Hiyas!

From a noob:

Do the SMs in a chapter look more alike, the "purer" it is? For instance, the Space Wolves - could they be almost "clones" in appearance? What about the Ultras?

Thanks!

L

Yes and no. Most space marines take on certain aspects of their Primarch's body as a result of the implant process. Though this doesn't have much of an effect, and only really seems to affect the Blood Angels all that much.

But, one of the implants (which is cannot remember the name of right now) allows a space marine to change his skin tone to better survive on a given planet.

In other words, there might be some similarity in marines form the same chapter they definately are not clones.

In most of the fluff the Marines keep most of their characteristics from before they were given the Gene-Seed. There may be some change though, such as adopting some of the more prominent features of their primarch.

They are by no means clones however.

To clarify further; it may be as if they are members of the same family, but they will not be identical twins.

One notion that recurs in 40K fiction is that to outsiders, Marines of most Chapters look almost like clones... but to the Astartes themselves, they look and act entirely differently from one another. It's certainly possible that a non-Astartes could confuse or mistake two brethren of the same Chapter for each other.

On the other hand, it's improbable that a Space Wolf might be mistaken for an Ultramarine, or for a Salamander.

Things to consider:

Recruitment. Chapters which recruit from a single home world (like the Space Wolves, from Fenris) will probably have a little bit more resemblance to each other than chapters which recruit from many worlds (like the Black Templars, or Dark Angels).

Geneseed Idioscyncracy: Some chapters have mutated geneseed which affects appearance to a greater or lesser degree. All Raven Guard are pale with dark hair and black eyes. All Salamanders are ebony skinned with glowing red eyes. All Space Wolves (are supposed to) have their hair turn grey by the time they are a Grey Hunter. Marines from these chapters will look much more similar to each other than they would to some other Marines. No one is going to confuse a Salamander for a Raven Guard.

Geneseed Changes. Regardless of his appearance before becoming a space marine, every marine's bones lengthen and thicken. Every marine develops additional musculature. Every marine has a black carapace implanted. Regardless of what they look like, they are all changed in the same way. Think of taking different video game character "skins" and stretching all of them over the same bulky, muscular body shape.

In short, there's NO way that " all Marines look alike". However, it is quite plausible that if you only interact with a few marines from a few chapters, you might think that they all look a lot alike. If you've only ever seen 5 marines, and three were from the Ultramarines, and two were from the White Consuls, you might think they all look alike.