Variety of Life Thinking About Science The biogeographic laws state that 1) Most species’ ranges are very small; few are very large; 2) Species with small ranges are locally scarce; 3) The number of species found in a given area varies greatly and according to common factors; and 4) Species with small ranges are often geographically concentrated. Which of these laws imply that a small number of bird species contributes a disproportionately large number of individuals to the world’s bird population? a) Laws 1 and 2 b) Laws 2 and 3 c) Laws 3 and 4 d) Laws 1 and 4

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Sustaining the Variety of Life Thinking About Science The biogeographic laws state that 1) Most species’ ranges are very small; few are very large; 2) Species with small ranges are locally scarce; 3) The number of species found in a given area varies greatly and according to common factors; and 4) Species with small ranges are often geographically concentrated. Which of these laws imply that a small number of bird species contributes a disproportionately large number of individuals to the world’s bird population? a) Laws 1 and 2

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Sustaining the Variety of Life Interpreting Data and Graphs The biogeographic laws state that 1) Most species’ ranges are very small; 2) Species with small ranges are locally scarce; 3) The number of species found in a given area varies greatly and according to common factors; and 4) Species with small ranges are often geographically concentrated. Which law(s) is/are supported by the figure? a) Law 1 b) Law 2 c) Law 3 d) Law 4

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Sustaining the Variety of Life Interpreting Data and Graphs The biogeographic laws state that 1) Most species’ ranges are very small; 2) Species with small ranges are locally scarce; 3) The number of species found in a given area varies greatly and according to common factors; and 4) Species with small ranges are often geographically concentrated. Which law(s) is/are supported by the figure? c) Law 3 d) Law 4

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Sustaining the Variety of Life Interpreting Data and Graphs Which of the following regions has the largest area of remaining habitat? a) West Africa b) South-Central China c) Tropical Andes d) Central Chile RegionOriginal Habitat (thousands of km 2 ) Percent Remaining West Africa 1,26510% South- Central China 800 8% Tropical Andes 1,25825% Central Chile 30030%

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Sustaining the Variety of Life Interpreting Data and Graphs Which of the following regions has the largest area of remaining habitat? c) Tropical Andes RegionOriginal Habitat (thousands of km 2 ) Percent Remaining West Africa1,26510% South- Central China 800 8% Tropical Andes 1,25825% Central Chile 30030%