Big brains…what are they good for?

An interesting thought experiment: what if intelligent dinosaurs had evolved? Would we know it?

If, in the final 7,000 years of their reign, dinosaurs became hyperintelligent, built a civilization, started asteroid mining, and did so for centuries before forgetting to carry the one on an orbital calculation, thereby sending that famous valedictory six-mile space rock hurtling senselessly toward the Earth themselves—it would be virtually impossible to tell. All we do know is that an asteroid did hit, and that the fossils in the millions of years afterward look very different than in the millions of years prior.

So that’s what 180 million years of complete dominance buys you in the fossil record. What, then, will a few decades of industrial civilization get us? This is the central question of the Anthropocene—an epoch that supposedly started, not tens of millions of years ago, but perhaps during the Truman administration. Will our influence on the rock record really be so profound to geologists 100 million years from now, whoever they are, that they would look back and be tempted to declare the past few decades or centuries a bona fide epoch of its own?

I agree.Two of the major consequences of great intelligence seem to be heightened conceit about your importance, and an enhanced ability to exploit and wreck the environment on which your success depends. Maybe those are the two things we ought to be working on reducing, if we hope to last a little longer.


  1. hemidactylus says

    If crows and magpies had access to blogs I imagine there would be some angry (wait no limbic system?)…offended smart dinosaurs swarming this thread right now.

  2. PaulBC says

    I can’t believe it was way back in 1996 that Enik the smart Sleestak made his presidential run (link to “cybermad” won’t post) Seems like yesterday (now I know who’s the real dinosaur).

  3. hemidactylus says

    I may have misspoke. A cursory glance at the webs reveals there may be avian brain structures construed as “limbic”. So angry birds after all? But my faint memories of Joseph LeDoux’s deconstruction and own readings on MacLean’s triune hypothesis could result in my pedantic dismissing of a limbic system in humans too.

    Still a chirping outside the window makes me fear a bird uprising with “Make Archosaurs Great Again” red hats.

  4. dorght says

    The Earth After Us: What Legacy Will Humans Leave in the Rocks? by Jan Zalasiewicz delves into the question of our geologic evidence millions of years in the future. Along the way it does an excellent job of teaching about geology in general. He foresees we’ll leave a thin strata of iron oxide in rectangular patterns (steel rebar used in concrete) as the K-T like boundary marking the end of the Anthropocene.

  5. thirdmill says

    I’m a Mensan. At one of our last national gatherings, one of the most popular seminars was why do smart people do stupid things. It was very enlightening; I wish I had taken it 30 years ago.

    It’s important that at least some people have oversized brains, otherwise we would still be living in caves and dying of smallpox. The problem arises when our brains evolve faster that our moral sensibilities do, thus enabling us to destroy the planet without having an internal compass telling us not to. The secondary problem is that since we are animals, we still have an animal nature that looks to its own best interests ahead of everything else.

  6. robro says

    Is it the “heightened conceit about [our] importance” or the heightened belief that we are intelligent in the first place?

  7. xohjoh2n says

    One if the lightweight climate denial arguments is that the world is so big, and we are so small, how could we possibly cause such a large scale effect? Well, there are nearly 8 billion of us now, and with machine driven force multiplication the scale of our reach is also so big it can be hard to imagine…

    Those 8 billion are basically everywhere, so we will enter the fossil record. Whether a future species that attains intelligence could infer anything about our natures from that…

    But the scale of our industry will leave scars. So, none of our buildings will survive, any artifact that we might take pride in will likely be unidentifiable dust. But we have basically tapped out a number of useful minerals: all naturally occurring mercury or helium is basically gone by now. Would a future geologist be able to spot that things that ought to be there no longer are? Or would they, like us, look at the world around them and figure maybe that’s just the way it is?

    But then what have we put back that might survive? The rebar example above is interesting, but there is another. Future geologists might notice that there are a small number of vast deposits of gold, that their local distributions are way too tight, that elsewhere it can be found in small concentrations in specific types of strata, but in the strata where you find large amounts there is just no reasonable natural explanation for why it might build up there, nor for why concentrations where such explanations exist are somewhat lower than you might expect.

    So, that’s how we’ll be caught: follow the money, as always.

  8. stroppy says

    Did me a google. Starting with Anthropocene at Wikipedia:

    It appears that this is a serious consideration among geologic nerds who are wonky on categorizing things–not necessarily just a politically correct notion. The Atlantic article does seem to be making some rather broad assumptions about how geologists construct their models.

