How can we obtain and communicate information to support claims that natural and human-made factors can contribute to the extinction of species?
Background Information
During this unit you may remember that the fossil record suggests that many organisms such as the dinosaurs have gone extinct and that catastrophic have occurred many times throughout Earth's long history. These catastrophic events have caused mass extinctions that have ultimately shaped not only the geologic time scale but the biological evolution of species that have continued to exist on this planet.
Introduction
Over long periods of time, the number of species becoming extinct can remain fairly constant, meaning that an average number of species go extinct each year, century, or millennium. However, during the history of life on Earth, there have been periods of mass extinction, when large percentages of the planet’s species became extinct in a relatively short amount of time. These extinctions were caused naturally and have had widely different causes. In more recent geologic time however, many scientists warn that, because of human activities such as pollution, overfishing, and the cutting down of forests, the Earth might be on the verge of—or already in—a sixth mass extinction. If that is true, what new life would rise up to fill the niche that we currently occupy?
Essential Question
What are some of the greatest factors that cause mass extinctions on Earth?
Take a moment to think about what you would really like to learn this week about extinction and whether or not humans are causing the next mass extinction today and add your question(s) to your science journal.