Why the sixth mass extinction was inevitable

Why the sixth mass extinction was inevitable

Palaeontologists have a fine time of it. They fossick around in obscure parts of the world where there are few people and take a hammer to rocks.

They have done this for generations, found lots of fossils, and come up with some interesting conclusions.

Here are five of them.

  • 444 million years ago 86% of species were lost.
  • 375 million years ago 75% of species were lost
  • 251 million years ago 96% of species were lost
  • 200 million years ago 80% of species were lost
  • 66 million years ago 76% of species were lost.

These are, of course, the five mass extinction events in the fossil record. The last one being the most famous when all the dinosaurs copped it.

Here is another pattern they found

Over time diversity has increased despite these mass extinctions and several smaller ones in between them.

There are more species alive today than at any other time in evolutionary history, despite the obvious fact that humans are kicking the sixth mass extinction into existence.

This is the history of life on earth. It is dynamic with huge shifts in diversity but with an underlying driver powerful enough to increase diversity over time.

If you believe this evidence then a few core concepts become clear:

  1. Extinction happens.
  2. Large extinction events happen often enough to make another one inevitable.
  3. After extinction events, diversity recovers
  4. And for at least 150 million years the trend is for diversity to increase rapidly, noting that the non-avian dinosaurs were lost during this time.

Diversity happens because there is time enough for mutation and natural selection to hone any number of specialisms. When organisms specialise they are successful in a relatively narrow set of conditions. A proportion of species become vulnerable to change in those conditions.

Enter human beings. Modestly specialised initially but with a distinct advantage. They had the brains and communication to adapt to a wide range of conditions, especially when they tamed fire and then much later discovered fossil fuels.

Once in control of energy humans have appropriated over half the global biomass production, removed vegetation, getting rid of wildlife and altered the composition of the atmosphere. More than enough change for mass extinction.

Humans affected the change but change would have happened at some point. Tectonic plates moving to cut off ocean gyres, volcanic eruptions, another meteorite strike, it would happen soon enough, maybe 50 million years hence.

Is the reality of extinction too painful?

Perhaps it is. Perhaps we are just too much in the present day to accept timeframes beyond ourselves. Certainly, there will be huge consequences of extinction for our production systems, the ecosystem services we rely on, and the very liveability of the planet for our species.

We’ll need a lot of adaptation to survive.

What we might also remember as we plan for change and seek to retain what we can of the diversity of life, that extinction is real and inevitable. It is as much a part of the process of evolution as the creation of new types.

Objectivity

Objectivity

I’m sure you would say that you are impartial and that you are “not influenced by personal feelings or opinions in considering and representing facts”. Indeed you would say that objectivity is a feature of your everydayness.

At least this is what our parents and teachers taught us to say.

What these good folks often forgot to mention was that being objective takes effort and a lot of it. In order to be objective a person must know or have access to real kernels of truth, irrefutable information, that is things that are known or proved to be true.

In short, objectivity requires evidence.

This means that becoming and remaining an objective person takes constant effort to assemble and evaluate evidence. It means knowing a fact when you see one and also where to look for those that you do not have to hand. It takes rigour.

This should be easy enough in this world of internet searches and virtual assistants but just because an important or famous persons says something or it is reported on commercial media, does not make it a fact. There is learning, skill and experience in making sure that information is factual, reliable and accurate, not to mention relevant.

Just yesterday there was typical vision on the news of a windswept reporter wearing logo embossed gore tex standing in front of a collapsed shed. There had been a supercell storm. An event so powerful “the town was all but destroyed”. Only wait a minute. The ‘town’ was home to 20 people, it was a hamlet at best where most of the houses were still standing. Pan out from the close crop of the flimsy shed and the destruction was hard to see.

Access to information is only the first part of objectivity.

There is information in profusion and some of it is irrefutable. The shed was in a mess. The problem is there was no town and no information beyond the close up of the shed to indicate destruction. What we actually have is a visual fact and a host of loose interpretation and opinion. We must also trust the reputation of the news channel and believe that the reporter was indeed in central Queensland. She could have been in a studio with a wind machine and a green screen.

One irrefutable fact – an image of an upside down shed – is not enough.

