Genetic Material

 Phylogenetics is the area of research concerned with finding the genetic connections and relationships between species. The basic idea is to compare specific characters (features) of the species, under the natural assumption that similar species (i.e., species with similar characters) are genetically close. The term phylogeny refers to these relationships, usually presented as a phylogenetic tree (see below).Classic phylogenetics dealt mainly with physical, or morphological features - size, color, number of legs, etc. Modern phylogeny uses information extracted from genetic material - mainly DNA and protein sequences. The characters used are usually the DNA or protein sites (a site means a single position in the sequence) after aligning several such sequences, and using only blocks which were conserved in all the examined species.An interesting example is a research project that used phylogenetics in order to trace the origins of the human population on earth. Researchers investigated the mitochondrial DNA of 182 people all over earth (the mitochondrial DNA is especially good for phylogenetic research since it is copied completely from mother to son, without recombining with the father's DNA). The phylogenetic analysis provided evidence that all humans have a common female ancestor who lived in Africa. When studying phylogeny using nuclear genes, we encounter a serious problem.