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Science is a process for learning about the natural world, and also the knowledge generated through this process.
One of the most challenging concepts in thinking about evolution is the idea of "deep time," the profoundly different timescale involved in geological and evolutionary processes than those we deal with in our daily lives. It is rare for those of us in North America to see buildings that are more than 100 years old. If the geological history of the world were represented by the height of the Empire State Building, the time since mastodons walked across North America 14,000 years ago would be represented by the thickness of a single dime.
By Joel R. Primack and Nancy Ellen Abrams
by Steven Newton, Public Information Project DirectorThe age of the Earth is 4.54 billion years (Ga or Gyr), a number which geologists have determined by several independent methods. Because of the recycling of crustal rocks by plate tectonics, no direct material from the earliest Earth still exists. However, geologists are able to analyze meteorites and lunar rocks returned by the Apollo missions.
Science uses specialized terms that have different meanings than everyday usage. These definitions correspond to the way scientists typically use these terms in the context of their work. Note, especially, that the meaning of “theory” in science is different than the meaning of “theory” in everyday conversation.
by Kevin Padian
Department of Integrative Biology & Museum of Paleontology
University of California, Berkeley CA
What is Paleontology? The Fossil Record and Evolution
A bit of history: the progression of life through time, as shown in the fossil record, was well known and generally accepted in the early 1800s, long before Charles Darwin ever sailed on the Beagle. People in England and on the Continent knew that life had changed through time, and that the deeper one went in the rock column, the more different from living forms the fossils became. Since that time the fossils have always documented evolution; the question in Darwin's time was the mechanism or mechanisms that could cause the change.
The word "evolution" can evoke a variety of meanings, especially for students and members of the general public. For some, evolution is equated with natural selection. Others think that evolution addresses the origin of life. Still others impose a distinction between micro-evolution and macro-evolution. Part of the issue stems from an unclear understanding of what evolution is in a scientific sense.