Simply defined, genomics is the study of an organism’s set of genes and their functions. An organism’s genome could be considered its instruction manual, and genomics is the science of reading and interpreting that set of instructions. The information contained within an organism’s genome controls every aspect of its life, including growth, maintenance, and development, and for humans, it includes instructions on behavior, physiology, and susceptibility to some diseases. This is not to say that the environment does not count. We are only beginning to unravel the complexities of the interplay among genes and environmental exposures involved in growth and development and the occurrence of disease. On the genetics side, genomic scientists analyze the function of genes within an organism to determine how the genes determine or influence phenotypic outcomes. The study of human genomics will be applied in areas of research such as biological evolution, human migration, molecular medicine, and a vast array of other disciplines.
The field of genomics encompasses many areas of science, because it involves the smallest building block of life, DNA. Genes contain DNA, chromosomes contain genes, and genomes are comprised of all these levels of genetic structure. Almost every cell within an organism contains its unique genome. Genomes can be categorized by individual and by species. Each species has a unique genome, and every individual or organism within that species has certain derivations of that genome. Genomes of individuals within a species are similar enough that it is only necessary to study one or a few genomes to glean information for the population.
Some question why it is necessary to know the entire sequence of a genome instead of simply determining the sequence of individual genes. Not every gene is recognizable. Knowing the full sequence of a genome will help scientists determine what sequence is an actual gene and also allow them to examine how the whole genome works and how genes work together. In addition, knowledge of the entire genome sequence will help scientists study those areas that do not code for proteins in order to determine their importance and function.
Now that the Human Genome Project has published the full sequence of the human genome, scientists will begin to examine the variations among species closely and distantly related to humans. Studying the genomes of organisms distantly related to humans will provide information on species evolution. Sequencing and examining the genomes that are closely related to human, like that of the chimpanzee, with which we share 98.8% identity, could tell scientists exactly why we are different. Comparing the two genomes may show why the physical and mental development of humans is so much more advanced than that of chimps.
Along with studying the variation between species, the differences in the genomes of humans will be a tremendous tool for medical genetics, forensic anthropology, agriculture, and many more disciplines. For molecular anthropologists, genomes contain the history of the human species. Genomic studies can provide historical information on the migration and mating patterns of human populations. Genomics is also a tool for molecular geneticists studying human diseases and complex traits like personality. Scientists believe that slight variations between human genomes can make one individual have a higher or lower risk for heart disease, different forms of cancer, or Alzheimer’s disease. Genomics will be an invaluable tool for all of science in the years to come. One can only hope that the real benefits of genomics for humankind will outweigh the effects this advancing knowledge is bound to have in terms of ethical issues, such as who will have access to its application in medicine and to the information derived there from.
References:
- Brown, T. A. (2002). Genomes. Hoboken, NJ: Wiley.
- DeSalle, R., & Yudell, M. (2005). Welcome to the genome: A user’s guide to the genetic past, present, and future. Hoboken, NJ: Wiley.
- Inlow, J. K., & Restifo, L. L. (2004). Molecular and comparative genetics of mental retardation. Genetics, 166, 835-881.
- Smith, G. (2005). The genomics age: How DNA technology is transforming the way we live and who we are. New York: AMACOM.
