Reconstructing the History of life a Genetic Approach

Humans have always been curious about the origins of life on earth. Many theories and explanations have been offered over the course of human history. When Darwin and Wallace first presented the theory of evolution by natural selection, it led to a great deal of controversy. However, today there is indisputable evidence for this theory. Evolution, according to Darwin, proceeded through ‘Descent with modification’, which simply denoted the passing of traits from parent to offspring, albeit imperfectly. Offspring, while being largely similar to their parents, may show some differences. Over time, these differences may be selected and result in a divergence strong enough for a new species to be formed. This new species is still related to the older one since it is derived from it. Just like my cousin and I share a common ancestor in the form of a grandfather, species too share common ancestors with other related species. Going sufficiently far back in time, we can actually trace the ancestor for all life on earth (about 3.8 billion years ago). Therefore, we can reconstruct the history of life on earth by carefully reconstructing relationships between species. Phylogenetics is the field of biology that focuses on the reconstruction of relationships between different species, and the reconstruction of the evolutionary history of lineages