How to compare genetic diversity

Genetic biodiversity can be assessed by calculating the percentage of gene variants (alleles) in a genome within isolated populations. A high genetic biodiversity means there is a large variety of alleles in the population's gene pool.

Measuring genetic diversity also allows quantification of diversity within and between species.

Genetic diversity can be compared by:

1. Comparing the frequency of measurable or observable characteristics.
2. Comparing the base sequence of DNA.
3. Comparing the base sequence of mRNA.
4. Comparing the amino acid sequence of the proteins encoded by DNA and mRNA.

Using observable characteristics to measure genetic diversity

Traditionally, genetic variation was assessed by examining observable phenotypic traits.

However, this method has its limitations:

• Traits are often polygenic - This means they are influenced by several genes, which makes it challenging to separate the influence of individual genes.
• Environmental factors can alter traits - This leads to variations that are not genetically based.
• Traits may change gradually across a range - Traits not falling into distinct categories makes them difficult to differentiate.

Height in humans is an example of continuous variation where multiple genes contribute to the trait, but environmental factors like nutrition also play a significant role.

Using comparative biochemistry to measure genetic diversity

Comparative biochemistry involves studying the molecular aspects of organisms to uncover genetic diversity.

For instance, DNA sequencing allows direct observation of DNA base sequences, providing a more accurate measure of genetic diversity.

Useful molecules to compare genetic diversity:

• DNA - Populations that are more genetically diverse will have more differences in their DNA sequences.
• Messenger RNA - Base sequences of mRNA are complementary to DNA so can assess genetic diversity.
• Amino acids - Populations that are more genetically diverse will have more differences in their amino acid sequences because they are determined by mRNA and DNA.