The diversity and unity of life are equally significant and surprising aspects of our Earth (Dobzhansky, 1973). Although a staggering 1.2 million species have already been identified, it is estimated that another 8.7 million have yet to be discovered and classified (Mora et al., 2011). By understanding what unites us – our genes – our understanding of the organisms we share our planet with will continue to grow. Genomic sequencing is the process of determining the precise order of nucleotides within a DNA molecule. It includes any method or technology used to determine the order of the four DNA bases – thiamine, adenine, guanine, and cytosine – in the DNA strand (NHGRI, 2011). In each organism, these bases are arranged in a unique and specific sequence, and it is this sequence that constitutes the genetic code of the organism. Genomic sequencing has impacted nearly every field of biological research, including human genetics and genomics, plants and agriculture, microbes, medicine, viruses and infectious diseases, environmental genetics, and evolutionary biology. By first examining the development of gene sequencing technology we will be able to see its role in evolutionary biology, its contribution to phylogenetics, and how it has changed our understanding of the biological tree of life. Development of Gene Sequencing Technology Most of the scientific work in genetics and genomic sequencing has been done over the last 155 years. In 1859, Charles Darwin published The Origin of Species in which he proposed evolution by natural selection. Evolution is the change in the hereditary characteristics of biological populations over successive generations. However, the principles of genetics needed to explain how traits are… middle of paper… a tremendous amount of information in many biological processes, our phylogenetic relationships, and our evolution (NHGRI, 2011). Successful sequencing of complete genomes has provided us with a virtual map of many organisms (Zhaurova, 2008). This result should not be seen as an end in itself, but rather as a starting point for further research. The future promises further advances in genetic and evolutionary biology and other areas of biology, science and technology. Armed with accumulating genomic sequences, researchers are now trying to unravel some of the most complicated processes in biology (NHGRI, 2011), such as discovering the genomic events that led to the formation of early life and the development of new species (Hudson , 2008). As the complexity and enormous amount of genomic information grows, so will our understanding of the evolution of life on Earth.