[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
Re: exobiology possibilities
On 03/12/2015 07:55 AM, Thomas R. Holtz, Jr. wrote:
> On the contrary: we have every reason to think that all life on Earth studied
> so far are descendants of a single instance of life, and every reason to
> dismiss the possibility that any known terrestrial life is of independent
> origin. A good reason for this is the fact that A, T, C & G are NOT the only
> possible nucleotides. Furthermore people have synthesized nucleic acid
> analogues in the lab that work essentially like DNA and RNA but which have
> different backbones. The fact that all living things use only the one system
> when there are numerous alternatives which are seemingly just as likely
> points to a common origin. Statistically, we would expect alien life will
> like have DNA/RNA analogues using other nucleotides and/or backbones, if
> indeed they used these forms of molecules as the carrier of genetic
> The Lost City microbes fall within the family tree of other life, and use the
> same genetic carriers in the same fashion the rest of Earth life does.
Do you have a reference for any nucleotide pairs outside of the ones in
DNA and RNA which can form a double helix and be injected into a life
form? Or nucleotides that have properties of DNA or RNA.
> Thomas R. Holtz, Jr.
> Email: firstname.lastname@example.org Phone: 301-405-4084
> Office: Centreville 1216
> Senior Lecturer, Vertebrate Paleontology
> Dept. of Geology, University of Maryland
> Fax: 301-314-9661
> Faculty Director, Science & Global Change Program, College Park Scholars
> Fax: 301-314-9843
> Mailing Address: Thomas R. Holtz, Jr.
> Department of Geology
> Building 237, Room 1117
> University of Maryland
> College Park, MD 20742 USA
>> -----Original Message-----
>> From: owner-DINOSAUR@usc.edu [mailto:owner-DINOSAUR@usc.edu] On Behalf Of
>> Ruben Safir
>> Sent: Thursday, March 12, 2015 4:17 AM
>> To: email@example.com
>> Subject: exobiology possibilities
>> This article is worth reading only because it point to the possibility of an
>> independent evolution of life, which brings up a question I
>> have long had.
>> We really don't know if all life on this planet comes from a single
>> continuous linage. The organism that exist in the lost city might not
>> be related to anything on the planet. And similarly, is possible that
>> flowering plants, as an example, some from several branches of
>> plant life, in a form of convergence where closely related specifies
>> simultaneously develop like features, even controlled by similar
>> haplans and control genes?
>> Why should the course of evolution be simple?