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1、1 of 6 Boardworks Ltd 20092 of 6 Boardworks Ltd 2009Evolution by natural selectionThe English naturalist Charles Darwin noticed that there were many similarities between different species. Charles Darwin and Alfred Wallace proposed natural selection as the mechanism by which the most successful chan
2、ges are passed on, allowing organisms to evolve to suit their environment.He believed that these similarities pointed to a common ancestry and that new species form by gradual changes over the generations.3 of 6 Boardworks Ltd 2009Darwins evidence for evolution4 of 6 Boardworks Ltd 2009Molecular evi
3、dence for evolutionlAll have DNA or RNA as their genetic material.lThe genetic code is universal.lATP is the universal molecule for energy storage. lThe proteins in all organisms are formed from the same 20 amino acids.lAll have phospholipid membranes. lVital physiological processes follow very simi
4、lar metabolic pathways in all organisms.All organisms share a number of molecular characteristics, which suggest a shared origin of all life on Earth. 5 of 6 Boardworks Ltd 2009GenomicsGenomics is the study of all the genes in an organism. By comparing the genomes of different animals, their relatio
5、nship can be established. Differences between proteins can also be used to establish evolutionary relationships.There are likely to be huge differences between the genomes of different species. Scientists can compare the genes that encode proteins used in important biochemical processes. These proteins, such as haemoglobin, rarely change, as most modifications would affect a key biological pathway.6 of 6 Boardworks Ltd 2009Tracing evolution using molecular data
