Category Archives: Ecology

Mesmerizing Marine Mimics: Fooling Across Phyla

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This post is the second in a six post series outlining the evolution of mimicry within the ocean realm. These posts detail various ways in which organisms may copy other organisms in appearance and behavior, and the evolutionary context for how these mimic-model pairings have come to be. The first entry in this series goes over some fundamental introductory concepts and definitions regarding mimicry in general.

A fish that has evolved to mimic a completely different, potentially entirely unrelated species of fish is relatively impressive. It is a testament to the power of natural selection, this honing and whittling down of a creature so that it may converge on the same exact external form for the sake of protection or the easy procurement of food.

But fish all have the same overall “blueprint.” Paired fins, vertically oriented tail fin, eyes in the front, big, snappy mouth, gills behind the eyes, generally sleek and muscular…there are a number of distinctly “fishy” features that evolution doesn’t fuck around with too much. This sort of basic body plan of a taxonomic group is sometimes down as a “bauplan” and its sort of the generic physical shape and scaffolding with which a given lineage of organisms ends up modifying as different branches break off and try out different tweaks and strategies. The “bauplan” for a motor vehicle, for example, is basically four wheels with tires, a broad cabin for passengers resting atop the rolling chassis, windows, engine, headlights, perhaps a trunk in the back. Anyone can tell you that there are many differences between a Chevy Camaro, a Subaru Outback, and a Hummer, but all of them are superficial when you consider the motor vehicle bauplan they all share. Similarly, the alterations and adaptations associated with the evolution of mimicry in these fish are limited by the constraints generated by their overall body plans. A fish can only fake it so far, and imitating another animal with the same bauplan is completely within any developmental constraints.

But there are fish that manage to step outside the “vertebrate box” when it comes to pulling a fast one on their ocean community. There are some fish that are mimics of invertebrates; spineless, squishy, squirmy things that they haven’t shared a common ancestor with for well over 550 million years. These fish convincingly pass themselves off as things that aren’t even remotely built the same way, all through some clever innovation through the prism of evolution.

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Eucalyptus regnans, Tallest Tree in the South

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I like really tall trees.

I suppose the possession of this adoration of our planet’s living, heaven-raking spires comes as a kind of birthright. I grew up in the Pacific Northwest, an area not only richly coated with swaths of the densest temperate rainforests in the world, but also the tallest forests in the world. I came of age spending a great deal of time hiking and navigating forests largely consisting of several tree species that are among the world’s tallest. Coast redwood (Sequoia sempervirens), douglas-fir (Pseudotsuga menziesii), and Sitka spruce (Picea sitchensis) are all found in the lush coastal forests of Oregon and far Northern California where I spent many long, summer days of my youth; each of them generally regarded as being within the top five tallest tree species on the planet, based on the consistency and frequency of superlatively monstrous individuals within each. Even the “smaller” trees in the region seem to reach uniformly towering heights. Western redcedar (Thuja plicata) can top out at 200 feet (61 m) or more above the soft, spongy soil of the dark, coastal woods of Washington and Oregon. Western hemlock (Tsuga heterophylla), a very common sight in the Pacific Coast Ranges, can easily grow to some 250 feet (76 m) at its droopy crown. The bottom levels of the canopy in a Pacific Northwestern old-growth rainforest can potentially be no less than 150 feet (46 m) high, which is a value not often matched in any other forested region on Earth.

A shaggier version of myself standing with the Quinault Lake Redcedar, the largest western redcedar in the world, on Washington’s Olympic Peninsula in June 2011 (Photo credit: Werner G. Buehler)

It’s no wonder that growing up immersed in this place has left me with a love for these great trees; old-growth forests full of venerable, enormous trees are incomparably majestic places. The sense of perspective and scale that these trees provide is invariably humbling. It’s difficult not to walk alongside them in a kind of hushed reverence, as if you were traversing the floor of an ancient and solemn temple or cathedral, one crafted from humongous, gnarled pillars of wood and moss, rounded with smoothed with deep time and dark silence. The temperate rainforest springs to life in intense bursts of emerald from wherever these trees have embedded their water-ravenous feet, with lithe lances of ferns and the ghostly baubles of root-associating mushrooms erupting wherever soil space is available. These dampest and darkest of woods, blanketed from the sun a football field’s length upwards, have been described as primordial, as a place of senescence and decay, but I think this is a misplaced conceptualization. The sites where the greatest of these trees grow is positively choked with life; life that clings to and parasitizes other life, life that reaches achingly skywards in even the weakest, most diluted sunbeam to touch down on the forest floor. In my mind, these are places of as much birth and flourishing as they are museums.