    So in terms of scales and impacts, in how short a time does something have to occur to qualify as an “event?” How much information has to be left in the geologic record to qualify for inclusion in one of the smaller sub-categories? (We’re talking epochs–or maybe lower–not periods.)

    If dinosaurs built a civilization, would it be “virtually impossible to tell?” Thats quite an assumption. It depends on what kind of a civilization. If it were a messy global one like ours, I think there would certainly be evidence around, or at least as much evidence as we would expect find from other recent epochs, looking at them from 100 million years hence. No?

  9. PaulBC says


    One if the lightweight climate denial arguments is that the world is so big, and we are so small, how could we possibly cause such a large scale effect?

    And if that were true, as I’m annoyingly fond of pointing out, how could solar energy be “piddle power” when it’s the main thing powering this big wide world of ours?

    One thing I really don’t get about climate-deniers is why they seem to think fossil fuel is the ultimate virtuous, macho power source and we can never do better (uh, with the position exception of nuclear power and even that has lost its cachet among the right).

  10. PaulBC says

    The pylons left by the sleestaks (pardon me, Altrusians) would also be very durable, so absent evidence, I’m not buying this intelligent dinosaur theory.

  11. hemidactylus says

    @16- PaulBC
    I have found intelligent dinosaurs known as flying rats to have no respect for human technology, dive bombing my car with poop droppings, but even the intelligent corvids congregate at grocery store parking lots for some reason.

    The contribution to geological record may come as human implements used to house the domesticated ones.

    And think of the carbon footprint we leave to emulate their most natural ability. Dinos live amongst us.

    Also there is a progressive gradation in intelligence, knowledge, morals, and wisdom. Humans are short on the last two.

  12. stroppy says


    For sure.

    It’s not just the artifacts of civilization that will leave a record but the lasting impacts on climate, chemistry, geomorphology, the fossil record, etc. We are part of, and intimately entangled with, the planet’s biology and evolution, which we will no doubt continue to modify if not stupidly inflame for quite some time to come. I’d suggest that even in some imagined post “civilization” world, we’d be perfectly capable of having lasting effects.

  13. Oggie: Mathom says

    The Anthroposcene will, most likely, be fairly obvious. The carbon isotope signatures are going to show a massive excursion into 12C as we burn the fossil fuels stored by Carboniferous life as coal, or the oils stored by bacterial action over the past 200 million years. Life preferentially utilizes lighter carbon isotopes as it makes certain biochemical reactions easier. As the coal forests and swamps of the Carboniferous moved carbon from the active carbon cycle into long-term storage, most of the carbon was the lighter isotope. Which means that we are, right now, putting into the geological record a very sudden and abrupt negative excursion of carbon weight. Considering that we can get consistent carbon isotope ratio readings from the Vendian and Cambrian, our carbon footprint in the rock record should be easy to spot.

    Additionally, as the globe warms and more and more of the polar ice caps and upper latitude glaciers melt, the oxygen isotopic ratio will also change. 18O is better than 96.7% of the oxygen on earth (and most of it is tied up in compounds). But, when water evaporates, less than 96% of the oxygen molecules within the water are 18O, An extra one or two percentage points are 16O or 17O which falls as precipitation. This means that the average weight of the water in glaciers and ice caps is only about 96.6% 18O, making the water lighter. When those glaciers and ice caps melt. the atmospheric 18O content drops which shows up in rocks, especially any silicates. So oxygen acts as a very accurate proxy for global temperatures — colder means heavier oxygen, warmer means lighter oxygen (keep in mind that I am talking (writing?) about differences of 2 or 3 parts per mil) — and our current experiment in global warming will show up as a sudden and abrupt excursion of oxygen isotopes into much lighter isotopes.

    Fossils may survive in a few locations, but keep in mind that the early Cretaceous exposures worldwide are isolated and small, and the ones that are fossiliferous are even more rare. What will show up, though, is the isotopic ratios. And plastics. Those should leave some really weird chemical markers even 100ma in the future.

    (take with a grain of NaCl — written by an historian who dabbles in paleo everything)

  14. fishy says

    So, we need to search the asteroids for ancient mining sites?
    Maybe dinosaur colonists live under the ice on Ganymede and have evolved a new form.