Objectivity requires numerous validated facts that must override a host of deep, ingrained and often long standing feelings that are part nature, part nurture and part sheer bloody mindedness. Objectivity means not just accumulation but the ability to sift through facts and put them into context, a process of evaluation to generate relevance.

Now we are lurching rapidly toward some serious effort.

Not only must we have asked Alexa or said hey Google for the relevant facts, we must not just take what the virtual assistants on the smartphone says as gospel. There is another step to objectivity that requires we evaluate the facts for their individual efficacy – are they true – as well as what that piece of information brings to the challenge or conundrum we are trying to be objective about.

Knowledge is not just about committing facts to memory, it requires an additional step, relevance.

A koala example

Let’s consider an example and try to be objective about the following statement:

The koala is in serious danger of going extinct therefore we must do all we can to protect it.

Australians understand what this means but it doesn’t have to be the koala, it could be the lion, tiger, African elephant or the ghost orchid, Dendrophylax lindenii, known only from a handful of tiny sites in Oxfordshire.

Feel free to insert into the clause whatever species you are told is in danger of extinction. The challenge is how to be objective when presented with such an edict of irreversible loss.

Begin with getting yourself across the suitable, irrefutable and relevant facts.

And here is the initial challenge. What facts are these?

Well given the edict, it would have to be facts about how many koalas are currently alive, what has happened to their numbers in historical and recent times, and evidence for the presence and veracity of threats to their continued existence.

In other words you need to be cognisant of and able to evaluate the population dynamics of koalas as well as the key drivers of those dynamics before you can be objective about the clause regarding extinction.

Curiously, the Australian government factsheet on Koala populations in Queensland, New South Wales and the Australian Capital Territory and national environment law does not say how many koalas there are in Australia. What is does say is there are koalas living wild across a range that stretches the entire eastern seaboard of the continent.

Similarly the NSW government’s $44.7 million NSW Koala Strategy does not mention how many koalas there are in the state of NSW.

The Australian Koala Foundation estimates that there are less than 100,000 Koalas left in the wild, possibly as few as 43,000. However, the link that sends you to a page on how this estimate came about was broken.

You need to go to the science literature to get a more robust estimate.

Phillips (2000) reports koala population trends in the reputable journal Conservation Biology as declining from a population size somewhere <100,000 to “an order of magnitude larger”. That’s a discrepancy estimate of around 900,000 that, even for an error estimate, is quite a few more than the 43,000 the conservationists would have us believe are currently extant.

More recently McAlpine et al (2015) looked at ‘Conserving koalas: A review of the contrasting regional trends, outlooks and policy challenges’ in the equally reputable journal Biological Conservation and presented some density data but no actual numbers for total population.

I could go on but I suspect you are getting the message.

The suitable, irrefutable and relevant facts are not easy to find or may not exist at all. In the case of koala numbers, it would seem that nobody knows how many there are in Australia right now, let alone historically. The key facts are actually a known unknown (although nobody close to the problem would admit to this).

In the absence of accessible facts we might choose to rely on the Commonwealth Scientific Committee that gathers information to match the status of species and habitats believed to be at risk of extinction and evaluates this information against agreed IUCN criteria, the global standard. This is the independent body of scientists tasked with deciding if a species or habitat type is at risk of extinction across Australia.

What they said about the koala in the koala population factsheet was nothing about the populations of koala, that is, how many there are now or were around in the past. There’s a nice map of where they are known to occur and if you are a species with a distribution that covers a third of a continent you are probably not too worried. But even in the absence of evidence and a truth that the koala is unlikely to go extinct soon, if at all, the federal environment minister listed Australia’s most at risk koala populations in April 2012 as vulnerable under national environment law

This means that the system set up to evaluate the evidence for decision making on whether a species is at risk of extinction in the wild did not find enough evidence, but it made a decision anyway. Perhaps the scientific committee invoked the precautionary principle or, dare I say, they temporarily put objectivity aside in favour of political expediency or public opinion.

How dare you!

What to do?

This example is typical. It means that it is very hard to obtain and evaluate enough relevant facts to be truly objective. There will usually be holes in your own or the collective knowledge, known unknowns and unknown unknowns. It is rare that we are across all the relevant facts.

