Sea Spiders

Sea spiders.

I can already hear the exasperated groans coming from the readership of this entry. Sea spiders? Seriously? Why, arachnophobes the world over sigh, are spiders not content to just stay where they belong; many miles away from any potential interaction with my relatively exposed, swimming body? Need they go out of their way to ruin my summer vacation at the beach too? Why do there have to be marine versions of our creepy, spindly-legged friends, especially when we already have sea snakes, saltwater crocodiles, and what are the equivalent of massive “sea wolves” patrolling the briny depths? Perhaps, given the unsettling, lanky body shape of the sea spider, reminiscent of the daddy longlegs clustered in the dark, dusty recesses of our garages, it provides little comfort to say that these animals are not what their common name suggests.

In the same way that “sea cows” are not actually cattle equipped with flippers, and “sea wasps” aren’t really our delightfully sting-happy, land-lubbing acquaintances finding a new home beneath the waves (a nightmarish scenario if there ever was one), sea “spiders” are not simply spiders with water-proof webs and an appetite for calamari. They are something altogether different, belonging the taxonomic class Pycnogonida (meaning “thick knees”, perhaps referring to the shape of the joints in their segmented legs, or a cruel high school nickname for the group). This class is currently allied within the arthropod group known as Chelicerata, which does include arachnids; but, these “sea spiders” are, as previously mentioned, not arachnids themselves. However, even this classification may not provide enough recognition of the pycnogonid’s unique pedigree. There have been some recent studies (from both molecular genetics and evolutionary development angles) that suggest that sea spiders are not nested alongside arachnids at all, but instead are a part of a much older offshoot of the arthropod line…and are potentially the only surviving, highly-derived representatives of some of the first groups of arthropods to evolve (perhaps more closely related to enigmatic, extinct animals from more than half a billion years ago like Anomalocaris). If this is the case, then the pycnogonid lineage is effectively among the oldest animal groups on the planet.

Yes, no matter which classification assignment is correct, these critters occupy a unique branch on the great tree of life, and once someone takes a look at these pycnogonids up close, it becomes abundantly clear that these animals definitely deserve severely distinct classification, and have a tangibly alien quality to them. Seriously, pycnogonids are about as weird as it gets.

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Arachnids: Amblypygids

Arachnids.

Yes, arachnids; our eight-legged “friends” that cling to the shadowy, forgotten corners of our homes, under the damp seal of a rock, to the harsh, hot crust of the desert, and to their feathery webs, crafted overnight in our gardens. Arachnids, as a group, are not at all unfamiliar to us humans, and while, overall, the relationship between ourselves and these ubiquitous invertebrates is a bit complex, by and large in Western culture, arachnids are feared and reviled. The most familiar groups of arachnids, spiders, scorpions, ticks, and mites, have earned reputations as some of the most terror-inducing, retch-provoking, and spine-shuddering animals we encounter in our day-to-day lives. We cringe at the thought of ticks embedded in our skin, face first, bodies inflating into pulsating balloons of blood. We attempt to ignore the unsettling fact that millions of microscopic mites graze on our dead skin cells, both separated from our bodies and still attached. We regard scorpions, prehistoric beasts made of plates, claws, stingers, and venom, as symbolic of the uninhabitable desert wilderness.

And then, of course, there are the oh-so common spiders, creatures who receive reactions from humans ranging from praise for their beautiful, radial web architecture, to mild annoyance when encountering a surprise face and mouthful of this same web on a forest trail, to revulsion and a swift, life-ending blow with a shoe or newspaper (turning the hapless critter into a drab smear of entrails), to blinding, full-on arachnophobic panic. These last group of arachnids, in particular, are the animal kingdom’s ‘black sheep’ in our culture, becoming a fixture in our conceptualization of the spooky atmosphere of Halloween; curiously, along with bats, spiders are among the few living, non-fictional entities we set alongside the stereotypical ghoulish folklore characters like zombies, skeletons, witches, and sundry other monsters. Apparently, we consider spiders among the creepiest, darkest, and most unnerving of all living things.Those that fear spiders, and creepy-crawly arachnids in general, cite these creatures’ long, spindly limbs, soul-less eyes, hairy bodies, venomous fangs, fast movements, and a tendency to inhabit abandoned, abyssal areas where we are already at unease, as some the reasoning behind their prejudice. This instinctual aversion is strong enough, and prevalent enough, to inspire scores of films and literature where spiders are featured as agents of terror. Seriously. There are plenty. Of examples. Our overwhelmingly negative view of spiders, especially, obscures some of their talents, many of which are immensely useful to humans. These include the production of a silk that is tougher than Kevlar (which has instigated research into super-strong materials), and an inarguably critical ecological role that keeps populations of their prey items (insects) in check. Spiders, like most arachnids, in the immortal words of Rodney Dangerfield, “get no respect.”

