Homology Is A Central Concept Within The Field Of Phylogenetics

A cladogram is a chart that show similarities through a selected species of organism or completely random organisms. They are basically tree like structures to show similar characteristics. Some of these characteristics may be opposable thumbs, hair, cells, or segmented bodies, although all characters can be used. There are many different names for these such charts: phylogeny, evolutionary tree, phylogenetic tree, and cladogram.(reading trees, 2006) In cladograms, there are clades, a clade is a group of species that shares a common ancestor. Each of these organisms share a common trait or traits with this ancestor. While cladograms show certain similarities between species, there is no defined strength of any of the similarities, thus all must be treated with equal meaning. This can lead to awkward situations of species which seem to bare no resemblance to each other being actually correct. This can show great evidence towards evolution only depending upon the organisms used in such a chart.

The diagram on Figure 3-1 demonstrates a tree-like structure or web with several different branches going in multiple directions. The top of the tree lists the three domains of life and specific kingdoms or groups within each domain. These groups are put together because they contain similar characteristics that define them to a specific domain. In the middle of the figure there are many arrows intertwining signifying that each of the groups within the domain are somehow related to each other and may share some of the characteristics from another domain. Finally, the bottom of the structure demonstrates the cut off web that arose from the same direction, proposing they each are derived from a common ancestor. The cladogram is a much different structure that demonstrates the three domains of life and their relationship through detailed characteristics that they share or make them unique.

For a long time, it had been assumed that evolution happened in a systematic manner and that no two or more species of human ancestors existed at the same time. Because of such an assumption, it has become very hard to determine the exact ancestors when two populations dated to the same geographical location and time. In this essay, I will discuss the difference between the Homo Habilis, Homo Rudolfensis, and the Paranthropus Boisei in order to show why I believe the Homo habilis is our direct ancestor despite the three populations having existed within the same region and time span.

The study of chemicals found in cells, in biochemistry, allows for a deeper exploration of the evolutionary links between humans and other organisms. Amino acid sequencing, DNA-DNA hybridization and DNA sequencing are relatively newly developed forms of technology that have enabled a more thorough consideration of the evolutionary relationships. Previous to these technologies, scientists such as Darwin and Wallace were more reliant on comparative anatomy and embryology as the means of

Homologs refer to proteins or DNA that share the same ancestry. These genes, related by linear descent, are found in different species.

conclusive theory is till date available as experimental validation in evolutionary time scale is impossible but the proposed hypothesis to some extent try to explain the origin of homochirality.

Their structural similarities are the reasoning behind why one might say that they belong to the prokaryotic domain, being structurally very similar, especially on the first glance. The unique properties will be discussed further later in this essay. SIMILARITIES BETWEEN EUKARYOTES AND ARCHAEA Though structurally, prokaryotic cells seem more similar to archaea than eukaryotic cells, yet when one inspects their DNA, similarities between DNA replication, transcription and translation appear. The DNA polymerase in archaea and eukaryotes are not related to any prokaryotic DNA polymerase, suggesting that these two are of common origin. Other components used in DNA replication are similarly only shared between eukaryotes and archaea (y).

The phylogeny described in this paper is based on molecular data (similarities in DNA sequences)

In an Evolutionary map, students assume that the closer species are to each other the more similar they are to one another. From my understanding all the species would share a common ancestor, just that some might be closely related to one another. When genes are altered then a branch is added on.

(1a)The history of any species is a fascinating thing that is constantly changing. Mutation and sex are two mechanisms that take a huge part in creating history. Sex combines two different strands of DNA to create a new sequence of amino acids. While mutation changes the sequence of DNA by substitution, insertion, deletion, and frameshifting. (1b)Every species has some relation to another species since we all came from a common ancestor. A way we represent this is with phylogenetic trees. In the example below organisms are arranged based on the differences in their cytochrome c amino acid sequences.

The first hypothesis essentially states that segmentation was acquired independently in all of the three phyla. The second goes on to say these segments are in fact homologous within the protostomes, but that chordates evolved segments independently. Lastly, the third hypothesis also believes that segmentation is homologous but only throughout the Bilateria.

2011). Different organisms can evolve in similar ways even if they are not similar by descent from a common ancestor and this is known as homoplasy (Hawks, J. 2005).

Introduction: This report talks about evolution and four factors that contributed to evolution. The four factors are fossil record, geographical distribution, similarities in embryos, and homologous body structures. Evolution is the change of features over generations from different species of animals.

Scoville, H. (n.d.). What is the difference between analogy and homology in evolution? Retrieved October 25, 2017, from

In the area of knowledge of science, Darwin’s theory of evolution is evaluated to provide understanding of the statement “facts are needed to establish theories but theories are needed to make sense of facts.” Evolution is the change in heritable characteristics of a species over time. Isolated populations, after a long period of evolution, gradually diverge into a new species. Facts of Darwin’s theory comes from evidences such as fossil records can proves that many species have become extinct. Secondly, it shows succession in the forms and shapes of