This thread relates specifically to the genre of science fiction and the art of creating believable non-terrestrial creatures/beings. Flipping through my old Genetics I book from my days at the University of Florida, I came across an interesting portion that made me think about how I create my alien beings and the brethren that share their worlds. It concerns certain rules (of which there are many) that rule morphological arrangement and accoutrement of the beings of our planet, Earth. The ones that gave me pause are the following: 1) No higher order* of vertebrate shall have more than a maximum of four (4) appendages (Legs or arms. The head is not considered, as it is the apex of the vertebral structure and not an offshoot of said structure ) *Fish are arguable because they are vertebrates, and many have more than two sets of ventral fins which can be argued to be analogous to limbs. Vertebrates with four appendages are called tetrapods. 2) No tetrapod shall have more than a maximum of five (5) digits* at the end of any given appendage. *There is fossil evidence that there were very early tetrapods with more than five digits, but for reasons only Mother Nature can answer, they did not survive. 3) All mammals shall have no more and no less then seven (7) neck vertebrae. Now, obviously these are only a tiny subset of the rules which apply on Earth. But my point is, rules do exist which sometimes seem unbreakable even when it would be more advantageous for the rule to be broken. For example, a giraffe, which is a mammal, has the same number of neck bones as you or I, even though it would seem to make sense that if it had more, it would be more limber, more flexible. But, alas, the rule is unbreakable in mammals, and the poor giraffe must sprawl in the most ungainly manner just to take a sip of water. Now, obviously not speaking about the rules we have here on Earth, but would genetic rules of some kind apply to an alien biosphere? If so, how would it affect your literary creation of alien beings?
"Rules of Creation" - isn't that an oxymoron? LOL In my current book, I created a major race with 5 appendages . . . they evolved from a sub-sentient, reptilian species. Despite evolving sentience, they retained the functional tail of their ancestors because it is necessary for their survival. Ascension in this warrior society demands success in personal combat . . . the functional tail provides for balance and acts as an additional weapon. Due to its importance for survival, evolution actually enhanced the power and movement of this appendage. I also have an emerging sentient race with unique paranormal capabilities and six appendages. Here's the link to my website page describing some features of the major players and their societies: http://www.lasthumanwar.com/Aliens.html SHAME ON ME! I forgot to read the "rules" of creativity! HAR HAR!
Clearly, these rules hold on this planet as a direct result of evolution from common ancestors (a common vertebrate ancestor in the above cases), from which the basic skeletal template was derived. (Creationists may have their own answer for this, but I will take evolution as a given based on an enormous body of evidence). In an alien ecology, or exoecology, there would probably be one dominant precursor as well, although I might accept the presence of a second precursor species with radically different structure. Three or more templates among the higher species on the food chain would stretch my credulity. Therefore, I would expect a similar biochemistry and a structural parallelism among species on an alien world; similar to other species there, but probably radically different from our own. We exhibit approximate bilateral symmetry along a dividing plane which includes our spinal column. I doubt there is anything that requires that pattern of symmetry, although some form of symmetry probably favors balance. Radial symmetry exists among terrestrial species like starfish, for example. And we do have wildly different structural systems on Earth, but in different niches. Plant life is life also, but the rules are very different from those for vertebrates. Arthropods like insects and arachnids follow yet a different template. Read The Mote in God's Eye, by Larry Niven and Jerry Pournelle. The Motie species follow a consistent template among themselves, even with wide variations between specific forms. Vestigial features can add some interest and authenticity, like the coccyx as a vestigial tail in humans, ant the appendix as a vestigial second stomach (ruminants like cattle have a fully developed second stomach).
I agree. Life on alien worlds may not even be carbon or water based, although most of the life forms within one evolutionary bio system should share certain basic characteristics. In my book for example, the primary race on one planet has begun to evolve psycho kinetic ability. Unknown to them, a lesser species on the same planet has recently evolved to the point of full sentience and they have strong telepathic links. This paranormal evolution resulted from evolving in a common biosphere.
