Huge Ancient Sea Brain is Ancient and Huge

“Fellow scientists, follow me. You have nothing to lose but your grants.” – James Lovelock

Assume the existence of an ancient, super intelligent life form that has dwelled for an eon in the abyssal zones of the ocean, surviving multiple catastrophic extinction events.  Its longevity has allowed continual increases in its complexity and intelligence, which in turn has allowed it to become uniquely adapted to survival at geological time scales. As I argued earlier, based on the observation that we have discovered none of its artifacts, the most likely outlet for the Abyssal Ganglia’s superior intelligence is an almost undetectable but highly effective biotechnology. What adaptations for surviving periodic global catastrophe might be developed by a being with millions of years of experience and sophisticated tools for manipulating and harnessing biology?

For a widespread organism (spanning up to half of the Earth’s surface) that relies on biological solutions rather than the construction of artificial structures, geoengineering-type responses are plausible. In the 1970’s, James Lovelock proposed his Gaia Hypothesis. Originally tasked by NASA with detecting signatures of life on other planets, he noticed the remarkable effect that life has had on the Earth, specifically, how the Earth seemed to maintain favorable conditions for life over its entire history. Even in the early days of the planet when the sun only provided 70% of its present warmth, life compensated with a thick atmospheric blanket of CO₂. Over time the sun progressed to its full luminosity while the CO₂ dropped, keeping conditions stable. Mars and Venus provided cautionary tales of promising planets gone wrong. Frigid Mars with its wispy thin atmosphere and hellish Venus, choked with greenhouse gases, both could support life if they had Earth’s talent for regulating the climate. Lovelock hypothesized that the Earth was a self-regulating system, and that species that promoted favorable conditions were selected over those that fouled their environment. In the spirit of the times, and with the help of his highly literate neighbor, he named this idea after the Greek Earth goddess, Gaia. While evocative, this name is perhaps unfortunate, as Gaia has been hyperbolically romanticized by New Age spiritual materialists, and irrationally vilified by right-wing religious fanatics as a pagan belief that threatens their Christian hegemony.

Since the time that Lovelock first published on Gaia, the signal of human-induced climate change has grown to proportions that are undeniable to any informed, rational mind.  It may be a small consolation, but this dangerous unintentional experiment of uncontrolled growth and resource extraction has driven a desperate flurry of research on Earth Systems Science, and as a result, we have started to understand how the atmosphere, biosphere, land and sea create feedbacks to climate change. These feedbacks act on many time scales, and can either accelerate or correct disturbances. The Earth’s history is filled with examples where external events such as wobbles in the Earth’s orbit or cosmic bombardments initiate changes in the global climate, leading to positive feedbacks that amplify the changes, followed by slower negative feedbacks that bring the dynamic system back into equilibrium. For example, when ice forms near the poles it reflects heat, cooling the planet faster, and when ice melts away it lets heat be absorbed, speeding up global warming. Meanwhile, changes in ocean circulation and productivity control how fast CO₂ gets pulled out of the atmosphere. These Earth System feedbacks will determine the long-term effects of the great petroleum potlach in which we now revel.

Do these global feedbacks require intervention by an intelligent superbeing?  An actual Earth goddess? Probably not. Lovelock, himself, illustrated his point by showing how a planet occupied by two daisy species, one light and one dark, could stabilize the climate as their sun varied in intensity by changing the albedo of the planet’s surface. Under a cold sun, the dark daisies spread, absorbing heat. As the sun warmed, the light daises took over, reflecting heat back into space. These were not super-intelligent or divine daisies, merely well-adapted. And yet, a subtle knowledge of Earth system feedbacks could allow a sufficiently advanced lifeform options for regulating its own environment in advantageous ways.

A natural response to this argument is “wouldn’t it be easier just to adapt one’s own physiology and behavior to changing conditions, rather than trying to alter the behavior of an enormously complex system to suit one’s needs?” And to this I would retort, “Shut up bitch, that’s loser talk.” No, seriously, normally this argument would be valid. But several times in Earth’s history, catastrophe has struck suddenly, and the majority of life has gone extinct. Adaptations at the species level were not sufficient to prevent these mass extinctions. Our hypothesized organism is one that has transcended these extinction events, and so must have extraordinary powers to adapt to or to mitigate catastrophe. And an organism that spans the abyssal zone of the ocean depends on the vitality of the whole planet. If the ocean’s ecosystem were to collapse, gone would be the rain of organic matter from above, and much of the oxygen. It might still find refuge near a few thermal vents, or gnaw lithotrophically on the stale crust of the seafloor, but at what cost? For an ocean spanning neural network, reduction in biomass inevitably means reduction in intelligence. And a mind is a terrible thing to lose. The ability to engage in global climate feedbacks in subtle ways that even partially dampen climate oscillations would be strongly adaptive.

