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There's a reason for this. We've been told that the numbers
point to there being a high probability of life existing out
there somewhere, this sort of sets the table for the
Not just a silly exercise in semantics, at some point if we
find extraterrestrial life, even if there
are great similarities
between life forms from there and Earth, we'll want to
the categories separate for book keeping purposes alone.
that a Earth marmoset or a Rigelian fluzwuzzler? They're
the same kingdom sort of but you don't want to have to
start adding (Earth) or (Rigel 4) after every plant and
animal entry in
There's also a high likelihood that Earth categories won't
apply to life from other planets anyway. They may be some
kind of weird crystalline cell like based life form or
that would need their own planetary category to start the
categorization off from a sensible starting point.
Plus it gives a bit of a looking-towards-a-possible-future
to biology. And nobody can deny that, even though there's
only one discovered overarching life category right now
"Planet" isn't a legit category.
So to clarify, when and if life is discovered on another
world, this will of course happen anyway, the idea is to
start referring to it now for the reasons referred to above.
I think Carl Sagan might have liked this one.
Panspermia and Moore's Law
As mentioned in an annotation. [Vernon, Aug 25 2015]
Some Panspermia details
Note: There are much older and bigger impact craters on Earth than Chicxulub. --one is the Vredefort Ring in South Africa. Bacteria launched by that impact could be as much as 1000 light-years away by now. [Vernon, Aug 25 2015]
A potential space traveller
This microbe can repair itself perfectly, after having its DNA chopped to bits by gamma radiation or cosmic rays. A rumor says it can live inside nuclear reactor coolant-lines. [Vernon, Aug 25 2015]
||Hey, [8th]; they've found your fluzwuzzler. Was there a reward?
||See, that's the trouble with Tribbles.
||Even if species on two different planets were
outwardly similar, modern taxonomy would give them
distinct classifications (in, as you suggested, a level
above the current top taxonomic level), since they
would be different by descent.
||And what of the species that exists on Earth as well as
elsewhere? Who can say that "Pasteurella multocida" doesn't
exist on Coruscant or another M class planet somewhere?
||Introducing the requirement for a planet-based taxonomy
would mean we'd have to duplicate or otherwise confuse our
data concerning a species which is common to 2 or more
||You might want to add "galaxy" as another higher-level
The notion of "panspermia" (see link) could cause all
carbon-based life in any one galaxy to be related, but
galaxies are generally too far apart for that to be true.
||Well, it's about book keeping. The incidence of
species on various planets while remote could
certainly happen, but an animal in a particular class
living on a planet with an average temperature that's
ten degrees colder than Earth is going to be vastly
different in enough ways that they should have their
||Plus categories are about being able to zero in on the
particulars of this animal for discussion, research etc.
Knowing we're talking about Kepler 438b protozoa or
Earth protozoa is going to be the first order of
business in the real world.
||It's also HIGHLY unlikely that the ranks would be the
same across the board for two planets, especially the
lower you get, like, "Here's the Kepler
sphenisciformes and here's an Earth penguin. The
Kepler penguin has all the same characteristics, it's
just from Kepler."
||My guess is you'd have similarities and differences to
how life forms adapted to their environment, but the
purpose of a name is to know what we're talking
about. We're certainly going to want to compare
Earth animals to Keplar animals, and that's tough to
do if you don't give them their own category, which
would be the case anyway. Nobody is going to talk
about a Keplar penguin without saying first "We're
talking now about Keplar penguins, not Earth
penguins." if there were such a thing. I'm saying just
throw that category out there now as a harbinger of
the exiting new discoveries we may have waiting for
us in the future. Hell, you could start theorizing
about various ways Keplar ranks might be different.
