Species and taxonomy

Courtship in animals is a behaviour that eventually results in mating and reproduction

Phylogenetics is the study of how organisms are evolutionarily related — often shown using a phylogenetic tree

classifying organisms into groups

The phylogenetic system of taxonomy arranges organisms into groups based on their evolutionary origins and relationships

Phylogenetic systems use DNA, RNA, and protein similarities to identify evolutionary links For example, two species with more similar DNA sequences are assumed to have a more recent common ancestor

-Scientists can communicate clearly about different species -Knowledge that relates to one species can often be partially applied to other, closely related species, e.g. if one species in a taxon has medicinal properties then it is likely that other species will too -It allows scientists to gain an accurate count of the number of species, which is useful for conservation purposes

-The hierarchical classification system of organisms in biology is used to organise and group similar organisms together -so that they can be more easily understood -A hierarchical system is one in which larger groups contain smaller groups with no overlap between groups

• domain, kingdom, phylum, class, order, family, genus and species • Species is the lowest taxonomic rank in the system and domains are the highest taxonomic rank in the system

Bacteria, Archaea, and Eukarya

the scientific name of a species

It consists of the organism’s genus and species name in modern Latin

Advances in genome sequencing and immunology have allowed scientists to further investigate the evolutionary relationships between species

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

Scientists will choose specific proteins or sections of the genome for comparison between organisms. Looking at multiple proteins or multiple regions of the genome will allow for a more accurate estimate of evolutionary relatedness

the protein used needs to be present in a wide range of organisms and show sufficient variation between species. Cytochrome c is often used as it is an integral protein to respiration

the more closely related the species are

Sequence analysis and comparisons

The proteins of organisms can also be compared using immunological techniques

The protein albumin is found in many species and is commonly used for these experiments