The earliest form of life on Earth arose at least 3.5 billion years ago.
[1][2][3] Earlier physical evidences of life include graphite, a biogenic substance, in 3.7 billion-year-old metasedimentary rocks discovered in southwestern Greenland,[4] as well as, "remains of biotic life" found in 4.1 billion-year-old rocks in Western Australia.
[13] Examples of biotic materials are wood, straw, humus, manure, bark, crude oil, cotton, spider silk, chitin, fibrin, and bone.
However, not all biotic materials are used in an environmentally friendly way, such as those that require high levels of processing, are harvested unsustainably, or are used to produce carbon emissions.
In soil science, biotic material is often referred to as organic matter.