This aesthetically spell-binding quality, mixed with these forests’ complex ecology and somewhat unique, insular propensity to harbor endemic species…creatures found nowhere else in the world…is what persistently attracts me back to them time and time again (and also inspires me to write about them…multiple times…because I’m a little insufferable).

It is these types of places, misty, verdant groves of titanic conifers, that come to the mind of most when they envision the world’s tallest trees…granted they call the Northern Hemisphere home. It’s somewhat widely known that California’s coast redwoods are the world’s tallest species, and across the North American continent the sheer size of Pacific Northwest forest trees is no secret…especially when compared against the far more “compact” deciduous trees that are common on the Eastern Seaboard. But a very close contender for the title of the most gravity-taunting plant in the world comes from a location not often associated with impenetrable forests. One of the tallest organisms on Earth is an altogether different kind of plant than the behemoth redwoods, and it hails from the opposite side of the globe from the dewy haunts of Cascadia…a place far more associated with rust-colored, alien deserts, blinding heat, and a faunal assemblage that constitutes the world’s largest bucket of shorts-soiling “hell fucking no.”

I’m of course talking about Australia.

Yes, Australia is a place of extremes…where the venom flows like water, the coral reefs are supersized, and summer turns the landmass into a not-so-metaphoric broiling pan of unending solar-powered punishment  (one that keeps getting hotter). From a biological perspective, Australia is a continent perpetually locked in rebellious teenager mode, deviating from the rest of the world’s biota and letting its freak flag fly proudly for millions of years in a parade of pouches, flightless birds, weird plants, fangs, spikes, and scales. It is therefore quite fitting that one of the tallest trees in the world, the only one in the top five that is not a conifer, in pure contrarian style, is Australia’s Eucalyptus regnans…the “mountain ash” or “swamp gum.”

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Evolutionary Anachronisms

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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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The Klamath Bioregion

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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

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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

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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

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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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Fungi

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Fungi.

Quite possibly the most overlooked of the eukaryotic kingdoms. Not as mobile as their animalian close cousins, and they tend to be more discrete than the giant, showy plants. For most of us, at their best, they are an edible foodstuff, adding a bit of gummy texture to stir-fries. At their worst, they ruin an old strawberry or cause a bit of itchy feet, much to the chagrin of John Madden. They are the completely benign decomposers of the shadows, the wood-rotting, spongey, alien-like denizens of coastal forests and poorly ventilated bathrooms. Soft. Passive. Life’s unassuming and dutiful janitorial crew. Wouldn’t hurt a fly.

Oh.

The unfortunate insects above, now reduced to crumbling husks, were parasitized by a species of Cordyceps fungus. More closely allied with common bread mold than your average forest mushroom, Cordyceps make a decent living out of selectively infiltrating the bodies of various insects, growing inside of them, and eventually killing them and erupting through their exoskeletons. Some can even impact the minds of their insect hosts, making them into little zombies that position their bodies in such a way so that when they succumb to their insides being turned into a palatable slurry, the spore producing fruiting body (or “stroma”) of the fungus can have an advantageous location over the forest below, allowing for the maximum amount of exposure possible to other unwitting victims. Observe below:

Sir David Attenborough’s soothing narration, coupled with the music, make this video far more creepy than necessary. There’s something vaguely nightmarish about those wailing strings and circus-tent music playing alongside images of death-by-killer-fungus. Cordyceps are found worldwide, but enjoy higher density and diversity in the lower latitudes. As far as we know, they tend to go after insects only.

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Ladybugs

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The ladybug.

Adorable, right? The cheery, apple-red carapace garnished with but a few, large black dots; as if a tiny pixie had painted them on, and the paintbrush tip was just too big to fit more than a few dots on. This, combined with its bumbling walk along the flowers, and its round, squat body evokes imagery of a kindred Russian grandmother, tending her garden in her brightly-colored babushka. If you are fortunate enough to get one to crawl on your hand or finger, its tiny legs tickle your skin and it eventually pops open its carapace (made of modified wings called “elytra”), and silently takes off as an itty-bitty summertime jewel of cuteness and sunshine and sparkles (and it’s supposed to be good luck! awww). Definitely adorable. Right?

