Difference Between Genetic Distance and Physical Distance

The key difference between genetic distance and physical distance is the type of sequence used in analyzing the distance between two populations of the same species. Genetic distance measures the genetic divergence between species or between populations within a species while physical distance measures the number of nucleotides between the two markers.

Genetic distance and physical distance provide an insight into the evolutionary relationships between two populations of a species. Therefore, distance maps provide linking of populations based on genetic data. Genome sequencing and bioinformatics analysis play an important role in determining both genetic and physical distances.

CONTENTS

1. Overview and Key Difference
2. What is Genetic Distance 
3. What is Physical Distance
4. Similarities Between Genetic Distance and Physical Distance
5. Side by Side Comparison – Genetic Distance vs Physical Distance in Tabular Form
6. Summary

What is Genetic Distance?

Genetic distance is the measure of the genetic divergence between species or populations. This distance is measured using ancestral relationships and evolutionary patterns. The similarity between genes is important in the measurement of the genetic distance. Genetic distance also defines the distance of the species to its ancestor. Moreover, the main usage of genetic distances is in the evaluation of the relationships between populations across the world. Therefore, it relates the human species populations across the world based on their genetic patterns.

The calculation of genetic distances takes place by finding the genetic similarity of species and populations as a whole. Therefore, bioinformatics plays an important role in the determination of the genetic distance between different species and populations.

Moreover, there are different models that are representatives of the genetic distances between populations. They include the Nei’s genetic distance, Cavalli-Sforza and Edwards measure and Reynolds, Weir and Cockerham’s genetic distance.

What is Physical Distance?

The physical distance is the measurement of the number of nucleotides between two species or populations. Thus, in calculating the physical distance, the measurement level goes further into monomeric levels. This involves analyzing individual nucleotide sequences or entire genomes as a whole. The physical distance between marker genes plays an important role in determining the number of nucleotides between them.

Therefore, if the physical distance between two populations increases, the genetic distance also increases. This may, in turn, increases the complexity of the organisms as well. Both genetic distance and the physical distance together build an evolutionary relationship between two populations.

What are the Similarities Between Genetic Distance and Physical Distance?

• Genetic distance and physical distance determine the evolutionary relationships between two populations of a species.
• Both use bioinformatics and sequencing data to analyze the distances.
• They are accurate techniques in suggesting evolutionary and ancestral relationships.
• Moreover, an increase in one will increase the other.

What is the Difference Between Genetic Distance and Physical Distance?

The key difference between genetic distance and physical distance relies on the type of sequences used in deriving the distance map. Genetic distance is the distance between two populations concerning a genetic divergence while physical distance measures the nucleotide distances between two populations.

The below infographic represents more information regarding the difference between genetic distance and physical distance.

Summary – Genetic Distance vs Physical Distance

Genetic distance and physical distance are both suggestive of the evolutionary and ancestral relationship between two populations of a species. Therefore, both are important to arrive at a conclusion regarding evolutionary distances. Genetic distance refers to the distance between two populations with respect to specific genetic markers while physical distance refers to the distance between nucleotide sequences flanking the selected marker genes. Thus, this is the key difference between genetic distance and physical distance.

Reference:

1. Beaumont, Mark A., et al. “Measuring Genetic Distance.” SpringerLink, Springer, Dordrecht, 1 Jan. 1998, Available here.
2. “Physical Distance in Genetics.” Elibrary, Available here.

Image Courtesy:

1. “The history and geography of human genes Luigi Luca Cavalli-Sforza map genetic” By Blank_map_of_world_no_country_borders.PNG: Ephert (talk)derivative work: Ephert (talk) – (CC BY-SA 3.0) via Commons Wikimedia

ncG1vNJzZmivp6x7pbXFn5yrnZ6YsqOx07CcnqZemLyue8OinZ%2Bdopq7pLGMm5ytr5Wau26zxKecraGTYrGqv9OapZydXZa7pXnPobCsoZOWuW6wyKyrmqaTmnw%3D