According to bio-evolutionary theory, when were most fossils formed?

The theory of bio-evolution emphasizes that most fossils formed gradually over millions of years through processes such as sedimentation and mineralization. This gradual formation is consistent with the slow pace of evolutionary changes that occur within populations over long timeframes. As organisms lived and died, their remains were buried under layers of sediment, which eventually hardened into rock, preserving the evidence of life. This process reflects the continuity and gradual change in the history of life on Earth, evident in the fossil record, which showcases transitional forms and the diverse stages of evolution.

In contrast, options suggesting sudden fossil formation, such as during volcanic activity or instantly through divine intervention, do not align with the established scientific understanding of how fossilization typically occurs. The notion that fossils only formed during the last Ice Age is also inaccurate, as the fossil record extends back to much earlier geological periods, indicating a much longer timeline of biological development.