I guess what I find so intriguing is the rigidity with which nature adheres to some templates once they are set. No more than five digits on the end of any tetrapod limb. Less is no problem (horses,) but more is completely out of the question. Why? I understand that the limit number comes from the common ancestor, but why so rigid this particular rule when other concepts, including basic metabolism, seem to be maleable? If you are a tetrapod, then: Skin color/type? Anything you want. Poikilothermic or Homeothermic? Your choice. (And for a limited time we are offering Tachymetabolism) Carnivore or Herbivore? The world is your oyster (or carrot.) Oviparous or Viviparous? Well, that's all about fashion. (And if you choose Viviparous, OH what a range of choices we have for you this season!) Saché, chanté! But if you are a tetrapod, woe unto you should you ask for a sixth or seventh digit. And for those of you who have gone the mammal way, we will suffer no complaint about the neck arrangement! And centaurs!? Hmmm, let me see… 1,2..3,4….5….6 limbs!! Thunderbolts and lightning shall strike you down!!!
The shapes of the bones have variety from the relatively recent common vertebrate ancester, but the number of structural bones and their connection points doesn't change much. Sure you may have some cats with extra toes, but not stable genetic material to take the change to subsequent generations. With more time, some of the rules may well develop exceptions. The ones that already developed exceptions din't make the list.
I believe in evolution, but does anyone else here think it is crazy as hell that all the varied species we have on earth would have to come from one tetrapod ancestor. I can imagine thats like starting over at the base of one again for every creature considered a tetrapod from birds to humans and cows. So we all started as cingle cells. of all the cingle celled organisms that grew into more complicated creatures there was only one tetrapod. and from that one multicelled organism came the life that walks the land. We are genetic experiments of an alien race. I said it you know it iam done.
Not ALL species. Just the vertebrates. Just one predecessor that incorporated a central nerve trunk sheathed in a structure of joined, bones with a hollow channel. There's a lot of evolution between the single cell organism to the first vertebrate. Some of the side branches are the many plant species, the huge class of exoskeletal arthropods (mollusks, insects, arachnids), many species without skeletons, etc. But the vertebrate form has been renarkably successful in competing for a solid presence in the food chain.
Some of the earliest amphibians had 8 digits on lobes extending as arms. Recent fossil discoveries of an 8-fingered amphibious fish were found in Greenland and near Lake Erie. These fossils are thought to be evidence of transitional stages of evolution between land and water. Looks like evolution tried to give us bigger feet but we just didn't need all those extra toes! LOL "370--Fish similar to Sauripterus. A very recent discovery in Pennsylvania by Daeschler and Shubin (1998, p. 133; Kinney, 1998) is of a fish which has fins, which is not unusual, except that inside of the fins were 8 fingers attached in a similar way to those of the earliest amphibians (see below). While many doubt that this creature is on the direct line of descent between fish and amphibians, the existence of fins with 'fingers' is illustrative of the fact that intermediate forms (broadly defined) do exist. Interestingly, as we shall see some of the earliest amphibians also had 8 digits on their hands." Taken from an article in Tufts.Edu site. "363 MYR-Ichthyostega-- Is the first animal with feet but the feet are different than most tetrapod feet. They are much like Acanthostega but has 7 digits on his hindlimb." "363 MYR-Ichthyostega-- Is the first animal with feet but the feet are different than most tetrapod feet. They are much like Acanthostega but has 7 digits on his hindlimb." "363 MYR- Acanthostega- has four legs, lungs but still has internal gills. (Coates and Clack , 1991, p. 234) He has 8 digits on his front leg (see second picture below); seven on his back feet."
