The new movie is playing in town, so I’m hoping to see it tonight…except that I’ve been prescribed cetirizine to suppress the allergies that might be causing my tinnitus, and I’ve been known to slip into unconsciousness at odd times of the day. It’s annoying, and worst of all, it doesn’t seem to be doing anything. So, if I can keep my eyes open tonight, I’ll be going to see Godzilla, King of the Monsters.

It’s about science, don’t you know. It just got a write-up in Science magazine!

The “evolutionary biology” of Godzilla is a topic of enduring interest among devotees, with numerous fan pages and forums dedicated to the subject. If we accept Godzilla as a ceratosaurid dinosaur and Lazarus taxon—a species thought to have gone extinct, only to be rediscovered later—then it represents a sensational example of evolutionary stasis, second only to coelacanths among vertebrates. Yet, the creature’s recent morphological change has been dramatic.

Godzilla has doubled in size since 1954. This rate of increase far exceeds that of ceratosaurids during the Jurassic, which was exceptional. The rate of change rules out genetic drift as the primary cause. It is more consistent with strong natural selection.

The strength of this selective pressure can be estimated by using the breeder’s equation, where the response to selection “R” is the product of the heritability (h2) of a given trait and the strength of selection. If we assume that h2 = 0.55 for body size—a reasonable estimate according to quantitative genetic studies of lizards—then the observed increase in Godzilla’s body size would require a total strength of selection of 4.89 SD. To put this number in context, the median value of natural selection documented in a review of more than 2500 estimates in the wild was 0.16. Godzilla, it seems, has been subject to a selective pressure 30 times greater than that of typical natural systems.

One problem with this analysis: isn’t it the same Godzilla in every movie? I could be wrong, but I think this is a specific individual returning over and over again, not a member of a population of Godzillas over many generations. It would have to be a very large and prolific population to hold up under that kind of selection pressure, too. It seems more likely to me that this is an example of a long-lived individual that is undergoing continuous growth over its lifetime, and therefore this is more of a matter for the developmental biologists, and is an example of a physiological adaptation.

Even if Godzilla is multiple different members of a changing population, we have no idea of the extent of the variation present within the population. The 1954 Godzilla could have been the Peter Dinklage of Godzillas, while the 2019 Godzilla could be the Yao Ming of the group. We don’t know, but I think that trying to argue for rates of selection is premature.

I must disagree with this diagram as well.

The 1998 monster does not look anything like the others, and must be from a completely different species, so don’t try to tell me it’s a Godzilla.


  1. says

    In the animated Godzilla cartoon from Japan, the creature survives for millions of years, growing to a size of 300m.

  2. HappyHead says

    Didn’t the monster in the 1998 movie also get killed? Further evidence that it was not even related to Godzilla, since that’s not a thing that can happen to Godzilla.

  3. davidnangle says

    One thing in the trailer bothered me, as an animator. GZ breaks into a jog (or run) indicated by his up and down movement. But the speed of him falling at each step seems suspiciously fast, given his actual size.

    Consider a 2″ toy of GZ falling for one second. Compare that to a full-sized GZ falling for one second and you’ll see my point.

  4. microraptor says

    It’s at least the second generation of Godzilla: the original Godzilla had a son for a few movies, and then in one of the movies Godzilla was undergoing a nuclear meltdown and ended up dying at the end of the movie and Godzilla’s son absorbed the excessive radiation to prevent a nuclear catastrophe, which caused him to instantly grow into the next Godzilla.

    And yeah, I’m looking forward to this movie myself. Probably going to go see it Monday.

  5. pilgham says

    The 1998 one was my favorite! Jean Reno! Matthew Broderick!

    Does the chart include the trilogy of films on Netflix? That was a bit of a mess.

  6. Rich Woods says

    There’s no way the 1954 Godzilla could have been the Peter Dinklage of Godzillas. The 1954 Godzilla couldn’t act his way out of a soggy paper bag.

  7. kingoftown says

    As I remember, the 1998 thing is supposed to be a mutated lizard or something, not a dinosaur. I think Darren Naish did a good article about Godzilla biology a while ago.