Oh jeez. Are you guys happy now?

In the same way that spiders and other more familiar arachnids are misunderstood and have unrecognized, underappreciated roles in our lives, the very definition and realization of what arachnids, in the broadest sense, actually are typically is met with limited experience and knowledge. For example, most people, if prompted to “name an arachnid” would answer firstly (overwhelmingly so) with ‘spider.’ Some might follow up with ‘scorpion’, or perhaps ticks and mites…pretty much everything with eight legs and without insect-like antennae that comes to mind. However, the diversity of arachnids extends far beyond the web-bound orb weaver bobbing in the breeze in your front yard’s hedges, or the chigger causing lovely, itchy welts to form on your skin. While these groups are the most speciose, and most common accompaniment to our daily lives (good or bad), there are entire taxonomic orders of arachnids that go quite completely, and miserably, ignored.

This entry is to serve as the first in a series of explorations into the less-loved (or, perhaps, less-persecuted, simply out of unfamiliarity) arachnids.

But first, perhaps it is helpful to start with the following question: what is an arachnid, exactly?

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Evolutionary Anachronisms

The avocado.

You may think you have a good relationship with the avocado. The buttery fruit of this plant may regularly accompany your turkey sandwich, sliced and fanned out across the bread. Or, it may serve as a hearty dip in the form of guacamole. More recently, avocado is seemingly being utilized in a greater variety of ways, being deep-fried, thrown in macaroni and cheese, and finding its way onto burgers, Subway sandwiches, and even into ice cream. You’d expect that with all this attention, our green-fleshed, knobby-skinned friend, the avocado, would be content with its current role in human culinary efforts.

However, the avocado may very well be lonely.

Despite all our affection, this loneliness stems from the avocado potentially having eyes for another. I mean this, of course, in the sense of the concept of co-evolution (which I examined in a previous post), which is directly tied to the reproductive role of the fruit itself. The main function of a fruit (a botanical fruit, typically meaning the structure derived from the reproductive tissues of the flower housing the seed(s)), is to move seeds away from the parent plant and into areas that promote growth and survival. Many types of adaptations in fruits exist to help achieve this goal of seed dispersal; from the wind-catching dual blades of maple tree fruits (known as samara), to exploiting the appetites of the ubiquitous (and notably mobile) animals in the neighborhood. This latter evolutionary strategy involves the development of fruits that enrapture animal taste buds and provide irresistible caloric value, allowing consumed seeds to travel safely inside the gut of an unwitting, far-traveling chauffeur until being excreted away from the crippling shade of the parent plant. This is called “endozoochory.”

Most endozoochorous fruits have evolved to be eaten by fairly specific animals. Predictably, fruits adapted to be taken by songbirds are going to have different physical attributes than those associated with insects or elephants. You can try and fit a peach pit through the body of a sparrow, but you aren’t going to get very far. Similarly, expecting tiny, thin-walled seeds to withstand an elephant’s battery of grinding teeth isn’t realistic either. The suite of fruit traits evolved for dispersal by a given group of animals roughly categorize into “seed dispersal syndromes.” By interpreting these syndromes, we can often get a good idea of what the primary dispersing animal, the other partner in a co-evolved relationship, is likely to be.

