Name: _____________________________________________ Date Due: _____________ Article Reading and Review: Wake, D. B., & Vredenburg, V. T. (2008). Are we in the midst of the sixth mass extinction? A view from the world of amphibians. Proceedings of the National Academy of Sciences, 105(Supplement 1), 11466-11473. INTRODUCTION What 5 examples are given as human-based influences threatening to cause extinction? 1. 2. 3. 4. 5. FIVE MASS EXTINCTIONS Name the “Big Five” mass extinction events, give their respective time periods, magnitude of species lost, and summarize the proposed causes for the extinction event Name Time Type and Magnitude Proposed Cause Period of Species Lost A SIXTH EXTINCTION? When do the authors suggest the sixth extinction began and what was its cause? What is the overkill hypothesis and why is it suggested to have not happened in Africa? What other five explanations are given as the source of the sixth extinction? 1. 2. 3. 4. 5. AMPHIBIANS IN CRISIS Explain the two main compelling reasons why amphibians are receiving so much attention during the last few decades. Explain at least 4 reasons why amphibians are recognized as “multipurpose sentinels of environmental health” 1. 2. 3. 4. 5. Provide 3 reasons why frogs are used more than any other amphibian in research studies. 1. 2. 3. RANA IN THE SIERRA NEVADA OF CALIFORNIA Biological surveys conducted nearly a century ago by Grinnell and Storer (1924) provide a great basis for modern day comparison. Based on those historical values, what is the story of the Yellow-legged frog? COMMON THEMES IN AMPHIBIAN DECLINES What seem to be the 3 common environmental changes that affect the disappearance of frog species across the globe? IS GLOBAL WARMING A REAL EXTINCTION THREAT? What is the range of temperature change that can be expected within the next 100 years? What interesting facts about amphibians were observed as additional mountain peaks were surveyed for species ranges? What will climate change likely do for these mountain range specific species? WHAT WILL WE LOSE? What is the current extinction rate for amphibians in comparison to the background extinction rate? What populations of amphibians are the most susceptible to extinction? Why? WHAT IS THE PRINCIPAL CAUSE OF THE PRESENT EXTINCTION SPASM? Describe the domino-like series of human influences that the authors claim to be causing the major environmental impacts on amphibians What is the authors’ call to action?