  8. slithey tove (twas brillig (stevem)) says

    It seems more likely to me that this is an example of a long-lived individual that is undergoing continuous growth over its lifetime, and therefore this is more of a matter for the developmental biologists, and is an example of a physiological adaptation.
    Isn’t this the null hypothesis? Why go all evolution on a single individual.
    Look at recent alligators that are about 30 ft long while the typical is about 12 ft. , did it evolve to be bigger, or, is it simply older, as reptiles tend to not have a growth plateau like mammals? I wonder which is more likely./s

  9. slithey tove (twas brillig (stevem)) says

    e 12:
    only that last use of evolve was to be italicized, not the rest of the sentence. apologies

  10. Frederic Bourgault-Christie says

    Nope. All different ones. Many supposedly regenerated from the same original one, aside from Zilla (Emmerich’s Godzilla In Name Only), the animated series one in the US (which was actually ostensibly pretty good and had it as the child of the one from Emmerich’s), and the new one. Specifically, there’s the 1954 serious one, the Showa era one, the Heisei era one, the 2000/Millennium era one, the Shin one, and the Godzilla: Planet of the Monsters (Godzilla Filius) one from Netflix. There’s a whole thing about Godzilla having special cells called G-Cells. And @coreyschlueter directs you to an awesome scene from an awesome movie.

    Which does make one wonder how much evolutionary pressure there can be on macroscopic organisms that effectively regenerate after death and get stronger.

    Me? I just want to watch Ghidora and Godzilla beat each other up. I am so excited.

  11. disgruntleddog says

    Godzilla died in 1954 by the oxygen destroyer.

    Every Godzilla since then hasn’t been real.

  12. joehoffman says

    Maybe the movies are like medieval bestiaries. The moviemakers have never actually seen Godzilla, so they’re working from eyewitness descriptions. Eyewitness aren’t particularly reliable, even when they’re not scared out of their minds, which explains the variations in size, fins, etc.

  13. Stevko says

    In a local cinema they played Godzilla as double feature. That is they played two Godzilla films – the oldest one (1954) and this one. So when oxygen destroyer is mentioned in the new one, we knew that it appeared in the first one.
    I liked the old one more. It seemed more consistent and more realistic. In the new one some plot lines are abandoned without explanation and more surprisingly without consequences. Also in the old one, the dilema of Dr. Serizawa was more believable.
    The new one has some nice visuals but I was expecting more spectacular fights. There are some but with too many closeups so it is unclear what exactly is going on.

  14. ridana says

    Looking at that chart I see at least three and possibly 5 different species of reptile here. The True Gojira species can be seen in specimens from 54-75, 91-95, and 2004. The distinguishing feature is the 4 large, serrated spinal plates on its back, ending at the nape of the neck. 2016 may be a member of this species, if it can be shown to grow an additional fringe on the back of the head with age (much like hair growth inside the ears of old human men), as well as that the plates begin to merge as the creature enters old age. Otherwise, it would seem to be a new offshoot.
    The second most represented species is the Flame Ridgeback Godzilla, seen in specimens 1999-2003 and 2014. In this species the distinct back plates have all merged into a single fringed ridge running down the entire back from head to tail. The 2016 specimen may possibly be an example of this species rather than the True Gojira, though in that case it would appear that the fringe wears down over time and loses its fiery appearance.
    1998 is a Zilla, not a Godzilla. While the two are related, they are definitely different species. The specimen at 1984-89 cannot be classified since its back is turned and I don’t feel like looking up images from the movies.

  15. Crudely Wrott says

    Ars Technica has a less than flattering review of the NEW!! Gorjirra movie that I read with some surprise and not a little satisfaction. I was also annoyed a bit; not by the review itself but by the state of movie making today in general.
    Here is a link for the interested:
    One takeaway from the review goes like this:

    Instead, I’m holding out hope that this week’s sloppy, plodding, and logically bankrupt film eventually becomes the subject of a “how did this happen?” documentary, the kind that might explain why the film’s scriptwriters, director, and editors all seemed to abruptly quit working simultaneously.

    Nonetheless, go see it, without me. I’m passing. As always, YMMV.
    I first saw the American version of the original with the Raymond Burr scenes in about 1957. Oh! The memories!!

  16. says

    So before the 1998 movie, I only disliked Mathew Broderick. After the 1998 movie I wanted nothing more than to see him eviscerated by a giant lizard monster, along with everyone else involved in that film. It was so bad, it was worse than the Phantom Menace.