• Question: How did and when human life begin?

    Asked by aileenjcat to Colin, John, Kevin, Shikha, Triona on 13 Nov 2014. This question was also asked by Ro.
    • Photo: Kevin Motherway

      Kevin Motherway answered on 13 Nov 2014:

      Human life as defined by the appearance of Homo Sapiens about 195,000 years ago (there’s endless debate and always a new fossil or date being found, so by the time I finish this sentence that date may have changed). But Homo Sapiens are just one in a seamless sequence of life that has evolved over billions of years. Even that date is the earliest fossil evidence date, not a date on the stroke of midnight when Homo Sapiens officially came into existence. If you look at individual from a species that is evolving, from one generation to the next you cannot spot any distinct difference but if you compare generations that are thousands or hundreds of thousands of years apart you will start to spot differences and over millions of years the differences are very big! We still share a lot of commonality with our ancestors from which Apes also evolved. Did you know that in the womb for about 5 months babies are completed covered in hair just like an ape? It then all falls out and the baby actually consumes it; and when the baby is born after 9 months it does a spectacular ( i.e. the most shocking thing that any new dad can face!!!) and black coloured poo called meconium, that’s made up of among other things the hair the baby ingested. We still have a lot in common with our Ape-like cousins.

    • Photo: Shikha Sharma

      Shikha Sharma answered on 16 Nov 2014:

      Hi aileenjcat,

      Approximately four billion years ago, the air was unfit to breathe. The earth was without life. The sun beats down; storms lash the coasts; volcanoes pour hissing lava into the ocean’s waters. These natural jolts fuse simple molecules into more complex ones. Amino acids are formed, then interact with each other, and primitive protein, perhaps a worm-like molecule is formed. Somehow the right molecules get together and the first living cell appears.
      As time went on, this first cell developed into amoeba-like organisms and other primitive creatures that could survive in the ocean. After millions of years, these creatures evolved into fish. Some of these fish developed lungs so that they could survive outside of the water. Gradually they began to make their way onto land as the first amphibians. These amphibians then evolved into reptiles and the earth soon became populated with great dinosaurs. Some of these reptiles started to develop legs that could move around better, and these creatures became what we today would call mammals. Other reptiles developed wings and flew away to become birds.
      One of these early mammals was known as a tree shrew. He was not much larger than a squirrel and in many ways looked like a squirrel. This creature lived in trees and gradually evolved into primitive monkeys and other apelike creatures. From these apelike creatures there evolved two major groups: 1) the great apes that we can see in zoos today, such as the gorilla, orangutan, gibbon and chimpanzee; 2) a creature who came down from the trees and who started walking on two legs. He is now known as HUMAN! Earliest fossil evidence shows ancient human which is combination of ape-like, human-like creatures came in to existence 1.9 to 2.4 million years ago.