A-LEVEL BIOLOGY AQA NOTES
species and taxonomy
Classification
- The Biological Species Concept- a species contains all organisms that are capable of breeding together to produce living, fertile offspring.
- Courtship and mating behaviour are a vital part of species survival. Courtship behaviour enables individuals to: recognise same species members & identify mate capable of breeding
- Classification is the process of sorting living things into groups.
- Classification hierarchy comprises the taxa: domain, kingdom, phylum, class, order, family, genus and species.

- Classifications are constantly updated as new methods are discovered to infer relationships e.g. DNA sequencing, amino acid sequencing or immunological comparisons.
- The binomial naming system names species by their genus and species name.
- Phylogeny is the study of evolutionary relationships between organisms.
- In a phylogenetic diagram, branch tips represent species at the end of their specific lineage, branching points represent common ancestors & The closer the branches, the closer the evolutionary relationship.