In light of this, it becomes obvious that despite our love of the avocado (specifically, domesticated cultivars with lots of flesh; wild avocado fruits have a thinner layer of green deliciousness surrounding that pit), it is not “meant” for human consumption and seed dispersal. Any attempt to chew up the whole fruit and swallow the massive pit is bound to land your asphyxiating ass in the cemetery. However, the situation for avocado’s seed dispersal isn’t much better in its wild Neotropical range. Many smaller animals (like monkeys) that partake in avocado consumption are “pulp thieves”, ingesting the oily layer and tossing the seed at the base of the parent tree. In fact, no native animal is known to consistently and effectively disperse wild avocado. Why then does the avocado make a big, energetically expensive fruit that doesn’t cut the mustard on dispersal? Also, who is the true “buyer” of avocado’s product?

The answer to both those questions may be that the avocado’s chief dispersal agent is extinct. Kaput. Gone. Effectively an “ex-animal.” This would mean that the avocado fruit is an evolutionary anachronism, equipped with traits fine-tuned by evolution for interaction with a species that has quite suddenly disappeared, leaving the once perfectly capable seed vessel under-appreciated and inadequately used.

“Fruit’s almost ripe, guys. Come and get it! Hello? ….Guys?!”

It’s a very serious case of being all dressed up with nowhere to go.

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Metatherians (Part 2 of 2): Odd Living Representatives

…so, some more about those metatherians/marsupials.

In the previous part to this two part series, I went over some of the now-extinct metatherian megafauna that once graced Australia and South America. These animals were fantastic and marvelous pinnacles of metatherian specialization, yes, but there are plenty of surviving metatherians, all of them of the ‘marsupial’ clade, that are also largely ignored and their lives obscured. There are some truly bizarre and amazing marsupials outside of the traditional koala/kangaroo/wombat/possum group that essentially everyone on the planet associates with the marsupial infraclass, and all of them somehow survived invading hoardes of humans and other placental species (although, in most cases, just barely).

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Metatherians (Part 1 of 2): Extinct Megafauna

Marsupials.

The immediate association most people have with the term ‘marsupial’ is that of fantastical, adorable, fluffy beasts in the far-away magical land of Oz, equipped with built-in fanny packs for storing their tiny, even more adorable, offspring. Bounding, big-eared kangaroos, sleepy koalas, and perhaps a hyperactive sugar glider or a waddling opossum might cross their minds. Not too far beyond this is where the train of thought pulls into its final stop, and suddenly they’re caught up in the romanticism of Australia itself; the sun-baked, tawny Outback scabland, didgeridoo droning in their mind’s ear, impossibly colorful fish flitting about the Great Barrier Reef, and perhaps Hugh Jackman or Nicole Kidman (whatever their fancy) driving cattle across the Northern Territory during The Dry.

While this idealization is all well and good, there is actually a lot more to these pouched animals than what fits on the in-fold of a Qantas brochure.
Marsupials are really bizarre by mammalian standards, and have a rich and relatively unrecognized evolutionary history that spans back 125 million years. This entry is one of two that will be devoted to these weird little creatures, focusing first on their unrealized illustrious past, and then on lesser known representatives of their clan in the present.

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Dragons

Dragons.

We’ve known them as ancient, mythical, winged, pyromaniacal reptilian beasts with a flair for the dramatic and destructive. They have been a fixture in our lore, in some form or another, the world over. While most of these tales of dragons are fictional, or at least highly embellished, there is still a very strong chord of truth in them. The blaze-setting, screeching hell-drakes so common in storybooks have not existed for a very long time, and it is unlikely that Medieval humans actually had contact with them (this stands in contrast with unicorns, which went extinct in 1982 when the last specimen escaped from her enclosure and ingested some antifreeze). However, dragons have had a rich and colorful evolutionary history that dates back 225 million years, and their unique biology and rise and fall in biodiversity is worth discussing.

