Other scientists have argued that human beings originated in Africa before moving to other regions 150,000 to 200,000 years ago. Homo sapiens discovered in Middle Awash, Ethiopia, from 160,000 years ago were believed to be the oldest 'modern' human beings.Other remains previously found in Israeli caves are thought to have been more recent and 80,000 to 100,000 years old.ther scientists have argued that human beings originated in Africa before moving to other regions 150,000 to 200,000 years ago. Homo sapiens discovered in Middle Awash, Ethiopia, from 160,000 years ago were believed to be the oldest 'modern' human beings.
The structure of DNA lends itself easily to DNA replication. Each side of the double helix runs in opposite (anti-parallel) directions. The beauty of this structure is that it can unzip down the middle and each side can serve as a pattern or template for the other side (called semi-conservative replication).However, DNA does not unzip entirely.It unzips in a small area called a replication fork, which then moves down the entire length of the molecule. Let's look at the details: 1  An enzyme called DNA gyrase makes a nick in the double helix and each side separates. 2  An enzyme called helicase unwinds the double-stranded DNA.NA Replication. Â­DNA carries the information for making all of the cell's proteins. These proÂ­teins implement all of the functions of a living organism and determine the organism'Â­s characteristics. When the cell reproduces, it has to pass all of this information on to the daughter cells.
DNA helicase unzip, or separate, a strand of DNA at positions called origins. This means that the hydrogen bonds between complementary base pairs are removed (DNA is double stranded!).