In our online lecture we include a quote by E. O. Wilson, “The one process now going on that will take millions of years to correct is the loss of genetic and species diversity by the destruction of natural habitats.  This is the folly our descendants are least likely to forgive us.”

Throughout Earth’s history, we have had long periods of innovation and radiation of new species which have been interrupted periodically by five major extinction events that eliminated large percentages of the life on Earth. The last of these appears to have involved a collision with a large asteroid resulting in the loss of the dinosaurs at the end of the Cretaceous. Each of these events has been followed by a new period of radiation of new species and innovation.

As Wilson states, we are now in the midst of a sixth major extinction event that has been brought on by the actions of humans.

Assignment:

Describe the common pattern of alternating extinctions and radiations. Consider Wilson’s statement. What evidence can you find to support or refute that statement? Do you agree with Wilson? Explain why you do or don’t agree and present the evidence supporting your opinion.