Present extinction Archives - Demons Dance Alone

Blood of birds, disintegrating butterflies, two end-Permians, innocent volcanism

So, this blog has a loooooong backlog of stuff I wanted to talk about but I didn’t. Old stuff, like, one year old or more. Alas, I cannot hope to make a complete post on all that, but I don’t want to let it rot. Let’s do a bit of quick catching up:

Bird blood on our hands. In 2019 a couple of papers pointed directly the fingers at humans for the extinction of the great auk and the Carolina parakeet, two once-widespread, iconic species of birds that went extinct in the XIX century. Both papers analyzed paleogenomes (is it right to use the ‘paleo’ prefix when it’s a couple centuries ago?) and found out that both species populations had a vibrant genetic diversity until their numbers fell abruptly to zero. Which means: no, they weren’t already fragile, declining species that we gently pushed off a cliff they would have met anyway. We systematically exterminated two robust, healthy bird species in the space of a few decades or centuries. Not exactly unexpected, but now there’s more proof.

Singapore Coney Island Butterfly - Free photo on Pixabay

Butterflies that we will never know. In Singapore, 46% of the butterfly species disappeared (locally) in a mere 160 years, according to a paper of February 2020. Interestingly enough, the study accounts for extirpations of undetected species, using a model. I’m in no position to comment on the math, but the very idea is intriguing and melancholic: about a hundred of species would have gone extinct before we ever discovered them. Of these, some could have well been endemic species: ghosts, of which now we have nothing else than numbers in a statistical analysis. “14.9% of the species discovered before 1900 also were extirpated before 1900. These high early observed extirpation rates, during a period where many species remained to be discovered, suggest that a high number of species were never detected before they were extirpated”
The Karoo Basin, in South Africa, where the best deposits on terrestrial end-Permian/early-Triassic fauna are preserved.
A tale of two end-Permians. Discerning a single event that happened 252 millions of years ago is incredibly hard; discerning a complex interplay of events even harder. Compared to the relative simplicity of the Chicxulub impact, the Permian extinction is a maddening puzzle, muddled by its remoteness in time. There were always hints of multiple extinction events or at least multiple “hits” that led to the Permian catastrophe, but now a paper of March 2020 seems to imply that the extinction on the sea was different from the extinction on the land. It seems that whatever happened on the continents, leading to the demise of most terrestrial fauna and the temporary dominance of Lystrosaurus, happened 300.000 years before the extinction in the oceans: “Instead of the currently favored paradigm of calamitous and globally synchronous turnover in ecosystems, the reported terrestrial turnover in Gondwana occurred hundreds of thousands of years before the marine one and, therefore, marine and terrestrial responses likely had different extinction mechanisms.“. We have to see if and how it will be confirmed, but if so, it seems that the end-Permian extinction is truly two extinctions, above and below water. It will be extremely interesting to grasp how did one influence the other, and how does it translate to our current situation.

Innocent volcano. In January 2020, Pincelli Hull and coworkers put another nail in the coffin of the volcanic hypothesis for the K/T extinction. The K/T event has the distinction of having two competing or possibly synergic explanations: the well known Chicxulub asteroid impact, and the Deccan traps, a major volcanic event. For decades scientists have fought on what of these events was most important, and even if the impact seemed more and more clearly the culprit, the Deccan enthusiasts didn’t lose their grip. However, if the study is correct, it seems that 1)Deccan outgassing isn’t chronologically correlated to the extinction, but the impact is, and 2)the Deccan volcanism simply wasn’t generating enough gas to trigger an extinction, since similar events didn’t alter the biosphere so much. Another paper a few months later even argued that, if the Deccan volcanism had any effect, it was mitigating the extinction effects.

Diese Liebe macht krank

One of the things probably most people do not suspect about Germany is that it has a vibrant gangsta rap scene, whose main leaders is the infamous crew 187 Strassenbande from Hamburg. And, especially, one rapper: Gzuz.

As he himself sings, “the guy is real, whether he comes from Compton or Altona“. He’s indeed a character: He did, among other things, two or three years in jail for armed robbery, slapped a swan, and celebrated New Year with automatic weapons. His over the top, so-real-it’s-unreal videos shocked hip hop fans in Usa.

