- #1
SpaceGuy50
- 25
- 0
Did viruses exist before bacteria ever existed on Earth?
mgb_phys said:No, viruses (virii?) need bacteria to live.
They probably evolved from parasite bacteria or even from bits of raw nucleic acid that got out of bacteria cells.
They need cells and the only cells around at the time were bacteria. Virus now infect just about everything.Phrak said:That's a new one on me. They simply need some other living organisms to proliferate, don't they?
mgb_phys said:They need cells and the only cells around at the time were bacteria. Virus now infect just about everything.
They do have some good points, they swapped a lot of genes with early cells and may even have contributed to inventing sexual reproduction.Phrak said:It becomes a predator, or parasite upon the relatives from which it sprang.
mgb_phys said:They do have some good points, they swapped a lot of genes with early cells and may even have contributed to inventing sexual reproduction.
mgb_phys said:No, viruses (virii?)
Phrak said:Do I have this right? Do all viruses require the DNA or RNA of another organism to synthesize molecular elements to construct their own structure?
jamesv87 said:Viruses require the molecular machinery and building blocks of another organism to replicate (i.e. enzymes, nucleotides, amino acids). They provide their own DNA or RNA. To address the original question, almost by definition "bacteria" would have to have existed before any phage (a bacterial virus) because of a phage's inability to independently self-replicate. However, it seems logical to me that the earliest true viruses probably showed up very early on, taking the form of self-replicating genes that could insert themselves into the nucleic acid polymers of early protocells. Today, these self-replicating genes are known as transposons and are found in all forms of life. In my opinion, bacteriophages, viruses, and plasmids probably evolved from these early "genetic parasites".
There is still debate among scientists about the origin of viruses and their relationship to bacteria. Some researchers believe that viruses and bacteria evolved together and have always existed alongside each other. Others suggest that viruses may have emerged before bacteria, possibly even predating the split between prokaryotes and eukaryotes.
The exact origins of viruses are still a mystery, but one theory suggests that they may have evolved from small pieces of genetic material that were able to move between cells. These genetic elements may have gained the ability to infect and replicate within host cells, eventually giving rise to the diverse array of viruses we see today.
Unlike bacteria, viruses cannot survive or replicate outside of a host cell. They are considered obligate intracellular parasites, meaning they require a host to carry out their life cycle. Outside of a host, viruses are essentially inert and do not exhibit characteristics of living organisms.
Some scientists believe that viruses may have played a significant role in the evolution of bacteria. Viruses can transfer genetic material between bacterial cells, leading to genetic diversity and potentially driving evolution. Additionally, some viruses can infect bacteria and alter their behavior, potentially influencing their evolution.
Viruses and bacteria can interact in various ways. Some viruses are able to infect bacteria, while others can transfer genetic material between bacterial cells. Additionally, bacteria have evolved various defense mechanisms against viruses, such as CRISPR-Cas systems. The relationship between viruses and bacteria is complex and continues to be an area of active research.