A group of organisms that can interbreed to produce fertile offspring.
Courtship behaviour
A necessary precursor to successful mating.
Allows individuals to recognise and reproduce with individuals of the own species- prevents infertile offspring.
Allows individuals to recognise other sexually mature individuals
Signals of courtship behaviour
Visual
Auditory
Chemical
Tactile
Courtship behaviour is species-specific. It can be used to classify organisms. The more closely related a species, the more similar their courtship behaviour.
Phylogenetic classification system
Arranges species into groups based on their evolutionary origins and relationships
Scientists use anatomical features, fossils and biochemical analysis of base sequences in DNA or amino acid sequences in proteins.
Hierarchal
Phylogenetic trees
Each branch point= common ancestor
The more closely related two species are, the more recent their common ancestor existed.
The first branch point in the first common ancestor of all species.
Hierarchy
Smaller groups within larger groups
No overlap between groups
Taxonomy
Study of classsification
Taxa
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
Why are scientists able to update classification systems?
Advances in immunology
Genome sequencing
-> clarification of evolutionary relationships between organisms
Binomial naming system
Each species is universally identified by its scientific name
