The mystery of consciousness and the tenacity of belief in mind-body dualism is still a very common refuge for theistic evolutionists, IDers, and creationists (the whole spectrum of theists basically). It makes sense too, because the workings of the brain remain the biggest remaining “black box” in biology.
1. Though there’s much we don’t understand about the evolution of human intelligence, nothing about it is especially mysterious. A specific ability to do physics, abstract philosophy, higher math, and the other problems that vexed Wallace never evolved in the first place – they require millennia of accumulated knowledge in a culture, and decades of education and honing in an individual. A more generic ability entertain concepts of number, objects, living things, causality, and so on, and to combine them into lawful generalizations, is patently adaptive, as we see in the ways that all human cultures depend on acquired technological know-how for their survival, outsmarting the fixed defenses of local flora and fauna. While human-level intelligence is species-specific (as are many zoological traits, such as the elephant’s trunk), impressive levels of numerical cognition and cause-and-effect reasoning have evolved several times, including in corvids, cetaceans, cephalopods, and primates.
2. Nor is morality any mystery. Abstract, universal morality (e.g., a Kantian categorical imperative) never evolved in the first place, but took millennia of debate and cultural experience, and doesn’t characterize the vast majority of humanity. More rudimentary moral sentiments that may have evolved – sympathy, trust, retribution, gratitude, guilt – are stable strategies in cooperation games, and emerge in computer simulations.
3. No feature of consciousness has ever been discovered that does not depend 100% on neurophysiology. Stimulate the brain with chemicals or an electrical current, and the person’s experience changes; let a person’s experience vary, and you can measure the changes in chemistry or electrophysiology. When a brain is damaged, the person’s mental life is diminished accordingly, and when the brain’s activity ceases, the mind goes out of existence – Wallace’s séances notwithstanding, no one has found a way to communicate with the dead. The very existence of a subjective correlate of brain activity may not be understood (if it’s an intellectually coherent problem at all, which some would deny), but positing a “soul” simply renames the problem with no insight, and leaves the perfect correlation between consciousness and neurophysiology unexplained.