The koala is in serious danger of going extinct therefore we must do all we can to protect it

Most of us don’t have the time, inclination or access to the facts to evaluate this statement with objectivity. Somewhat ironically you can find reference to the science on Google Scholar but not all of it has free access. You also need to know where to look for not all sources are credible.

Reality is that it takes too much time to hunt down and assemble the facts (oops, poor choice of words), that’s before you put in the intellectual effort to evaluate them and find the truth.

We would also have to work hard emotionally to suspend our feelings enough for healthy skepticism. There is a reason koalas, pandas, polar bears and other creatures with fur are used in these extinction statements: to humans they look cute.

So we resort to our default source of objectivity; what we feel. Our instinct, the gut response we have somewhere deep down that is part guide and part conscience.

Should we be brave enough to discuss our objectivity with others, this gut feel will be exposed to serious peer pressure, and must pass some collective logic that comes from group gut feel, known round these parts as the ‘pub test’.

How to be be objective without the effort

And this is just one of the many opinionated statements we have to filter every day.

Koalas are cute because humans beings have a genetic predisposition to find expressive forward pointing eyes either side of a nose clustered together rather low in a much larger “face” impossibly attractive… Think about it.

We are going to need an inordinate amount of seriously powerful facts to overturn such innate prejudice. Most people would not even see the need to try.

Koalas are cute after all, what’s your problem dude?

Any objectivity has a precipitous, ice-covered cuteness cliff to climb.

Species

Species

…the fact that ecological communities constantly experience temporal turnover, and that consequently some species will not only fluctuate markedly but also become either locally or globally extinct, is something that, while well appreciated by ecologists generally, is often omitted from popular news stories. 

Mugurran et al 2010

By research paper standards this is an accessible quote. You may only need to read it a couple of times to get the gist. It means what it says.

Everything in nature changes and species disappear from both the backyard and from the planet.

Ask any ecologist who has more than a few minutes of fieldwork on their resume if they agree with this premise and they will say yes. There is change over time. They would concede that if you stare at a patch of nature long enough, it will start to move. Organisms will come and go, sometimes never to return, their place taken by an equivalent.

In my own garden that backs onto eucalyptus forest in the Blue Mountains of NSW I have seen this happen with the seasons as the grass stops growing in winter, during drought when even the trees droop, and also through the decade we have lived in the house.

When we moved in the garden was blessed with tree creepers, fairy wrens and wagtails. There were regular visits by resplendent satin bower birds and even occasionally a lyre bird or two. I have stared at a frogmouth in its daytime roost and had glossy black cockatoos drop casuarina cones on my head. Delightful.

Then, three years ago the noisy miners arrived. An especially aggressive social breeder that with brazen behaviour worthy of a panzer corps will chase all the other species away. Only the big beaked cockatoos and the butcher bird are unmoved.

None of the aforementioned chorus are extinct but they are not longer in my garden.

More recently some new neighbors moved in next door. They have a nervous pointer and a black labrador with a limp. The swamp wallaby no longer hops up from the creek to pick at our herb garden.

There are several important things in this simple everywhere reality of ecological change.

The first is change itself.

Nothing in nature has ever been or ever will be stable. It is not how nature works. At times the dynamic is subtle and hard to see with human perception of time and space. Typically though we can see, smell or hear it. All it takes is a little patience and some observation.

If a human who might live three score years and ten can perceive this change with just a little patient observation, then…

the second important thing is that change is fast.

Incredibly fast on an evolutionary or geological time scale. Happenings that take decades are the blink of an eye equivalent for a planet that is billions of years old.

Such rapidity means that the idyllic lilly pond with the weeping willow tickling the water will not be there in a thousand years or so. Sedimentation and succession will make dryland of it unless there are humans with the spare time to occasionally dig it out.

This is the third important reality, stability requires inputs.

The main reason that nature is so dynamic is due to entropy, more strictly, the constant struggle organisms must undertake to counteract it. It takes an enormous effort to keep things the same. Energy must be pumped in to prevent chaos.

Humans have, of course, become true masters of this use of energy to counter entropy. We have figured out where to find and use external fuel sources to change the world to suit ourselves. It’s our superpower. But it has also duped us into believing that we can keep things the same, despite all the evidence to the contrary. We even think we can save species from local or real extinction.

