Science Myths: The Theory of Evolution

Few topics in the world of science inspire as much debate as the Theory of Evolution. Unfortunately the debate is plagued with misinformation, misperceptions and generally poor science. Here are a few common myths about evolution:

Humans Evolved From Monkeys

Many people think the theory of evolution describes humans as descending from monkeys or apes. This is not technically true—evolutionists believe that humans, monkeys and apes all share a common ancestor from millions of years ago. Humans are not descended from monkeys any more than dogs are descended from cats.

Evolution is only a theory

Many people think of a theory as a "guess" or "possibility", as if someone can simply think of an idea and call it a theory. This is not true. A theory is an organised set of ideas that typically describes something about the natural world and includes a credible amount of support from objective sources (e.g. physical evidence). If an idea does not have any objective support, it's not a good theory. Evolution is accepted as a valid theory because it does have objective evidential support.

Note that many theories are universally accepted as being proven, e.g. number theory (mathematics) and music theory (how sound waves interact harmoniously). No one doubts them but they are still theories.

There is another angle to this argument. Evolution is indeed a theory and as such it is open to criticism or even being disproved. It is quite feasible that the theory will be replaced if a better theory comes along (for example, aliens might arrive and produce solid proof that they planted humans here). The point is that evolution may be "only a theory", but it's the theory with the most evidential support.

Evolution is precluded by the second law of thermodynamics

This law relates to entropy, which is often described as "disorder". To over-simplify, it means that things tend to decay into a more random state, implying that evolution could not happen because it relies on increasing order (complexity). In this case, however, the law is being misinterpreted. Entropy can, and does, increase locally all the time. There is no scientific law that says complexity can't increase all over the earth.

There are no intermediate fossils

Anti-evolutionists sometimes claim that there are no records of "intermediate" fossils, i.e. animals which provide the evolutionary link between species. This is not true, for example:

• Archaeopteryx was a bird with a reptilian skeleton, teeth, feathers, and four paws with jointed fingers.
• Therapsids are the intermediates between reptiles and mammals.
• Crossopterygians and ichthyostegids are the intermediates between fish and amphibians.1
• There is evidence that some dinosaurs had hair and feathers.