Sample CER information Extinction over Time Sample CER information

Claim I believe we are part of the sixth mass extinction. Or I do not believe we are part of the sixth mass extinction.

Evidence (YES) According to the text, “hundreds of extinctions have been caused by human activities in the past few centuries” including the passenger pigeon, the Dodo bird, Stellar’s sea cow, Labrador duck, Rocky mountain locust, Tasmanian wolf, Deepwater cisco fish, Hawaii chaff flower, Golden toad and the St Helena olive tree to name a few. (pg. 1 section 2) The author mentions that recent studies estimate at least 15,000 species are threatened with extinction out of the approximate 8 million species on Earth. (pg. 1 section 3)

Evidence (YES) The text also informs us that scientists have used the fossil record to determine the baseline extinction rate of about one species per every one million species per year. Yet “today’s extinction rate is hundreds, or even thousands higher than the natural baseline rate”. (Top of page 2 –section 3 continued) The author states that paleontologists have evidence from the last 10,000 year that human’s behaviors, such as overhunting, habitat changes, and pollution, have caused many species to go extinct. And that the industrial revolution has accelerated this problem.

Evidence (Yes or No) All the news is not all bad through. Conservation biologists, such as Dr. Brian Gratwicke, are studying ways to manage “ecosystems to prevent species from going extinct”. They can’t save all the species, but can target species that are important to the ecosystem and to people. (pg. 3 section 6) In addition genetic engineers have been researching the possibilities of bringing back extinct species from DNA samples that have stored in museums like the Smithsonian. This idea is controversial and further discussions are needed. (pg. 3 section 7)

Evidence (YES) Paleontologists have determine that 5 mass extinctions have occurred in the past and that all of these were due to natural causes including an asteroid hitting Earth, volcanic eruptions, global cooling and lower sea level. (pg. 2- section 4)

Reasoning Mass extinction is when all the organisms of a species die in a relatively short period of time. Although the past 5 mass extinctions were all due to natural causes, we are now losing large numbers of species due to human activities. The world population is estimated to be 7.4 billion people. All these people need food and shelter. If humans change their behaviors to be more environmentally conscience and conservation biologists figure out ways to manage ecosystem to minimize species loss, then maybe we can slowdown or even reverse the loss of so many species. If not, we are well on our way to a sixth mass extinction.