Having a "Planet" rank for that reason alone makes it
something to consider.
||I'm assuming of course that there's life only on
planets, not asteroids or, I don't know, hidden
someplace in the electromagnetic spectrum. That's a
pretty fair assumption but we've only been doing this
science thing for a teeny tiny fraction of our
existence. Who knows what we're going to find out?
||For instance check out Vernon's links. I'm pretty sure
we've only scratched the surface.
||If everybody has a doppelganger on Earth, then doesn't
Earth have a doppelganger somewhere in the galaxy or
||//And what of the species that exists on Earth as
well as elsewhere? Who can say that "Pasteurella
multocida" doesn't exist on Coruscant or another M
class planet somewhere? //
||That could happen if, and only if, life travelled
between systems. It's quite likely (in fact, very
likely) that bacterial life swapped between Earth
and Mars, assuming that they both had habitable
environments at the same time. But within a very,
very short time, populations on the two planets
||Even if life travelled between different stellar
systems (by Hoyle-like panspermia), the
evolutionary divergence would probably be much
faster than the transit times.
||So, it's unlikely that we will find the same species
(ie, interbreedable populations) on two different
planets, with the possible exception of intelligent
beings who can move around, like us.
||So, the most common situation will be that life on
two different planets has arisen independently (or
from a common ancestor very, very long ago). In
this case, even if species on two planets appear
identical, they will be very different at the
molecular level - their similarity will be the result
of convergent evolution.
||For this reason, it makes perfect sense to have the
planet of origin indicated in a prefix before the
generic and specific names.
||Since we are terrestrial, we might opt to drop the
prefix for terrestrial species.
||//Well, it's about book keeping.//
||No, it's not really. Modern taxonomy is about
evolution, and hierarchical classification systems
should, ideally, reflect origins. Terrestrial taxonomy
got a bit screwed up because we started doing it
before we understood evolution or genomics, but it
sort of holds together (even though we've spent
decades moving species around in the light of
modern molecular evidence).
||//So, it's unlikely that we will find the same species
(ie, interbreedable populations) on two different
planets, with the possible exception of intelligent
beings who can move around, like us.//
||Exactly. The wildly divergent paths organisms take to
fill various ecosystems here on Earth show that life
takes a pretty wild course through the challenges of
gathering nutrients, reproducing, defending itself
from the elements and other creatures, and that's
just here where we have 24 hour day cycles and
solid, liquid and gaseous water. The idea that
a different planet would come up with another exact
match for a penguin is pretty far fetched. Heck, the
North Pole and South Pole couldn't even both come
up with penguins and as far as I can see they're
pretty much the same. Now you raise or lower the
average temperature by even 20 degrees and oxygen
content of the atmosphere by 40%, even if it's
football shaped, swims,
walks on land and has a beak,
that's not a penguin. Not biologically and probably
not even on a molecular level. Forget about the
shape of the body, get it's bits under the microscope
that's probably where you'll see the main differences
as Max pointed out. That outer space penguinoid is
going to need it's own
classification, and since it's overall traits are going to
have many similarities to the other life forms on its
planet, the planet classification is going to be vital to
||This seems like something that obviously would be done in the event that life forms from non-Earth sources are discovered and able to be examined. That is to say, it's an interesting idea but fairly intuitive should the situation arise. Until such time there is no need for it.
||Right, which is why the idea is to refer to the
category now when speculating about and exploring
concepts of extraterrestrial life and specifically
comparing them to life we're familiar with here on
||Or forget about waiting to find life out there, what
about when we start designing life forms to inhabit
other worlds? Let's not forget, rather than
terraforming an inhospitable planet or running
around looking for one that exactly matches San
Diego California's climate, we might decide to meet
the challenge halfway by re-engineering our bodies to
better suit the planet and at some point we may be
so different as to become a different species or even
genus. In this case certainly this would be a useful
designation. I for one would be proud to think that
my great, great, great etc grandchildren might be
Keplar Humanis, 8 foot tall (or 3 foot tall as
necessary) magnificent relatives of primitive
Earthlings making their homes light years away from
||Anyway, in other words, we can start using it today
discussing astrobioengineering if there is such a
thing. If there's
not there should be.
||I am quite optimistic that, one day, molecular
genetics will enable to precisely date the point at
which lawyers branched off.
||//Artificial life vs Natural life//
||Won't be a difference, life is life, no matter from the
hand of God or the hand of man.
||//Its interesting how dramatic the revisions of
phylogenetic relationships are as things are looked at
||Interesting post Ian, cool stuff.
