We have entered cold and flu season. This time of the year a lot of attention is focused on why some viral strains can be so deadly while others elicit a relatively minor response.
To address this question, researchers from the University of Wisconsin at Madison used the type I herpes simplex virus (HSV-1) as a model system.1 Though not responsible for the common cold, this virus serves as an excellent case study because some strains cause oral mucocutaneous lesions (cold sores) and others cause deadly encephalitis.
To better grasp the relationship between virulence and genetic make up, the researchers sequenced and compared the entire genomes (consisting of about 152,000 base pairs, or genetic letters) for 31 different HSV-1 strains collected from around the world. The scientists discovered that the viral strains clustered into six groups that corresponded to different parts of the world. The groups labeled III, IV, V, and VI consist of strains found in East Africa. These groups tend to be the most diverse and appear to be the oldest. It seems as if the HSV-1 virus had its origin in East Africa. Meanwhile, group I locates to Europe and North America and group II pinpoints to East Asia.
Using molecular clock analysis, the researchers estimated the strains outside of Africa arose around 50,000 years ago (± 17,000 years) and the European and North American strains separated from the East Asian strains about 33,000 years ago (± 11,000 years). They also discovered a strain that they interpret to be of Amerindian origin that arose about 16,000 years ago (± 5,000 years).
The geographic distribution and time scale for the origin of the various viral strains corresponds closely to the results of human genetic variability studies that track the origin and spread of humanity around the world. For more on these previous studies, check out the following articles:
Anthropologists interpret the results of these studies as support for the Out-of-Africa hypothesis. Briefly, this model (also called the replacement model) maintains that modern humans evolved recently (about 100,000 years ago) in East Africa from a small hominid population and then migrated around the world to replace pre-existing hominids.
Though often presented and discussed within the context of the evolutionary paradigm, this model has profound biblical implications. If humanity’s genesis happened in the way Scripture describes it, then genetic diversity patterns observed among people groups around the world would be very similar to those discovered by anthropologists.
The agreement between the genetic variability pattern of the HSV-1 strains and human genetic variability provides independent support for the Out-of-Africa model (and consequently for the biblical account of humanity’s beginnings). This not the first study of its type. Researchers have also been able to trace the origin and migration patterns of humanity using several other types of human pathogens and parasites. For relevant discoveries, check out the following articles:
- “Diseases Follow Human Origin and Spread”
- “Scientists Send Note Home: Source of Ancient Lice Outbreak in America Uncovered”
As researchers continue to study our origin using the human genome and the genomes of human surrogates, such as HSV-1, the scientific credibility of Genesis 1 and 2 continues to advance. And that is nothing to sneeze at.