Comparative Genomics consists in the comparison of the genomes of different species. It is a powerful tool as it can give scientists insights about which genes they might find in an organism they are studying by simply looking at the genome of related species.
It can also help scientists better understand the mechanisms of evolution and adaptation.
Origin of Life, Evolution
In fact, the evolutionary history of a species depends on its adaptation to the environment; this adaptation depends on the plasticity and the variability of its genome. This plasticity is allowed by mutations that take place randomly in the genomes of individuals (according to the actual theories of evolution). Some mutations are conserved particularly if they provide an advantage to the individual that bears them.
Comparing the genomes of closely related species but that live in different environments enables to understand the plasticity of genomes, what their strategy of adaptation is.
Tree of life presenting eukaryotic lineages issued from molecular and structural data
Document extracted from S. L. Baldauf, Science, 2003 (vol. 300)
As far as evolution, understanding how an organism adapts to new conditions can help us understand how we, humans have appeared. One capital event in the history of evolution of development is the appearance of the bilateral symmetry axis. 99% of animals on earth have this kind of symmetry including humans and among the 1% left, most have a radial symmetry. Comparing the genomes of species that have a different symmetry can allow scientists to understand the big steps of evolution.
