Could someone kindly explain me the difference between Phylogeny, Phylogenetic Tree, Evolutionary Trees, Phylotype, Clusters, OTU (Open Taxonomic Units). Or if possible please do suggest me a beginner's book on that said topics.
Source of information
Understanding Evolution is a free online introductory course of evolutionary biology that will probably answer these questions.
Wikipedia will also make a decent job at answering your questions.
Any introductory book to evolutionary biology would do it.
To answer your question
- phylogeny = phylogenetic tree = evolutionary tree: evolutionary relationship between lineages
- phylotype: An observed morphological similarity that is used to classify a group of organisms.
- OTU: An observed genetic similarity that is used to classify a group of organisms.
Both OTU and phylotype are often used for asexual lineages where the concept of species poorly apply. See more info on the concept of species here.