To review: Huge ancient sea brain is ancient and huge. Being a huge brain, it is smart. Being ancient, it has survived multiple global catastrophes. Why is it ancient? Because it’s based on a simple microbial cell type that evolved billions of years ago. Why is it huge? Because (1) it has adapted to the abyssal plain, the largest environment on Earth, (2) it grows in a network that allows it to expand its modular structure at will, and (3) with increase in network size, there is a corresponding increase in complexity, intelligence and fitness.

How ancient is it? A highly connected microbial network could have arisen early in the Precambrian ooze. However, given the Snowball Earth events between 850-630 million years ago (Ma) as the supercontinent, Rodinia, was fragmenting, this proto-metamicrobial network was certainly not yet capable of preventing large phase changes in the Earth’s state. At any rate, the global Snowball events were so severe that an ocean-spanning microbial network would have been unlikely to survive. Therefore, the earliest possible date for the emergence of an adaptive geoengineering ability would be around the Cambrian explosion (~541 Ma), when the world and its species rebounded gloriously from the dark, anoxic, frozen oppression of the last Great Snowball (635 Ma). Since that time there have been five mass extinction events the Abyssal Ganglia would have had to navigate: ample catastrophes to learn from, along with minor lessons learned from higher frequency variations on smaller time scales. However, since the last Great Snowball, the Earth seems to have developed a more robust sense of balance, and none of the five more recent catastrophes have wacked the Earth so hard it became completely covered in ice, the ocean anoxic and dead except for a few scattered hydrothermal refuges. The great leap in diversification and development of life on the planet might have helped stabilize conditions; Gaia may have learned something from Rodinia, but her homeostasis was still vulnerable to major trauma. Each of the five mass extinctions that followed was caused by a new combination of geological, biological, and sometimes astronomical events. Each was catastrophic, and fucked things to varying extents up for thousands to millions of years, but in each case, most of the major phyla of complex lifeforms survived, and diversity rebounded relatively quickly.

The first crisis occurred around 444 Ma (end of the Ordovician). This was probably caused by the uplift of the Appalachians, exposing silicate minerals that absorbed CO₂ from the atmosphere as they weathered, leading to an ice age. About 86% of plant and animal species were lost. Next was the Karoo ice age, brought on by the green explosion of vascular plants, taking over dry land, sucking down CO₂, chilling the climate, but also churning their roots in the newly exposed soils, eroding rocks and minerals, releasing nutrients, causing eutrophication and anoxia in the surrounding seas. Around this time (~375 Ma, late Devonian) about 75% of the species went extinct, and the ice age that followed this event continued for about a hundred million years. It is worth noting, maybe even ironic, that while the colonization of land by vascular plants caused this massive disturbance, terrestrial vegetation has now become an essential part of Earth’s climate system, and its degradation is a major contributor to biodiversity loss and climate change.

The mass extinction at the end of the Permian (253 Ma) was the worst of the five in terms of species lost (96%). The cataclysmic culprit was a Siberian supervolcano that belched billows of greenhouse gases, warming the world and stifling the seas with sulfide (by the way, I have a rare form of Tourette Syndrome which causes me to alliterate excessively. Be respectful of my condition). Lurking under kilometers of ice in Antarctica, known only by its gravitational anomaly, is an impact basin that was directly antipodal to the Siberian Traps at the time a giant meteorite struck [13]. This cosmic spanking may have sent shock waves that produced supervolcanos 180 degrees away. Anyway, tough break for a planet, but she pulled through.

200 million years ago, at the end of the Triassic, 80% of plant and animal species disappeared with no clear cause. A mysterious shadow of death that left in its wake a handful of Conodont teeth.

The last of the Big Five was around 66 Ma, at the Cretaceous-Tertiary (KT) boundary. At this time, the Earth had the misfortune of being struck by a 10-km diameter asteroid, which left the 110-km wide, 12-km deep, Chicxulub crater in the Gulf of Mexico, lined with iridium (a pretty, iridescent space rock). A blast of about 100 million megatons, for those of you who like explosions. To make matters worse, the Deccan Traps volcanos also erupted, emitting masses of SO₂ into the atmosphere. Both events could have caused rapid cooling from ash, dust and aerosols, along with acid rain and ozone destruction, followed by a phase of greenhouse warming. Around 75% of plant and animal species were lost, famously including the dinosaurs, but also many marine plankton, and invertebrates like the ammonites (who grieves the ammonites, though they faintly resemble their more sinister and intelligent cousins, the now-defunct Cretacean squid people? But this is a tale for another time). As traumatic as the KT boundary may have been, most of the major life forms survived and quickly rebounded. There were a few million years of chaos as climate and ocean productivity wildly fluctuated, but life carried on as survivors gradually diversified to fill the vacant niches.

