Originally posted by ashmok
As to DNA, that's hard to destroy. Some scientists think there's even a chance of recovering some from cremated remains, others disagree but it
does show what might be possible.
Thank you for making the point about crematorium temperatures versus heated aluminium temps, too - it's a point that some theorists keep forgetting
and/or ignoring
Perhaps more importantly, fires such as those in the WTC complex may not have been at a sufficiently high temperature and/or had not burned at that
temperature for the adequate time to insure complete destruction of DNA; this is why it's not uncommon to take (and successfully test) DNA samples
from building fires, house fires, warehouse fires etc.
In practice it's actually somewhat difficult to completely incinerate human remains. Commercial crematoriums typically expose bodies to 2,000°C for
two hours and under these conditions, the ashes will generally not yield DNA, though it's not outwith the realms of possibility. Most remains
recovered from building fires, however, are not totally incinerated and will contain viable DNA.
Within the bone, DNA is very stable and can withstand temperatures of several hundred degrees or more for short time periods. It's really only as a
bone becomes calcined or has been completely cremated (ie, is ash) where the difficulty becomes impossibility in terms of extracting DNA.
Ah, this turned into DNA 101, and that's not what I'd intended...apologise in advance! My point was simply that it's perhaps not prudent to
conclude that because aluminium has melted/been otherwise destroyed at a certain temperature, then no body parts/DNA could have survived.
Because it can