About 25,000 years ago in what is now southwestern France, human beings walked deep into a cave and left their enduring marks and art. Using materials like sticks, charcoal and iron oxides, they painted images of animals on the cave walls and ceilings. Animals such as lions and mammoths and spotted horses, walking and grazing and congregating in herds. For years scientist have thought these images were just idealized representations. But due to the study of comparing horses DNA of today to the DNA of the prehistoric ones, the cave paintings were accurate. People of those times actually painted what they saw. From the study, scientists have also found that there were really only three color patterns, spotted or dappled; blackish ones; and brown ones.
As techniques for working with ancient DNA have matured, scientists are now using it to answer an increasing variety of questions about the past from what happened to a species’ genetic variation as its environment changed to how humans recolonized Europe after the last ice age to what type of microbes lived in the guts of people and animals thousands of years ago.