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The Klamath Bioregion

When I actually get around to updating this blog I have going here, I typically spend my time talking about specific biological phenomena, or species, that go relatively underappreciated by the non-biologist public. After all, the name of this project is Shit You Didn’t Know About Biology, is it not? However, as someone with a background in evolutionary biology, as well as ecology, I can attest to the significance of communities of organisms and large scale patterning over landscapes. Our planet can be broken up into distinct ‘bioregions’ or ‘ecoregions’, which contain geographically distinct groups of communities of species, and these regions tend to be unique to other defined regions. Think of them as neighborhoods of sorts, each one defined by a specific combination of factors from local geology, geography, climate, and recent biogeography (or, the local distribution of organisms in that region; for example, you aren’t going to find tigers in the grasslands of Brazil, or sloths in the jungles of Central Africa, since a combination of evolutionary history, lineage migration, and plate tectonics has influenced the biogeography of these critters). The one I’ve chosen to talk about sits in an isolated and generally unfamiliar corner of the United States. This bioregion is very dear to me, because I spent more than three years of my life living there in high school, and although I was not there long, I was continually impressed by how special of a location it is. It is known as the Klamath Mountains ecoregion, as those mountains are a dominant feature in the region; the region, more generally, is also referred to as the Klamath Uplift, the Klamath Knot, and the Klamath-Siskiyou area. From a historical and political perspective, the region is effectively the coastal two-thirds of the proposed U.S. state of ‘Jefferson’, which straddles the current border between Oregon and California.

The map above shows some formal boundaries of designated ecoregions in the Pacific Northwest, and 78 is generally accepted as the Klamath Mountains zone. I’ve circled a slightly differently oriented area in red as to show the areas with which I’m most familiar, and additionally, because the presence of the Klamath Uplift itself influences the climate and resulting biodiversity of coastal zones (zone 1 on the map), so that the coasts of far southern Oregon and far northern California are very different from rest of the coastlines from their respective states. In blue, where the Klamath ecoregion, and its associated uplands, come closest to the Pacific, is where I went to high school; Brookings, OR. The 150 sq miles surrounding this small town, down the coast and inland, are unique even within this special ecoregion due to this close juxtaposition of these ecological entities. I feel as though this region needs some devoted attention not only because of its one-of-a-kind attributes, but because it is an almost undiscovered place. This is true of both outsiders to the Northwest (or as I like to call them, the Those That are Seriously Missing Out), as well as people that have lived in the Northwest, even within Oregon, their entire lives. Part of the reason for this is because this area is sparsely populated; the nearest large cities, like Portland and San Francisco, are hundreds of miles north and south, along narrow, ill-maintained, rain-beaten coastal roads. Simply getting there is an arduous endeavor that involves transversing harsh, forested terrain, cutting through largely uninhabited river canyons, and putt-putting down Hwy 101 on the coast, trying not to drive off a cliff in the face of Biblical-style rainstorms with violent winds. It is largely because of this lack of habitation that this area has remained so pristine and the unique biodiversity has kept intact. The coastline does attract a modest seasonal tourist population every year, because the area has a more amiable climate than areas north and south of there, and the natural beauty of the place is unparalleled and untainted by the suffocation of human influence. It is this natural beauty and ever-present access to undistilled wilderness that many that I knew that grew up there to say ‘yeah, I guess it’s pretty special.’ But this doesn’t go far enough. The Klamath ecoregion is more than special for being pretty to live, work, and recreate in. This region of the world has among one of the highest levels of species endemism on the Pacific Coast; species endemism refers to species that are found in only one, distinct geographic area and that area only, often evolved to conditions in that special little micro-range. By this definition, it is exceptionally unique, ecologically, and this distinction, I believe, is more impactful than aesthetics.

Due to its warmer climate, which has more in common with California than Oregon and the rest of the Pacific Northwest, it has been described as a ‘chunk’ of California brought up north and transplanted across the border. But this isn’t an accurate description either. The climate and geology-fueled Klamath ecoregion is wholly unlike anything found in Oregon, in California, or technically anywhere else in the world.

This region is a rugged paradise wilderness existing within the larger relative wilds of the Pacific Northwest, if that can be imagined. A land of lush forests, pristine waters, bright, hot sunshine, and the overwhelming silence of isolation from humans and their business, the Klamath bioregion is an unrecognized gem in the U.S.’s crown. The region is possibly the most enigmatic and enchantingly beautiful natural space I have ever known. And to it, the following entry will serve as my love song…

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Bioluminescence

Bioluminescence.