This is the fourth of the important things, the often crazy notion that we can save species from ourselves, the most severe new driver of ecological change in aeons.

Change as the norm is “omitted from popular news stories” because the acknowledgement not only questions our god-like ability to rule the planet, it would mean admitting our role in the acceleration of change.

After all, the noisy miner spread with the suburb.

Positive future

Scenarios with pragmatic outcomes

It is a short time into the future, nowhere near an aeon. Against all likelihoods, Homo sapiens did not join the hundreds of thousands of species that have crossed the extinction finish line because miraculously there was a meme that spread through the social fabric of every nation on the planet faster than pictures of Harry and Meghan.

The meme said, “ecological communities constantly experience temporal turnover”.

The miracle of course was twofold. People not only understood this gibberish but they extended it to the practicalities of the real world.

Everyone recognised change everywhere and embraced it. They let species move around, leaving some places and moving into others. They saw vegetation as fluid not as a vase on a shelf, still but fragile.They realised that there were some species that would go extinct and that if a particularly cute one was popular enough to save, then this was going to need effort specific to that species. It was a choice.

And they saw the whole landscape, all at once, despite its altered state, and they focused on what that landscape could do, not what was in it.

It was truly remarkable.

It even made the news.

Insects

Insects

All around the world there are entomologists, people who study insects. We should be very proud of these fine folk for without their understanding it would be harder to manage many diseases transmitted by insects, resolve many pathogens, figure out how to assist insects pollinate crops and, most importantly, support insects and their invertebrate cousins maintain soil fertility.

Then there are insect people you might know about. The pest control folk who make sure the fly spray kills the flies and not us.

Sounding a bit posh and, dare we say a little ivory tower, ‘entomologist’ usually refers to the researchers who gather the data and sift through it to find evidence for the good, bad and ugly on the insects that share our spaces. So we can listen to them with some confidence. Not only are they spending their days with ‘bugs’, yuck, they are also the right kind of skeptic using the numbers to find inference.

Lately the number of insects observed by entomologists are in decline. This is not because the entomologists are getting lazy, spending more time watching TV than setting malaise traps or peering down microscopes, but because there are fewer insects around to be studied.

A recent publication confirmed from long-term trapping data in 63 German nature reserves, what many have casually observed in many parts of the world. Insect numbers are going down. And not just by a little bit, they are plummeting.

Hallmann C.A., Sorg M., Jongejans E., Siepel H., Hofland N., Schwan H., Stenmans W., Müller A., Sumser H., Hörren T., Goulson D., de Kroon H. (2017) More than 75% decline over 27 years in total flying insect biomass in protected areas. PLoS ONE, 12(10), eo185809

Three quarters in a generation.

If such a collapse had happened to the Dow Jones the sky would have fallen in. Imagine trying to survive on a quarter of your wages you earned when you started out. Heaven forbid if the defence budget from the 1990s was reduced by all those billions, how scared and vulnerable would we feel?

“Not a problem” the observant reader cries out. “The crawling insects will simply fill the space left by the loss of the flying ones, that’s what you ecology types tell us all the time.”

Perhaps.

Equally a loss in numbers does not necessarily mean a loss of function. Pollination only needs one bee to transfer pollen from stamen to stigma. Fewer mosquitos has to be a good thing and those beetle larvae can’t be doing that much to soil when we have fertilisers.

It is always very easy to play the ostrich. Only they are remarkable and very dumb birds.

When an observation so dramatic and material to so many key ecological processes becomes known we dismiss it at our peril. If we ignore these numbers just because we like the idea of fewer midges at summer evening picnics without looking deeper to find out what is going on, we increase risk to our already precarious food security.

We need to enable our entomologists to find out why the numbers went down and if the decline is going to affect the key ecosystem services we rely on.

Or, of course, we could ignore them and buy more submarines.

Science and Policy

Science and Policy

In a recent article on why science gets shut out of policy Anthony Bergin from the Australian Strategic Policy Institute contends that

“The extent to which scientific knowledge gets traction in policy will depend partly on the state of science knowledge on the issue, and partly on the degree of controversy surrounding the issue under consideration. It will also depend on the degree of public and political attention the matter gets.”

