Hooke, Fossils and the Anti-Evolutionists
The Nature and Meaning of Fossils
Before Hooke and his contemporaries Steno (Nicolaus Stenson, who in 1669 published his classic Prodromus) and John Ray (Three Physico-Theological Discourses, 1692), the nature of fossils was legitimately in doubt. But the quality of the fossils that Hooke described in Micrographia and Earthquakes forced the issue that fossilization was a process:
Those Animals or Vegetable Substances they represent (were) converted into Stone, by having their Pores fill'd up with some petrifying liquid Substance . . . .
Most fossils are not of extant species; therefore, Hooke argued, some life forms have become extinct—a view at odds with The Book of Genesis (specifically, Chapter 1, verse 25). Hooke rejected the idea that fossils were simply evidence of Noah's Flood and concluded that the earth must be far older than the 6,000 years that Bishop Ussher had so famously inferred from his 1650 study of calendars and Biblical chronologies:
I think it will be evident that it could not come from the Flood of Noah since the duration that which was but about two hundred natural days, or half an year, could not afford time enough for the production and perfection of so many and so great and full grown Shells . . . besides the quantity and thickness of the Beds of Sand with which they are many times found mixed, do argue that there must needs be a much longer time of the Seas residence above the same . . . .
Another difficulty in interpreting fossils was that they were mostly "sea-shells" yet were found on mountains, far above sea-level. Hooke recognized that present day landforms are constantly being eroded and the resulting gravel, sand and silt washed inexorably into the sea. He saw also that, if the earth consisted of the remains of different ages, buried layer upon layer, then erosion could not have continued for eons without some offsetting effect. There must have been a process responsible for "the raising of very considerable Mountains out of a plain and level Country" (earthquakes, the heat at the center of the earth and change in the earth's axis were his explanations).