PALEOBIOLOGY  OF  ARIDA

IN THE BEGINNING

The Planet Arida is approximately 6.5 billion years old.  It is older than the planet Earth, and so is its life.   Life forms first appeared on Arida almost 6 billion years ago - predating life on Earth by at least 2 billion years!  Like the earliest life on Earth, life on Arida is thought to have begun in an ancient aqueous solution. Arida is a relatively dry planet today, but it is also a planet with an extensive past. Water was plentiful in the early geological history of Arida. In the distant past, as the planet Arida formed so did a vast ocean that entirely encircled the planet. The ancient ocean was rich in the chemical precursors needed for the genesis of living organisms. This kind of aqueous solution is known as a "primordial soup." The primordial soup of Arida contained water, carbon compounds, nitrogen, as well as trace amounts of virtually every known element in the Universe.  The early atmosphere of Arida was mainly comprised of hydrogen, carbon dioxide, carbon monoxide, ammonia, methane, and nitrogen.  Water vapor was produced from venting due to heavy volcanic action and heating of the oceans.  Water was also brought to the surface from meteorites and comets.

ancient Arida oceanscape
 

THE FIRST CELLS 

Life began on Arida as the chemicals in the ancient primordial soup combined to produce a cellular organism capable of harnessing energy and replicating itself.  The first life forms to arise on Arida were rudimentary single cell organisms known as “Primordia.”  The earliest Primordia cellular organisms used RNA as the genetic material to replicate themselves by a simple process of binary fission. The RNA seems to have developed from PNA (peptide nucleic acid). The first of these prokaryotic cells were autotrophs, they synthesized their own energy by harnessing the solar energy of the star Venda.  Ancient Arida was void of oxygen, and the first Primordial cells were anaerobic – they did not require oxygen to survive.  Primordia contained chloroplast like structures.  Primordia produced sugars and oxygen from water and carbon dioxide, using the process of photosynthesis to use the energy of sunlight. Oxygen was used by the cells in the process of respiration.  Mitochondria were found in Primordia.  As the Primordia basked and flourished in the vast ancient oceans of Arida they released copious amounts of oxygen gas into the oceans. 
Ancient Primordia cell
Gradually, after several hundred million years the ocean water could no longer hold any more oxygen, and the atmosphere slowly began storing the vital gas.  Ozone formed as the oxygen built up in the atmosphere, shielding the planet from the harmful ultraviolet solar radiation that had limited the earliest life forms to the seas where water had protected the early life forms from harmful radiation. 

The Primordia arose near the shores of the ancient oceans of Arida.  It was here where the precursor chemicals needed for life accumulated, and the first cells were able to form.  Ocean currents and rainwater runoff carried the material needed to form cells.  The shallow water was likewise warm enough for biological processes to emerge.   It is possible that the first cells formed in a lagoon or other body of water that was cut off from the main body of water.  As water evaporated at a greater rate than it was replenished, chemicals could concentrate into more viable life giving liquids.  Life itself may have been initiated by the energy provided by lightning

LIFE EVOLVES

The first Primordia cells did not have any mobility mechanism – they simply drifted with the tides and currents of the oceans and waters in which they lived.  These ancient Primordia resembled a sort of primitive algal form not unlike the plankton found on Earth.  Eventually, other forms of life evolved from the ancient Primordia. 

Ubber Primordia directly evolved from the early Primordia forms.  The genetic material of the Ubber Primordia was DNA and sexual reproduction became the primary mechanism for replication.  Ubber Primordia organized the DNA within a cell nucleus – they were essentially eukaryotes. From the Ubber Primordia many life forms emerged. Most developed mechanisms for self-locomotion.  Multicellular life forms eventually emerged from these early organisms and began to take center stage.  Life was able to move from the sea to the land.  Heterotrophs and decomposers joined autotrophic forms.

 

COMMON PRIMORDIA TYPES

Ciliated Primordia : The ciliated Primordia cellular organisms are able to move about by way of using their hair like cilia to essentially paddle their way about.  Most Ciliates retain their photosynthetic capabilities and will respond to light stimulus in the search of energy.  The feeding habits of Primordial ciliates of Arida are similar to the euglenas of Earth.  They have proved to be highly adaptable. 

Adridan False Foot : The Aridan False Foot is much like the pseudopodia found on Earth.  It has no chloroplasts and has lost its photosynthetic ability.  It is a dedicated consumer.  It oozes about encircling and engulfing its food. 

