What is the primary purpose of DNA hybridization in biology?

The primary purpose of DNA hybridization in biology is to measure genetic relatedness between species. This technique involves the pairing of complementary DNA strands from different organisms to form hybrids. The degree of hybridization can provide insights into how closely related two species are at a genetic level. If the DNA from two species can hybridize extensively, it indicates that they share a more recent common ancestor and have more similar genetic sequences.

In contrast, determining the age of fossils typically relies on techniques such as radiometric dating rather than DNA hybridization. While assessing genetic diversity can involve various molecular techniques, it does not specifically focus on the hybridization of DNA. Lastly, while DNA hybridization may play a role in research related to genetic traits and breeding, it is not primarily aimed at enhancing plant breeding techniques as other methods like marker-assisted selection are more commonly employed for that purpose. Thus, the measurement of genetic relatedness is the most direct application of DNA hybridization.