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- Charles Darwin came up with the idea of natural selection (ref. see below)
- Charles Darwin is famous for his theory of evolution, but he was not the only person to develop such a theory.
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- Charles Darwin was an English naturalist. He studied variation in plants and animals during a five-year voyage around the world in the 19th century. He explained his ideas about evolution in a book called On the Origin of Species, which was published in 1859.
- Darwin's theory caused controversy among his contemporaries and his ideas were only gradually accepted, although some people still do not believe them today.
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- 1. Individuals within a species show variation because of the differences in their genes e.g. some rabbits have big ears and some have small ones
- 2. Individuals with characteristics that make them better adapted to the environment have better chance of survival and so are more likely to breed successfully e.g. big eared rabbits are more likely to hear a fox sneaking up on them, and so are more likely to live and have millions of babies. Small eared rabbits are more likely to end up as fox food.
- The genes that are responsible for the useful characteristics are more likely to be passed on to the next generation e.g. all the baby rabbits are born with big ears.
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- Darwin's theory of evolution explains how life on Earth has changed over geological time. Scientists believe this is the reason why all living things on Earth exist today. The theory is supported by evidence from fossils, and by the rapid changes that can be seen to occur in microorganisms such as antibiotic-resistant bacteria. Many species have become extinct in the past and the extinction of species continues to happen.
- Not everyone agreed with Darwins ideas though.... Darwins idea was very controversial (Giving rise or likely to give rise to public disagreement) at the time for various reasons.
- 1. It went against common religious beliefs about how life on Earth developed- it was the first plausible explanation for our own existence without the need for a Creator or "God"
- 2. Darwin couldn't give a good explanation for why these new, useful characteristics appeared or exactly how individual organisms passed on their beneficial characteristics to their offspring. But then he didn't know anything about genes or mutations- they weren't discovered until 50 years after his theory was published.
- 3. There wasn't enough evidence to convince many scientists, because not many other studies had been done into how organisms change over time.
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