Why are we talking of gangsta rappers here? One of the best known Gzuz hits is CL500. A celebration of his car, symbol of the wealth he got by rapping, it’s about as deliciously Asozial (a term that in Germany is about the same as chav in England) as it can get:

Why are we discussing German gangsta rap here? I was intrigued by how, in the song, Gzuz is proud to show how much he loves to waste energy and fuel. He loves to enjoy his car even when it does not make sense:

Die Straßen hoch und runter, auch wenn ich keinen Grund hab’

(«Up and down the streets, even when I have no reason to»)

And in the end:

Und wir blubbern, blubbern, blubbern
Blubbern, blubbern, blubbern, blubbern
Wir blubbern, blubbern, fünf Euro weg
Zehn Euro weg

(«And we gurgle, gurgle gurgle, we gurgle, five Euro away, ten Euro away.», referring to the engine roaring and easily burning five, ten Euros of fuel)

This sounds funny, a kind of childish boast: but is it so different from what happens actually all the time in our civilization or, perhaps, in every civilization that has been blessed with cheap energy? It’s the Jevons paradox: the more energy is cheap and available, the more energy consumption is efficient, the more we use it. But there’s more: the CL500 of Gzuz is actually, as far as I can read, quite fuel consuming. He’s not just consuming more fuel because he can, he loves that waste. It’s more of a potlatch, a waste of valuables to show off wealth.

It’s hardly the most pressing issue in the whole problem of climate change, but it’s interesting to see that there are, indeed, cultural barriers to reduce energy and fossil fuel consumption. We are in love with the sheer ability to use cheap energy whenever we can, however we can. This very blog post is inessential: it consumes energy when I write it, when you read it, when it is stored on a server. But oh, how easily inessential things today become essential tomorrow; how necessary is luxury after a while.

Alles ist entspannt wenn er rollt, rollt
Digga, erst der CL und Erfolg folgt

(«Everything is easy when it rolls, rolls
Dude, first the CL and then success follows»)

It rolled for a while. Western civilization has had an intense love story with fossil fuels, which as many love stories first inebriated us, then intoxicated us. They gave us an unprecedented freedom, but at a price. Getting out of toxic relationships is a hard job, and painful. But we have to, because, as Gzuz says, when describing his addiction to the smell of gasoline:

Diese Liebe macht krank

«This love makes you sick».

Stealing iron from a snail

What is an island? One thinks of a patch of land circled by the ocean, but islands are concepts. From a biological point of view, whenever you are stranded on a place with no hope to escape, you are on an island.

Hydrothermal vents, among the weirdest and most fascinating environment on Earth, are insular environments. Their hot, peculiar and extreme conditions quickly give space to the usual cold peace of the abyss, and creatures which live on a vent rarely can venture elsewhere. They are submerged islands: patches of an environment surrounded by something entirely else, its creatures prisoners depending on their prison and, as such, fragile.

Deepsea Scaly foot gastropod (Crysomallon squamiferum ) from Dragon vent field, Indian Ocean.

The reality of the fragile vent ecosystems has been put forward last year with the debut, in the IUCN Red List, of the scaly foot snail (Chrysomallon squamiferum), the «scaly foot snail» or «pangolin snail».

I name it the iron snail: since it’s the only one metazoan which naturally uses iron (in the form of iron sulfide) to build its armor. As it often happens, islands allow the tree of life to explore avenues it couldn’t elsewhere, in relative peace. The iron snails are little, parallel experiments of evolution, running since tens of millions of years; current hydrothermal vent species started to diverge after the K/T event and the Paleocene/Eocene thermal maximum.

The iron snail however reverberates, in its unsightly scales, the much more ancient history of its lineage. An analysis of its genome reveals that its sclerites are formed by repurposing an ancient biomineralization genetic machinery, perhaps more ancient than mollusks themselves. Distant cousins of mollusks which teemed in the Cambrian seas, such as Halkieria, were covered of a chain armor of sclerites as well. «It is unclear whether the evolution of the sclerites in the Scaly-foot Snail should be interpreted as a recurring ancestral phenome, or a recently derived adaptive novelty.», states the paper. Whatever the truth, it means that covering themselves with scales is a recurring option in the evolutionary toolkit of mollusks and mollusk-like organisms. The iron snail, in the blind warm depths of the oceans, tells us a story much larger than itself.

