In Mind and Cosmos, Thomas Nagel argued that there can be no materialistic neo-Darwinian explanation for how consciousness evolved, and that the only credible naturalistic alternative involves teleology: consciousness was destined to evolve. The Two-Phase Cosmology proposes that the explanation for this apparent teleology is not the undiscovered teleological laws that Nagel suggests we should be searching for, but the same thing that resolves the Hard Problem and the Measurement Problem. The Cambrian Explosion is now permitted to have the explanation that should always have been obvious. The unifying characteristic of the Cambrian fauna was that they actually look like animals as we intuitively understand that word to mean. This is in contrast to very simple animals like sponges, which many people assume to belong to some other branch of life entirely (as did early naturalists). The same applies to the Ediacaran fauna which dominated the world in which LUCAS lived – they were either sessile (they didn't move at all), or their mobility was akin to that of jellyfish. Jellyfish lack brains, and it is hard to see how they can be intuitively aware of different possible futures about which they can make decisions. Their movements are purely reflexive. They are likely to be examples of the most advanced level of behavioural complexity that unconscious animals are capable of. I obviously cannot prove this, but my tentative conclusion is that their nervous system does not cross the Embodiment Threshold. A “central processing unit” is required: a brain.
The immediate ancestors of LUCAS must have been stymied by the Frame Problem. Their increasing cognitive complexity would have amplified the combinatorial explosion of potential futures they could model, but at that point they had no mechanism to assign meaning or value. Without the capacity for valuation that only comes with consciousness, effective decision-making would have been difficult. However, so long as reality remained superposed, meaningful choice was metaphysically impossible anyway – all physically possible outcomes existed in parallel, just as believers in MWI think they still are.
The only way for the informational structure to continue coherently in this situation is through a selective mechanism – a mechanism experienced as free choice. This moment is psychegenesis and the beginning of phase 2. Cosmic history before this point was actualised retrocausally: the entire evolutionary trajectory leading to LUCAS was selected as a unified classical timeline. After this point, evolution could proceed with genuine decision-making capacity. A new sort of phase 1 information structure began to exist. The original phase 1 history, selected for realisation at the moment LUCAS becomes conscious, was a timeless and unchanging block. Now there was a dynamic structure in which the Void was embedded and animals were conscious.
My suggestion for the best candidate we're aware of for LUCAS is a worm-like organism smaller than a grain of rice. It lived at the end of the late Ediacaran Period, around 560 to 555 million years ago, not long before the Cambrian Explosion. It is the earliest confirmed organism exhibiting bilateral symmetry, a through-gut, and a clear front-back axis. It is the simplest known organism that might have been capable of making choices in a metaphysically meaningful way. Ikaria wariootia was small, blind, and simple, but for a brief period of time the Earth was its oyster; at the end of the Ediacaran nothing could challenge it. It appeared when the only other complex “animals” were so unlike anything living today that scientists are uneasy using the word “fauna” to refer to them. Maybe they weren't animals at all, but some other branch of life which died out, because it was unable to compete when the Cambrian got going. Under 2PC we can shed some more light on this.
The Ediacaran ecosystem existed at the start of phase 2 of cosmological history, but its origin was in phase 1, and like everything else in phase 1 it was retroactively selected because it was on the path that led to LUCAS. The Ediacaran fauna were the supporting cast of actors which were necessary for there to be a functioning ecosystem for LUCAS to evolve within. On the direct line to LUCAS (which was necessarily one very specific lineage) this evolution was directed by teleology rather than natural selection, but presumably some kind of natural selection did apply to everything not on that direct line. Some of these organisms must have had nervous systems but no brains, like jellyfish and comb jellies today. Ikaria was the first bilaterian, and with this new symmetry came the capacity to move forward with purpose, to push through the microbial mats of the sea floor in search of nourishment. It was the first organism which had a solution to the Frame Problem, and this must have provided an overwhelming advantage. So Ikaria multiplied and spread, and feasted on whatever it liked, since most of the species with which it shared an ecosystem were defenceless against an animal which could think.
This sort of abundance never lasts. Boom leads to bust. Nothing was stopping Ikaria from multiplying until the easy food was gone, the microbial mats stripped bare and the sediment was fouled by overpopulation. And then, inevitably, came die-off: dead Ikaria, littering the seabed. Any that were able to scavenge the remains survived longest, and a new opportunity was born. The first to discover a carcass had the best chance of feeding and surviving, and in this game, the slow, the hesitant, and the dull-witted perished. To find food in a world where it appeared and vanished unpredictably, some Ikaria needed to process more than simple chemical gradients.
Evolution responded, and this time it was natural selection as we understand it: nervous systems began to centralise and specialise. Some neural circuits became more attuned to the predictable – to recognising patterns that indicated a meal or a mate. Others stayed watchful, scanning for novelty – for the unexpected signs of opportunity or threat. The left and right sides of the brain began to diverge, one side categorising and predicting, the other staying vigilant, wary of being trapped by its own expectations. Only essential information was communicated between them, so that each could optimise its own function (see the work of Iain McGilchrist).
What began as scavenging eventually became hunting. While some animals grew better at locating dead flesh, others began to chase the living. Predators emerged, sharpening their senses, growing swifter and more deliberate. The seas, which had been silent and slow, became places of pursuit and evasion. Prey species responded with speed, armour, camouflage or cunning. The arms race between predator and prey accelerated, and with it, the relentless push toward neural complexity. Among the early predators were creatures that would give rise to molluscs and arthropods, animals with shells, eyes, and limbs. In their brains, the hemispheric divide deepened. One side projected the path of fleeing prey, calculated the angle of pursuit, anticipated where the target would be. The other side watched for surprises, for sudden changes in the terrain, or for signs of an ambush in the shadows. The brain became a balance between the known and the unknown, prediction and vigilance. At the peak of this evolutionary escalation stood Anomalocaris. It was unlike anything before it: a metre-long predator with powerful swimming flaps, stalked eyes with compound lenses, and great grasping limbs for snatching prey. Anomalocaris was the full flowering of attention and decision. Its eyes saw movement and subtle shifts. Its brain processed that input, split between prediction and watchfulness, continually solving the Frame Problem on the fly, deciding in an instant whether to strike, pursue, or veer away.
It took about 40 million years to get from the simple burrower Ikaria to the formidable Anomalocaris. The story of conscious animal life was, and remains, all about meaningful choice. No amount of speed or strength can substitute for the ability to make the right decisions at the right time.