An
archaeologists is a scientist who studies human history by discovering and examining human remains and artifacts. The most common image of an archaeologists is someone on their hand and knees digging through dirt, carefully using a brush to dust off an artifact from the distant past. A
geneticist, on the other hand, is someone who specializes in the science of genetics. This field of biology deals with the pattern of inheritance, molecular structure and function of genes, and gene behavior in context of a cell or organism. Both professionals are highly skilled, and use the same basic principles of science to test hypotheses, gather data, and make conclusions. However, why do archaeologists and geneticists sometimes reach different conclusions about human evolution?
Although they are both considered
anthropologists, archaeologists and physical anthropologists specializing in genetics examine very different types of evidence to study human evolution. Archaeologists deal with fossil bones and artifacts, which are rare and are only found at a few locations. Sophisticated dating methods used by archaeologists help place surviving fossils and artifacts in a chronology that can inform conclusions about the course of human evolution.
Physical anthropologists who specialize in molecular genetics, in contrast, draw on enormous samples of genetic material in living human beings. They study mitochondrial deoxyribonucleic acid (DNA), or mtDNA, a type of genetic material that mutates very quickly. By analyzing the mtDNA of two populations, geneticists can determine whether the populations are closely related. Based on an estimate of the rate of expected mutation in the mtDNA, they can calculate when the two populations shared a common ancestor, the so-called
Mitochondrial Eve.
Despite some differences of opinion among scientists in both fields, there is broad consensus that modern humans evolved in Africa between 200,000 and 150,000 years ago.