||//I am quite optimistic that, one day, molecular
genetics will enable to precisely date the point at
which lawyers branched off.//
||Hopefully in the chapter on extinction.
||////Artificial life vs Natural life//
|| Won't be a difference, life is life, //
Ah, but there will be. The most fundamental
difference will be that natural life evolves,
whereas designed life can make large jumps. If
you find a fossil of a long-leggedy animal, and an
older fossil of a short-leggedy animal, you will
probably find a fossil inbetween of a medium-
leggedy animal. With engineered life, the
intermediate one might have a different number of
legs, or wings or whatever.
||[MaxwellBuchan], did you ever read "Code of the
LifeMaker" by James P. Hogan? Think "evolved von
||So the planet classification would indicate both time and conditions in the complete universal evolutionary tree. Nice.
||//evolved von Neumann machines// Yes, synthetic
life can certainly evolve. But it can also progress by
routes other than classical evolution. As a simple
example, there are no evolutionary intermediates
between the RS232 socket and the USB socket on a
||// the complete universal evolutionary tree//
||Technically, unless panspermia is the only means for
life to arise on new planets, it would become an
evolutionary forest rather than a single all-empassing
tree. All life on earth probably has a single common
ancestor; life on Kepler 348b has a different common
||[Max] //panspermia is the only means for life to arise
on new planets// - logically, for panspermia to be the
only means for life to arise on new planets, time
must be a closed loop rather than simply linear.
||It was/is/will be/will have been always there
||//logically, for panspermia to be the only means for
life to arise on new planets// Yes. What I meant but
didn't explain was that life would have had to arisen
once, somewhere, and then panspermed its way
||//why would there be a need to also do it the hard way
by actually travelling?//
||Because the lease is up on Earth in 7 billion years, time
to start packing.
||The universe has programmed us to develop real estate.
Those fish with the crawling fins "knew" that despite
being harsh and dangerous, dry land was a "fixer upper
opportunity with loads of potential". Mars beckons, other
worlds beyond call to us. It's just what we do.
||As far as letting other life forms pop
up and do the job, what if they all said that? Somebody's
gotta clean this place up and make it livable. (the
universe I mean) Might as well be us.
||//rely on the possibility that similar life will occur to fill similar
||The basic problem in estimating the number of inhabited planets
out there is that we honestly, truly, really have absolutely not the
first shred of an idea about how easily life originates.
||It may be that life will tend to get started on any planet, within a
million years of its becoming habitable. If so, then every habitable
planet will have life. On each planet, life might evolve to the stage
where it wonders about life on other planets.
||It could equally well (and I stress equally) be that, given a habitable
planet, life has a one in a quadrillion chance of getting started. In
that case, there might be only one inhabited planet. On that
planet, life would evolve to the stage where it wonders about life
on other planets.
||The point is that we really, really _really_ don't know. Everything
that we do know so far, is equally applicable to a densely-populated
universe and to a universe with only one life-bearing planet.
||Life may be very rare, in fact it's not beyond the realm of
possibility that we're the only example, or at least the
first example of life in the Universe. There has to be a
||I'd take that as a responsibility not to be taken lightly. As
weird as it sounds, we may be the Universe's only
example of consciousness. Talk about an important
burden to shoulder.
||But as Max says, we really, really, really, really, don't
know. So we should proceed on our best assumption.
We're here, we've got the tools to expand beyond our
birth planet, and it's probably a good idea to work
||//I take the view that life ... could (or even must)
spontaneously occur given the correct
||I am sure you will believe me when I tell you that I
say with the greatest respect that that is bollox.
||It is perfectly possible that, given ideal conditions
(a warm wet planet with all the basics, for ten
billion years), life has a one in a quadrillion chance
of arising. In that case, there is no "must" about
it, and most habitable planets will remain barren
throughout their star's existence.
||The only real clue we have, regarding the ease
with which life can arise, is the fact that it seems
to have happened quite soon after Earth became
habitable. That _suggests_ that life arises fairly
easily; if Earth had sat in a habitable but barren
state for a billion years before life arose, we might
infer that life is very difficult to start. But this is a
single datapoint, and it's difficult to say much
without a lot of arm-waving.