Interestingly, there are a number of large impacts that occurred since the KT that did not cause global mass extinctions: the Ries crater in Germany (15 Ma), the 90-km wide crater in Chesapeake Bay (35 Ma), and the 45-km wide Montagnais crater in the North Atlantic (51 Ma). Maybe these impacts were just a little too small to cause global mass extinctions, maybe the KT impact happened to hit at an especially vulnerable time, or perhaps Gaia is somehow learning to deal with these crises.

Over the course of these five disasters (along with several close calls) an intelligent, ocean-spanning, biotechnologically advanced lifeform would have had over 500 million years to evolve or invent mechanisms for constructively interacting with the Earth’s climate system. Since the KT, especially in the last one million years, conditions have been relatively placid, with only glacial-interglacial cycles every 100,000 years or so, as the Earth’s orbit dances in millennial polyrhythms. The most extreme of these fluctuations was about 5°C, with a 120-m sea level change. It would appear that the Earth has been in a fairly good groove. Until quite recently, that is.

Modern human civilization appears to represent the sixth mass extinction event [14]. Current extinction rates are orders of magnitude higher than the long-term average, and projected extinction rates in the near future are yet larger. By changes in human land use alone, even neglecting the impacts of climate change, a mass extinction on the order of the previous five great ones is imminent. The devastating impact of Homo sapiens is as old as our species. Our early migrations across the globe were accompanied by a wave of mutilation, seen as extinction events in the fossil record [15]. And now the signals of human-induced climate change have already reached the ocean depths, as remote and protected as they seem. Warming of the abyssal zones is one of the clearest decadal signals of anthropogenic global warming [16]. As Antarctic ice sheets melt and precipitation increases, more fresh water surrounds the Antarctic continent, slowing the downward flow of cold, salty water that forms the Antarctic Bottom Water (AABW), the major force that feeds the ocean floor with frigid water. These changes will alter the Global Overturning Current (GOC), affecting all the world’s oceans, including the thermohaline current that regulates climate in the north Atlantic. How such a being as the Abyssal Ganglia, adapted to cope in innovative ways to global catastrophes, might respond to the current crisis is an open question.

Continental Drift and Abyssal Geography: How Huge is it?

The dates of major ice ages and extinction events help constrain the age of the AG and its ability to engage in global homeostatic mechanisms. Another factor cogent to the question of age and crisis-management is continental drift. Continental drift, when it isn’t causing global catastrophes by smashing together or tearing apart continents, causes a constant inconvenience to an eon-spanning, seafloor- dwelling being: the ephemeral nature of ocean plates before the inevitable power of subduction. In general, these changes are slow and continuous, allowing ample time for recolonization. But over time old habitats are destroyed by subduction under continental plates and new ones are created by spreading at undersea plate boundaries. This could lead to something resembling population dynamics and even speciation by geographical distance or isolation.

During the period of 300-175 Ma, the Earth was in an elemental state, with a single land mass amidst a global ocean. The supercontinent, Pangea, was surrounded by the superocean, Panthalassa, which eventually became the Pacific. The Atlantic formed when Pangea split. It is tempting to imagine that the abyssal Ganglia gained prominence in Panthalassa, where it would have presided over the single, vast contiguous space of the world’s ocean. Since that time, most of Panthalassa’s original crust has been subducted under continental plates, though fragmented remnants remain, such as the Juan de Fuca, Gorda, Cocos and Nazca plates. Should fossils exist of a Panthalassan Abyssal Ganglia, this is where they would lay. If Panthalassa was the epicenter of the Abyssal Ganglionic network, the modern Pacific should represent the oldest, continually-occupied habitat. Conversely, the Atlantic basin would represent more recently colonized territory, a younger sea brain. However, continuous crustal recycling and colonization of newly exposed basin at spreading zones may render these speculations moot. At present, all the abyssal zones of the world’s oceans are connected, with a few small exceptions, such as the Arctic Ocean, the Gulf of Mexico, the Caribbean and the Mediterranean, where the deep areas are isolated by relatively shallow waters. There are deep water connections among the Pacific, Southern, Indian and Atlantic oceans, albeit circuitous and narrow in places (Figure 3). It is therefore conceivable that an Abyssal Ganglionic network could span most of the world’s abyssal plains below about 60° N latitude.

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Having finished the first draft of this section, I felt satisfied, saved the file, put my computer to sleep, and went out for a quick bite. Walking from my office across campus, I overheard a student describing his geology course, “Geology sucks, dude. The Earth fucking sucks!”

I shook my head, smiled, and went to grab a fish burrito.