Question

Define cladistics.

Answer 1

Hint: There are some methods of classification of animals and plants that aim to recognize and take account of only those shared characteristics which are thought to originate from a common ancestor of a group of species during evolution, not those arising by union.

Complete Answer:
Cladistics refers to a biological organization system which involves the classification of organisms based on collective traits. Organisms are in general grouped by how closely related they are and thus, cladistics can be used to mark out ancestry back to shared common ancestors and the evolution of various characters.

Even If the classification of organisms began in the early 1900’s the cladistics analysis and definite methodology first originated in the 1960’s by Willi Hennig and it is referred to as “phylogenetic systematics”. This process involves creating phylogenies by means of morphological and molecular data to envisage evolutionary history and relationships between species.

Cladistic Methodologies:
- Cladistic methodologies involve the purpose of various molecular, anatomical, and genetic qualities of organisms. For that reason, with the introduction of computational modelling and molecular techniques e.g., polymerase chain reaction [PCR], cladistics are frequently used in evolutionary biology for the production of phylogenetic trees.
- Cladistic data is besides used to create cladograms which consist of diagrams proposing a hypothesis of phylogenetic relationships among species based on shared characteristics. Therefore, depending on a given dataset the resultant cladogram may vary.
- For instance, a cladogram based entirely on morphological traits may produce diverse results from one constructed using genetic data.
- At present, highly advanced computational methods let the use of multiple datasets to construct more precise cladograms. Careful analysis is required to wisely determine which cladogram may be a more correct representation than others.

1. Cladistic Character States: In the field of cladistics, specific terms are used to portray particular characteristics which is termed as character states between the groups of organisms. The subsequent are common terms used to describe such character states
2. Plesiomorphy: Plesiomorphy refers to the ancestral behavior that a taxon retains right through evolution.
3. Apomorphy: Apomorphy is the character that refers to a resulting state used to describe specific clades.
4. Homoplasy: Homoplasy refers to the character that state, it is shared by at least two organisms but which is not seen in the common ancestor or predecessor.

Note: Cladistics gives hypotheses concerning the associations of organisms in a way that dissimilar other systems, predicts properties of the organisms. This can be particularly important in cases when meticulous genes or biological compounds are being required.