Phylogenetics

areas where this definition can be difficult to apply. There are four major definitions and concepts that can be applied to a ‘species’. The biological species concept, the morphological species concept, the ecological species concept and the phylogenetic species concept. Throughout the course of this essay, I will discuss various definitions, tackle the difficulties associated with defining a species and I aim to answer the fundamental…

Human phylogenetic trees differ according to available data. In some, for example, Homo erectus is shown to be one of Homo sapien’s ancestors. Neanderthals are shown to be co-descendants with archaic Homo sapiens and as a dead end in the human phylogenetic tree. This would mean that they went extinct without contributing genes to modern humans. In other trees, Neanderthals are shown to have interbred with modern Homo sapiens. There are sources that claim that Homo erectus is the first hominid to…

mistakenly copied, chromosomes misalign, and break up into wrong cell. The new evolutionary approach, a phylogenetic tree, allows scientists to calculate which genes are more likely to be copied or die and become grow or survive. The tree approach is better to predict which primary tumors later metastasize. Other scientists are now starting to examine…

: This table quantifies the number of amino acids that are different in the same position of the amino acid sequence of myosin heavy chain 6 alpha protein in zebra fish, cod, tilapia, salmon and flounder. The sequence alignment from the NCIB website is used to compare the genetic sequence of myosin and determine how closely related two species of fish are based on the number of amino acid sequence they have in common. The table indicates that flounder and tilapia have the least variation in the…

genes that humans have that any other species do not have. Once these genes have been identified and their effects determined, the genes that code for proteins affecting brain development or growth could be isolated. The DNA comparisons would allow phylogenetic relationships to be established, which would help determine when traits emerged or disappeared. This would provide insight on when brain size and complexity started to increase. Once the time frame of when the traits for brain size and…

The emergence of cytochrome oxidase is considered to be a very important event in evolutionary history. However, not much is known on the development and emergence of this enzyme. Molecular data demonstrates how cytochrome oxidase emerged before the divergence of archaea and bacteria, and well before the great oxidation event. This paper proposes a research plan to investigate the origins of cytochrome oxidase. Background Throughout the three domains of life, a variety of metabolisms are present…

anatomical, physiological, and ecological characteristics (Sokal, 1986). Phylogenetic classification Grouping of organisms based on evolutionary relationships rather than mutual similarities or general resemblance. A century ago groupings were designed to support the Darwian principle of a common descendant. Molecular Evolution studies, which use DNA sequence analysis, are used in the 21st century to determine the phylogenetic braches of the evolutionary tree of Life, based on evolutionary…

features between mammalian cells and unicellular cells. More specifically, the unicellular eukaryote L. major clearly expresses many features that can also be inspected in mammalian cells. Leishmania major is a protozoan parasite from an ancient phylogenetic branch of unicellular eukaryote who only has a single mitochondrion. To begin, a protein kinase inhibitory drug, staurosporine, can induce apoptosis in mammalian cells and it can also induce like features in L. major. This draws an…

(Muller, 1838) . “In this study, we have examined crocodilian relationships in phylogenetic analyses of seven mitochondrial genomes that have been sequenced in their entirety. The analyses did not support the morphologically acknowledged separate position of the gharial in the crocodilian tree.” (Janke,2005). This study is about the relationship of the phylogenetic analysis and how they don't relate to the phylogenetic analysis. “Why must we protect crocodiles? Perhaps surprisingly,…

A coelomate has a fluid filled body cavity, which is completely lined by the mesoderm. The organs of a coelomate are suspended within the fluid filled body cavity. This provides protection from any shock put on the organs. This fluid also provides shape to animals without a hard skeleton. Animals like Arthropoda and Echinodermata are examples of coelomates. Acoelomates lack internal cavities and fluid altogether. Their organs are located within the mesoderm which means less protected from shock…