Changes

It takes a considerable amount of time to transform normal [[human]]s into [[Space Marine]]s. They receive implants known as [[gene-seed]] which transform their bodies and give them superhuman abilities - making them capable of spitting corrosive venom, absorbing the memories of the dead by eating their flesh, darkening their skin to protect it from radiation, and operating for long periods without sleep by switching off parts of their brains at a time.{{Fn|1}}{{Fn|2a}}{{Fn|3}} Wounds suffered by a Space Marine that would take a baseline [[human]] months to heal, if they ever healed at all, take only days to recover from.{{Fn|17}}

Recruits are subjected to psycho-indoctrination and conditioning, strengthening their resolve and honing them into dedicated and merciless warriors. Not all recruits survive the brutal training, of course, and not all are accepted.{{Fn|1}}

Recruits are typically chosen from the best warriors among humanity. Naturally this makes [[Death World|Death]] and [[Feral World]]s prized recruitment grounds, as such harsh and primal conditions produce the best warriors. However, [[hive world]]s are considered the ideal source of potential recruits; while the populace of the lower levels are often composed of some of the most murderous scum in the human [[Imperium]], more importantly, the higher the population of a world, the higher the chance to find truly impressive individuals. Whole gangs of hive scum are sometimes hunted down and captured for recruitment, although chapters typically prefer volunteers. Among the most valued traits in a recruit are aggression and psychotic-level killer instinct. More rarely, certain [[civilized world]]s are also recruited from.{{Fn|4}}

Recruits must be fairly young, because implants often do not become fully functional if the recipient has reached a certain level of physical maturity. They must be male because the geneseed zygotes are keyed to male hormones and genetic structure. Only a small percentage of people are compatible with the implants and hypno-suggestion necessary to turn them into Marines. Before the process of implantation begins the potential recruit receives tissue compatibility tests and psychological screening. If the testing proves successful the recruit becomes an [[aspirant]]. After the organ implantation process begins he becomes a [[neophyte]]. When the final implant is in place and the requisite training and hypnotherapy complete, he becomes a full [[brother]].{{Fn|1}}{{Fn|2a}}{{Fn|3}}

Even once the organs are implanted they are generally inactive or useless without associated training, hypnotherapy, and chemical treatment. Most recruits join the ranks as a [[brother]] between the ages of 16-18 years.{{Fn|2b}}

**If the Marine is receiving Primaris implants, the Sinew Coils and Magnificat are introduced between Phases 3 and 4, in that order or simultaneously; their ideal age is 12-13. The Belisarean Furnace is ''presumably'' introduced during this time as well, but in what order, and at what ideal age, is unknown; apparently all three are always introduced across at most 2 steps, so the Furnace is presumably always simultaneous with at least one of the other two. These 1-2 phases are unnumbered, and are instead known as the Primaris Alpha and Primaris Beta phases.

'''Phase 1:''' This simplest and most self-sufficient of implants allows a Space Marine to survive his other heart being damaged or destroyed, and to survive in low oxygen environments. Not just a back-up, the secondary heart can boost the blood flow around the Marine's body.{{Fn|1}}{{Fn|2a}}{{Fn|3}}

'''Phase 2:''' A small, complex, tubular organ, the ossmodula secretes hormones that both affect the ossification of the skeleton and encourages the forming bone growths to absorb ceramic-based chemicals that are laced into the Marine's diet.{{Fn|1}}{{Fn|2a}}{{Fn|3}} This drastically alters the way a Space Marine's bones grow and develop. Two years after this implant is first put in the subject's long bones will have increased in size and strength (along with most other bones), and the rib cage will have been fused into a solid, bulletproof mass of interlocking plates.{{Fn|1}}{{Fn|2a}}{{Fn|3}} It is not clear how a Space Marine's (non-implanted) lungs operate without a rib cage that can expand and contract.

