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It is easy to say that species are constantly changing, and branching off into totally new species.

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It is easy to say that species are constantly changing, and branching off into totally new species. But how do we know where the species originate? Phylogenies help to show us how all kinds of species are related to each other, and why. These relationships are put into what can be called a cladogram, which links species to common ancestors, in turn showing where, when, how, and why these ancestors diverged to form new species. Without phylogenies, it would be extremely difficult to put species in specific categories or relate them to one another. Along with phylogenies can come conflict on which species should be related to one another. This conflict causes many hypotheses and experiments, which can lead to phylogenetic retrofitting, …show more content…

The parareptile hypothesis is taken back at least two decades. It has recently been rediscovered and contradicted by parsimony. Bayesian inferences support this parareptile conclusion, but parsimony concludes the idea of turtles being a sister group to pareiasaurs, which is an anapsid group, including Eunotosaurus. To test these hypothesis, a multitude of data is compiled to observe the stability behind the inferences made. In this article, one main experiment was discussed through the collection and analysis of two retrofitted matrices, phylogenetic analyses, and molecular scaffolds. In one matrice, Eunotosaurus was added to a diapsid-focused data set, while turtles were added to an anapsid-focused data set. The diapsid sets included a broad sampling of diapsids, which placed turtles as sisters to sauropterygians. The anapsid set, on the other hand, included a broad sampling of anapsids, especially parareptiles. Turtles were not included in the anapsid set. When the experiment moves on to the phylogenetic analysis, Bayesian inferences and parsimony were brought into the mix. After these analyses, the experiment finally includes molecular scaffolding. The effect of molecular scaffolding was to see where extant linneages interact with molecular phylogenies. The, the Bayesian and parsimony analyses were again repeated with these backbone constraints while everything else is indifferent. The idea

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