Changes

It is believed that approximately one thousand Space Marine Chapters exist at all times though extremely violent warzones, attrition, space phenomena and other factors change the number of Chapters so radically no one can track them accurately. {{Citethis}} Over half (60%) of all Space Marine Chapters were descendants of [[Ultramarines]] genestocks,{{Fn|11c}}{{Fn|11d}} by the start of the 41st millennium, this percentage had increased to over two-thirds (67%) of chapters.{{Fn|76}} During the [[Pariah Crusades]], [[Apothecary Biologis]] [[Brutus (Apothecary)|Brutus]] stated that three out of four (75%) Successor Chapters are of Ultramarines lineage,{{Fn|79}} suggesting the percentage is increasing. This massive proportion of Ultramarines successors is partly due to the stability of Ultramarine gene-seed, and also due to the large quantity of available gene-seed.{{Fn|76}}