Hello everyone and welcome back to another week of learning about Salamander.
Let’s just do a quick recap before we jump into this weeks discussion. In the last blog, we discussed one unique feature of the salamander. The one unique feature we discussed was salamanders being able to rearrange their cells at their wound sites so they can regrow their body parts.
But enough of that, lets dive into today’s discussion, the taxonomy of the salamander with the help of a phylogenetic tree.Why do we use phylogenetic trees you may ask? Well, we use a phylogenetic tree to demonstrate the evolutionary history of most organisms.
In this phylogenetic tree, the author compared 36 species that fall into the Ambystoma genus. There are several sister groups, and 9 are outgroups. An example of a sister group is the Ambystoma textanum and the Ambystoma barbouri. This phylogeny tree was constructed by comparing morphological characters. What is a morphological characteristic? It is basically the shape or size of an organism. The Ambystoma Annulatum, Ambystoma Cingulatum, Ambystoma Mabeei, Ambystoma Barbouri, and the Ambystoma Texanum were grouped here based on specific characteristics of its skull. In the group containing the Ambystoma Tigrinum, it is branched off based on its geographical location. One thing that unifies the members of this genus together is their ability to regenerate their limbs.
![](https://sites.gsu.edu/fderricott1/files/2019/04/2nd-tree-2675k3b-212x300.png)
https://www.semanticscholar.org/paper/Species-tree-reconstruction-of-a-poorly-resolved-of-Williams-Niedzwiecki/ff86a8cac792c3e9c672c0373794a91560da4c3c
In the picture above, there are two different phylogenetic trees. While looking for a second phylogenetic tree to compare, I noticed that many of the articles stated that Ambystoma has a phylogenetic conflict. To solve or bring light to the situation a group of people came together and made the two trees pictured above. The first tree that is labeled “A” is separated by morphological characters like the very first tree we discussed. There were 32 morphological characters used to compare each Ambystoma. The characteristics included size, the shape of the skull, and spinal muscles. The numbers that are on the branches represent bootstrap values. A bootstrap value is when random sets of data combined with the re-run of phylogenetic analysis are reported as a percentage.
There for the sister group between the Ambystoma texanum and Ambystoma barbouri are well supported at being labeled closely related. In the second phylogeny tree “B” were based on a different hypothesis of Ambystoma. The authors also used morphology to different group Ambystoma. This tree also included the allozyme and mitochondrial sequence-based estimates. There were a total of 26 allozyme characters and the numbers on this tree represented jackknife values. Even though the authors were trying to show the difference in the two trees both still came out very similar.
Well, that’s enough for this week. Be on the lookout for the next post about this unique animal!!!!
References:
- https://www.semanticscholar.org/paper/Species-tree-reconstruction-of-a-poorly-resolved-of-Williams-Niedzwiecki/ff86a8cac792c3e9c672c0373794a91560da4c3c
- http://tolweb.org/Ambystomatidae/15448
- https://books.google.com/books?id=x-ZhDwAAQBAJ&pg=PA48&lpg=PA48&dq=Kraus,+1988;+Shaffer+et+al.,+1991&source=bl&ots=FgqQel4m_r&sig=ACfU3U31stDcvKbiqFujMlXqxH9n7qbVdA&hl=en&sa=X&ved=2ahUKEwir_YWOg7_hAhXvp1kKHYKsCboQ6AEwAXoECAkQAQ#v=onepage&q&f=false