He goes on to suggest a few reasons for why scientists are not all that good at getting the message across in what is always a consensus and value driven process. Similar to the thinking in Are scientists ready?

In short, scientists too often revert to their necessary scepticism in the face of uncertainty and so come across as weak communicators.

Alternatively Bergin suggests that

“Too often, scientists tend to think they know what is best or what is needed, and then they are disappointed, frustrated or angry when their ideas and hard work are rejected or put on the shelf.”

In other words, they also form and promote values too, just like all the other players in the game. Then their egos get in the way, just like all the other players in the game. Lovely.

I doubt that Bergin is correct in his claim that policymakers do care about scientific evidence if it helps them make decisions. If it helps them make the decision they want to make, perhaps, but that is not quite what he meant. My experience with natural resource management policy is that policymakers understand very little of the science despite their access to considerable in-house and review style expertise. Their political masters understand even less.

Needless to say they all care when evidence helps the spin.

And before everyone whines that policy makers are not in the business of politics, dream on people. It’s 2018, the decade when fake became more influential that fact and public servants found it harder than ever to serve the public when the minister of the day wants her own specific outcome.

So Bergin is right in his tone.

Science into policy is very difficult especially for the scientists.

Scientists do have to front up with confidence, develop communications skills, and learn that their audience has never understood a probability, let alone an inference level.

The use of scenarios makes good sense. It’s the approach that helps AfterBefore Systems to understand options for investment in land management, as does delivering advice in multiple forms. Only my academic experience suggests very few scientists are any good at either of these things. They are hypothesis testers not scenario modellers. They are geared towards output as peer-reviewed papers that create some of the most turgid reading experiences known to man. The poor dears are staring at a very steep cliff.

As with most opinion pieces in this space, the conjecture is easy. In this instance, policy and science are hard to reconcile given the nature of the people involved.

Equally the suggestions are sound. They are easily summarised into “chill out and communicate”.

But wait. The premise here is that inference and evidence will be used should they be understood and available. There is an assumption that human beings are so rational that in the face of evidence they will make the decision pointed to by the evidence.

I doubt it.

Sometimes the evidence is clear. The voluntary inhaling of smoke into your lungs affects your health. Cut down the forest to make arable land and, in time, you will have to fertilize to get a crop. Burn enough fossilised carbon and it will change the composition of the atmosphere. But even blindingly obvious evidence will not always be heeded.

This creates the biggest psychological challenge for the scientist. Trained to find evidence and believe in inference, the scientists is incredulous when obvious evidence is ignored for the short-term expediency of the policy. And this will happen. It has many times already and will continue to happen for as long as there is politics.

The real challenge is making sure that the important evidence gets noticed. Perhaps by being truthful about what happens if it is ignored.


More on this general topic

Are scientists ready?

Post revisited – Leaders not heroes

Time for scepticism

Conservation questions

Conservation questions

The current loss of biological diversity is a problem that calls for a collective characterization of what we want to protect and conserve and of what biodiversity we value. Should the focus be on local or global biodiversity? Should alien species be eradicated to protect ecosystem integrity and endemism? Should mammals be favored over plants? Should priority be given to useful species over useless ones? Should natural diversity be valued per se, or should it be valued on the basis of the goods and services it ensures? It is likely there is no one answer to any of these questions; rather, different contexts will give rise to different outcomes. Conservationists should tackle this kind of uncertainty and attempt to bring to light and discuss the moral values at stake. Maris & Bechet (2010)

What an extraordinary set of questions. Ask any one of them in the pub late on a Friday and you will start a ruckus. There will always be a least two individuals with diametrically opposite answers and any number of weird and wonderful interpretations given half the revellers will not understand what on earth you are on about.

Ask the same questions at an ecology conference of learned academics and you will get equally passionate answers. The lecture hall will buzz with erudite responses argued from one or other theoretical position with responses debunking each one as simplistic or impractical. And just like in the pub the answers will be interpretations rather than definitive inference because each question is contentious in its own way.

Here are a few examples.

Local or global becomes… I really want to see the sea eagle when I go to my favourite beach and have no trouble with it being on the list of threatened species. Only this species is distributed widely from Mumbai to Melbourne and is often locally common and the IUCN list it under the ‘least concern’ category.