||(Of course, the evolution of wavable arms probably
says something about life, but I have no idea what
||The idea presupposes that life forms on different
planets may have similarities to Earth life such that
they might share a category with their analogous
Earth life forms, flying or swimming like birds or fish
for instance. It also supposes that these creatures,
despite their similarities will not be at all the same
kind of animal sharing perhaps only a shape and
features like wings, fins, antenna etc.
||A birdlike creature from another planet could not be
accurately categorized as a bird, it would have to be
categorized as an Tau Ceti bird, a Tau Ceti fish etc.
hence the planet categorization.
||The reason to do this now is to stimulate and assist
the science of speculative astro-zoology.
||//Is the idea confusing genetic heredity with location
||Sort of, but it's valid. Barring panspermia, location
will correspond with heredity. All the lifeforms on
Earth trace back to a common ancestor. Likewise, all
those on Sphincter 32B will trace back to a common
ancestor, et cetera.
||//Some lifeforms could have evolved from
disparate unconnected ancestors that just fancied
each other, rather than a single common ancestor
||Sort of true. Certainly organisms can merge after
they've diverged - for instance, mitochondria and
chloroplasts are both derived from ancient
bacteria that moved into a precursor of the
eukaryotic cell. And it's been proposed that some
organisms that undergo dramatic metamorphosis
are actually hybrids, with each metamorphic stage
being one of the original species.
||But could life originate twice, independently, on
the same planet and then merge? There are two
barriers to this:
||(1) It's unlikely the two origins will happen at the
same time. In which case, the first type of life
will probably establish itself and consume the
resources needed for the second one to get going.
For instance, any completely new lifeform arising
on Earth would probably just be a snack for
bacteria that have already been evolving for
billions of years.
||(2) If two lifeforms did arise
_completely_independently, the chances of their
metabolisms being compatible is small. For
instance, we use left-handed amino acids and have
right-handed DNA, and half a dozen other basic
handednesses. A new lifeform would probably
happen to differ in handedness of one or more
classes of molecule, so the gears wouldn't mesh.
||But, a possibility nevertheless.
||From the same mindset as the joker who named
||And keep in mind, there may be very little or no
overlap but this makes the assumption that nature
will do a little bit of the mirror engineering you see
man do from time to time when faced with similar
||These examples might be wrong but didn't two un-
related people invent the TV at about the same time?
telephone supposedly has the same story although it
smacks of urban legend. Germany and England had
independent turbojet programs during WW2 didn't
they? Perhaps nature might do the same is the point.
Best way for an organism to get through the water?
Fins. Through the air? Wings. Under ground in loose
dirt? Nothing but a long tube shaped body.
||As far as the Earth technology examples I may have
set a record for amount of misinformation in one
annotation but the point is valid despite all the info
probably being wrong.
||Agreed - it's likely that evolution will produce _outwardly_
similar solutions when faced with similar problems.
||This already happens on Earth, of course. Dolphins and
sharks are broadly similar in shape. Eyes evolved several
times. And bats do not all come from one bat-like
ancestor: they have evolved from non-flying mammals at
least twice, independently - and both groups
independently evolved echolocation.
||However, the underlying molecular machinery is often
arbitrary. All life on earth has one set of machinery (more
or less). All life on Sphincter 32B would almost certainly
have a different set. It's possible that DNA would re-
evolve independently (it works well), but for example the
coding system is mostly arbitrary and would not be the
same on another planet. Likewise, the choice between
left- or right-handed chiral molecules is arbitary, and life
elsewhere would make different choices.
||Analogously, software developers converge on different products which are similar in how they look and work - e.g 'Microsoft Outlook' for PCs and the OSX 'Mail' program - but which are very different at the code level.
||That's probably as good an analogy as you'll find. Under
surface, the chemistry of life forms from different
going to be as different as the chemistry of the planets
||Penguin and penquinoid from planet Cornholio 9 are both
going to burn fuel when they're walking, but that fuel is
going to be very different between the two, as will the
process that fuel, right down to the cellular level.
