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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Lemurs are the world’s most endangered mammals, but planting trees can help save them (Links to an external site.) Discusses how deforestation is threatening the survival of lemurs which are found only on the island of Madagascar. (Note–this has replaced the originally posted article which was nonfunctioning) (Links to an external site.)

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 original post, 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. Your post should be at least 150 words long. 10 points for original post.

• 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?