Grey matter blues: why has the human brain been shrinking?

There is a disturbing fact about our species that the public don't appear to know, and few specialists seem to want to discuss: over recent millennia, the human brain has been shrinking. There have been plenty of non-scientific warnings about the alleged deleterious effects on IQ of first television and more recently smartphones and tablets, but palaeontological evidences proves that over some tens of thousands of years, the Homo sapiens brain has shrunk somewhere between ten and seventeen percent.

There are usually two key indicators said to provide an accurate measure of smartness: encephalisation quotient and absolute brain size. Encephalisation quotient or EQ is simply the ratio of the mass of the brain to the mass of the body. Overall size is seen as critical due to the number of neural connections required for complex thought processes; you can only squeeze so many neurons into any given volume. Having said that, there is some considerably flexibility around this, thanks to variation in neuron density. The reason that some birds, especially the crow and parrot families are highly intelligent despite the small absolute size of their brains is due to their higher neural density compared to mammals.

Analysis of data from the examination of thousands of human fossil remains suggests that our species reached a peak in EQ around 70,000 years ago, followed by a gradual decline. The reduction in brain size appears to be due to a loss of the archetypal grey matter itself, rather than the white matter that provides support to the neural architecture. However, one key issue is lack of agreement as to a definitive start date for this decline, with 20,000 to 40,000 years ago being the most commonly cited origin. With such basic points remaining unsettled, it's perhaps not surprising that there is a plethora of opinions as to the cause. Here are some of the more popular hypotheses for the decline in human brain size:

1. Change to body size

The first and perhaps most obvious - but easily refuted idea - is that human body size has been steadily declining and so cranial capacity has kept in step with this. While it is true that archaic sapiens may have had a higher mass and even stature than modern humans, the reduction in brain size is greater than would be expected when compared to the overall shrinkage. The assumption is that the development of material culture, from clothing to weapons, has given humans a less calorie-demanding lifestyle.

This would allow - although not dictate - natural selection to trend towards a smaller body size. This doesn't appear to offer any help for the comparatively greater reduction in brain mass, although we should remember that an overall reduction in body size means a smaller birth canal. This in turn requires a smaller skull at birth; as is well known, the human gestation period is three months' less than for similar-size mammals, but our seemingly premature delivery is necessary for the pelvis to maintain efficient bipedalism.

2. Self-domestication

Another idea is that humanity has become domesticated via the impact of culture upon natural selection. Following the population bottleneck of 70,000 years ago - the cause of which is not yet confirmed, despite attempts to correlate it with the Toba super-volcano - there has been continual growth of the human population.

Just as all our domesticated animal species have brain sizes some 10-15% smaller than their wild cousins and ancestors, so the move to larger groups sizes may have led to a more docile humanity, with associated traits such as a smaller cranial capacity being carried along with it.

There are several issues with this hypothesis, ranging from a lack of data on the size of gatherer-hunter bands to the biological mechanisms involved. As regards the latter, there has been some speculation concerning neoteny, in which a species no longer grows to the final stage of maturity. The idea is that if adults are more aggressive than juveniles but peaceful collaboration can lead to larger groups, mutual aid and longer lifespans, then unintentional selective breeding for the retention of juvenile characteristics, including smaller brains, may cause a shift away from the fully mature but more aggressive individuals.

Research in recent years has suggested our brains may continuing to grow into our early thirties rather than cease growing in our teens, so it's possible there could be some truth to this; it would interesting to seek evidence as to whether the brains of archaic sapiens continued growing longer than ours do.

3. The impact of culture

Taking this a step further, increased population density allows a more rapid development and transmission of new ideas, including those that lead to better health, longer lifespans and so to an increased birth rate. Culture and sophisticated language may have reduced the need for most people to gain a wide range of skills - courtesy of a higher intellectual capability - as tasks could be shared and specialisation take hold. In effect, larger societies provide a safety net for those who would be less able to cope in smaller groups.

If ideas could be handed down, then individuals wouldn't have to continually 'reinvent the wheel' in each generation, allowing survival despite a smaller brain size and decreased level of intelligence. The problem with this scenario is that we have no proof the 10-17% reduction has led to an associated drop in intellect; it may well be that the size of certain lobes, used in specialist thought processes such as formulating complex speech, far outweigh any decline in less critical areas.

4. The expensive big brain

One possibility that has a clear cause-and-effect concerns the energy demands of having larger brains. Although they consume a quarter of our daily calories, the human brain is less than five per cent of our body weight. Therefore, there could be a case for arguing the existence of an evolutionary competition between smaller-brained individuals who can survive on less food with those who use their larger brains to improve food collecting strategies. Unfortunately, there are so many variables that it's difficult to judge whether the former would continually trend against the latter and - considering it clearly occurred - why the larger brain managed to evolve in the first place?

