And DrDeth do please provide some support for your claim that past mass extinctions were a few thousand years or shorter. My reading is that when they say “sudden” in geologic terms they mean less than 500,000 years. With that as a referent we are keeping up a pretty brisk pace and gaining.
Colibri and Essured, thank you for your replys.
It would be interesting to know what kind of a future you predict for the greater animals in the course of this century. If my memory serves me correctly, we lost 3 of the 8 remaining subspecies of tigers during the 20th century, as well as several other animals. How far will this trend continue? Also, what is the outlook for life at sea? Off the coast of Norway it was recently discovered that most of the seaweed had disappeard, apparently abruptly (<10 years), along a coastline of several hundred miles. Is this a local phenomenon, or something happening elsewhere in the world as well? What is the impact of this?
Sorry, my apologies! That’s what comes of reading through the replies too fast.
Many of the larger mammals are probably going to end up surviving mainly in captivity, if at all. Such animals frequently have very large home ranges, and normally exist at low densities. Even large national parks may not contain enough individuals to escape the effects of inbreeding, or chance extinction due to local catastrophes such as droughts or disease outbreaks, over the long term. As the habitat becomes more fragmented, it may be necessary to manage such populations intensively to keep them viable.
This problem has lead to such initiatives as “Paseo Pantera,” (The Puma’s Path), a plan to link protected areas in Central America with corredors of natural habitat through which large animals can pass to maintain the integrity of regional populations. It remains to be seen if such plans can succeed in the face of intense economic and social pressures.
Oceanic ecosystems are collapsing worldwide due to overfishing, pollution, climatic effects, and other factors. Here’s a bit more Jackson’s *Science * 2001 article on historical overfishing. Jeremy says that, by removing top levels of the food chain, we are pushing ocean ecosystems so that they become dominated by organisms at ever lower trophic levels - we are moving towards a world in which bacteria and jellyfish will be the prevailing marine life forms
For more information, you can view a slide show on Jackson’s research. The main website, Shifting Baselines, has a great deal more information about the situation of ocean ecosystems.