Phylogenetics, translating roughly from the Greek phylon (race) and genetikós (origin) is the study of how living organisms are intertwined and inter-related in regards to evolution. You can picture your family as a tree, with parents, grandparents, cousins, and distant relations all forming the branches. Phylogeneticists attempt to map the evolutionary relationships between all living creatures in a similar family tree, as all living things stem from a common set of ancestors, likely single-celled organisms, which lived billions of years ago. However, this is difficult, because many branches on the tree have not yet been discovered, and may never be.

Scientists must use mathematical models in order to create the family tree with the likeliest probability of correctness given the information they possess. This use of mathematics to calculate the tree is known as computational phylogenetics.

The history of phylogenetics goes back as far as the history of evolution. Early figures include the ancient Greek philosopher Anaximander who lived around 500 BC and proposed the first fledgling ideas on evolution, as well as William of Ockam, a 14^th Century monk who is credited with defining parsimony. Parsimony, also known as Occam's razor-which says that the shortest explanation for something is the best one-is one of the methods used by phylogeneticists today to narrow down the most likely evolutionary tree.

Charles Darwin is universally known today as the man who discovered evolution. He drew an early evolutionary tree in his notebooks. Other precursors which paved the way were two Germans-Heinrich Georg Bronn, a paleontologist born in 1800, and Ernst Haeckel, a biologist born in 1834. Haeckel was important to the early growth of the discipline, but he also made one major blunder which has since been dismissed. This blunder was a theory called the "biogenetic fundamental law," which hypothesized that the growth of a single organism from infancy to maturity reflected the evolution of that organism's species over the millennia. In other words, that human beings evolved from creatures which resembled fetuses or embryos. This theory has since been disproven.

The mid-1900s saw the most advancements in phylogenetics. These include term "cladistics," which involves sorting organisms along shared traits, and "implied weighting," or giving the most categorical importance to homologous traits-or traits which are shared among creatures in the same category. For example, whale flippers and human arms share very similar bone structures, leading scientists to believe they had a common ancestor at one point.

Today, phylogenetics is aided by computers to create advanced models of life on Earth which includes genetic rRNA data along with visible traits. The tree is split into three major branches-the first two are Bacteria and Archaea, which include microscopic organisms too numerous to list. The third branch, Eukaryota, contains all other creatures, including animals, fungi, plants, and some microscopic organisms. Through the mechanisms provided over the history of phylogenetics, scientists may one day be able to create a full picture of life on Earth, and perhaps even figure out how life came to be in the first place.

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