5. The more efficient brain

Although a smaller brain might have fewer neurons than a larger version with similar architecture, it has been suggested that its shorter pathways would lead to more rapid thought processing than in a larger counterpart. In addition, there might be fewer neural pathways, again increasing the efficiency. This 'nimble thinking' approach certainly seems logical, although again it doesn't explain the evolution of larger EQ in archaic sapiens.

This is certainly a subject ripe for much more research. I've often concluded with a statement along the lines that it wouldn't be surprising if some or all these factors were involved, since nature rarely conforms to the nice, neat patterns we would like to lay upon it. There is an even possibility that brain size - like so many other aspects of all animal species - fluctuates around a mean value, so that what goes up may come down again, only to later go up again.

At least one anthropological study on both Afro-Americans and US citizens of European descent proposes that over the past few hundred years there may have been an upward drift towards larger brains. Assuming the research is accurate, one possibility is that the superior nutrition available since the Industrial Revolution is allowing such development, thanks to the comparative ease with which its energy demands can be fulfilled.

It would certainly be interesting to investigate this hypothesis on a global scale, considering the wide differences between the clinically obese nations and those still subject to frequent famine. Whatever the results, they are unlikely to be the simple 'just-so' stories often passed-off as to the public in lieu of accurate but understandable science communication. The answers may be out there somewhere...I'd certainly love to know what's been happening to the most sophisticated object in the known universe!

Ancestral tales: why we prefer fables to fact for human evolution

It seems that barely a month goes by without there being a news article concerning human ancestry. In the eight years since I wrote a post on the apparent dearth of funding in hominin palaeontology there appears to have been some uptake in the amount of research in the field. This is all to the good of course, but what is surprising is that much of the non-specialist journalism - and therefore public opinion - is still riddled with fundamental flaws concerning both our origins and evolution in general.

It also seems that our traditional views of humanity's position in the cosmos is often the source of the errors. It's one thing to make such howlers as the BBC News website did some years' back, in which they claimed chimpanzees were direct human ancestors, but there are a key number of more subtle errors that are repeated time and again. What's interesting is that in order to explain evolution by natural selection, words and phrases have become imbued with incorrect meaning or in some cases, just a slight shift of emphasis. Either way, it seems that evolutionary ideas have been tacked onto existing cultural baggage and in the process, failed to explain the intended theories; personal and socio-political truths have triumphed over objective truth, as Neil deGrasse Tyson might say.

1) As evolutionary biologist Stephen Jay Gould use to constantly point out, the tree of life is like the branches of a bush, not a ladder of linear progression. It's still fairly common to see the phrase 'missing link' applied to our ancestry, among others; I even saw David Attenborough mention it in a tv series about three years' ago. A recent news article described - as if in surprise - that there were at least three species of hominins living in Africa during the past few million years, at the same time and in overlapping regions too. Even college textbooks use it - albeit in quotation marks - among a plethora of other phrases that were once valid, so perhaps it isn't surprising that popular publications continue to use them without qualification.

Evolution isn't a simple, one-way journey through space and time from ancestors to descendants: separate but contemporaneous child species can arise via geographical isolation and then migrate to a common location, all while their parent species continues to exist. An example today would be the lesser black-backed and herring gulls of the Arctic circle, which is either a single, variable species or two clearly distinct species, depending where you look within its range.

It might seem obvious, but species also migrate and then their descendants return to the ancestral homeland; the earliest apes evolved in Africa and then migrated to south-east Asia, some evolving into the ancestors of gibbons and orangutan while others returned to Africa to become the ancestors of gorillas and chimpanzees. One probable culprit of the linear progression model is that some of the examples chosen to teach evolution such as the horse have few branches in their ancestry, giving the false impression of a ladder in which a descendant species always replaces an earlier one.

2) What defines a species is also much misunderstood. The standard description doesn't do any favours in disentangling human evolution; this is where Richard Dawkins' oft-repeated phrase 'the tyranny of the discontinuous mind' comes into play. Examine a range of diagrams for our family tree and you'll find distinct variations, with certain species sometimes being shown as direct ancestors and sometimes as cousins on extinct branches.

If Homo heidelbergensis is the main root stock of modern humans but some of us have small amounts of Neanderthal and/or Denisovan DNA, then do all three qualify as direct ancestors of modern humans? Just where do you draw the line, bearing in mind every generation could breed with both the one before and after? Even with rapid speciation events between long periods of limited variability (A.K.A. punctuated equilibrium) there is no clear cut-off point separating us from them. Yet it's very rare to see Neanderthals labelled as Homo sapiens neanderthalensis and much more common to see them listed as Homo neanderthalensis, implying a wholly separate species.

