Charles Darwin

• Our modern ideas about evolution began with one of the most famous scientists of all time - Charles Darwin
• Charles Darwin set out as the captain's companion and ship's geologist and naturalist on HMS Beagle


  1831
• Darwin was only 22 years old at the start of the round the world voyage to South America and the South Sea Islands
• Darwin planned to study mainly geology on the trip, developing his knowledge of rocks and fossils
• As the voyage went on, Darwin became as excited by his collection of animals and plants as by his rock samples
• In South America, Darwin discovered

  • A new form of the common rhea, an ostrich-like bird
• Finding two different types of the same bird living in slightly different areas

  Set Darwin thinking
• On the Galapagos Islands, Darwin noticed


  • The variety of species varied from island to island
  • Strong similarities between types of finches on the different islands, yet each was different and adapted to make the most of local conditions
• Darwin collected huge numbers of specimens of animals and plants during the voyage, and made detailed drawings and kept written observations
• The long journey home gave Darwin plenty of time to think about what he had seen
• Darwin spent the next 20 years working on his ideas


  After returning to England
• Darwin's theory


  All living organisms have evolved from simpler life forms, through a process of natural selection
• Darwin's main ideas


  • The individual organisms in a particular species tend to show a wide range of variation for each characteristic
  • Reproduction always gives more offspring than the environment can support. The organisms that have inherited the characteristics most suited to their environment - the fittest - are more likely to survive and breed successfully
  • When they breed, they pass on the characteristics that have enabled them to survive to the next generation
• When Darwin suggested how evolution took place by natural selection, no one knew about genes. He simply observed that useful inherited characteristics were passed on
• Today, we know it is useful alleles that determine the characteristics of the phenotype that are passed from parents
• Charles Darwin came back from his trip on HMS Beagle with new ideas about the variety of life on Earth
• Darwin gradually built up his theory of evolution by natural selection
• Darwin knew his ideas would be controversial. He expected a lot of opposition, both from fellow scientists and from religious leaders
• Building up the evidence

  1. Darwin realised that he would need lots of evidence to support his theories

  2. He spent years trying to put his evidence together in order to convince other scientists
• Evidence Darwin used


  • The amazing animals and plants he had seen on his journeys
  • Organisms on different islands had adapted to their environments by natural selection
  • Breeding experiments with pigeons at his home
  • Studying different types of barnacles and where they lived
• Reasons Darwin's theory of natural selection was only gradually accepted

  • The theory challenged the belief that God made all of the animals and plants that live on Earth
  • Many scientists felt there was not enough evidence to convince them of his theory
  • There was no way to explain how variety and inheritance happened
  • The mechanism of how inheritance happens-by genes and genetics - was not known until 50 years after Darwin published his ideas
• By the time of his death in 1882, Darwin was widely regarded as one of the world's great scientists. He is buried in Westminster Abbey along with other great scientists such as Sir Isaac Newton