Biochemistry
A creature's biochemistry is the collection (sum total) of its chemical reactions. A realistic biochemistry with analagous chemicals, emitters and receptors to the real world is a big part of making creatures act realistically, because when their brains are linked up to monitor chemicals they can decide things like "maybe it would be a good idea to eat some food when my glycogen level is low".
This is also a good place to look when creatures are behaving oddly, as a mutation may have caused a positive reinforcement loop in their brain regarding ideas like walking into walls.
In Creatures 2 and Creatures 3, some of the genes involved in biochemistry depend on the organ that contains those genes being alive: so heavy metal poisoning or other diseases can cause a creature to lose some important biochemical reactions.
Half-lives
The half-life of any chemical, either in the Creatures series or our own universe, is the time it takes for a given amount of any chemical to decay to half the original value. In Creatures, altering this can have profound effects on biochemistry.
In creatures, the half-life of any chemical is determined by a big gene called, oddly enough, the half-life gene. The half-life gene is the longest gene in a creature, as it contains the decay rates of all the chemicals in a creature's biochemistry. A common mutation of the half-life gene produces a longer half-life for ageing or life, leading to longer-lived creatures.
As of Creatures 2, if you hex edit a gene file, and change the decay rate to values that are not in the included table, you will just get the same behaviour as the nearest lower value in the table. For example, any value from 0 to 7 will behave as 0 does, and any value from 64-71 will behave the same as 64. source
See biological half-life on Wikipedia for more on the real-life topic.
Emitters
An emitter (or chemoemitter) releases chemicals into the "bloodstream" of a creature, affecting its biochemistry. An emitter gene controls what chemical, how much, and under what circumstances.
One common mutation in this gene in C1 was instead of an emitter emitting DecASH all the time, it emitted alcohol instead, leading to a creature that was permanently drunk. Slave suffered from this mutation.
Creatures 1 Emitters
organ | tissue | locus | description |
---|---|---|---|
Brain (0) | lobe id (n) | Activity (0) | Lobe activity - # of neurons firing |
Numloose0 (1) | # Loose dendrites/neurons of type 0 | ||
Numloose1 (2) | # Loose dendrites/neurons of type 1 | ||
Output (n) | Output of neuron n - 3 | ||
Creature (1) | Somatic (0) | Muscles (0) | Muscle energy used this tick |
Circulatory (1) | Floating (0..7) | A floating recip-emit is a place that a receptor can use for storing a data value from 0-255 which an emitter can then use for any purpose. It's a means of linking a receptor directly to an emitter without going through a brain lobe. There are up to eight of these numbered from 0-7. The life kit norns use this for the hunger/glycogen equation. | |
Reproductive (1) | Fertile (0) | This will be a value of 0 until the norn becomes fertile in which case it will be 255. | |
Pregnant (1) | This will be a value of 0 until the norn becomes pregnant in which case it will be 255. | ||
Immune (3) | Dead (0) | 255 if dead, else 0 | |
Sensorimotor (4) | Const (0) | Always produces a value of 255 | |
Asleep (1) | 255 if asleep, else 0 | ||
Coldness (2) | Not connected in Creatures 1 | ||
Hotness (3) | Not connected in Creatures 1 | ||
Light level (4) | A value from 0-255 indicating the light level | ||
Crowdedness (5) | How many and how close others of your kind are | ||
Drives (5) | Drive (0..17) | The current value of a given drive |
Receptors
Receptors monitor chemical levels and change the brain's behaviour - for example, shivering to relieve coldness. They are fed by emitters. One of the things that receptors do is monitor the ageing or life chemical and tell the norn when to change life stages. In some instances, receptors may control the reaction rate of a chemical reaction.
In C3, receptors were updated to bind to the reaction rate locus as well as the organ clockrate locus.
See also
- Biochemistry Set (C3/DS)
External links
- A good illustrational overview of creature biochemistry
- Norn Biochemistry 101: A peek inside a Norn - the nitty gritty
- GEN File Format - Biochemistry at the CDN
- Genetics Lesson: Examining a Creatures Half-Life at Discover Albia - contains a table of half-life numerical values compared to real-world time for C1, C2 and C3/DS.
- Half-Lives and Other Genetic Mysteries at Naturing::Nurturing - critiques the official Genetics Kit's information about halflife times.
- Chemical emitter at the Creatures Developer Resource
- Receptor at the Creatures Developer Resource