Wrong.

Ladybugs (also known as “ladybirds” outside of North America, as well as “ladyclocks”, “lady cows”, and “Xena flys”) are voracious predators in their raised-bed ecosystem. Ladybugs, from the cradle to the grave, feed upon many different types of insects (many of them important crop pests, so yay), but most commonly on things like aphids. Ladybugs are built to seek-and-destroy aphids. Imagine a giant, armored tank, bearing down on you at stupid speeds, and you’re a squishy, slow, small, green thing…and you have an idea of what it’s like to be an aphid caught in the crosshairs of a hungry ladybug. Did I mention the tank’s front is equipped with more razor-sharp blades than an industrial agricultural combine? That cute little ladybug face hides a generous amount of sharp, curved mandibles that are designed by natural selection to pop an aphid’s body like a Screamin’ Green Apple-flavored Fruit Gusher. A single, adult ladybug can consume more than 1000 aphids in one day during the growing season. Seeing as how ladybugs can live up to about two years, that comes to roughly 360,000 aphid lives in the lifetime of a single ladybug, which is more than the metro population of the city I live in, Eugene, Oregon.

“Genocide? I don’t know what you’re talking about.”

Their squeal-inducing adorable coloration has particularly dark origins. Ladybugs are still quite small, and despite their armor, are no match for even more badass predators like birds and larger insects. So, through the wonderful ingenuity of evolution, ladybugs and their relatives have developed a potent deterrent from being gobbled up, and their bright colors serve as a warning and reminder of this capacity. Mechanical stimulation, like from a predator attack (or, you know, a human finger) releases a reflexive outpouring of alkaloid toxins from every joint and crevice in its exoskeleton. The toxins are incredibly bitter tasting, and the “goal” is that the ladybug is spat out so it can continue its merry life of slaughtering ‘lesser’ insects. Some can apparently even spray this shit when threatened, poisoning small mammals. So don’t let your hamster play in the garden. It’s thought that just being around these things can be hazardous, as in large enough numbers, they’ve been shown to aggravate allergies and asthma in humans. Ladybugs are not only homicidal maniacs, they also are walking dirty bombs.

But, you say, that cute wittle bug sort of negates all the inevitable aphid death and venomous ooze. With a face like that, who couldn’t look the other way?

Fucking Christ! It looks like something that would wrap around your face, lay its eggs in your stomach, and produce chest-bursting progeny that would terrorize Ripley for four, increasingly shitty films.

You see, in their childhood, ladybugs are essentially nightmarish hell-creatures that would battle, and eviscerate, Godzilla were they not so diminuitive. They look like this for the first two weeks or so out of the egg, shedding their skin (in a process called “molting” or “ecdysis”) four times, growing larger and more terrifying each time. They then pupate, and emerge as an adult, and only a few days later they become sexually mature…and thus have the ability to produce a dozen more killing machines.

So, feel free to admire the ladybug for its beauty and benign appearance. But the next time one drifts by on a warm summer breeze, and daintily lands on your arm, keep in mind those tickly feet are splattered with the blood of innocents and home-brewed drain cleaner.

© Jacob Buehler and “Shit You Didn’t Know About Biology”, 2012-2014. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Jacob Buehler and “Shit You Didn’t Know About Biology” with appropriate and specific direction to the original content.

Co-evolution

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Coevolution.

For those of us who have a basic understanding of biological evolution (and I hope that’s all of you), one of the easiest and most straightforward ways of conceptualizing the process of natural selection as it impacts evolutionary change is imagining an environmental pressure that eventually results in a genetically-based trait alteration in populations of living organisms. For example, a bunch of short-haired hamsters move into a cold area. The shortest haired individuals die off more readily than their more shaggy counterparts, selection favors longer hair, the trait increases in overall percentage in the population, bada boom you have evolution. But in reality, there is a lot more going on in nature than non-living factors impacting living things; other living things are very much a part of the environment, and are a very large component of the evolutionary trajectory of other living things. Since both co-influencing factors are of a biologic construction, reinforcing evolutionary change can occur as a response to the consequences of a relationship in both member species…this is known as coevolution. Coevolution allows the emergence of ecologically complex interdependent relationships, sometimes with many different species involved. Coevolution often results in predator-prey evolutionary dynamics, host-symbiont relationships (as well as host-parasite relationships), and a whole mess of interactions based on nothing but exploitation of an unwitting victim species.

