Scylla Posted January 11, 2013 Author Share Posted January 11, 2013 (edited) Hi Brent, My mother has been a high school biology teacher for the past 23 years, so yes I'm aware of the limitations concerning a teacher's salary. I'm a university student with even less income and I managed to get my hands on a copy of the book just fine, for free. The university libraries here didn't have a copy so I used interlibrary loan at my local county library and they had a copy for me within a week. If you absolutely must buy a copy it is easily sourced online for far less than the Amazon list price. ABE books has a copy for $12 in good condition. better to be smart than rich I think As far as catasrophic events are concerned I think any species going extinct is catasrophic for that species, but besides that I think that evolutionary change occurs on many levels at once. Just look at human evolution, what event caused the loss of H. erectus? What caused the loss of Neanderthals (ok, I know, they still live in Tuscany, just distributed in the genome) The bottom line is any population lowering event makes competition and extinction more likely, but slow change and new competitors can lead to extinction of established niche holders too. In short Chas and Brent are both right and it is an artificial argument to define weather more species go extinct due to catastrophe or gradual change since the fossil record is sooo incomplete that a statistically valid answer will be hard to believe. I believe we can measure extinction rates in fossil creatures, I just don't believe there are enough fossils to believe the answer. Just my 2 cents And you' re both invited to dinner if you ever come to Long Island Edited January 11, 2013 by Scylla Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now