  15. lochaber says

    A lot of the artifacts of our civilization will decay, corrode, and erode into nothing.
    But I think there will be countless traces of our civilization.
    If nothing else, the rampant disturbing of the geologic record. We can still find trace fossils or worm burrows hundreds of millions of years old, so I’m sure our building foundations and various tunnels, pits, etc. will leave similar trace fossils.
    I might be mistaken on this, but I believe that concrete eventually becomes limestone? So some of our larger comcrete structures may survive. The stuff with rebar will likely shatter as the rebar rusts and expands, but I am fairly certain there are other large pours of concrete without reinforcement.
    I really enjoyed the book The World Without Us:
    in which the author points out that large granite sculptures like Mt. Rushmore will likely still be recognizable for millions of years.
    I believe various ceramic items will also have the potential to exist well beyond our species extinction.
    Also, beyond just whether artifacts of our civilization will endure, they have to do so in a manner where they would also be discoverable by someone millions of years from now. So, they would have to exist in a place where they are likely to be preserved (depositional environ?), that is later eroded to expose them. But, I suspect we’ve altered enough of our planet’s surface that I think it’s pretty likely we will leave traces.

  16. Snarki, child of Loki says

    find some “dino wearing a space-suit” tracks in lunar dust, and there’s your evidence.

    Of course, NASA would just cover it up, same way they faked the moon landings, amirite?

  17. Rich Woods says

    If, in the final 7,000 years of their reign, dinosaurs became hyperintelligent, built a civilization, started asteroid mining, and did so for centuries … it would be virtually impossible to tell.

    Really? How did they kickstart their orbital mining program? Tell me it didn’t start with fossil fuels, and tell me we’ve had another Carboniferous in the last 70 million years. In most places around the Earth it takes about a quarter of a billion years for the geologic plates to undergo subduction. We’d have seen signs of any major industrial civilisation left over within that timescale.

  18. nomdeplume says

    Have thought in recent years, as climate change began to bite, in parallel with increasing determination by the Right (and some on the Left) to prevent any action to stop it, that the development of Homo sapiens type “intelligence’ on a planet may inevitably lead to the exploitation of fossil hydrocarbons (as an easy source of energy), resistance to stopping doing so (because easy hydrocarbons bring wealth to some), and the inevitable ecological catastrophe, and that this explains the “Fermi Paradox”.

  19. says

    The anthropocene event is nothing more than a large scale Tragedy of the Commons and Parkinson’s Law / Lewis-Mogridge Position. When there’s nothing to restrict population growth and consumption, you’ll eventually eat yourself out of house and home.

    It’s also how Trump “thinks” an economy works, that it’s a Ponzi scheme he can win. He thinks can spend his way out of debt and always find another way to borrow until he succeeds. But eventually it will all come crashing down when there are no more resources to exploit.

  20. A momentary lapse... says

    Our legacy is likely to be a thin stratum containing strange isotope abundances indicating the decay of short-lived radionuclides that have no business being present on a 4.5 Gyr-old planet. This would parallel the iridium-rich clay at the K/Pg boundary, which certainly does not require its own epoch name.

  21. mikehuben says

    I’m pretty sure that due to the durability of ceramics, we will be known as the “Bathroom Culture” because of the toilets and tiles preserved in the geological record.

  22. blf says

    mikehuben@31, Ha! Haven’t heard that one before… and I rather like it. One probable marker, alluded to by others, are chicken bones. Broadly, chickens are both ubiquitous and extremely common, and hence so are their bones. That will leave a mark or layer, albeit one not as distinct / sharp as certain radionuclides, plastics, &tc.

  23. lumipuna says

    If there’d been a global civilization 65 million years ago, we’d find that the ancestors of most modern species jumped wildly across oceans a the time, spreading all over the world.

    I suspect for a geologist living 100 million years from now, it probably wouldn’t make sense to divide early Cenozoic into several periods such as Paleogene, Neogene and Quaternary, especially since Quaternary would begin only a couple million years before a major extinction event. Entire Quaternary would be likely a stage, not even epoch, and any evidence of human civilization would be considered a boundary rather than layer.

  24. wanderingelf says

    The article struck me as an obnoxiously misleading piece of crap. Not quite as bad as Nicholas Wade’s attempt to resurrect scientific racism, but still pretty bad. Under the guise of criticizing human hubris, the subtext seems to be that humans couldn’t really affect the Earth in any way that would be all that significant, which is a favored trope for undermining concern about environmental issues. The author does not seem to actually understand the arguments for the Anthropocene and instead spends much of the article building and then tearing down straw men.

  25. stroppy says

    Imaging a geological future is a fun exercise to get the creative juices flowing, but…

    The geologic time scale is about evidence in the ground now and what concepts have utility for working stiff geo-types; hence the proposal.

    Ultimately it’s up to stratigraphers, the people who actually have to get their hands dirty with this stuff, to determine if this is help, hinderance, or something else.