Forum 4: Biodiversity and Extinction

We’ve recently discussed how new species arise and also how they end: the process of extinction. Recent research suggests that we may be in the middle of a sixth mass extinction event, in this case caused by humans.

The following articles deal with aspects of world biodiversity and extinctions. Read through at least two articles and draw from them in your posts and comments.

There Have Been Five Mass Extinction Events in Earth’s History. Now We’re Facing a Sixth (Washington Post) (Links to an external site.) Interview with Elizabeth Kolbert, author of the recent book The Sixth Extinction.

Mass amphibian extinctions globally caused by fungal disease (Links to an external site.) A third of all amphibian species are threatened with extinction.
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New Madagascar conservation map protects maximum number of species in biodiversity hot spot (Links to an external site.). The island of Madagascar is home to thousands of rare species found nowhere else, including lemurs.
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Climate Race Separates the Weeds from the Trees (Links to an external site.)(New Scientist). An interesting possible future trend is the rise of “weedy” species that flourish in disturbed environments and crowd out existing plants and animals.

This is a fairly open-ended forum. In your posts, please address two or more of the following. You can also draw from other sources you’ve read independently, or make other relevant comments on the topic of biodiversity and extinction.

• Madagascar, Indonesia and the Amazon basin have some of the greatest numbers of different species concentrated in a single area. What kinds of environments do you think encourage greater biodiversity?
• What are some examples of non-native “weedy” (hardy, easily adaptable) species of plants and animals that have entered North America and have caused or are starting to cause major problems for existing plant and animal (and human) communities?
• How are humans and human activities contributing to extinctions of plants and animals?
• Can humans realistically do anything to reverse these trends described in the articles? If so, what sacrifices (economic, demographic, etc) are we willing to make in order to preserve biodiversity?