< / coevolution intro>

Consider a flower. Most people enjoy flowers; they can be brightly colored, intricately shaped, often smell nice, and for those of us living in the seasonal latitudes, they are a symbol of the warm days of spring and summer. However, the pleasantries of a flower are not for you. Flowers do not care about you. The plant that makes the flower is doing it for reproduction, and this reproduction is almost never dependent on your swooning suspirations and giddy entrancement with color. For angiosperm (the division of plants that produce seeds and flowers) plants, flowers are the embodiment of sex. They are there to both disperse genetic material and grow fertilized offspring. This is where something called pollination syndrome comes in, and no, it’s not contagious and no it’s not what is killing all the honeybees. Pollination syndromes are essentially a suite of traits of flowers that have evolved as a response to a certain pollination vector (which could be abiotic, like wind or water, or biotic, like through living animals). The relationships with animals entirely for reproductive means allow for rampant coevolution. The difference between the biological vectors is significant because it determines many characteristics of the targeted flower. The plant has to do a good job of making a flower that attracts a certain group of pollinators, so the evolution of pollinator-flower relationships tends to drive towards the tailor-making of flowers to maximize the appeal to the vector. Most flowers we know and love are like fast-food billboard advertisements along a freeway. The sultry Carl’s Jr. billboard appeals to our desire for fatty, greasy, starchy goodness; a flower’s coloration pattern and scent tap into the sensory batteries of the bee brain.

Eat at Joe’s Rose

If Carl’s Jr. is successful, we end up making a detour, eating ourselves into a bloated and ashamed mess, and they get our money. If the flower is successful, the vector drops in for a sample of nectar, and leaves with a dusting of pollen to transmit to the next flower.

Bees get a lot of attention for their role in pollination. And they should, as they tend to pollinate many of our most important food crops…hence the anxiety about Colony Collapse Disorder. But often overlooked are the bigger, non-stinging vertebrate pollinators like birds. Flowers pollinated by birds, due to a different set of parameters for coevolution, tend to be different from insect-pollinated flowers. Bee-pollinated flowers tend to be yellow or blue with nectar guides, which are basically landing strip lights that show up as stripes only visible in the UV spectrum (which bees conveniently can see in) that say HEY BEE, THERE’S FOOD AT THE CENTER OF THIS FLOWER AND THIS IS HOW YOU GET THERE. Nectar production by the flower is moderate, as bees aren’t all that big, and they tend to be scented, as bees have finely tuned chemical sensors. With flowers that are bird-pollinated (or “ornithophilous”), a different strategy is taken. Red or orange is far more common color used to attract birds, since these stand out more readily in the vision of birds. The flowers are usually unscented, because birds have a shitty sense of smell, and making sweet-smelling compounds for no reason is counterproductive to overall fitness. Ornithophilous flowers also tend to make a LOT of nectar to keep the bird well-fed and coming back for more, hence keeping the relationship stable. Since nectar, being pure sugar, is energetically expensive, there is an evolutionary push towards trying to maximize benefit from each encounter, while minimizing the loss. Because of this, these flowers have evolved shapes that tend to be long and tubular. This forces the bird to force its face deep into the flower to get at the nectar in the back, potentially minimizing the amount it can lap up, and increasing the amount of pollen that gets all over the bird’s head. Many groups of birds have coevolved alongside this floral effort, combating this attempt to fleece them in the name of sex by evolving longer and thinner beaks and longer tongues. The most specialized nectar-feeding birds in the worlds (hummingbirds, honeycreepers, and sunbirds) all have long, curved beaks with insanely long tongues. This coevolution goes back and forth, selecting for ever longer bird beaks and tongues and ever deeper flowers. Hummingbirds and flowers have been engaged in a beautiful game of attempting to screw each other over for tens of millions of years.

Some plants have evolved to exploit the other flying vertebrates; bats. Bat-pollinated flowers tend to, of course, open at night. They are also large, white, incredibly odiferous, bell-shaped, and produce loads of nectar. The downcast bell uniquely suits the upside-down clinging of bats, the large size makes them easy to distinguish with echolocation, and seeing as how bats have an awesome sense of smell, all that sweet and sticky odor works out perfectly.

African baobab: Just for you, my web-winged friends.

