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| Nom, nom, nom... |
How come almost no designers or worldcreators thinks about where and what their beings are coming from? And how a different evolution on a very different planet would affect life. The only way mamals could be on top of things here on Earth is because the dinosaurs died out 65 mio years ago, and left the place to us! 
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| Bilba Baggins. Art by lanimalu |
Apollo 11 was the spaceflight that landed the first humans on the Moon, Americans Neil Armstrong and Buzz Aldrin, on July 20, 1969, at 20:18 UTC. Armstrong became the first to step onto the lunar surface six hours later on July 21 at 02:56 UTC. Armstrong spent about two and a half hours outside the spacecraft, Aldrin slightly less, and together they collected 47.5 pounds (21.5 kg) of lunar material for return to Earth. A third member of the mission, Michael Collins, piloted thecommand spacecraft alone in lunar orbit until Armstrong and Aldrin returned to it just under a day later for the trip back to Earth.- From wikipedia
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| Art by James Hance |
In many ways this plot of Episode VII is an echo of A New Hope. Instead of R2 coming to Tatooine it's a hand falling from the sky, but the basic sweep of the story is similar, and intentionally so. But things that seem familiar may not be as familiar as you think - don't assume that every ice or desert planet in the galaxy has already been visited, if you know what I'm saying. "
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| Anyone for squidditch? |
The connection between anomalocarids and today's animals has long been a source of debate, and some paleontologists believed that there was no way to classify them properly. But thanks to Cong and his team, we have some strong evidence that arthropods — a group containing spiders, crabs, scorpions, and centipedes — are the distant descendants of these anomalocarids.A team of paleontologists led by Peiyun Cong found three gorgeously-preserved anomalocarid fossils in Yunnan Province, and described them today in Nature.
The main overlap between the two groups, separated by 500 million years of evolution, is their brain structure. Arthropods have segmented, compartmentalized heads like anomalocarids. Plus, their brains connect to those "front appendages" which are called mouth flaps or antennae in today's arthropods. So both groups of creatures shared a very specific physical characteristic, which was a connection between those appendages and the brain.
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| -Illustration by Nicholas Strausfeld |
And above, you can see a side-by-side comparison of one of the fossils (gray) witha a modern arthropod called an onychophoran or velvet worm (green). Long nerves from the frontal appendages extend to paired ganglia lying in front of the optic nerve and connect to the main brain mass in front of the mouth. Anomalocaridids had a pair of clawlike grasping appendages instead of feelers.
New fossil discovery of Anomalocarids actually contains traces of their brain structure — and amazingly, their half-billion-year-old brains look a lot like an arthropod's. Though some anomalocarids may have been as big as 7 feet long, these newly-discovered specimens are closer to the size of today's large insects.
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| Free Willyanomalocarid!!!! |
Using what we have learned from life on Earth, what can we say about alien life? While it would probably be vastly different from life on Earth, alien life would probably adhere to certain universal guidelines, as the widely varying life on Earth does. These guidelines or ground rules include the following:Alien life would be governed by laws of physics and chemistry.
Alien life would be based on some type of chemistry (eliminating the sci-fi concept of pure-energy beings).
- Solvent - On Earth, the solvent for all of our biochemicals is liquid water. Other chemicals could be solvents as well, such as ammonia, methane, hydrogen sulfide or hydrogen fluoride.
- Temperature - Alien life may require temperatures at which its solvent can remain liquid.
- Pressure - Alien life may require environmental pressures (and temperatures) that allow solvents to exist in three states of matter (solid, liquid, gas).
- Energy source - Living things require energy to remain organized. This energy may come from a star or from chemical or geothermal energy (as in hydrothermal vents and hot springs). On any alien world, there would have to be some source of energy to sustain life.
- Complex molecules - Living things on Earth are organized and made of complex, carbon-based molecules that carry out biochemical functions. Carbon is a versatile atom that can form bonds with up to four other atoms, in many shapes, to make molecules. Although not as versatile as carbon, silicon can also form up to four bonds with other atoms and has been proposed as a basis for molecules of alien life (silicon-carbon hybrid molecules have also been proposed). It is likely that alien life forms would have some type of complex molecule to carry out similar functions.
Alien beings that are larger than microbes would have some equivalent of cells. As an organism gets larger, its internal volume (cubic function) grows faster than its surface area (square function). This places a limit on the organism's size, because substances from the outside of the organism must pass into and throughout the organism by diffusion, which depends upon large surface areas, short distances and differences in concentrations. As an organism grows larger, the distance to its center increases and diffusion gets slower. To maintain workable diffusion distances, an organism must have many small cells instead of one large cell. So, an alien would be multi-celled if it is larger than a microbe.
- Informational molecule - In Earth organisms, deoxyribonucleid acid (DNA) is a complex molecule that carries genetic information and directs the formation of other molecules in order for life to reproduce and function. Because a characteristic of life is that it reproduces, it seems likely that alien life forms would also have some type of informational molecule.
Alien life would evolve and adapt to its surroundings by the theory of evolution as previously explained.
The physiological make-up of a multi-celled alien would be most suited to its environment. Organ systems would be adapted to environmental conditions such as temperature, moisture and gravity.
A very nice article with a very straight forward approach, focusing on the nature and evolution of an alien world and whatever life might be found there. Especially that life on that planet ought to fit into it's native ecosystems, even if it has removed itself from it's natural place in the food chain (E.g. via civilisation), it would still have kept the same traits, physically as well as psychologic.
- The alien would have some way of bringing solids, liquids and gases inside its body, distributing them to every cell and removing waste products (equivalents of heart, blood vessels and kidneys, for instance).
- The alien would be able to take in energy from its surroundings, extract the energy and eliminate wastes.
- The alien would have senses (such as sight, sound, touch) to obtain information from the environment and respond to stimuli (while we use vision as our primary sense, this may not be true of aliens). They would also have some type of brain or nervous system to process information.
Alien organisms would probably have similar ecological structures to life on Earth.
- The alien would have some means of reproduction, either sexual or asexual.
- Population sizes would be limited based on the predominance of food, predators, disease and other environmental factors.
- Alien life forms would exist in food chains and food webs in their native environment, like life on Earth. Producers will make food, consumers will eat producers and/or other consumers and decomposers will recycle atoms and molecules from dead organisms back into the environment.
As you can see, life of any kind is intimately tied to its environment, so the characteristics of the planet would be extremely important in determining the characteristics of the life form.
- Alien life forms will be integrated with their habitats and ecosystems, like life on Earth.
"From the standpoint of physics, there is one essential difference between living things and inanimate clumps of carbon atoms: The former tend to be much better at capturing energy from their environment and dissipating that energy as heat.
Jeremy England, a 31-year-old assistant professor at the Massachusetts Institute of Technology, has derived a mathematical formula that he believes explains this capacity. The formula, based on established physics, indicates that when a group of atoms is driven by an external source of energy (like the sun or chemical fuel) and surrounded by
a heat bath (like the ocean or atmosphere), it will often gradually restructure itself in order to dissipate increasingly more energy.
This could mean that under certain conditions, matter inexorably acquires the key physical attribute associated with life."
