Genes and evolution:
Organisms vary because of the genes they inherit from their parents. Asexual reproduction results in clones. The offspring from sexual reproduction are different from their parents.
Clones can be created artificially by taking cuttings and carrying out tissue culture, embryo transplants and adult cell cloning.
Genetic engineering means taking a gene from one organism, and putting it into another. This is used to make human insulin from bacteria and to create GM crops.
Scientists believe that all life on earth evolved from single-celled organisms that lived 3.5 billion years ago.
Darwin's ideas about evolution axplained how living things evolved due to variation and survival of the best adapted. Many people did not believe his ideas until 50 years after they were published.