Biology Genetics 

Did Life On Earth Start as an RNA World?

By Emily Bentley You might not speak Latin, but you probably understand the concept of omnis cellula e cellula—all cells come from other cells. For several thousand years, many scholars endorsed the idea of spontaneous generation, which held that certain plants and animals are created whole from inorganic matter like dust, mud, or rotting meat. In 1668 this notion was disproved by Italian physician and biologist Francesco Redi. His experiments showed that maggots appeared only on meat that had been exposed to egg-laying flies, providing some of the first evidence…

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Viral DNA: Photo courtesy of Amanda Mills via the CDC Biology Health 

Virus DNA in Humans: What’s in Your Genes?

We all carry remnants of DNA from viruses that infected our ancestors millions of years ago. In fact, all mammals have virus DNA in their genes, but the human species has far less, according to a new study. Why? The reason could be that humans were exposed to fewer blood-borne viruses as we evolved to use tools, rather than our teeth for hunting and fighting. If you’re surprised to learn that we do have some virus DNA in our genes, don’t panic. It’s normal. Despite natural defense systems, a retrovirus…

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