Answer:
abiogenesis
Explanation:
a (not) biogenesis (coming from other life forms)
Biogenesis would mean that it's coming from other life forms,
Natural selection is a part of evolution (what is there to select?)
Variation is also a part of evolution (not related)
Cartilage is a flexible connective tissue that differs from bone in several ways. For one, the primary cell types are chondrocytes as opposed to osteocytes.
Explanation:
The modern theory of chemical evolution is based on the assumption that on a primitive earth a mixture of simple chemicals assembled into more complex molecular systems, from which, eventually came the first functioning cell(s).
