Martin Brown wrote in
news
On 02/07/2018 17:21, Jibini Kula Tumbili Kujisalimisha wrote:
RichA wrote in
:

On Friday, 29 June 2018 20:23:30 UTC-4, Chris L Peterson
wrote:
On Fri, 29 Jun 2018 17:14:01 -0700 (PDT), RichA
wrote:

So they send a mission to Enceladus. They find no life.
"Ah well, mayb
e the equipment isn't good enough yet?" 10 years pass,
another mission is sent. This time they find bacteria and
viruses. Now, was this missed the first time around, or was
it evolved contamination from the first ship?

https://www.bbc.com/news/science-environment-44630121

All life on Earth evolved from a single common ancestor, and
shares a huge amount of common genetic coding. Anything we
leave behind will be readily identifiable as originating on
Earth. Even if alien life uses the same genetic chemistry as
Earth life, there's no chance it's going to code for the same
genes (and especially for all the inactive segments).

Unless panspermia is right and it came from the same comet,
comet swarm, etc.

If it's contamination from the previous probe, there will be
virtually zero genetic shift from the parent. If it's native,
even if it is carbon based (highly likely), even if it uses the
same gentic bases, even if it uses DNA, it will be at least as
different from anything on earth as the variation within earth
based bacteria and viruses, and will match none of them.

The odds of bacteria evolving separately that are that similar
to ours are pretty slim. The odds of them being *identical* are
indistinguishable from zero.

They might not be in terms of what extremophiles have to look
like in order to survive in that environment. More than one
plant family has solved the environmental constraints of living
in a desert and reached the same physical shape as the optimum
solution.

Physical shape isn't DNA. I'm pretty sure the scientists at NASA
know it, too.

--
Terry Austin

Vacation photos from Iceland:
https://plus.google.com/u/0/collection/QaXQkB

"Terry Austin: like the polio vaccine, only with more asshole."
-- David Bilek

Jesus forgives sinners, not criminals.