(Finally got to sit down and make an attempt at keeping up with this thread)
One thing I think is worth mentioning, given that it was said earlier that the odds of specific things happening in nature were impossible. I beleive this is a misunderstanding of probability (the chance that something will happen). If we say the odds of a specific beneficial mutation occuring are 1000 to one, but we give it billions of years to happen, the odds become higher as time goes on. If we give it forever the odds are 1 in 1.
for example I could take 20 six sided dice, lets say that our desired mutation, perhaps the mutation that enabled us to begin developing the ability to breath oxygen through our mouths (early step needed to live on land) happens only if we roll all six. I roll the dice but, it's not very likely that they will all land on 6 and give me the mutation but, if I keep doing it forever it will eventually happen.
Becki, in response to your question of how do we know the e. coli ancestors did not have this trait. We are able to identify what traits the starting strands had from the beggining, what lines of genetic code were present. I am not particularly well versed in the methods used but, we have been able to observe genetic traits for a few years now if memory serves. On this however I will do some more research and will share the referances I find.
One thing I think is worth mentioning, given that it was said earlier that the odds of specific things happening in nature were impossible. I beleive this is a misunderstanding of probability (the chance that something will happen). If we say the odds of a specific beneficial mutation occuring are 1000 to one, but we give it billions of years to happen, the odds become higher as time goes on. If we give it forever the odds are 1 in 1.
for example I could take 20 six sided dice, lets say that our desired mutation, perhaps the mutation that enabled us to begin developing the ability to breath oxygen through our mouths (early step needed to live on land) happens only if we roll all six. I roll the dice but, it's not very likely that they will all land on 6 and give me the mutation but, if I keep doing it forever it will eventually happen.
Becki, in response to your question of how do we know the e. coli ancestors did not have this trait. We are able to identify what traits the starting strands had from the beggining, what lines of genetic code were present. I am not particularly well versed in the methods used but, we have been able to observe genetic traits for a few years now if memory serves. On this however I will do some more research and will share the referances I find.
