4.2.2 (d) classification and phylogeny- unfinished

relationship between classification and phylogeny.

Phylogeny

• past scientists classifies organisms based of shared visible features

• todays scientists classify organisms on the basis of phylogeny

  • (which is the evolutionary history of organisms)

• meaning species that share a more recent common ancestor are classified together

• while species with a more distant common ancestor are classified in separate groups.

• Advances in DNA, RNA and protein sequencing have allowed the classification of organisms according to their phylogeny more accurately than using visible characteristics.

Three types of sequence data used to investigate evolutionary relationships

• DNA

• mRNA

• Amino acids (of a protein)

• Sequencing technology can determine the order of DNA bases, mRNA bases and amino acids within an organism's genome

• This technology is especially useful for comparison with an extinct species (using ancient DNA) or when distinguishing between species that are very physically similar

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