![]() Except for the fish and the frog, all have amniotic eggs, or eggs featuring a membrane structure called the amnion. The platypus, elephant, and kangaroo all have hair and feed their young milk. For example, all six have internal bony skeletons. What sort of characteristics do they exhibit? While they all have very different overall appearances, some of the animals nevertheless share features in common. Consider the group of six vertebrates (animals with backbones) shown above. In an analysis featuring morphological data (broadly defined), the features of the group of taxa to be analyzed are studied and categorized. The phrase "morphological data," however, is often used to encompass a variety of user-delimited characters, such as morphological, anatomical, developmental, and life history data, as well as sometimes chemical characters and other types of data. Technically, morphology (from the Greek morphe = form or shape) is the study of form. Broadly speaking, however, most analyses use one of two types of data. Characters may include anatomical/morphological features, developmental and life history traits, chemical characters, proteins, amino acids, DNA sequence data, etc. One function of an outgroup is to root a phylogenetic tree, or establish where the base of the tree is. Let us consider our outgroup to be represented by an angel fish.Ĭhoosing the characters and building the matrixĪfter the taxa have been chosen, the characters to be analyzed must be selected. ![]() Taxa thought to be closely related to the ingroup are typically selected as outgroup taxa. As the word suggests, outgroup taxa fall outside the group of interest. In addition to an ingroup, one or more taxa representing the outgroup are also typically selected. Others might be poorly known or not well represented in natural history collections. For example, some species might be endangered or live in areas that are not easily accessed. Practical considerations, however, often limit our ability to sample an ingroup as much as we might prefer. If a broader ingroup–such as a phylum of animals–is studied, representatives of each major subgrouping (e.g., one species from each family) should be included. If one genus of plants is analyzed, an attempt should be made to include every species in that genus. He was an executive committee member of the British Society for Matrix Biology.Ideally, the ingroup should be taxonomically sampled as completely as is feasible. Dr Kafienah holds 3 patents that resulted recently in a University of Bristol spin-out company ( Azellon Cell Therapeutics). The team is building on this work by investigating the more versatile pluripotent stem cells. That work lead to significant public (see BBC news story “ New hope for arthritis sufferers”) and scientific interest ( Arthritis and Rheumatism Journal) and earned him the prestigious Garrod Prize 2008 awarded by the British Society of Rheumatology. He has many years of experience in the UK and US developing methods for cartilage tissue engineering using stem cells. Group: Pluripotent and Embryonic Stem Cells Backgroundĭr Wael Kafienah leads a team focused on understanding the molecular biology of stem cells for applications in skeletal tissue engineering.
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