||So to get back to the idea, if we're going to re-use some
existing categories from planet to planet, we just look at
the menu. Could that penguinoid's phylum be designated
chordate? Does it possess a a notochord, a hollow dorsal
nerve cord, pharyngeal slits, an endostyle, and a post-
anal tail for at least some period of their life cycles? If it
does, even if it's silicon based rather than carbon based,
its phylum is chordate.
||How often would we use these same categories from
planet to planet? Impossible to speculate. But if different
planet's creatures share the same characteristics enough
to share a category, would this category designation be
useful? Absolutely, but only if it's under the heading of the
||Ok, got a little wordy there for some not exactly world
shattering concepts. Sometimes I think the clicking of the
keyboard lulls me into a trance. Hope reading this
rambling doesn't have the same effect. Eh, probably
||//Could that penguinoid's phylum be designated
||Not if you wanted to be taxonomically consistent.
phylogeny is so tightly hooked into evolution, you
have two animals in the same phylum (or genus,or
any of the other levels) if they don't share a
||So, if you classified the penguinoid as a chordate,
imply that it had descended from the same
ancestor as the
penguin (and all other chordates); yet the planet
at the top of the hierarchy, would indicate
In effect, you would be implying an evolutionary
tree that had
two origins (two planets), fused to make a single
and then split again into penguins and penguinoids.
||So, each planet is going to need its own
phylogeny. Maybe you'd define "chordatoids" for
the new planet,
to indicate that they had features in common with
||There is one situation in which unrelated animals
can share part
of their phylogenetic name - the specific epithet
need not be
unique. So, for instance, there are lots of species
edulens", where the XYZ will be any of several
and the specific epithet "edulens" just means
lots of things are called "XYZ minor", etc.
||So, to summarize, the terrestrial Little Penguin is:
Species: E. minor
||whereas a small penguinoid from Cornholio 9 might
||Planet: Cornholio novem
Species: T. minor
||//Planet: Cornholio novem
Class: Avioides etc//
||So if we're calling it a penquinoid, we're going to have to
apply that suffix to everything on the tree because
and penguinoid may have similar traits but may have
there via disparate routes? So they may have similar
characteristics but hail from different orders?
||If that's not what you're saying, it's what I'm saying. If
what you're saying I agree.
||I guess the main thing I'm saying (wait, what the hell was
I saying again?) oh yea, is, I don't think we need to wait to
see what's out there and then make up categories for
them. I think we can start with the planet category, then
using our taxonomy menu as a TEMPLATE, begin filling in
the possible life forms that would populate these
||Why should we spend time speculating about such things?
I don't know, beats playing video games.
||Well, and beyond something interesting to mull over, I
think the path to colonization of different planets is going
to require us to put some thought into changing our
selves to match the environment, perhaps even going full
mechanical with full consciousness transference into
robots, something that doesn't seem totally impossible.
Large capacity electronic data storage has only been
around for decades and look how far it's come.
||Forget about conquering the cosmos, that truly could be
the cure for death. And make no mistake, we will cure
||Ok, I need to get some work done today. "Ok Mr Future
Guy, before you populate the cosmos and cure death,
that garbage isn't going to take itself out and lawns
don't mow themselves."
||//Sticking to the idea that things have to be
descended from other things to qualify for a step
the tree is a bit needlessly rigid.//
||That is why we have common names for things.
can call the penguinoid a "flightless bird" if you
But the latin terms have (and should have) precise
meanings. And they are used primarily by people
with a technical interest, who value those
and depend on them. Taxonomy is a tool used by
professionals, and it doesn't do to go messing with
||Well yes and quite so. Half the fun of astrotaxonomy
will be in tracing back the threads of migratory
species to their planets of origin.
||We'd best get on Worm-Hole tech if we ever want to classify galaxy of origination.
||One of my recurring nightmares is discovering that
(a) panspermia is true and (b) life originated in
Wales. At some future date, we will be visited by an
immense robot which will say "Klaatu barada nikto,
isn't it boyo?"