Define the term 'phylogeny', how it is related to classification of species, and what kind of evidence is used in phylogenetics. (3 Marks)

Phylogeny is the evolutionary relationships between different species. Species within the same taxonomic group have shared phylogeny (i.e. they have a common ancestor). (1) Phylogeny is what taxonomic classification is based upon. (1) Molecular evidence is examined to classify organisms based on their genetic similarity. Examples of molecules used are DNA/RNA sequences, amino acid sequences from proteins, cytochrome C, haemoglobin and enzymes in the ATPase class. (Include 1 example) (1)