Wednesday, July 29, 2009

Ask the Experts: How do you know the animals are extinct?

This is a very interesting question - how can we be sure that an animal is really extinct? How do we know there aren't still some lost mammoths - or even dinosaurs - hidden in a Lost World in some remote corner of the globe? Well, the most honest answer is we really can't ever be totally sure - but we can say that the chances of a species surviving are so amazingly slim that it would be virtually impossible to find one remaining.

That's not to say it still can't happen, though - and in fact it has, several times! Famously, in 1938, fishermen off the east coast of Africa caught a kind of fish, called a coelacanth, that scientists had thought went extinct with the dinosaurs. Other animals, like a certain type of ant and a certain type of shellfish, as well as several types of plants, have also been rediscovered by science after they were presumed long extinct. When a species or group reappears after disappearing from the fossil record for a long period, scientists call it a Lazarus taxon.

Still, its one thing to rediscover a type of ant, and another to rediscover a 12,000 pound mammoth. It might be possible to hide from scientists and explorers in the far recesses of inaccessible rainforest, or down in the deepest depths of the ocean, but mastodons and giant sloths roamed the same hills and plains and woodlands that humans visit and inhabit.

If they still exist somewhere, where is the evidence of them? Why do we suddenly stop finding bones and other evidence of Ice Age mammals at the end of the Pleistocene? Where could they have been hiding for the last 12,000 years? Even the very last mammoth bones we see anywhere on Earth, from remote and sheltered Wrangel Island in Siberia, are still at least 4000 years old - and those mammoths only managed to survive that long by changing dramatically.

In short, it always may be possible to discover a member of some Lost World in the remote Arctic or at the bottom of the sea. But the larger the animal, the less remote its natural habitat, and the longer its been since we stop finding evidence of it, the more certain we can be that it really has gone extinct.

DJ

Friday, July 10, 2009

2nd Place in 2009 "Battle of the Boards"

The Western Center took 2nd place in the 2nd Annual Romona Bowl Amphitheater "Battle of the Boards" Lip Sync competition held at Soboba Casino on June 26th. Thanks to a rousing and hilarious Cher performance by our own Peter, Sue and Darla, $1,500 was won for the Western Center Community Foundation. All the boards represented put on a wonderful show and all proceeds went to the Ramona Bowl Amphitheater. It was a great event!


Wednesday, July 8, 2009

Ask the Experts: How did paleontology start?

The study of animals' remains, both living and extinct, goes back to the beginning of human civilization itself. Several ancient cultures such as the Greeks, Chinese and Persians studied the natural world, including preserved animal remains, and made many discoveries, such as that climates and environments could change over time. However, the modern science of paleontology did not emerge until the 1800s.

Fossils themselves have been found throughout history around the world - what modern paleontology provides is the understanding of what they are and what they can tell us. What we call dinosaurs and mastodons today, ancient cultures called dragons and cyclopes, because they lacked all the basic information needed to understand their true nature.

Throughout the 19th Century, the understanding of the natural sciences in Europe became increasingly more advanced as scientists made discoveries that let them explore more and more complex questions. Scientists began putting forth ideas that would become the foundations of the modern sciences: James Hutton in Scotland put forth theories about rock formation that would lead to the understanding of geologic time; George Cuvier of France would provide conclusive evidence that animals could go extinct; and Charles Darwin would propose the idea of natural selection and adaptation. Even President Thomas Jefferson had a keen interest in paleontology and was perhaps the first vertebrate paleontologist in America, with a species of giant ground sloth named for him (Megalonyx jeffersoni, which can be seen at the Western Center).

As more and more of the pieces fell into place, the picture we understand today of the biologic and geologic history of Earth became more clear. This gave scientists the background they needed to figure out what all those dragon and cyclops bones really were. Comparisons to other animals let scientists classify fossil animals and determine their relationships with other organisms. Geology provided a timeframe for the fossil record and suggested how bones might be preserved as fossils. The ideas of extinction and evolution suggested that animals could change over time, and that not all animals that ever existed are still alive today.

The modern fossil craze that continues through today can trace its origins back to 1822, when an English doctor and paleontologist named Gideon Mantell first described a dinosaur, Iguanodon. This started a public fascination with dinosaurs that continued through the Great Exhibition of 1851, when concrete statues of dinosaurs were displayed - the first major paleontology exhibit - and the Bone Wars in America in the 1870s-1890s, when rival paleontologists O. C. Marsh and Edward Drinker Cope fought bitterly to see who could describe more new species of dinosaurs, discovering almost 140 between them.

From there, understanding of Earth's paleontological history became ever more thorough as more new discoveries and studies were made, leading to the level of knowledge we have today and share at the Western Center.

DJ