Offspring Development Conditioning (ODC): A Universal Trend in Evolution of Higher Organisms’ Reproduction

Abstract All organisms evolve, according to Darwin. The question is how? Is there any general pattern or trend in the organisms’ evolution? These are rarely asked – and almost never answered – questions. This situation makes the evolution frustrating and mysterious to many. Here, after surveying the reproductive modes in most animals and plants, we propose that all (at least most) of higher organisms demonstrate the similar trend underlying their reproductive evolution, namely, Offspring Development Conditioning (ODC). Such a pattern makes the origin and evolution of reproductive organs in both animals and plants rational and understandable. To the best of our knowledge, this pattern appears universal, although we encourage future authors to identify exceptions. We hope this will help frame the evolution of higher animals and plants, and make the latter understandable to the public.