Modern humans (Homo sapiens), the species? that we are, means ‘wise man’ in Latin. Our species is the only surviving species of the genus Homo but where we came from has been a topic of much debate. Modern humans originated in Africa within the past 200,000 years and evolved from their most likely recent common ancestor, Homo erectus, which means ‘upright man’ in Latin. Homo erectus is an extinct species of human that lived between 1.9 million and 135,000 years ago.
Historically, two key models have been put forward to explain the evaluation?of Homo sapiens. These are the ‘out of Africa’ model and the ‘multi-regional’ model. The ‘out of Africa’ model is currently the most widely accepted model. It proposes that Homo sapiens evolved in Africa before migrating across the world.
On the other hand, the ‘multi-regional’ model proposes that the evolution of Homo sapiens took place in a number of places over a long period of time. The intermingling of the various populations eventually led to the single Homo sapiens species we see today.
Genetic studies tend to support the ‘out of Africa’ model. The highest levels of genetic variations?.in humans are found in Africa. In fact there is more genetic diversity in Africa compared with the rest of the world put together. In addition, the origin of modern DNA in the mitochondria (the ‘powerhouses’ of our cells) has been tracked back to just one African woman who lived between 50,000 and 500,000 years ago – 'Mitochondrial Eve'.
Our genomes are a combination of DNA from both our mother and father. However, mitochondrial DNA (mtDNA) comes solely from our mother. This is because the female egg contains large amounts of mitochondrial DNA, whereas the male sperm contains just a tiny amount. The sperm use their small amount of mitochondria to power their race to their egg before fertilisation. Once a sperm merges with an egg, all the sperm mitochondria are