How inevitable was modern human civilization—data

We have a sam­ple of one mod­ern hu­man civ­i­liza­tion, but there are some hints on how likely it was to hap­pen.

Ma­jor types of hints are:

  • Time—if some­thing hap­pened ex­tremely quickly; or ex­tremely late, it sug­gests how likely it was.

  • In­de­pen­dent in­ven­tion—some­thing that was in­vented in­de­pen­dently mul­ti­ple times is like­lier; some­thing in­vented only once in spite of plenty of time, iso­la­tion, and pre­req­ui­sites is less likely.

Data for:

  • Life seems to have de­vel­oped ex­tremely quickly af­ter cre­ation of Earth. [Ori­gin of life]

  • Mul­ti­cel­lu­lar­ity seems to have evolved mul­ti­ple times in­de­pen­dently, at least in an­i­mals, fungi, and plants. [Evolu­tion of mul­ti­cel­lu­lar­ity]

  • Similar pro­cess also hap­pened mul­ti­ple time on higher level—eu­so­cial­ity de­vel­oped in aphids, thrips, mole rats, ter­mites, and at least 11 times in Hy­menoptera (ants, bees, and wasps). [Eu­so­cial­ity]

  • Life did not die out on Earth, or on any par­tic­u­lar en­vi­ron­ment where it pre­vi­ously thrived, in spite of ma­jor changes in tem­per­a­ture, com­po­si­tion of at­mo­sphere, and mul­ti­ple large scale dis­asters. This sug­gests life is very re­silient. Every time life is wiped out in some part of Earth, it is quickly re­colonized.

  • Many differ­ent lineages of an­i­mals de­vel­oped so­cieties. [So­cial an­i­mal]

  • Many differ­ent lineages of an­i­mals de­vel­oped com­mu­ni­ca­tion. [An­i­mal com­mu­ni­ca­tion]

  • All tran­si­tions from Mid­dle Pa­le­olithic on­wards hap­pened rel­a­tively fast to ex­tremely fast on evolu­tion­ary scale. [Pa­le­olithic]

  • In­ven­tion of Me­solithic and Ne­olithic cul­ture in­clud­ing agri­cul­ture, bow, boats, an­i­mal hus­bandry, pot­tery were all in­vented mul­ti­ple times in­de­pen­dently, in Afroeura­sia, and Amer­i­cas. [Stone Age]

  • Like­wise many of lat­ter in­ven­tions in­clud­ing met­al­lurgy, writ­ing, money, and state were de­vel­oped mul­ti­ple times in­de­pen­dently.

Data against:

  • Uni­verse is not filled with tech­ni­cal civ­i­liza­tions. Some (du­bi­ous due to zero em­piri­cal ev­i­dence) mod­els sug­gest once such civ­i­liza­tion de­vel­ops any­where in the galaxy, it is very likely to colonize the en­tire galaxy in rel­a­tively short pe­riod of time. As it didn’t hap­pen, it’s a strong ev­i­dence that there are very few, per­haps no, ad­vanced tech­ni­cal civ­i­liza­tions in our galaxy; or any­where else in the uni­verse if our galaxy is a good rep­re­sen­ta­tive. [Fermi para­dox]

  • Life can sur­vive in a very wide range of cir­cum­stances, so there are plenty of places where we might ex­pect to find life if its de­vel­op­ment was also likely. Mars, Venus, moons of Jupiter and Saturn, and per­haps some other places just in the So­lar Sys­tem might be suffi­ciently friendly to life. Yet, as far as we know, none ever de­vel­oped in any of them, what puts strong limits on in­evita­bil­ity of life. [Ex­tremophile]

  • In spite of all the the­o­ries pro­posed, we know of no mechanism un­der which cre­ation of life seems even re­motely plau­si­ble. Some­where be­tween the pri­mor­dial soup (or equiv­a­lent) to the first repli­ca­tor with rea­son­ably sta­ble hered­ity and metabolism (or equiv­a­lent), there’s a large num­ber of un­known steps of un­known but most likely ex­tremely low prob­a­bil­ity. [Ori­gin of life]

  • Ner­vous sys­tem evolved only once, about 3 billion years af­ter life started, and noth­ing analo­gous to it ever evolved in any other lineage. [Ur­bila­te­rian]

  • It took life 3 billion years to reach stage of rea­son­ably com­plex an­i­mals, what sug­gests it is not very likely. [Cam­brian ex­plo­sion]

  • Al­most all an­i­mals seem to have very low en­cephal­iza­tion quo­tients, sug­gest­ing that high in­tel­li­gence is un­likely to de­velop. The only two ma­jor ex­cep­tions are pri­mates and dolphins. [Brain size and EQ]

  • Any­thing re­sem­bling hu­man lan­guage de­vel­oped only once. [Ori­gin of lan­guage]

  • It is far from cer­tain, but it seems that Ne­an­derthals had the same ca­pac­ity for speak­ing lan­guage as mod­ern hu­mans. This pushes de­vel­op­ment of lan­guage very far back, and sug­gest de­vel­op­ment of civ­i­liza­tion even given lan­guage is un­likely. [Ne­an­derthal]

  • Tran­si­tion from an­i­mal life to some­thing as com­plex as early Homo life (Lower Pa­le­olithic), like man­u­fac­tur­ing of tools, con­trol of fire etc. seem to have hap­pened only once in his­tory of life, and ex­tremely late. [Hu­man evolu­tion]

  • Like­wise tran­si­tions to Mid­dle Pa­le­olithic, and Up­per Pa­le­olithic seem to have hap­pened only once. It could be ar­gued that if it was iso­lated hu­man pop­u­la­tions had chance of de­vel­op­ing in­no­va­tions con­tained in them in­de­pen­dently, but didn’t.

  • Some in­ven­tions like wheel, and iron smelt­ing were in­vented only once. How­ever by this time the world was go­ing so fast and global­ized enough that it’s very weak ev­i­dence for their difficulty. In­ven­tions later than an­tiquity also provide lit­tle ev­i­dence due to lit­tle time and lit­tle iso­la­tion.

To me it looks like life, an­i­mals with ner­vous sys­tems, Up­per Pa­le­olithic-style Homo, lan­guage, and be­hav­ioral moder­nity were all ex­tremely un­likely events (no­tice how far ago they are—vaguely ~3.5bln, ~600mln, ~3mln, ~200k or ~600k, ~50k years ago) - ex­cept per­haps lan­guage and be­hav­ioral moder­nity might have been linked with each other, if lan­guage was rel­a­tively late (Homo sapi­ens only) and be­hav­ioral moder­nity more grad­ual (and its ap­par­ent sud­den­ness is an ar­ti­fact). Once we have be­hav­ioral moder­nity, mod­ern civ­i­liza­tion seems al­most in­evitable. Your in­ter­pre­ta­tion might vary of course, but at least now you have a lot of data to ar­gue for your po­si­tion, in con­ve­nient for­mat.