Virus Evolution

HIV is a reverse-transcribing, single-stranded positive-sense RNA virus, belonging to family Retroviridae. It brings along the enzyme reverse transcriptase (RT) when entering the cell. Reverse transcriptase facilitates reverse transcription - the process through which the enzyme generates complementary DNA (cDNA) from a template RNA strand. HIV's reverse transcriptase enzyme generates complementary DNA from the virus' RNA genome. The cDNA recombines with the host cell's DNA and remains dormant/non-active.

Proviruses can sometimes infect a germ cell. Since germ cells produce gametes, the viral DNA can be passed on to the future generation of offspring. (ADD THIS?)

https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/retroviridae#:~:text=Introduction,hence%20the%20name%20'retroviruses'.

Horizontal transfer occurs when the genetic information of one organism is horizontally passed on to an organism of a different species. In fact, 5-8% of the human genome is from ancient retroviruses which incorporated their DNA into the normal cell DNA (known as endogenous retroviruses). As a virus (specifically a retrovirus which incorporates itself into the cell's DNA) mutates and passes onto another species, it will carry its viral DNA along with historic cell DNA. This virus is essentially cutting an organism's DNA and passing it onto another organism. Horizontal transfer is significant because it increases diversity within population and encourages evolution.