Sometimes there is another level of complexity in these pollination syndromes that takes advantage of a specific dietary affiliation of their target pollinator. Instead of appearing to be an ambiguous food source, they appear to be something altogether different. One example of this are the Dracula orchids of Ecuador, of which there are many species. Dracula flowers tend to be large, drab, and in possession of a modified petal that is pale, upturned and folded to resemble a gilled mushroom. As if that wasn’t enough, the orchid steps it up a notch and also produces an aromatic compound that mimics, perfectly, the rich smell of a rainforest fungus…the same fungus that the fungus gnat uses for sustenance. The gnat follows the scent, comes across a convincing visual mimic in the warped mushroom petal, and attempts to dig in. By the time the gnat figures out it’s not on top of its favorite food, it has already been covered in the orchid’s pollen. Fungus gnats must live a pitiful and frustrating life, constantly being duped by a goddamn plant.

“I vant to take your pride and shit on your self-vorth. Ahahaha.”

Plant-animal coevolution doesn’t always have to entail trickery, callous self-interest, and feigned kindness. Sometimes what’s known as a symbiotic relationship can evolve, in which both parties legitimately benefit from the interaction, and are completely dependent on each other for survival. Individual fitness is still the ultimate factor, but a car salesman-esque swindle isn’t the primary way of getting there.

This is the bullhorn acacia (Acacia cornigera), native to much of Central America. Taxonomically, it shares a family with such familiar plants as beans, peas, lupine, and vetch; a look at the leaves provides a good hint. Anyways, the bullhorn acacia is so named for its swollen and hollowed out stipular spines, pictured above, which resemble cow horns. Most acacia trees, found in tropics worldwide, possess very bitter alkaloid compounds in their leaves which serve as a deterent to being eaten by insects and large herbivores. This species went on a different evolutionary trajectory, nixed the nasty taste, and formed a symbiotic relationship with the ant Pseudomyrmex ferruginea in order to protect itself. The ants spent a lot of time in the shelter of the hollowed out spines, and when any sort of animal interacts with the tree, be it a frog, deer, or human, they rush out in a rage and swarm and sting the unfortunate beast that brushed up against the coveted acacia. The ants pack a hell of a punch in their sting, and are more like wasps in that regard. Most herbivores learn quite quickly, of course, not to fuck around with bullhorn acacias. It is also thought that some herbivores, after interacting with these plants, learn what the alarm pheromones of the ants smells like, and give the plants quite a bit of room based on that. The ants are also so dutiful to their gracious plant host that they routinely clear away seedlings of other plants growing around the acacia that threaten to grow up and block access to sunlight. The ants do all this because their beloved acacia provides more than just a boss as hell spiny loft in the jungle to crash in; the bullhorn acacia produces protein and lipid-rich nodules on its leaflet tips called Beltian bodies (pictured below), along with a sugary nectar from glands on the leaf stalk. The ants essentially live purely on these products, and will go apeshit on any threat to their food supply. So, while the relationship works well both ways, there is some passive manipulation going on. The acacia gets a private army of hyperaggresive ant slaves by getting them hooked on readily available, energy rich food, and the ants live contently…but have to fight and die in order to get their fix.

I blame the schools.

Stepping away from plants and bugs, and towards the antagonistic predator-prey interactions, one must look on the west coast of North America, a place very dear to my heart. Anyone who has lived there undoubtably is familiar with the rough-skinned newt (Taricha granulosa), with its ubiquitous presence in rivers and streams, pebbly gray back, bright orange belly, and adorable amphibian face. As children we were wisely warned by our elders to wash our hands after handling the newts, not because they are dirty, slimy, bacteria-ridden critters…but because rough-skinned newts are among the most toxic amphibians in the U.S. They produce tetrodotoxin, which then seeps through their skin; tetrodotoxin is same toxin that pufferfish possess…and that kills a certain number of Japanese and too-ballsy-for-their-own-good tourists from fugu consumption every year. Tetrodotoxin is also used by some lethally toxic poison dart frogs. For humans, the toxin isn’t much of a concern unless it’s ingested or introduced through the mucuous membranes or through a cut. SO ATTENTION FELLOW WEST-SIDE OREGONIANS: If you are “upriver”, and you cut your hand on a blackberry bush struggling to get down to a sandbar, because you didn’t want to spill your Ninkasi or smash your Newman-O’s…you might want to think twice about handling that cute little newt you spotted on your last dive to the river bottom. Part of the reason these little guys are so damn toxic is because of this:

