CNN —Zoologists and disease experts have told CNN that changes to human behavior — the destruction of natural habitats, coupled with the huge number of fast-moving people now on Earth — has enabled diseases that were once locked away in nature to cross into people fast.
Scientists are still unsure where the virus originated, and will only be able to prove its source if they isolate a live virus in a suspected species — a hard task.
But viruses that are extremely similar to the one that causes Covid-19 have been seen in Chinese horseshoe bats. That has led to urgent questions as to how the disease moved from bat communities — often untouched by humans — to spread across Earth. The answers suggest the need for a complete rethink of how we treat the planet.