- A modern approach to taxonomy
Biologists today may try to combine several systems of classification. However, most use Phylogenetics.
Phylogenetic: The analysis of the evolutionary or ancestral relationships among taxa.
Phylogenetic Diagrams: Shows how closely organisms within a subset of taxa are related, based on hypothesises.
- Several types of evidence are used to hypothesize, Including: Visible similarities, Embryonic development, Patterns of similar chromosomes, and Dna or Rna.
- The greater the number of homologous structures, the more closely related organisms are.
Cladistics: A system, of phylogenetic analysis that uses shared and derived characters as the only criteria for grouping taxa.
Shared character: A feature that all members of a group have in common
Derived character: A feature that evolved only within the group under consideration
Clade: The group of organisms that includes an ancestor and all of it's descendants
Molecular Cladistics: ( such as similar amino acids or nucleotide sequences), as well as chromosome comparisons, can help determine common ancestry
Chromosomes: analyzing karyotypes can provide more information on evolutionary relationships , and are independent of physical similarities and molecular data
No comments:
Post a Comment