Final answer:
Horizontal gene transfer (HGT) is a natural occurrence in which foreign DNA is transferred between different species, allowing for genetic diversity and evolution. Examples include gene transfers between various plant species and fungi acquiring genes to synthesize paclitaxel.
Step-by-step explanation:
The transfer of foreign DNA from one species to another does indeed occur in nature. This process, known as horizontal gene transfer (HGT), allows for the sharing of genetic material between different species, which can even include eukaryotic species. Examples of HGT include transposons or "jumping genes" that have facilitated gene transfer between plant species such as rice and millet, and in the case of fungi that feed on yew trees, the acquisition of genes to produce the anti-cancer drug paclitaxel. Moreover, the DNA-based studies often show genetic admixture, hybridization, and adaptive introgression, which are all processes that result in the exchange of genetic material across species, influencing their evolution and adaptation.