Natural selection is the important process that results in changes in populations over time. All the structual, functional and behavioural adaptations we have discussed over the past few months have evolved as a result of natural selection. However, because the effects of natual selection can only be seen over many generations, it is difficult to visualise. There are a number of computer simulations that allow us to visualise natural selection. The Peppered Moth Simulation, from the Biology Corner, uses a well known example of a case study of natural selection. The Biology in Motion lab uses more stylized images for it’s Evolution Lab.
Image Source – The United Kingdom 10 pound note.
This year many scientists are celebrating Charles Darwin’s 200th birthday. Darwin is famous for his book, “The Origin of Species” which was a revolution in biology and controversial in it’s day for the theory that species could evolve over generations to form new species – and that humans had evolved from an ape-like ancestor! Darwin was the first scientist to propose this theory and provide a simple mechanism – survival of the ‘fittest’ – that could explain how it works. Even before chromosomes and genetics had been discovered, he proposed that there was some ‘hereditary factor’ that was passed through generations and conferred characteristics that made individual organisms more or less likely to survive, breed and pass on those characteristics to their offspring.
Catalyst is celebrating Darwin’s 200th birthday with a special edition, that includes interviews with famous scientists, articles about DNA and missing fossil links and archives of related stories. Read a biography of Charles Darwin from the BBC and find out more at “Darwin – the Genius of Evolution“.