Phylogenetic/Evolutionary—Overview

The phylogenetic evolution of consciousness, at first blush, is not a specific theory of consciousness per se. Rather, it is recruited as the mechanistic process for many (but not all) of the theories on the Landscape. Yet, is there a sense in which phylogenetic evolution can become a prime explanation of consciousness in its own right?

Certainly, according to Dennett, LeDoux, and Ginsburg & Jablonka, consciousness exemplifies Theodosius Dobzhansky's famous adage, “Nothing in biology makes sense except in the light of evolution” (Dobzhansky, 1973).

Evolutionary Pathways

Neuroscientists and writers Ogi Ogas and Sai Gaddam present a step-by-step simulation of how evolution produced consciousness. It is a tale of eighteen “increasingly intelligent minds,” as they say, from the simple stimulus-response of microbes interacting with their environments to the limitless creativity of humankind (and beyond). Leveraging the “resonance” theories of Stephen Grossberg, their mentor, they tell a story of what each “new” mind could do that previous minds could not (Ogas & Gaddam, 2022).

To physicist Lawrence Krauss, “consciousness is a slippery quality because it exists on a spectrum in the evolutionary development of life that is very difficult to measure or quantify” (Krauss, 2023). He stresses “the phenomenon of consciousness is the one area I know of in science where the forefront discussions seem to be made by philosophers equally as often as they are made by experimental cognitive scientists,” which, he says softly, is “an indication of a science in its early stages” (Krauss, 2023).

Amidst the surfeit of competing neurobiological theories, Krauss is most comfortable pursuing “the possible distinct evolutionary advantages that consciousness might endow humans with.” He follows the thread that “feelings emerged as ever more complex systems evolved to incorporate higher-order cognitive processing to issues of survival and homeostasis." Consciousness, through introspection, he says, “could build on the nervous system monitoring of basic internal body conditions to produce novel, rather than innate, survival strategies. The ability to use internal representations of goals, whether from cognitive maps or stored memories, to flexibly respond to the changing environmental conditions, was a huge evolutionary leap, and has been noted to probably exist only in some mammals and perhaps in birds” (Krauss, 2023).

Philosophers David Buller and Valarie Hardcastle offer an alternative to the strong evolutionary claim that “the mind contains ‘hundreds or thousands’ of ‘genetically specified’ modules, which are evolutionary adaptations for their cognitive functions.” They argue that “while the adult human mind/brain typically contains a degree of modularization, its ‘modules’ are neither genetically specified nor evolutionary adaptations. Rather, they result from the brain's developmental plasticity, which allows environmental task demands a large role in shaping the brain's information-processing structures.” They maintain that “the brain's developmental plasticity is our fundamental psychological adaptation, and the ‘modules’ that result from it are adaptive responses to local conditions, not past evolutionary environments” (Buller & Hardcastle, 2000).

Who (and What) is Conscious?

Questions remain. What creatures are conscious, and to what degree? How low on the phylogenetic scale must one descend to wink out anything resembling human consciousness? For example, does an octopus have phenomenal consciousness? Philosopher (and scuba diver) Peter Godfrey-Smith not only affirms octopus higher intelligence, he also traces the evolution of mental properties in the primordial seas, claiming that “evolution built minds not once but at least twice (Godfrey-Smith, 2016).

Appreciating Godfrey-Smith's work, Carlo Rovelli uses the “complex intellectual abilities” of octopuses as “a valuable case study” of consciousness. In recent decades, he observes, “the phrase ‘the problem of the nature of consciousness’ has taken the place of what in the past used to be the problem of the meaning of soul, spirit, subjectivity, intelligence, perception, understanding, existing in the first person, being aware of a self …” Consciousness is neurobiological, Rovelli asserts, and one way to tackle the issue is to observe our non-human cousins and even octopuses, an extremely distant relative. The octopus, he offers, “is the extraterrestrial that we have been looking for in order to study a possible independent realization of consciousness” (Rovelli, 2020).

Raymond Tallis questions the entire enterprise of assuming “the [evolutionary] advantage of being a conscious organism rather than a self-replicating bag of chemicals innocent of its own existence.” His skeptical argument against “what seems like a no-brainer” is “not to start near the end of the story, with complex, sophisticated organisms such as higher mammals … [whose] life depends on conscious navigation through the world.” No, he says, “we must begin at the beginning: by asking, for example, what survival value is conferred on a photosensitive cell in virtue of its organism being aware of the light incident upon it. And the answer appears to be: ‘none.’” Tallis argues, “If there's no reason to believe that the sentience of primitive organisms would give them an edge over the competition, there is no starting point for the evolutionary journey to the sophisticated consciousness we see in higher organisms like you and me.” The mystery of consciousness, he concludes, “remains intact” (Tallis, 2023).

Most experts, scientists, and philosophers who study the evolution of mind support a gradual, incrementalistic theory of mental development, much like Dennett, Godfrey-Smith, and Ogas/Gaddam. There are dissenting voices: for example, Nicholas Humphrey and perhaps Noam Chomsky.

Here's the point. In considering the multifarious theories on the Landscape of Consciousness, one should overlay each theory with its putative phylogenetic evolutionary development. Ask, “What was the process that brought it about?”