Aliens becomes… We really should remove willows from creeks across the Australian countryside as they are a nasty invasive alien species. Only when they are removed and not replaced habitat and water quality declines and erosion can accelerate to the point where multiple values are degraded.

Mammals obviously… If the koala goes then it’s just not the same to have its food trees around the place. Plus if you keep the koala you also keep the trees and the umbrella works to protect more than just the animal.

Useless species… No species is completely useless because they all have existence value and a moral right to be, except in the minds of those people who believe that human beings are the apex of evolution and the moral right to lord over nature.

Services take precedence… Given there are so many people and with people coming first it is impossible not to value services over natural diversity. Unless we can use species somehow, directly or indirectly, there is no point in keeping them in a crowded world where every single patch of land and water has to do something for mankind. After all what is nature if it is not in the service of humanity. Only without nature there would be no humanity.

Questions of value

There is contention everywhere because whilst the questions appear scientific, the answers are all about values. Even in a room full of experts loaded opinions flash from every corner with no obvious way to separate them or decide which has the most to offer.

I doubt that conservationists have any idea about how to tackle this value conundrum any more than the average Joe. My experience is that they jump onto values and run with them without even realising there was any uncertainty in them. They also seem intent on the dichotomy as the wrong that only their opinion puts right.

Inevitably they will be up against those who see nature as a resource for humans to exploit, the gift that was given to mankind that no other creature ever has or will possess.

Context will favour one or other view as more logical or moral, consequently, as Maris & Bechet (2010) conclude “there is no one answer to any of these questions”. In other words each question has an uncertain answer.

Recognition of uncertainty would be a major advance but I doubt that holders of strong opinions, especially when claimed as the moral high ground, easily conceded their answers in a values argument.

Perhaps the best we can hope for in values debates is some objectivity.

This begins with recognition of all answers to the various questions and of the plurality of values. Objectivity would also recognise that if we land on one or other side, then the other side has compromised, often massively. Same for plurality. If you want to keep koalas, then the objective arguments says that this cannot happen everywhere, choices must be made on where effort is put to keep them alive. In other words morals are compromised to let some of them go.

Objective answers should let everyone one win, some of the time, in some places.

Incredulous

Incredulous

Here is a recent headline from an ABC online article, a reputable publicly funded media source

Bush stone-curlews popping up in suburbs as bird once extinct in ACT makes a comeback

Nice you might think given that headlines containing good news are like threatened species themselves, rare and at risk of being lost forever.

Here is the problem.

The IUCN lists the conservation status of the Bush stone-curlew as “least concern”. In other words, its not under any immediate threat of extinction in the wild.

In fact, the species has a broad habitat preference throughout Australia pitching up in open forest, eucalyptus woodland, rainforest edges, grassy plains, arid scrubland and along inland watercourses across much of the vast continent. It is a common species in the cities of Brisbane, Cairns and Townsville and is abundant in the tropical and subtropical north. In other words, it’s not a rare species at all.

I’m told there are pubs up north where you can sup on a stubbie alongside a foraging stone-curlew.

To use the word extinction, the termination of a lineage, where the moment of extinction is generally considered to be the death of the last individual of the species, is a lie.

This bird is not extinct.

Placing a geographic limit so as to use the term is disingenuous. Strippers are extinct in the Vatican is about as crazy a statement.

So is this fake news?

I think it is. The bird species is not actually extinct. It’s not even at risk unless you specify a discrete subset of its natural range. And when we learn that the Canberra specimens were almost certainly taking a wander from a nearby reserve artificially stocked with a few pairs to “reintroduce” them to the local scene, then the implicit hope in the story takes a huge dive.

I know that there are feeds to feed in this modern age of lightning fast news cycles. And I also know that there are good reasons for at least trying to be upbeat when, for the conservation minded, the world appears to be crashing down. But, like cricketers crossing the line, there are consequences for cheating on the truth. In the end people do not respect you, they dismiss everything you say even when you are actually being honest.

So my call to myself, and everyone who is in the business of information, let’s be as honest and as truthful as we possibly can and leave the spin alone when it comes to the facts.

This is easy to say and not at all easy to do but we all have to try.