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The Hidden Biology of Unlikely Animals

I have a new piece in the New Yorker’s Elements blog about our tendency to underestimate animals that are very different from us, such as sponges and ctenophores. Check it out.

Last month, in the journal Trends in Ecology & Evolution, a group of scientists published a tub-thumping defense of sponges and other supposedly simple animals. In their paper, Casey Dunn, Sally Leys, and Steve Haddock argue that humans have systematically underestimated these creatures, largely because of our innate bias against organisms outside our taxonomic clique. That clique, actually called a clade, includes all of the so-called bilaterians—animals with left-right symmetry that share a single ancestor. Tigers, hummingbirds, octopuses, scorpions, crocodiles, mantises, sharks, earthworms: all are bilaterians.

Dunn, Leys, and Haddock write that, as bilaterians ourselves, and rather narcissistic ones at that, we tend to look down on the other four animal clades: the placozoans (flat, creeping mats that are represented by just one known species); the cnidarians (jellyfish, sea anemones, corals, and their stinging kin); the ctenophores, or comb jellies; and the sponges. Even some professional biologists disregard sponges as lowly, primitive proto-animals, sitting at the bottom of an evolutionary ladder with us on the top rung. We treat their biology as an impoverished subset of our biology. We relegate their existence to a checklist of missing traits: no limbs, muscles, nerves, or organs, and none of the tiger’s fearful symmetry. But these creatures, according to Dunn, Leys, and Haddock, are not primitive relics; they are modern animals that excel at their own particular life styles. By ignoring them, we blind ourselves to a wondrous hidden biology and get a misleading view of evolution.

4 thoughts on “The Hidden Biology of Unlikely Animals

  1. It is always good to see articles such as this which underline the importance of thinking in terms of networks.

    In fact, it it better to try to view all biological processes, particularly evolution, within a co-evolutionary context, rather than the traditional “chicken or egg -which came first?” way of framing of questions.

    Or, better still, to use a wider networked based perspective in which species (or phyla, or cells, for instance) are recognized as hubs in a highly integrated and interactive evolving system which, at its largest scale, equates to the biosphere.

    Moreover, our biosphere itself can similarly be viewed as but a component of a much broader evolutionary process which can be traced at least as far back as the formation of chemical elements in stars.

    Such network based issues are explored in my “The Intricacy Generator: Pushing Chemistry and Geometry Uphill”. Now available as 336 page illustrated paperback from Amazon, etc.

    Also, very informally, in “The Goldilocks Effect: What Has Serendipity Ever Done For Us?”, a free download in e-book formats from the “Unusual Perspectives” website

  2. Given our relatively recent appearance as a recognizable “breeds true to form” species, our arrogance, the classic “Johnny-come-lately” vanity, should be a cringe-worthy embarrassment. Sure we can build amazing things like airplanes, but WE cannot fly. We build world-wide navigation networks, but can’t find our way like a Monarch Butterfly. To go to the depths of oceans, near submarine volcanic plumes, we build fit-for-one-purpose pressure resistant transporters but hordes of other creatures live their life there without need of our mechanical Behemoths. And what of bacteria that live in crude fuel oil, and so forth? We may be the latest but we sure lack the skills and universal knowledge built into so-called “lesser beings”.

  3. Unfortunately a very common human trait – ignoring and fearing beings that are neither behaving nor looking in any familiar way. Bravo- articles like yours are a great way to change human perception!

  4. It’s funny isn’t it how certain life forms are considered ‘primitive’ and less sophisticated than mammals/primates. I volunteered for a while at the American Museum of Natural History in NYC, and was lucky enough to be in the live spiders exhibit where we had a rare trapdoor spider. Their segmentedbody form is thought similar to the earliest spiders, but as I always pointed out to visitors, the fact that these incredible animals still exist after so many years shows just how brilliant their body form and behaviour is!

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