Are the religious beliefs and easy-to-digest just-so stories blinding us to the complex, muddled background of our origins? Obviously, the word 'race' has profoundly negative connotations these days, with old-school human variation now known to be plain wrong. For example, there's greater genetic variation in the present-day sub-Saharan African population than in the rest of the world combined, thanks to it being the homeland of all hominin species and the out-of-Africa migrations of modern humans occurring relatively recently.

We should also consider that species can be separated by behaviour, not just obvious physical differences. Something as simple as the different pitches of mating calls separate some frog species, with scientific experiments proving that the animals can be fooled by artificially changing the pitch. Also, just because species appear physically similar doesn't necessarily mean an evolutionary close relationship: humans and all other vertebrates are far closer to spiny sea urchins and knobbly sea cucumbers than they are to any land invertebrates such as the insects.

3) Since the Industrial Revolution, societies - at least in the West - have become obsessed with growth, progress and advance. This bias has clearly affected the popular conception that evolution always leads to improvements, along the lines of faster cheetahs to catch more nimble gazelles and 'survival of the fittest'. Books speak of our epoch as the Age of Mammals, when by most important criteria we live in the era of microbes; just think of the oxygen-generating cyanobacteria. Many diagrams of evolutionary trees place humans on the central axis and/or at the pinnacle, as if we were destined to be the best thing that over three billion years of natural selection could achieve. Of course, this is no better than what many religions have said, whereby humans are the end goal of the creator and the planet is ours to exploit and despoil as we like (let's face it, for a large proportion of our existence, modern Homo sapiens was clearly less well adapted to glacial conditions than the Neanderthals).

Above all, these charts give the impression of a clear direction for evolution with mammals as the core animal branch. Popular accounts still describe our distant ancestors, the synapsids, as the 'mammal-like reptiles', even though they evolved from a common ancestor of reptiles, not from reptiles per se. Even if this is purely due to lazy copying from old sources rather than fact-checking, doesn't it belie the main point of the publication? Few general-audience articles admit that all of the earliest dinosaurs were bipedal, presumably because we would like to conflate standing on two legs with more intelligent or 'advanced' (a tricky word to use in a strict evolutionary sense) lineages.

The old ladder of fish-amphibian-reptile/bird-mammal still hangs over us and we seem unwilling to admit to extinct groups (technically called clades) that break our neat patterns. Incidentally, for the past 100 million years or so, about half of all vertebrate species have been teleost fish - so much for the Age of Mammals! No-one would describe the immensely successful but long-extinct trilobites as just being 'pill bug-like marine beetles' or similar, yet when it comes to humans, we have a definite sore spot. There is a deep psychological need to have an obvious series of ever-more sophisticated ancestors paving the way for us.

What many people don't realise is that organisms frequently evolve both physical and behavioural attributes that are subsequently lost and possibly later regained. Some have devolved into far simpler forms, frequently becoming parasites. Viruses are themselves a simplified life form, unable to reproduce without a high-jacked cell doing the work for them; no-one could accuse them of not being highly successful - as we are currently finding out to our cost. We ourselves are highly adaptable generalists, but on a component-by-component level it would appear that only our brains make us as successful as we are. Let's face it, physically we're not up to much: even cephalopods such as squid and octopus have a form of camera eye that is superior to that of all vertebrates.

Even a cursory glance at the natural history of life, using scientific disciplines as disparate as palaeontology and comparative DNA analysis, shows that some lineages proved so successful that their outward physiology has changed very little. Today, there are over thirty species of lancelet that are placed at the base of the chordates and therefore closely related to the ancestors of all vertebrates. They are also extremely similar in appearance to 530-million-year-old fossils of the earliest chordates in the Cambrian period. If evolution were a one-way ticket to progress, why have they not long since been replaced by later, more sophisticated organisms?

4) We appear to conflate success simply with being in existence today, yet our species is a newcomer and barely out of the cradle compared to some old-timers. We recently learned that Neanderthals wove plant fibre to make string and ate a wide variety of seafood. This knowledge brings with it a dwindling uniqueness for modern Homo sapiens. The frequently given explanation of our superiority over our extinct cousins is simply that they aren't around anymore, except as minor components of our genome. But this is a tautology: they are inferior because they are extinct and therefore an evolutionary dead end; yet they became extinct because of their inferiority. Hmmm...there's not much science going on here!

The usual story until recently was that at some point (often centred around 40,000-50,000 years ago) archaic sapiens developed modern human behaviour, principally in the form of imaginative, symbolic thinking. This of course ignores the (admittedly tentative) archaeological evidence of Neanderthal cave-painting, jewelry and ritual, all of which are supposed to be evidence of our direct ancestor's unique Great Leap Forward (yes, it was named after Chairman Mao's plan). Not only did Neanderthals have this symbolic behaviour, they appear to have developed it independently of genetically-modern humans. This is a complete about-turn from the previous position of them being nothing more than poor copyists.