So far, the iron snail does not know anything about being in danger. But it is threatened by deep sea mining, since two of its three known hydrothermal vent habitats are now considered for exploitation. Ironically enough, they could be mined for iron, among other metals. The iron snail evolved millions of years to exploit the metals of a deep ocean. Until a few thousands of years ago no other animal on Earth knew how to use them. How weird would it be for the snails, if they could know, that a species that breathes air and evolved in the savannahs now wants to steal their metal, the metal that for millions of years was theirs, and theirs alone.

Paper: Sun, J., Chen, C., Miyamoto, N. et al. “The Scaly-foot Snail genome and implications for the origins of biomineralised armour.” Nat Commun 11, 1657 (2020). https://doi.org/10.1038/s41467-020-15522-3

A lesson from the Iceland walrus

One of my pet peeves is the persistent delusion, implicit in many discussions, that the ecological crisis is a recent phenomenon. Industrialization, pesticides, intensive agriculture on a massive scale would have only recently tipped the scales, while before humanity was more or less in equilibrium with the environment. That we were sustainable. Noble savages. Truth is, we’ve never been. The current Anthropocene extinctions are nothing more than the continuation of the Pleistocene extinctions, and all together they are phases of the Sixth Extinction.

There are endless stories about that, from the American or Australian megafaunas, to the dodo. But it is always interesting to have another clean-cut example. Apparently, there was a distinct populaton of walruses in Iceland, until a few centuries ago. Then they disappeared, abruptly. The killers, as suggested by a recent study by Xenia Kéighley et al. published on Molecular Biology and Evolution (and open access, yay!), were the Norse, that colonizing Iceland found a bonanza of meat, fat, skin and ivory under the guise of long-toothed pinnipeds, and hunted them to extinction. It is a deliciously interdisciplinary work, where you find genetic analysis of ancient DNA intertwined with the analysis of Norse sagas. So much for who wants to keep the two cultures separate.

There is a twist. Human-driven extinctions are ancient, but they are land extinctions. Sea ecosystems were, indeed, mostly untouched until recently as far as we know. The Iceland walrus seems to be one of the earliest cases where our hand started to waste marine blood:

This is to one of the earliest examples of local extinction of a marine species following human arrival, during the very beginning of commercial marine exploitation.

A very significant event for the Sixth Extinction indeed. And the cause was, quite remarkably, capitalism, or at least its basic driver: trade.

We show that commercial hunting, economic incentives, and trade networks as early as the Viking Age were of sufficient scale and intensity to result in significant, irreversible ecological impacts on the marine environment. […]

Therefore, the extinction of the Icelandic walrus provides an exceptionally early example of hunting not driven solely for subsistence, but rather international demand for valuable trade commodities including walrus ivory, oil, and skin sold across medieval markets in Europe, the Middle East, and Asia.

In contrast to other species, the Iceland walrus did not die because the Vikings needed it. It died because they sold it. It was easy cash, until it lasted. While we have never been capable of a sustainable coexistence with many ecosystems, we live in an age of what has been called the Great Acceleration, where lots of ecological parameters skyrocket into the abyss. And what drives this acceleration if not trade, economic growth, exploitation of resources? To those who think that the socioeconomy of the human species has little to do with the Sixth Extinction, the Iceland walrus is a stern warning. The Invisible Hand is tainted forever with the blood of human and non human creatures.

The paper is: Xénia Keighley, Snæbjörn Pálsson, Bjarni F Einarsson, Aevar Petersen, Meritxell Fernández-Coll, Peter Jordan, Morten Tange Olsen, Hilmar J Malmquist “Disappearance of Icelandic Walruses Coincided with Norse Settlement”, Molecular Biology and Evolution, Volume 36, Issue 12, December 2019, Pages 2656–2667, https://doi.org/10.1093/molbev/msz196

Hope for the bugs?

It is so hard to find good news from the ongoing sixth extinction that, when this happens, one can be forgiven for disbelief. But a new paper by Macgregor et al. published on Nature Ecology and Evolution seems to cast doubt on the ongoing narrative of insectageddon, the apparent catastrophic decline in insect population.

The trick? Most papers observing a decline in the insect populations don’t go back in time much beyond year 1980. Can we grasp what happened before that, and how do data look like in this larger context? Macgregor et al. do exactly that: they found a thick dataset on British moth populations going back up to 1967, from 34 sites – the Rothamsted Insect Survey. These are mostly light traps that are counted daily, since more than 40 years. The very fact there is such a monitoring, while most of insect populations worldwide are so poorly known, is amazing.

