Cladogram Lab

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  • Topic: Mammal, Phylogenetics, Cladistics
  • Pages : 6 (1919 words )
  • Download(s) : 358
  • Published : March 15, 2013
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ABSTRACT
Phylogenetic systematics is away to determine the relatedness between species by creating cladograms. In this study, we observed the difference between cladograms created with morphological traits and molecular DNA with respect to Felis cattus, Canis familiaris, Didelphis virginiana, Odocoileus virginianus, and the Equus caballus. The results demonstrated that although a species is similar or closely related in regards to morphological traits, it does not mean that their DNA composition will be the same. This study is significant because it demonstrates the importance of phylogenetic systematics of both morphological and molecular traits.

INTRODUCTION
The study of phylogenetic systematics was first introduced in the 1950’s (Biology Department, 2012). It is defined as a concept used to delineate species as the smallest aggregate population that can be united by shared derived characters (Russell et al 2010). Phylogenetic systematics is a way to determine the relatedness between species by creating a cladogram. It is based on the fact that evolutionary processes in species can be represented through a branching pattern that demonstrates the time span and degree of relatedness between the species or taxon (Biology Department, 2012). These branching trees are used to determine the common ancestor between the species and where the original trait that has evolved into slightly different forms in the descendants derived from. In this study, morphological traits were observed as well as haemoglobin A was used to determine the morphological and molecular relatedness between the species respectively. Haemoglobin A is created by a string of amino acids and is the oxygen carrier in the bloodstream of animals (Biology Department, 2012). Due to its important role in the body, the assumption can be made that certain parts of the haemoglobin A would not have much variability in it because high variability would yield mutant molecules that would not be able to carrier oxygen properly (Biology Department, 2012). This fact makes haemoglobin useful to study for molecular systematics. The five species that were studied in this lab were the Felis cattus (cat), Canis familiaris (dog), Didelphis virginiana (opossum), Odocoileus virginianus (deer), and the Equus caballus (horse). The Felis cattus is from the animalia kingdom, the mammalia class and is a carnivore. These domestic cats are well known for their flexible bodies, keen eyesight, good balance and agility (LaBruna 2001, ISSG). The Canis familiaris is from the animalia kingdom, the mammalia class and is a carnivore. Dogs come in an abundance of different breeds and sizes with various physical attributes, sensory capabilities, and behaviours (Bhagat, 2002). The Didelphis virginiana is from the animalia kingdom and the mammalia class. Opossums are found in a variety of environments, ranging from relatively arid to mesic environments. They prefer wet areas, however, especially streams and swamps (Newell et al 2003). The Odocoileus virginianus is part of the animalia kingdom and the mammalia class. They inhabit most of southern Canada and are able to survive in a variety of terrestrial habitats. Ideal whitetail deer habitat would contain dense thickets in which to hide and edges that would furnish food (Dewey, 2003). The Equus caballus is a part of the animalia kingdom and the mammalia class. Horses have been strongly bred by humans that there is extensive variability in their weight and size. Vision and hearing are key senses for horses (Sorin, 2001). The purpose of this study was to differentiate between morphological traits and molecular based cladograms and to use outgroup comparison, synapomorphy and parsimony to construct phylogenies. Our research question was: Is there a relationship between the morphological traits based cladogram and the molecular cladogram with respect to Felis cattus, Canis familiaris, Didelphis virginiana, Odocoileus virginianus, and the Equus...
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