Question of the week: Are there any significant challenges to naturalistic evolution that predate the Cambrian explosion?
My answer: There are many. The origin of Earth’s first life, the origin of photosynthesis, the origin and proliferation of sulfate-reducing bacteria, the origin of eukaryotes, the origin of sex, the origin of cryptogamic soils, and the origin of the first large-bodied animals (the first and second Avalon explosions) are a few of the most outstanding pre-Cambrian challenges to naturalistic evolutionary models for the origin and history of life. In addition to these biological challenges, many features of the origin and history of the Milky Way Galaxy, the Sun, the solar system planets and asteroid/comet belts, the Earth, and the Moon must be fine-tuned to make the existence of life possible on Earth. For details and documentation see my book, Improbable Planet.