The Naked Scientists

The Naked Scientists Forum

Author Topic: did the first microbes have DNA?  (Read 6399 times)

paul.fr

  • Guest
did the first microbes have DNA?
« on: 14/10/2007 12:43:33 »
the first microbes on the earth were some 3.8 billion years ago (may be wrong, please feel free to correct). Did they contain DNA, as we would recognise it today?


 

Offline JimBob

  • Global Moderator
  • Neilep Level Member
  • *****
  • Posts: 6564
  • Thanked: 7 times
  • Moderator
    • View Profile
did the first microbes have DNA?
« Reply #1 on: 16/10/2007 02:48:06 »
Blue-green algae or Cyanobacteria were around and replicating at least 3.8 billion years ago. There is a geologist in Australia that has found a small outcrop that is over 4 billion years old by dating the volcanic rocks above and below it but will not reveal it's location for independent verification. The reason, he says is that the fossil stromatolite is so small a collector would pay many millions of dollars for the oldest fossil on earth. That is a reasonable argument buy the way. There are very compulsive collectors out there.

The answer is yes - they still exist and grow today in the same form.
 

Offline Carol-A

  • Sr. Member
  • ****
  • Posts: 141
    • View Profile
did the first microbes have DNA?
« Reply #2 on: 16/10/2007 07:40:37 »
We don't actually know what the very first microbes were like. It is quite possible that the earliest replicating units had RNA, or even some protein like material as its inherited unit. What is clear is that once DNA came on the scene, it took over.... and now all living things use DNA as the unit of inheritance (there are some viruses that have just RNA, but I'm not sure if to call a virus a living thing..... and prions have no DNA or RNA but manage to replicate)
 

Offline MayoFlyFarmer

  • Hero Member
  • *****
  • Posts: 863
    • View Profile
    • http://www.myspace.com/wiguyinmn
did the first microbes have DNA?
« Reply #3 on: 21/10/2007 05:04:15 »
like carol said, there is no way to know for sure what early life was like.  the theory that i was taught to be most-accepted, is that the first units of life were actuallly small RNA-like molecules, and evolved from there to have components around them to help them survive and replicate; and thus came about the first single-celled organisms.
 

The Naked Scientists Forum

did the first microbes have DNA?
« Reply #3 on: 21/10/2007 05:04:15 »

 

SMF 2.0.10 | SMF © 2015, Simple Machines
SMFAds for Free Forums