'''Phase 3:''' This small, circular organ is inserted into the chest cavity and releases hormones that vastly increase muscle growth throughout the marine's body. It also serves to form the hormonal basis for many of the later implants.{{Fn|1}}{{Fn|2a}}{{Fn|3}}

'''Phase 5:''' A liver-shaped organ about the size of a golf-ball, this implant is placed within the chest cavity and connected to the circulatory system. It generates and controls 'Larraman cells', which are released into the blood stream if the recipient is wounded. They attach themselves to leukocytes (white blood cells) in the blood and are carried to the site of the wound, whereupon contact with air they form a near instant patch of scar tissue, sealing any wounds the Space Marine may suffer - acting like platelets, only better.{{Fn|1}}{{Fn|2a}}{{Fn|3}}

'''Phase 6:''' Implanted into the back of the brain, this pea-sized organ influences the circadian rhythms of sleep and the body's response to sleep deprivation. If deprived of sleep, the catalepsean node cuts in. The node allows a Marine to sleep and remain awake at the same time by switching off areas of his brain sequentially. This process cannot replace sleep entirely, but increases the Marine's survivability by allowing perception of the environment while resting{{Fn|1}}{{Fn|2a}}{{Fn|3}}. This means that a Space Marine needs no more than 4 hours of sleep a day, and can potentially go for 2 weeks without any sleep at all.{{Fn|1}}{{Fn|2a}}{{Fn|3}}

'''Phase 7:''' This is essentially a pre-stomach that can neutralise otherwise poisonous or indigestible foods. No actual digestion takes place in the preomnor, as it acts as a decontamination chamber placed before the natural stomach in the body's system and can be isolated from the rest of the digestive tract in order to contain particularly troublesome intake.{{Fn|1}}{{Fn|2a}}{{Fn|3}}

'''Phase 8:''' This implant, also called ''"the Remembrancer"'', allows a Space Marine to 'learn by eating'. It is situated in the spinal cord but is actually part of the brain. Four nerve bundles are implanted connecting the spine and the stomach wall. Able to 'read' or absorb genetic material consumed by the marine, the omophagea transmits the gained information to the Marine's brain as a set of memories or experiences. It is the presence of this organ which has led to the various flesh-eating and blood-drinking rituals for which the Astartes are famous, as well as giving names to chapters such as the [[Blood Drinkers]] and [[Flesh Tearers]]. Over time, mutations in this implant have given some chapters unnatural cravings for blood or flesh.{{Fn|1}}{{Fn|2a}}{{Fn|3}}{{Fn|6}}

'''Phase 9:''' This additional lung activates when a Space Marine needs to breathe in low-oxygen or poisoned atmospheres. The natural lungs are closed off by a sphincter muscle associated with the multi-lung and the implanted organ takes over breathing operations. It has highly efficient toxin dispersal systems.{{Fn|1}}{{Fn|2a}}{{Fn|3}} The multi-lung even allows space marines Space Marines to breathe water.{{Fn|19}}{{Fn|20}} Space Marines are also able to hyper-oxygenate their blood by employing their third lung through panting. By doing this, a Marine can, for example, avoid passing out during a [[drop pod]] insertion onto a planet.{{Fn|23}}

'''Phase 11:''' Not only does this implant make a Space Marine immune to dizziness or motion sickness, it also allows Space Marines to consciously filter out and enhance certain sounds. To such an extent that a Marine is able to distinguish a human heartbeat from a kilometre away.{{Fn|22}} The Lyman's Ear completely replaces a Marine's original ears. It is externally indistinguishable from a normal human ear.{{Fn|1}}{{Fn|2a}}{{Fn|3}}

'''Phase 12:''' Initially implanted above the brain, this membrane eventually merges with the recipient's entire brain. Ineffective without follow-up chemical therapy and training, with sufficient training a Space Marine can use this implant to enter a state of suspended animation, consciously or as an automatic reaction to extreme trauma, keeping the Marine alive for years, even if he has suffered otherwise mortal wounds. Only the appropriate chemical therapy or auto-suggestion can revive a Marine from this state. The longest recorded period spent in suspended animation was undertaken by Brother [[Silas Err]] of the Dark Angels, who was revived after 567 years{{Fn|1}}{{Fn|2a}}{{Fn|3}} (d.321.[[M37]]){{Fn|11}}

