humanimpactevolution

How does Evolution impact Humans today?
Humans have been impacting evolution since the dawn of our existence. we have selected plants and animals for qualities that benefit us the most. We have had a significant impact on how well animals plants and micro-organisms survive. For example, it is widely hypothesized that the reason that there are no large mammals in North America, Australia or Asia, at least large in comparison with the animals in Africa, is because African animals and Humans evolved simultaneously and developed suitable measures of evasion and hunting. When Humans arrived in the heretofore unexplored America's, the animals were quickly over hunted and became extinct. Now we continue to affect evolution. Viruses like T**uberculosis** (TB) and the **Human Immuno-Defficiency Virus** (HIV) are evolving to beat us.

The TB virus evolves according to the anti-biotics being used. This is especially evident in Russia, where inmates in prison are contracting TB. While in the penetentiaries, prisoners take their anti-biotics and the TB virus is killed off. however if a prisoner finishes his sentance and does not finish his course of anti-biotics, then the remaining drug resistant TB virus cells will profligate. Once these multi-drug resistant cells become common, they are very difficult to beat. The Tuberculosis virus is moving very quickly throughout the world because of swift travel and increased contact with more people. Our own systems are working against us to breed these diseases.

Our Infrastructure and technology aren't the only things that work against us. Our own bodies can change viruses at speeds that would knock you dead. **Literally.**

The human immunodeficiency virus is one of the fastest evolving organisms in the world. It reproduces sloppily, accumulating lots of mutations when it copies its genetic material. while this should be a plus in our favor, it means that the virus makes mutations that can help it to live longer, even when it is barraged with medications aimed to fight it. The virus also reproduces at a lightning-fast rate—a single virus can spawn billions of copies in just one day. To fight HIV, Humans must understand its evolution within our bodies, and then ultimately find a way to control its evolution.

HIV, like any evolving entity, has been marked by its history. Scientists studying the evolutionary history of HIV found that it is closely related to SIVs (simian immunodeficiency viruses), which infect primates, and FIVs (the feline strains), which infect cats. However, studies of these related viral lineages showed something surprising: primates with SIV and wild cats with FIV don’t seem to be harmed by the viruses they carry. How did SIV and FIV evolve to be so deadly to humans? If scientists can figure out how non-human primates and wild cats are able to live with these viruses, they may learn how to better treat HIV infections or prevent them altogether.

HIV is by no means the first plague that human populations have weathered. Many pathogens have deeply affected our evolutionary history. In fact, the human genome is littered with the remnants of our past battles with pathogens — and one of these remnants, a mutation to a gene called CCR5, may lead researchers to a new treatment for HIV. The mutant CCR5 allele probably began to spread in northern Europe during the past 700 years when the population was ravaged by what most scientists agree was the bubonic plague. The mutant CCR5 allele confers resistance to HIV. Scientists hope that studying this by-product of past selection will help them develop new treatments for the HIV epidemic that is currently sweeping human populations. When a patient begins taking an HIV drug, the drug keeps many of the viruses from reproducing, but some survive because they happen to have a certain level of resistance. Because of HIV's speedy evolution, it responds to selection pressures quickly: viruses that happen to survive the drug are favored, and resistant virus strains evolve within the patient, sometimes in just a few weeks. However, basic evolutionary theory points out a way that this evolution of resistant viral strains can be delayed. Patients are prescribed "drug cocktails" — several different HIV drugs taken together. When taking any single drug, it is fairly likely that some mutant virus in the patient might happen to be resistant, survive the onslaught, and spawn a resistant lineage. But the probability that the patient hosts a mutant virus that happens to be resistant to several different drugs at the same time is much lower. Although multiple-drug-resistant HIV strains do eventually evolve, drug cocktails delay their evolution.



Through exploring the history of these deadly viruses, scientists can figure out how exactly they evolved, and from there, how humans can evolve to beat them.
Works Cited: http://evolution.berkeley.edu/evosite/relevance/IA2HIV.shtml http://www.understandingevolution.com/evolibrary/article/0_0_0/medicine_04