Marine fossils

Wherever you live, whether high in the mountains or by a beach, there´s a good chance that you will encounter rocks that have fossil shells in them. That´s because tectonic forces within the Earth, couple with erosion on the Earth´s surface, have worked to raise ocean floors above sea level. These lands are now high and dry, and can be full of marine fossils that provide us with clues as to the past environment of the rock layer.

Mass Extinctions

Paleontolists (scientists who study past life) are bemused by the mass extinctions that occurred about 65 million years ago. About 75% of all species disappeared rather quickly, but not all species seemed threatened. Different hypotheses to explain the worldwide, catastrophic disappearances include a sudden, drastic cooling of the Earth, or a shift in the magnetic field that allowed harmful radiation to enter the atmosphere. But most paleontolists agree that massive extinctions such as these were probably a result of a tremendous disruption of the food chain. What would destroy the food chain on a worldwide basis? Some scientists suggest volcanic explosions from the Deccan plateau in India, but the currently popular theory is that a massive meteorite that landed off the coast of the Yucatan peninsula in Mexico may be to blame. The meteorite impact would have caused enormous amounts of dust to enter the atmosphere, which would block out sunlight and lower temperatures for years, causing plants to die off. When the plants died, plant-eating animals would have starved and ultimately died off. That in turn would have caused their predators to die. The importance of protecting the bottom of the food chain is an important point to remember, since media coverage today typically focuses on protecting those animals at the top of the chain, not the bottom.

Creationism vs. Evolution

You might think that most earth scientists are atheists or agnostics, but that´s not the case. Most earth scientists prefer the idea of intelligent design, which states that an intelligent force guided creation.
But this idea is just as controversial. Some scientists, mostly Christian
scholars, are redefining the evolution vs. creationism debate.

Why Fossils Form

A fossil is a record of past life. Under most circumstances, there are two requirements before a plant or animal can become a fossil: hard parts and a rapid burial. Shells, bones, and teeth are hard parts that preserve well. But it´s not enough to have hard parts - those bones or teeth, left on the surface of the Earth, decay until nothing is left. However, if a dead animal or plant is buried quickly, for example, if it falls into a deep, muddy swamp or is buried during a sandstorm, there is less opportunity for the parts to decay, and a better chance to form a fossil.