Are moths declining? Yes – but only since 1982-ish. Before that, they were increasing. So much that today in Britain we still have more moth biomass than in 1967 -more than double, actually.

My former scientist self twitches a bit at seeing these graphs fitted with two straight lines with an arbitrary inflection point, but we can forgive this: it seems indeed in most cases the population is rising up to to the late ’70s and then plateauing or declining (Moth family Erebidae seems to just rise, however).

Another interesting thing of their dataset is that they sample urban and arable land, while other studies, like the ones from Germany, sample only protected areas. They see the population trends are different, with arable lands showing no decline, and woodlands showing the sharpest.

So, what does it mean? Is the current decline of insects a blip of a simply larger fluctuation trend? Callum Macgregor, first author of the paper, does not think we can go back to sleep, as he states on The Guardian:

“It’s absolutely not the case that everything is fine,” said Dr Callum Macgregor. “We do know that insects are in long-term decline as a whole, and also that the majority of insect species are declining.

“The concerning thing about the decline is that it’s over a 35-year period and there’s no real sign that that long-term declining trend is reversing.

“Having said that, the implication of a phrase like ‘insect Armageddon’ is that it’s an end-of-days scenario and it’s almost hopeless, and I don’t think it is hopeless. There is still time and opportunity for us to turn things around and make positive changes in the way we use our land.”

So, what was going on (apart from the birth of punk rock)? Hard to say, the author hypothesize perhaps yearly weather fluctuations such as droughts made the population oscillate, before the ongoing decline -mapping very well with the one measured elsewhere- took place.

Can we breathe? Hardly. We know that humans are causing a mass extinction since ages -at least, since we wiped out the Pleistocene megafauna. There is little doubt on that. Still, the data of Macgregor et al. are a interesting reminder that data only make sense in context, including the context of other data. Wild populations can oscillate, indeed, wildly, and long-term trends will be always superimposed on local phenomena. It’s a shame there are probably not many more long-term population data in the past to understand what is going on with insects worldwide. For now, I’m still not optimistic -but if the British moths teach us something, is that yes, there might be still time to reverse trends, since it was worse recently and ecosystems still did not collapse. But this time is not much. This is a reminder to hurry, not to relax.

The paper is: Macgregor, C. J., Williams, J. H., Bell, J. R., & Thomas, C. D. (2019). Moth biomass increases and decreases over 50 years in Britain. Nature Ecology & Evolution. doi:10.1038/s41559-019-1028-6

Coal knew, and the Climate Christ

The atmospheric greenhouse effect is known since more than a century, thanks to several scientists including Eunice Newton Foote and Arrhenius. It is thus pretty pleonastic, but still worthy of attention, that the coal industry knew of the issue since at least 1966 as documented digging an issue of the Mining Congress Journal. And of course they covered it up and continue peddling climate negationism, pumping millions into nefarious (un)think-tanks such as the Heartland Institute.

An amusing quote:

“Every time you turn your car on and you burn fossil fuels and you put CO2 into the air, you’re doing the work of the Lord,” Palmer told a Danish documentary team in 1997. “That’s the ecological system we live in.”

And I agree, it is the work of the Lord indeed, who told us in the Bible to exploit the Earth to the very end. But, you know, the Lord also planned this experiment of the Earth to end quickly. I wonder if there is some Hollywood script somewhere where one discovers that the global ecological crisis is just a prodrome of the Second Coming. Christian Conservatives would love it: they would not need to deny the role of fossil fuels, they would embrace it. Let carbon dioxide guide us to the Rapture, brethren!

At war with chimps

For all our prehistory and history, we clashed and fighted with other species. Sometimes they fight back: David Quammen reports on National Geographic of an ongoing and bloody conflict with chimps in rural Uganda. The details are gruesome, but it’s us who started:

The main driver of the conflicts, it seems, is habitat loss for chimps throughout areas of western Uganda, forested lands outside of national parks and reserves, which have been converted to agriculture as the population has grown. The native forest that once covered these hillsides is now largely gone, much of it cut during recent decades for timber and firewood, and cleared to plant crops.

It is a cautionary and worrying tale. The more we occupy habitats and resources of other species, the more we risk direct conflict with them -and so, the more these species will be further jeopardized. Climate change for example will probably add further competition with the rest of the biosphere, humans and non-humans clinging to land and water. Bleak times are ahead.