Evolution and common sense
Evolution and common sense
Nothing is so difficult as not deceiving oneself
Ludwig Wittgenstein

The real purpose of (the) scientific method is to make sure Nature hasn't misled you into thinking you know something that you actually don't
Robert Pirsig
The human mind reaches conclusions quickly from readily available explanations (availability heuristic) and then resists further evidence (confirmation bias). Common sense must avoid these intellectual traps.

Common sense contradicts evolution. It sees discontinuity in nature. For example, the connection between plants and animals became clear only in the mid 19th century after the discovery of cells. Common sense provides us with limited concepts of time and no concept of how the physical world changes at timescales longer than a human lifetime. "Emergent properties" such as butterfly wing patterns or human intelligence, which are complex, easily distract common sense. Darwin had to overcome these limitations to visualize evolution.

Darwin's experiences changed his perceptions. The voyage of the Beagle was critical. During the voyage Darwin read Lyell's Principles of Geology which described how existing processes acting over long time periods could produce the known geological world. During the voyage he experienced processes that Lyell described including a volcanic eruption and a major earthquake along South America's Pacific. The drama of these events reinforced Lyell's conclusions.

Darwin also observed species that hinted at biological continuity. In Argentina he observed the rhea; locals mentioned the lesser rhea, a separate species, which he later observed and which is now named after him. He observed the Galapagos tortoise and mockingbirds which varied discretely from island to island in the Galapagos. He collected what are now known as Darwin's finches in the Galapagos. The differences among these led Darwin to conclude that they represented different families. The professional ornithologist, John Gould, recognized a closer relationship. Darwin also observed fossils in South America which differed from, but resembled, existing South American species. These were glimpses of how time and space might connect species.

The barriers which Darwin overcame, including apparent conflict of evolution with scriptures, persist today