GN 311 Exam 5-1A скачать в хорошем качестве

GN 311 Exam 5-1A

Jacob Philbeck Lecture slides https://www.nature.com/scitable/topic... https://hastyreader.com/anagenesis-cl... This is Exam 5-1A. A phylogenetic tree is a diagram that displays evolutionary relationships between organisms. They are graphical representations of the similarities between operational taxonomic units, also known as OTUs. An OTU can be any individual organism or group of organisms as well as a strain of a virus or even different alleles within a species. In this example, we will be observing different types of drinks as our OTUs. This phylogenetic tree is a rooted tree which means all drinks will be compared to the outgroup, which is water as you can see on the bottom line of the diagram. Water is the outgroup because it diverged long before the others. The node where water diverges shows that all other drinks have a common ancestor. At the first node the drinks diverge into carbonated and non-carbonated drinks. At the top, carbonated drinks will diverge into alcoholic and non-alcoholic drinks. At the last internal node, the alcoholic drinks will diverge into beer and liquor. After seeing one path through, you can see how at each branch the drink is becoming less related to water, which is the root common ancestor. Below, we can see that non-alcoholic drinks diverge into soft-drinks and energy drinks. Then, if we go back we can see that non-carbonated drinks will branch into fruit juice and dairy product. Fruit juice will branch into apple juice and orange juice. Dairy product will branch into milk and creamer. After analyzing the diagram we can understand the relatedness between all OTUs. At each node, which is represented by the yellow highlighter, there is a common ancestor that divides into two OTUs. This is also referred to as cladogenesis where a new group of OTUs is formed through evolutionary splitting. Through cladogenesis we are able to see which OTUs are most similar. For example, we want to know if milk or soft drinks are most similar to orange juice. We can see that milk and orange juice's most common ancestor are non-carbonated drinks, but soft drink and orange juice's most common ancestor is water. which is the root of them all so we can see that milk and orange juice are most related.