Question: how does the human race have DNAs?

Jemma Ransom answered on 1 Jun 2012:

Hi @11hew

I’ll first answer ‘why’ we have DNA, and then I’ll attempt to answer ‘how’
So DNA in essence is a storage molecule of information. Much like your USB stick for your computer, DNA holds a huge amount of information in a tiny amount of space, it is essentially a set of instructions on how to make every single living thing on Earth. Why DNA? It’s incredibly stable. There is some argument that the early creatures used proteins to store information, however this is very unstable and gets damaged easily. DNA survives down the generations from parents to children, so it needs to be very tough. Another way of storing information is in a molecule called RNA, this is how viruses do it. However this is very very unstable. I suspect you have heard of the cold virus being different every year? This is because the RNA is so unstable that the information encoded changes due to damage yearly.

As for how, we think that DNA arises from the very earliest species of animals, bacteria probably, that would have formed at extremely hot temperatures, perhaps under the sea. This would have caused a fusion of something called nucleic acids which are the building blocks of DNA.

Hope that helps, if you didn’t get some of the words let me know.

Jemma