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Comparative Genomics

Throughout history, scientists have devised various methods to examine and come up with names for different species. However, the most effective method has been the Linnaeus Method, otherwise known as the binomial naming system, developed by Swedish botanist Carl Linnaeus. This method gives each species a unique, two-word Latin name consisting of the genus name and the species name.

Nevertheless, have you ever wondered how scientists and researchers have identified the different taxonomic categories of species? How do we know that a cat belongs to the same family as a lion? We know this due to the comprehensive field of study known as comparative genomics. Comparative genomics is an expansive branch of biological research in which the genome sequences of different organisms are compared and contrasted.

Image courtesy of The Irish Times.

The Purpose/Benefits of Comparative Genomics


Although not well known, comparative genomics can play a revolutionary role in understanding scientific, specifically biological research. Comparative genomics caters as an incredible tool for investigating and understanding evolution. Scientists can comprehensively interpret how the character, demeanour, and biology of living things have changed over time by analyzing the evolutionary conjunctions between species and the reciprocal discrepancies in their DNA.

Understanding the Genome

Furthermore, analyzing DNA sequences that have been preserved in many different organisms for over millennia is a crucial step towards understanding the genome itself. It distinguishes genes that are fundamental for life and highlights genomic signals that command genes across many species. This helps research scientists further understand what genes correlate with various biological systems, which may translate into ingenious approaches for treating human disease and enhancing human health.


As DNA sequencing technology is becoming more influential and inexpensive, comparative genomics is becoming more applicable in fields including agriculture, biotechnology, and zoology to examine the differences between different biological systems. These efforts have elucidated the evolutionary tree, enhanced domesticated animals' health, and mapped out new conservation strategies for rare and endangered species.

The Genome

The concept may be exact, but a significant part of comparative genomics is the genome itself. A genome contains all the information that is needed to build and preserve the organism. It is the complete sequence of DNA containing all the genes. The genome is composed of genes (the coding regions) and noncoding DNA, as well as mitochondrial and chloroplast DNA. The study of the genome is called genomics.

Image courtesy of the National Human Genome Research Institute.

The Difference between the Gene and the Genome

Many are often confused between the terms "gene" and "genome." Genes and genomes are composed of DNA, but the key difference between the two is that genes consist of only enough DNA to code for one protein, while the genome is the total of an organism's DNA. This ideology also applies to the difference between the field of genetics and the field of genomics. Genetics examines a single gene in isolation, while genomics investigates all genes, along with their interaction, to determine how they affect an organism's growth and development.

Results of Comparative Genomics

Comparative genomics has produced impressive results. Researchers use comparative genomics to explore various topics, including human development, metabolism, and disease susceptibility. Behavioural, neurological, developmental, and genetic studies uncover new pathways that are shared or related among species. Some researchers are working to reveal the genomic determinants of disease in animals to gain new insights into human disease development.

The following results have been obtained so far:

  • In comparing the genomes of nearly 50 bird species, bird researchers discovered a gene network underlying bird song, and it may play an important role in human speech. The bird researchers also found gene networks behind traits like feathers and beaks.

  • A study showed that about 60% of human and fruit fly genes are conserved, meaning that the two species share the same set of genes—two-thirds of human genes known to cause cancer to have fruit fly counterparts.

  • Researchers at the National Human Genome Research Institute (NHGRI) have undertaken research in recent years that examine the genomics of various cancer types in dogs and common types of cancer and other diseases to help us develop new insights into the human form.

  • Researchers have discovered a gene that makes cows more likely to produce high-fat milk, which could lead to a significant increase in revenue. This is one of many studies that aim to increase food production.

  • Comparative genomics analysis of six yeast species led to scientists revising their catalogue of yeast genes and predicting a new set of functional elements that play a role in regulating genome activity. This analysis applies not only to yeast but also to other species of organisms.

  • Scientists discovered genes that increase muscle mass in cattle by twofold; they found the same genes in racing dogs, and these results could influence human performance research.


Comparative Genomics Fact Sheet. (2020). National Human Genome Research Institute.


Comparative Genomics. (2007). National Human Genome Research Institute.


WHO definitions of genetics and genomics. (n.d.). World Health Organization.



Genetics VS. Genomics. (n.d.). The Jackson Laboratory. https://www.jax.org/personalized-


DNA. (2004). J. Craig Venter Institute. http://www.genomenewsnetwork.org/resources/



Article Author: Risheena Banerji

Article Editor: Olivia Ye