One of the more intriguing (at least to me), and beautiful quirks about the evolution of life on this planet is the repeated development of bioluminescence across many different lineages. Bioluminescence is simply the ability of a living organism to produce light. If it’s alive and luminescing, boom, you’ve got an example of a complex chemical cascade that allows sacks of meat not so different from ourselves to light up like a goddamned Christmas tree. Essentially, what is happening with bioluminescence is a highly controlled chemical reaction that releases energy in the form of light emission. This can be done by the beastie itself, or by a symbiotic microorganism that has been acquired by a larger creature. It occurs in multiple kingdoms of life, in terrestrial and marine environments. If I so desired, I could ruminate tearfully on how all of Earth’s life is chemically derived from components forged in a star in a Saganesque exposition of cosmic perspective…and how in some small way, bioluminescence is the means by which stardust can light the darkness of the universe once again. But, heavy-hearted sighs and poetic attribution of consciousness to a mechanically elegant and indifferent universe are for another day, and if done in all seriousness, for another person.

The thing about bioluminescence is that often our understanding of it is limited to a few well-known examples, and without any sort of context, biological or otherwise, other than ‘that is pretty; I like it.’ And while yes, indeed, fireflies and deep-sea fish do have a magical and/or alien quality to them, there is a whole world of bioluminescing organisms that go unloved and underappreciated and denied all the badass reasons for and applications of their abilities. Bioluminescence has evolved many times, and therefore, each example tends to have its own unique story.

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Odd Gymnosperms

Conifers.

Most of us living in North America and Europe know these as the “Christmas tree” trees. Those of us living in the Pacific Northwest know them as every single goddamn tree in sight. Towering, evergreen, and ubiquitous in environments ranging from temperate rainforest, to rocky mountaintops, to high desert and salty seashore barrens. Many of us with some life science background in high school learned that these are what are called “gymnosperms” (meaning ‘naked seed’), and are not quite like other land plants, in that they do not produce flowers, and reproduce using things like cones and copious amounts of wind-driven pollen. Due to the visibility and familiarity of conifers in our lives, and their vast economic and ecological importance (beyond the scope of being fabulous living room decorations one month of the year), cone-bearing trees like pines, firs, yews, spruces, and cypresses are the only gymnosperms that come to mind for those of us lucky enough to have a rudimentary background in the exciting field of evolutionary botany.

The reality is that a vast range of gymnosperms exist out there. Beyond the tree farm, beyond the city park, beyond the ornamental cedar in the front yard…is an entire world of alien plants that share that prehistoric, familial association with the relatively primitive conifers we all know and love.

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E pluribus unum

Well look at you. Aren’t you a masterpiece of biological evolution? You are a big, ambulatory, autonomous human being. You are separate from the insects on the ground, the birds in the air, and the steer in your burger. As a human, you envision yourself as lord of your surroundings, a unique animal risen and separate from other “lower” forms of life. Look at those clothes! And those thumbs! You are a whole and special individual, a single, isolated member of a species that has dominated and partitioned itself off from “nature” through years of rugged conquest and ingenuity. You could be very smug about all of that.

Except you’d be wrong.

You are not alone. While it is no secret that humans share their bodies with a bunch of microscopic, and smallish macroscopic, guests, the scope of their pervasiveness and impact on our lives is not commonly understood. The role of microorganisms and other parasites in the human experience extends far beyond a bit of armpit odor, bad breath, head lice, and dandruff.

In the perspective of a bacterium, the outside of the human body is an endless substrate, strewn with a ridiculous amount of nutrients and minerals, set on a lumbering factory that just churns out more goodies, making human skin an attractive place to settle down and colonize. The inside of humans is even better! It’s warm and moist and if you’re in the right organ system, new nutrients get delivered right to you! Human bodies are to bacteria as a mystical candy house in the woods is to Hansel and Gretel. It is only by the graces of the immune system provided, non-stop, by vigilant human cells that you and I aren’t eaten from inside out…and also from the outside in…by our plentiful tenants.

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