Easter Island: Ecoregion at the Edge of the World

The popular religious holiday that occurs near the northern spring equinox goes by a number of names. Easter. Resurrection Sunday. Pasch. Whatever it is called, the majority of the world’s 2 billion or so Christians observe this holiday with regional variations of religious activities, customary foods, and symbols. Common traditional proceedings include parades and religious services, but much of the fun is directed at the youngest attendees. For small children, the holiday is the most egg-focused spectacle they’ll see until they reach adolescence and discover the decorative inspiration of Halloween. Kids spend the day giving eggs food coloring swirlies, embarking on crazed, egg-based scavenger hunts, and, for some reason, palling around with a vaguely leporid husk filled with fear-sweat and the voiceless madness that reaches out from the Void. For godless heathens such as myself, Easter mostly functions as an annual excuse to wear a classy-as-shit collared shirt, get together with fine folks, inhale brunch and booze, enthusiastically and inefficiently stagger around the grounds in a quest for plastic eggs, and to catapult my pancreas into sputtering death-fits after shamelessly replacing much of the liquid in my body with a Marshmallow Peep-derived sugar slurry.


Re-enactment: Easter Sunday 2016

The only other association I have with Easter….outside of that day of the year when I thoroughly test every major organ system in my body through the gross irresponsibility of facilitating a gastrointestinal nuclear holocaust….is a place, not an event. And because I’m a HUGE nerd, I’m obviously talking about a small island in the southeast Pacific known as Easter Island. To the Chileans, who currently have political jurisdiction over the island and categorize it as a special territory, it is “Isla de Pascua.” The original Polynesian inhabitants of the island were the first to name it, and while there is considerable debate about what exactly the island was called long before Europeans ever set foot on it, for the last century and a half, the Polynesian name for the island has been “Rapa Nui,” a term that has also come to denominate the native inhabitants of the island, and the language originally spoken there.

The South Pacific is sprinkled with a multitude of small volcanic islands and coral atolls that spread eastward from Indonesia and Australia; Fiji, Tonga, Samoa, Tokelau, the Society Islands, the Gambier Archipelago, the list goes on. The expanses of open ocean between many of these islands and island chains are not insignificant, but nowhere is the level of isolation as extreme as in Rapa Nui. Rapa Nui sits in the subtropical zone, some 27 degrees south of the Equator. It is located at the most southeasterly point of the vast, triangular Polynesian cultural region, representing the furthest eastward extent (that we know of) of Polynesian diaspora and colonization, much like how Hawai`i and New Zealand sit at the northern and southern extremes of the region, respectively.

The nearest large landmass (South America; northern Chile, specifically) is 2,300 miles (3,700 km) directly east from there, and the nearest inhabited island of any kind is Pitcairn Island…more than 1,200 miles (about 2,000 km) to the west….an island that is only about two miles across, and was perhaps only sporadically inhabited up until a few hundred years ago, when it became wholly deserted. The closest bit of land of any kind is Isla Salas y Gómez (Manu Motu Motiro Hiva), about 250 miles (400 km) to the northeast, but this tiny fleck of exposed, volcanic rock only covers about 37 acres…which means it’s only one third as expansive as the Mall of America. Thus, Rapa Nui’s closest neighbors are even more diminutive than it is, which doesn’t exactly assist with the whole extreme isolation thing. The situation reminds me of when I lived in rural, central Idaho as a child. The tiny, high-desert town I lived in (Challis) only contained about 900 rugged souls, all of which grunted out a living 150 miles away from the nearest hospital, movie theater, or fast-food franchise. However, there were towns that existed out in the Great Brown Nothing between my town and the nearest semblance of civilization. But they were puny, the barely-discernible petechiae blemishing the pale, wrinkly, boundless expanse of septuagenarian back skin that is the State of Idaho. Our closest neighbor, a hour’s track away on lonely Highway 93, was the community of Mackay…..half the size of our own town. Good ol’ Challis, Idaho wasn’t much, but it was the biggest hub by far for many, many, many miles….much like Rapa Nui.

So yes, Rapa Nui sits way out in the ass end of nowhere, atop a seamount that has formed via the Easter hotspot, an upwelling of magma below the oceanic crust that has generated a range of undersea mountains (the Nazca Ridge) as the Nazca Plate drifted above it….nothing around it for many blue, featureless miles. However, this extreme isolation wasn’t enough to keep humans away, at least not for forever.

Rapa Nui was first colonized by Polynesian settlers (probably from Mangareva (in the Gambier Archipelago) to the west, or the Marquesas in the northwest) sometime around 1200 AD or so, making it nearly the last place in the Pacific to be discovered and settled by Polynesian peoples (New Zealand was more recently settled, around 1300 AD). It was the Rapa Nui society that persisted on the island completely solo until the 1720s, when Dutch explorer Jacob Roggeveen stumbled across the place (as one does) on Easter Sunday…giving it the name “Paasch-Eyland”, Dutch for “Easter Island.” The Rapa Nui people are of course quite famous for their proclivity for carving impressively massive, stern-faced statues out of the compressed volcanic ash found on one of the island’s main volcanoes.


You know, these fellas.

Nearly 900 of these figures (called “moai”) are known to exist in modern times either on the island (or in museum collections), and can consist of nothing but the regularly referenced “Easter Island heads” or heads and bodies that are complete down to the waist or thighs. Moai are so enigmatic and stark against their often open, rolling backdrops that they’ve managed to lend inspiration (with varying levels of cultural sensitivity) to various elements of modern popular culture, from Pokemon to major settings in early Mario videogames to Spongebob’s buzzkill of a neighbor’s house.

If you’re looking at the empty, treeless plains that cover the island and thinking “how in the everloving fuck did the Rapa Nui craft and move these things around? There’s not a trace of raw materials necessary for pushing, pulling, or carving jack shit!” you and decades of archaeological pondering have something in common. The thing is, when the first Polynesian settlers arrived on Rapa Nui, the island was covered in thick, subtropical forests. Within a few hundred years, around the time Europeans first saw the island, nearly every single tree was gone. Various explanations have been thrown around as to how and why Rapa Nui’s forests vanished; the most popular of which has been that this is a story of environmental degradation on a micro-scale precipitated by human overpopulation, limited resources, and eventual societal collapse (although more recently, it’s been suggested that European-introduced disease and slavery may have been the driving factor for societal and population decline, while the rats that were stowaways with the Polynesian settlers’ canoes did short work of the island’s vegetation). Whatever the cause, the native forests of Rapa Nui are kaput, which is a damned shame considering that Rapa Nui’s extreme geographic isolation means that much of the island’s native flora and fauna were (and are, for those that haven’t yet become extinct) unique, in an ecological and evolutionary sense.

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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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