Biohistorics

Biohistorics is an academic discipline that involves the study of living organisms in the past, including their evolution, ecology, and historical demographics.

Evolution
The history of life on Tetro began approximately 4.1 billion Earth-years ago on the continent of Reldiga when carbon-based self-replicating molecules formed into protocells in Parova Canyon. Sheltered from the elements by tall overhanging cliffs, the protocells grew in size and complexity over many generations, eventually undergoing a process of organelle differentiation. These early organisms absorbed vital minerals from the rocks and sand on the lake shore, and took in sunlight for energy.

These evolved into Tetro's various life-forms over the following 3.5 billion Earth-years.

By 600 million Earth-years ago, life on Tetro had become differentiated into several species of Photonates, and a single species of Pyronate known as the Protopyronate, which would become the progenitor of all modern species of Pyronates and Magnetates. Most of these Protopyronates lived together in a single nomadic community of approximately 4,000 individuals on the southeast coast of Reldiga. Their diet consisted mainly of slimeweed, an early Photonate species that dominated the landscape due to its ability to dissolve rock with its acidic secretions and anchor itself into the cracks, thus protecting it from being torn loose by the frequent storms that plagued the region.

Dawn of Civilization
Nearly 580 million Earth-years ago, the Protopyronates discovered a way to sculpt the rocks that formed their habitat by using the acidic slime produced by slimeweed. This allowed them to carve vast tunnel networks into the coastal cliffs which provided shelter from Reldiga's brutal climate. The development of permanent dwellings allowed the Protopyronates to stockpile food and thus put an end to their nomadic lifestyle. As the community spent less time foraging for food, they began to spend more time using their newfound rock-carving skill to develop tools. The discovery of fire 577 million Earth-years ago led to the ability to forge glass and metal objects out of ores mined from within the crust. Soon writing was developed, which the Protopyronates used primarily to document their scientific and technological advancements. Most of these writings have survived to the present, preserved in libraries hidden deep inside the cliffs.

A World-Changing Discovery
By 553 million Earth-years ago, telescopes had become sufficiently powerful to detect distorted images of the Harani Nebula reflected by the gravitational lensing effect of nearby black holes. Early astronomers had a fairly solid understanding of general relativity which they used to create specially-shaped lenses that could remove the distortion. The astronomers began a systematic survey of the stars and planets visible within the nebula, recording detailed images of every object catalogued. One such image stood out from the rest: it was a large terrestrial planet with seven continents separated by vast expanses of ocean. A small continent high up in the northern hemisphere had a very familiar coastline. The resemblance to ground-surveyed maps of Reldiga was unmistakeable: for the first time, Tetrians were looking at an image of their own world. The revelation that their planet had six other continents was astounding to explorers, who had never reached another land mass in their limited sea travel.

The Great Migration

 * See Main Article: Great Migration

By 550 million Earth-years ago, the burgeoning Protopyronate civilization was determined to continue developing technology that could improve their quality of life and help them to understand the world they inhabited, but it was becoming clear that they were severely limited in this endeavor by the dearth of natural resources on Reldiga. The recent discovery of other continents offered hope for the future. It was decided that the population would be split into six groups, each of which would travel by raft to one of the other continents and attempt to establish a permanent settlement. The groups agreed to each send a delegation back to Reldiga every 4,368 Earth-years to report on the status of their settlement and share resources from their continent. Prevailing ocean currents allowed the rafts bound for Narrelia, Zorvalgia, Terrelia, Venria, and Calvesia to reach their destinations within 50 Earth-years. However, the group destined for Gamiala was hindered by the currents and had to take an indirect route which led to most of the group being lost to starvation and storms. Only 214 Protopyronates out of the original 800 arrived on the shores of Gamiala after a 447-year journey. However, they were soon rewarded for their struggle by the discovery that Gamiala had a temperate climate, fertile soil, and vast deposits of rare minerals and natural gas.