The discovery of giant viruses led to evidence that viruses may actually meet all characteristics of life. These viruses encode for more than 1,000 genes and are even parasitized by smaller viruses, like the

Fossils of ancestors of the modern horses show a small 4-toed almost dog-like browsing animal named eohippus over time the horses got larger lost toes and changed to a grazing diet what is the best explanation of why this change occurred