Evolutionary theory states that the original cell, which is the source for all life, spontaneously emerged from Earth's inert chemicals. However, even the simplest cell is quite complex. To be considered alive, an organism - - and thus a cell - - must:
• Have a cell wall
• Maintain its cell wall and grow
• Process food from outside itself
Could such an organism really come about spontaneously from nonliving chemicals? It's possible that some sort of spontaneous creation occurred; some people say it could only have been supernatural creation.
Likewise, evolutionary theory says that a new species takes between 100,000 years and millions of years to evolve. However, this doesn't make sense. As Carl Sagan said in "The Dragons of Eden," human toes "are clearly evolved from fingerlike appendages for grasping and swinging, like those of arboreal apes and monkeys." This evolutionary process was only a respecialization, or the adaptation of an organ from one function to a different function, yet Sagan estimated it took about 10 million years to come about. How then, can every mammal have evolved from simple creatures like the Didelphodon over the course of just 65 million years, as evolutionary theory poses?
Scientists have found lots of support for different parts of evolutionary theory from fossils, as well as from insects and bacteria. However, these questions about evolutionary theory vex its supporters. Scientists constantly are trying to prove or disprove many aspects of the theory; it no doubt will continue to be modified as new knowledge is accrued. It's possible that new theories even will be proposed, based on new knowledge, to resolve some of the "loopholes" in current evolutionary theory.
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