LITTLE BUDDY!!!! D:

Garter snakes (Thamnophis sirtalis) have a penchant for newt flesh. In theory, the tetrodotoxin messes with a sodium channel in the snake’s nerve cells, making the above dining risky, if not deadly. However, some populations have developed genetic dispositions that make them resistant to the newt’s toxin, allowing them to munch on as many squishy, defenseless newts as they want, which gives them a unique advantage over other predators, as they are the only creatures that can exploit this food resource. In areas where toxin-resistant snakes occur, there is a selective pressure on newts for more potent toxins to protect against the super-snakes. This coevolutionary back and forth, with ever-increasing toxicity and reactionary resistance evolution, goes on and on, in what is referred to as an evolutionary “arms race.”

“Vengeance will be mine…just give me a hundred generations or so.”

This has occurred for a long time, sporadically, throughout the entire range of the rough-skinned newt. The end result is, in general, a species of newt that produces toxin levels far beyond what would be necessary to kill any other predator. This was made adundantly clear in 1979 when a 29-year-old college student in Oregon (of course) died not too long after swallowing a newt on a dare at a party. So yeah, thanks a lot garter snakes. Now we Oregonians are forced to resort to boring things like goldfish to throw down the gullet on a drunken whim. There’s no telling how far this arms race will go, but given the long history of such things, I’m worrisome.

Extremes exist on the more laid back, symbiotic side of things too.

This is lichen. It looks a little like a hardy plant, or a fungus, but in reality, it’s neither. Lichen is not actual a single “thing”, but a composite organism made of a species of fungus and a separate species of green algae or a cyanobacteria. The fungal component is known as the “mycobiont” and provides the greater structure and framework for the lichen. The cyanobacteria or algae, contained inside the mycobiont itself, is the “photobiont.” The photobiont is, predictably, a photosynthesizer, and produces carbohydrates for both partners from sunlight. The mycobiont provides shelter for the photobiont, and assists in the retention of water and minerals. Lichens have evolved multiple times over the past several hundreds of millions of years, and rightfully so, as lichens tend to be highly successful in extremely dry and cold environments. They represent some of the most specialized, ancient symbiotic marriages in the history of life. And we humans think making it to our 25 year anniversaries are hard.

“You can’t expect me keep water contained with this little sugar. I have NEEDS, damnit!” “Well MAYBE if you didn’t make hyphae weren’t so fucking thick, I could actually see the sun! We’ve been over this, but nooooo, it’s like talking with a brick thallus with you!”

But even lichens may not corner the market on symbiotic supremecy. Eukaryotes, which are organisms whose cells contain membrane-bound organelles (a nucleus, chloroplasts/mitochondria, Golgi apparatus), include all multicellular life. You, me, all animals, plants, fungi, algae, and single-celled protists are all eukaryotes. They arose roughly 2 billion years ago, and the evolutionary step towards having complex, membrane-bound structures like organelles inside each and every cell is arguably one of the most significant transitions in the history of life on Earth. One theory, which is now heavily supported, is that these organelles were not just manufactured by a bacterial or archaean cell. Endosymbiotic theory posits that eukaryotic cells are derived from a collection of bacterial cells that became symbiotic upon each other deep in evolutionary time. Mitochondria could be derived from a proteobacterium that became internalized inside another bacterium, becoming a dependent “endosymbiont.” Chloroplasts could be descendents of cyanobacteria that underwent the same process. Some evidence for this comes from the fact that mitochondrial and chloroplast contain their own, distinct DNA from the main cell’s nuclear DNA. They also replicate themselves in a similar manner to bacterial cells. If endosymbiotic theory is indeed true, you and I are less a cohesive, singular organism than we ever thought. Not only are we technically a giant collective of cells masquerading as a single, whole unit…but within those cells, we may have another level of collective organization. It may be that, although we conceive of ourselves as individuals (and certainly from an evolutionary and ecological standpoint, we are), at our most basic level, we are a collection of interdependent machines, supporting each other for billions of years, with the only thing “individual” about us being the singular goal of the replication of the “main” cell’s genetic material.

All of this collective organization is driven by a little known organelle called the marxochondrion.

Coevolution adds an additional layer of complexity to evolutionary dynamics on this planet, and is responsible for the much of the diversity of life on this planet. Life has a profound impact on other life, and by driving the biosphere into dizzying heights of diversity, helps ensure the long-term survival of life on Earth.

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