evidence

• why is it difficult to compare using physical characteristics

  they may have been developed under independent evolution
• what is a homologous structure

  same structure, different purpose
• why are fossil records incomplete

  most organisms decompose prior to fossilisation

  specific conditions needed

  lost due to geological processes

  many organisms haven't been discovered

  certain organisms are less likely to fossilise
• what are some examples of highly conserved proteins

  cytochrome c

  haemoglobin
• what is cytochrome c

  used for respiration

  useful for structural comparison over long periods of time
• what is neutral evolution

  variability in structure that leads to minimal change
• how can you compare phylogeny within smaller periods of time

  by comparing DNA/RNA