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worldgen:planets:lifelevel [2009/07/25 14:20]
sam
worldgen:planets:lifelevel [2018/01/14 11:44] (current)
sam
Line 2: Line 2:
  
 The //life level// of a world defines (in very broad terms) how advanced native life is on the world. It ranges from no life at all, through simple single celled organisms, to land animals and extensive (Earth-life) conditions. The //life level// of a world defines (in very broad terms) how advanced native life is on the world. It ranges from no life at all, through simple single celled organisms, to land animals and extensive (Earth-life) conditions.
- 
-The life level of a planet is defined in the enum [[http://​mapcraft.svn.sourceforge.net/​viewvc/​mapcraft/​trunk/​traveller/​src/​uk/​org/​glendale/​rpg/​traveller/​systems/​codes/​LifeType.java?​view=markup|LifeType]] 
  
 See: See:
  
-  * [[./​LifeLevel/​Proteins]] +  * [[./​LifeLevel/​Organic]] 
-  * [[./​LifeLevel/​Protozoa]] +  * [[./​LifeLevel/​Archaean]] 
-  * [[./​LifeLevel/​Metazoa]]+  * [[./​LifeLevel/​Aerobic]]
   * [[./​LifeLevel/​ComplexOcean]]   * [[./​LifeLevel/​ComplexOcean]]
   * [[./​LifeLevel/​SimpleLand]]   * [[./​LifeLevel/​SimpleLand]]
   * [[./​LifeLevel/​ComplexLand]]   * [[./​LifeLevel/​ComplexLand]]
   * [[./​LifeLevel/​Extensive]]   * [[./​LifeLevel/​Extensive]]
 +
 +//Organic// and //​Archaean//​ are quite common on worlds that could potentially support life, but life becomes significantly rarer as you move up through the classifications.
  
 ===== Evolution ==== ===== Evolution ====
  
-The evolutionary path on Earth can be considered to have been something ​like the following.+The evolutionary path on worlds ​can be very different in the details, but the initial steps are broadly similar at the high level. Diversity really comes in beyond the //Aerobic// stage. 
 + 
 +==== Early Life ==== 
 + 
 +[[:​worldgen:​commodity:​organicchemicals]] originally formed, which were simple amino acids. Most worlds with liquid water will form basic organic molecules ​like this, but few progress any further. Such worlds have an [[./​LifeLevel/​Organic]] classification. 
 + 
 +[[:​worldgen:​commodity:​protobionts]] are a form of non-living matter that is the precursor to living matter, and are a more complex form of //Organic Chemicals//​. 
 + 
 +The marker for [[./​LifeLevel/​Archaean]] worlds is the rise of [[:​worldgen:​commodity:​prokaryotes]],​ which are the first living organisms. They are very basic cellular life. Once they arise, they quickly come to dominate the ecosystem. They may be found in trace amounts on //Organic// worlds, but an //​Archaean//​ world will be dominated by //​Prokaryotes//​ or more complicated forms of life. 
 + 
 +Within a few tens of millions of years, these give rise to some form of [[:​worldgen:​commodity:​cyanobacteria]],​ which make use of photosynthesis for energy and produce oxygen. Because they are so much more efficient, they quickly come to dominate the biosphere, and are probably dominant during the late stages of //​Archaean//​ worlds. 
 + 
 +However, their production of oxygen changes the biosphere, and turns //​Archaean//​ worlds into [[./​LifeLevel/​Aerobic]] worlds. 
 + 
 +[[:​pcl:​EoGaian]] worlds are pre-Aerobic,​ with a mostly methane atmosphere. Once the life classification changes from //​Archaean//​ to //​Aerobic//,​ then terrestrial worlds is classes as [[:​pcl:​MesoGaian]]. 
 + 
 +==== Metazoa ====
  
-[[:​worldgen:​commodity:​base organics]] originally formedwhich were simple amino acidsThese gave way to [[:​worldgen:​commodity:​simple organics]] which were more complex ​and capable ​of simple ​replicationmaking them the first living things.+With the rise of oxygen, so the [[./​LifeLevel/​Aerobic]] stage is reached. ​[[:​worldgen:​commodity:​plankton]] consumes smaller life formsforcing the evolution of larger and more complex organismsLarger varieties of algae becomes ​[[:​worldgen:​commodity:​seaweed]] and [[:​worldgen:​commodity:​jellyfish]] evolve. Eventually, the arrival ​of [[:​world:​commodity:​simple ​marine]] organismssuch as starfish, sea urchins and worms marks the last stages of the Aerobic classification.
  
-The first multi-celled organisms arose in the [[./​LifeLevel/​Metazoa|Metazoan]] period, ​are are classed as [[:​worldgen:​commodity:​metazoa]]. +The [[./​LifeLevel/​ComplexOcean]] period ​is heralded by the arrival of [[:​worldgen:​commodity:​crustaceans]], [[:​worldgen:​commodity:​fish]] and other free swimming vertebrates
  
 ===== Alien Evolution ===== ===== Alien Evolution =====
  
 The above assumes that things progress in much the same way as they did on Earth. This is unlikely, but easy. The above categories probably fit most evolutionary paths, however the details of each are unlikely to be the same on all worlds - e.g. when grasses first evolve and so on. The above assumes that things progress in much the same way as they did on Earth. This is unlikely, but easy. The above categories probably fit most evolutionary paths, however the details of each are unlikely to be the same on all worlds - e.g. when grasses first evolve and so on.
worldgen/planets/lifelevel.1248531623.txt.gz · Last modified: 2015/02/04 22:39 (external edit)