Paleogenomics

Article By:

Organ, Chris Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts.

Last reviewed:2008

DOI:https://doi.org/10.1036/1097-8542.YB081330

Genomics is the study of the organization, structure, and function of the total complement of genes and other DNA within the cell(s) of an organism. This term usually refers to the haploid (possessing a single set of unpaired chromosomes) nuclear DNA content in eukaryotes. Genomics can be differentiated from genetics (along a continuum), with the former concerned about the function and interaction of multiple genes, noncoding DNA [such as introns (segments of DNA that do not encode part of the gene's protein and are spliced out of messenger RNA in processing) and intergenic DNA (DNA sequences located between gene clusters)], and genome architecture. The latter is concerned mainly with a single gene and its products. Following this scheme, paleogenomics focuses on recovering and understanding the genomic information in long extinct species. Strictly defined, paleogenomic research must include original fossil remains as its primary data source. Therefore, the term “paleogenomics” should not be applied to comparative genomic studies that infer ancestral patterns or character states from living species alone. Investigations into the genomes of recently extinct organisms are more properly termed “archeogenomics” or “ancient DNA studies.” Because the field of genomics is focused on living organisms, it is concerned with only a fraction of the genomic novelty that has evolved. Insights from paleogenomic research are therefore indispensable for a thorough understanding of the nature and evolution of the eukaryote genome.

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