There would be rules set by the environment on the specific planet. For example, the higher the gravity, the smaller the maximum possible size of a land-living creature. (Its skeleton will break if too heavy.) A world with less water than Earth would likely be harsh and infertile. The vegetation would be thinner, limiting the amount of food available to animals, also limiting their sizes. Life would seem less intense. Think steppes compared to jungles. High oxygen content would lead to frequent and rapid fires, and animals would have less need for lungs, while low oxygen content would lead to creatures with larger lungs, and possibly also more ancient forests. A dense atmosphere would provide for many large, flying creatures and less need for lungs, while in a thin atmosphere only insects would be able to fly, and lungs would be bigger. And so on. But there would also be limitations based on physical laws and the properties of materials, and those would be the same as on Earth. For example, I don't think a planet with ten times the gravity of Earth would produce creatures that were ten times as strong to compensate, because there are no ten times as strong materials to build their muscles and skeletons from. If there were, earth creatures would already have discovered them and used them to become superior predators. But as long as the physical and environmental rules are respected, I think it is largely up to circumstances how life forms develop. For example, until as recently as a couple of hundred million years ago, there was no grass. Today grass dominates over all other small plants. It could just as easily have evolved a couple of hundred million years earlier or later. If vertabrates would not have been there to crawl up on land, perhaps mollusks would eventually have developed exo-skeletons to move around on land more easily, and the dominant life-forms would be reminiscent of octopuses. So I'd pick a few basic earth-inspired life-forms, and ask myself how they would have developed given the chance to fill a niche on an alien planet. Then I would use them as templates for the dominant life-forms on that planet (just like insects, reptiles, mammals, etc are templates for the most visible life-forms on Earth).
Not to mention all the research going on with fungi. More and more it seems that the fungus amungus is more cousin than we ever thought.
Which brings to mind another question… Viruses. Now, because of definitions made at the hand of man, we do not consider these things to be living. But, in all truth, their non-living classification is an arbitrary definition. Along with the fungi (although, obviously not grouped along with them,) they occupy a classification/definition which seems patchwork at best. A poor fit. Could we be observing, here on our own planet, examples of other genesis? Are we simply limiting ourselves by our lack of comfort with what is other than what we understand? It has happened in the past. For arbitrary reason, we refused to recognize that dinosaurs live with us today in the form of birds. The morphological evidence has always been overwhelming, but we refused to see it because it would have required a complete rethink on the nature of birds or of dinosaurs or of both groups. We were blinded by our stubbornness, and only now does the scientific community admit the obvious in sotto voce.
Absolutely. For example, look at the surprise in our scientific community when they discovered thriving life around ultra deep "hot water flumes" in the Pacific Ocean. Anaerobic life forms are thriving under immense pressure, and if I recall correctly, they actually benefit from some of the toxic chemicals emitted by the vents...they didn't anticipate that. Here's an excerpt from the Natural History Museum: http://www.nhm.ac.uk/nature-online/earth/oceans/fathomseminar-deepocean/session6/no-oceans-fathomseminar-deepocean-session6.html "The water gushing out of deep-sea vents is laden with a cocktail of chemicals that would be deadly to most forms of life, so it is the specialised organisms associated with them that make the vents really remarkable. These organisms not only can withstand the toxic chemicals, but actually thrive in them. Many vents are surrounded by fantastic communities in which life may be hundreds of times more abundant than on the adjacent sea floor. This is because the vent animals have their own rich source of food, which is totally independent of the input from the photosynthesizing plants in the overlying surface waters. The food is produced by special bacteria which can make the complex chemicals the animals need. But instead of using the energy in sunlight, like plants, they get their energy from some of the chemicals in the vent water in a process called chemosynthesis." My question is, why can't a very different kind of life form evolve to sentience on another planet? This opens up a myriad of opportunities for a writer as long as one "rule" is observed . . . commonality within a closed evolutionary system should be maintained.
Precisely! A virus is not considered to be living because it doesn’t do this, that, or the other thing. I do not remember the list of requirements, but that is unimportant. What is important is that the definition is man made! When we go looking for life out there, are we really going to apply these same rules? Are we going to say, politely, to the being who has just greated us warmly into their ship, "Sorry, you are not alive because you do not excrete." Really? Is that how it's going to be?
It is cool to get a biology lesson here as well as help with writting. Is it possible that life could be based on somet other building blocks besides carbon. Silicon seems popular in sci-fi like X-Files or the movie With Duchovny and Orlando Jones. It was like ghost busters with aliens though. And what is this I hear about some creatures evolving on earth faster than we are now. Could they eventualy catch up with us liek the movie Mimic hints. And Racoon's have Oposable Thumbs(The thing that supposedly makes us superior) Why are there no Racoon men Running around building fire and driving cars
