Guest
A phylogenetic tree is a diagram used to show how organisms are related to one another. There are actually a lot of different ways to make these trees! As long as you have something you can compare across different species, you can make a phylogenetic tree. A phylogenetic tree can be built using physical information like body shape, bone structure, or behavior. Or it can be built from molecular information, like genetic sequences. In general, the more information you’re able to compare, the more accurate the tree will be. So you’d get a more accurate tree by comparing entire skeletons, instead of just a single bone. Or by comparing entire genomes, instead of just a single gene. Any DNA, RNA, or protein sequence can be used to generate a phylogenetic tree. But DNA sequences are most commonly used in generating trees today. Any DNA, RNA, or protein sequences can be used to draw a phylogenetic tree. But DNA sequences are the most widely used. It’s pretty cheap and easy now to get DNA sequences. Plus DNA contains more information, which can make more accurate trees. For example, some changes in DNA sequences do not lead to changes in proteins. To construct a tree, we’ll compare the DNA sequences of different species. Evolutionarily related species have a common ancestor. Before they split into separate species, they had exactly the same DNA. But as species evolve and diverge, they will accumulate changes in the DNA sequences. We can use these changes in the DNA to tell how closely related two species are. If there aren’t very many differences, they’re probably closely related. If there are a lot of changes, they might be more distant relatives. The first thing to do is align the two DNA sequences together that you’re going to compare. Make sure you’re comparing the same gene! (Or other sequence.) Otherwise you are comparing apples to oranges. This sequence alignment is often done with the help of computer programs. The strategy is to find the alignment that has the most matches and the least mismatches. #species #genus #phylum #kingdom #phyliogeneticTree #Evolution #speciation #diagram #branchingInAPhylogeneticTree #Genetics #bilology #taxonomy #cladogram #populationGenetics #hawaiiIslands #founderEffect #geneticDrift #geneticVariation #taxa #clade #Paraphyletic #Monophyletic #Polyphyletic #bioinformatics