Flagellated Primordia : The flagellated Primordia of Arida are also entirely heterotrophic.  Their flagella enable these cells to rapidly move about in search of food.  Flagellated Primordia have been enormously successful on the planet Arida. 

Primordia Photosythia :  Photosynthetic forms of Primordia are highly abundant on Arida.  Their ability to synthesize food by photosynthetic means has proved essential to their survival over the centuries.  Most forms still resemble the ancestral cellular organism.  P. Photosynthia is most akin to the Blue-Green algae on Earth, and they share the ability to "fix" nitrogen. Many other photosynthetic life forms of Arida are believed to have evolved from the Photosynthia.

Aridan Micro Jelly : The Aridan Micro Jellys are a most unusual organism.  Their shapes resemble miniature jelly fish.  "Micro Jellys" are a primitive unicellular organism.  Micro Jellys have also lost photosynthetic abilities, and most cellular structures are not well defined.  They move about in a similar fashion to the jelly fish of Earth, by a propulsive undulatory motion.  Though Micro Jellys are common in water environments much of their life cycle and habits remain a mystery. 
 

Many of the Primordia cellular forms have been found to thrive in the extreme environments found on Arida.  There are plenty of extremophiles to be found on the planet, a good many of which are decidedly thermophiles or even psychrophiles.  Temperatures often are extreme on the planet and the organisms have adapted.  All Primordia organisms are dependent on water for survival, and they are usually found in association with other life forms.  Primordia have been shown to form endospores in conditions void of water.

Larger forms of life have evolved as well.  Fungus like organisms became dominant for a time – they can still be found on Arida to this day.  Among the early groups of organisms were creatures that resembled jellyfish, sponges, corals, giant insects, snakes, lizards, fish, and birds.  Plant life evolved on land and in the seas.  Plants readily adapted to the conditions as they changed over time, and continue to thrive on the planet today.

TIME LINE

The evolution of life on the planet Arida has been a continuously ongoing process stretching back nearly 6 billion years.  Today life on Arida is well adapted to the extreme environments found in the biosphere of Arida.  Life teems in the Unola Ocean, abounds on the verdant plains, and tenaciously persists in the vast expanses of desert.  The history of life on Arida has been partially deciphered by analysis of the geology and fossil record of the planet.  The record reveals a history of major epochs or eras reaching up to the present time.

Arida formed and cooled during the Formation Era.  At the end of the Formation Era Arida was almost entirely covered with water.  The great land masses materialized and oceans receded during the Primordia Era.  During this time the conditions for the first cellular life to appear were met and the ancient Primordia cells came into existence.  Approximately 2 billion years later the Ubber Primordia cellular form evolved.  Sexual Reproduction and the advent of DNA in the Ubber Primordia enable rapid evolutionary diversification and life began to flourish on Arida.  During the Mushroom Era cellular life continued to diversify.  Multicellular life forms become well established, and consumer and decomposers species evolved.  The Giant Fungi of the planet Arida evolved and gained a foothold on the planet.  In the oceans and lakes of Arida the fish like organisms are evolving.  During the last billion years life on Arida, beginning in the Terrestrial Era, diversifies and evolves even further as larger organisms advance and adapt to life on dry land.  The oceans of Arida recede even further during the Torrid Era and the Unola Ocean and Omega Desert take shape.  Global temperatures increase fairly rapidly and organisms adapted to the changing conditions.  During the Modern Era life on Arida has undergone a period of continued diversification as modern life forms evolved and established themselves throughout the massive biosphere of Arida. 
 
 

ARIDA'S  GEOLOGICAL HISTORY
 

HIGHER LIFE FORMS?

Life on Arida predates life on Earth.  While there are no known "intelligent beings" or humanoid alien races presently living on Arida, there are signs that civilization has inhabited Arida in the past.  Strange stone structures discovered in the Devil' Ear Range appear to have been purposely constructed by intelligent life forms.  Most striking is a recently found site discovered deep within the inner most canyon recesses of the Devil' Ear region.  What are apparently the ruins of an ancient pyramid structure, referred to as "The Temple"  has been discovered.  Little else has been found, and nothing else is known of the would-be builders of The Temple.  Did intelligent life evolve on Arida?  Have intelligent beings previously visited the planet?  What has become of them?  One thing is certain - Arida has witnessed much over the great expanses of time.  

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created by G.Moore