'''Phase 13:''' This implant controls the amount of melanin in a Marine's skin. Exposure to high levels of sunlight will result in the Marine's skin darkening to compensate. It also protects the Marine from other forms of radiation.{{Fn|1}}{{Fn|2a}}{{Fn|3}}

'''Phase 14:''' In conjunction with the secondary heart this implant allows a Space Marine to filter his blood very quickly, rendering him immune to most poisons. This action comes at a price, however, as this emergency detoxification usually renders the Marine unconscious while his blood is circulated at high speed. The organ's everyday function is to monitor the entire circulatory system and allow other organs to function effectively.{{Fn|1}}{{Fn|2a}}{{Fn|3}}

'''Phase 16:''' This implant allows a Space Marine to sweat a substance that coats the skin and offers resistance to extreme heat and cold and can even provide some protection for the marine in a vacuum. This can only be activated by outside treatment, and is common when Space Marines are expected to be fighting in vacuum.{{Fn|1}}{{Fn|2a}}{{Fn|3}}

'''Phase 18:''' There are two of these glands, one situated in the neck and the other within the chest cavity. These glands are vitally important and represent the future of the Chapter, as the only way new gene-seed can be produced is by reproducing it within the bodies of the Marines themselves. This is the implant's only purpose. The glands absorb genetic material from the other implanted organs. When they have matured, each gland will have developed a single gene-seed corresponding to each of the zygotes which have been implanted into the Marine.{{Fn|1}}{{Fn|2a}}{{Fn|3}}

'''Phase 19:''' The most distinctive implant, it resembles a film of black plastic that is implanted directly beneath the skin of the Marine's torso in sheets. It hardens on the outside and sends invasive neural bundles into the Marine's body. After the organ has matured the recipient is then fitted with neural sensors and interface points cut into the carapace's surface.{{Fn|1}}{{Fn|2a}}{{Fn|3}} This allows a Space Marine to interface directly with his [[Power Armour]]. Without the Black Carapace many of the systems of the power armour will not function. While driving the vehicles of the Chapter, a special spinal interface plugged into the power armour and Black Carapace provides the Space Marine an intuitive 'feel' for vehicles systems and controls, literally making him a part of his vehicle.{{Fn|7}} A similar [[imperial bionics|cybernetic]] used by the [[Imperium of Man]] is the [[Mind Impulse Unit]].

*'''Chemical Treatment''' - Until his initiation, a Marine must submit to constant tests and examinations. The newly implanted organs must be monitored very carefully, imbalances corrected, and any sign of maldevelopment treated. This chemical treatment is reduced after completion of the initiation process, but it never ends. Marines undergo periodic treatment for the rest of their lives in order to maintain a stable metabolism. Marine power armour contains monitoring equipment and drug dispensers to aid in this.{{Fn|1}}*'''Hypnotherapy''' - As the super-enhanced body grows, the recipient must learn how to use his new abilities. Some of the implants, specifically the phase 6 and 10 implants, can only function once correct hypnotherapy has been administered. Hypnotherapy is not always as effective as chemical treatment, but it can have substantial results. If a Marine can be taught how to control his own metabolism, his dependence on drugs is lessened. The process is undertaken in a machine called a [[Hypnomat]]. Marines are placed in a state of hypnosis and subjected to visual and aural stimuli in order to awaken their minds to their unconscious metabolic processes.{{Fn|1}}*'''Indoctrination''' - Just as their bodies receive 19-22 separate implants, so their minds are altered to release the latent powers within. These mental powers are, if anything, more extraordinary than even the physical powers described above. For example, a Marine can control his senses and nervous system to a remarkable degree, and can consequently endure pain that would kill an ordinary man. A Marine can also think and react at lightning speeds. Memory training is an important part of the indoctrination, too. Some Marines develop photographic memories. Obviously, Marines vary in intelligence as do other men, and their individual mental abilities vary in degree.{{Fn|1}}