There are alternative hypotheses to the Great Leap Forward, including:

1. Founder of the Comparative Cognition Project and primate researcher Sarah Boysen observed that chimpanzees can create new methods for problem solving and processing information. Therefore, a gradual accumulation of cognitive abilities and behavioural traits over many millennia - and partially inherited from earlier species - may have reached a tipping point. 
2. Some geneticists consider there to have been a sudden paradigm shift caused by a mutation of the FOXP2 gene, leading to sophisticated language and all that it entails.
3. Other researchers consider that once a certain population size and density was achieved, complex interactions between individuals led the way to modern behaviour. 
4. A better diet, principally in the form of larger amounts of cooked meat, led to increased cognition. 

In some ways, all of these are partly speculative and as is often the case we may eventually find that a combination of these plus other factors were involved. This shouldn't stop us from realising how poor the communication of evolutionary theories still is and how many misconceptions exist, with the complex truth obscured by our need to feel special and to tell simple stories that rarely convey the amazing evolution of life on Earth.

Herbaceous dialects and dialectical materialism: how plants communicate with their pollinators

The inspiration behind this post stems from reading two of the giants of science popularisation during my formative years. The first component is from Carl Sagan's book Broca's Brain: Reflections on the Romance of Science, which remarks that the emotional lives of plants are an example of pure pseudoscience. The second is Stephen Jay Gould's essay on Pyotr Kropotkin, a nineteenth century Russian anarchist who wrote the essay collection Mutual Aid: A Factor of Evolution. What joins them together is recent research that uncovers an astonishingly complex relationship between certain plants and animals.

Kropotkin's hypothesis was that cooperation between species was as fundamental to life on our planet as natural selection. Although his socialist-motivated ideas have been somewhat downscaled by the evidence of the succeeding century, there are still some truths to be learnt about the mutual aid - or symbiosis if you prefer - between fundamentally different life forms.

I recently read about some experiments in Israel and Germany, which involved such esoteric boffinry as placing laser microphones close to tobacco and tomato plants in order to pick up any ultrasonic noises that they might emit. The plants were heavily pruned or moved into parched soil, in other words, subject to physiological stress.

Analysis of the recordings revealed high-pitch sounds (or in the researchers' words, 'squeals') emanating from their herbaceous guinea pigs. Not only did the sounds vary depending on whether the plant was suffering from mutilation or lack of moisture, but each species (both members of the Solanaceae family) had differing numbers of repetitions and time intervals between each sound. What's even more interesting is the noises differed according to the local invertebrate life, specifically the potential pollinating insects.

In addition to the scientists' equipment, animals such as bats and rodents were placed in the vicinity of the subjects and reacted to the sounds as they were being produced, verifying the shrieks as emanating from the plants. The physiological cause appears to be the movement of air bubbles within liquids such as sap, but how are plants able to perceive the problems, let alone respond to them?

It's been known for some years that plants can communicate with other members of their species via emitting chemical compounds; just think of the odour of freshly cut grass. Forest trees even share nutrients via a symbiotic root system in order to allow smaller members of their species to grow faster - so much for selfish genetics here!

Communication between plants by all three methods, namely direct contact, sound, and chemical odour, suggests purpose and awareness, only without a central nervous system to guide it. This might sound impossible, but then the marine bacteria species Bacillus subtilus uses potassium ions to communicate across its colonies and few would argue that bacterium are more advanced life forms than the kingdom Plantae. We should also remember that in even in animals, brains aren't the be-all and end-all: there are neurons in vertebrate (including human) stomachs and in the arms of cephalopods.

The symbiotic relationship between angiosperms (flowering plants) and pollinating insects evolved in the late Cretaceous, so natural selection has had over sixty-five million years to work on the communications systems between these collaborators. Could it be that plants have evolved a specialist messaging service for their pollinating symbionts, despite having no equivalent of neurons to coordinate it?

Some of the recent Israeli research seems to verify this – and how! When endangered by being cut or deprived of water, the specific noises were not only picked up by pollinating insects, they were acted upon. Insects such as hawk moths flew away from the plants that were suffering drought or mutilation to control specimens on the farthest side of the greenhouse laboratory and laid their eggs upon those plants. Meanwhile, other insects that were known pollinators on the same plant species but not local the region ignored the audio signals. Somehow, there is a level of fine-tuning going on that reveals the sensory world of plants is far superior to what is usually credited.

Parallel experiments successfully tested for the opposite effect. Individual tobacco plants with mature flowers sent messages that attracted the attention of local pollinators such as stilt bugs. All in all, it appears that certain plant species – at least of the Solanaceae family - engage in a form of mutual aid that Kropotkin would be proud of. Not only do plants use ultrasonics to target useful insects, they have developed a messaging service that is regionalised towards those insect species, essentially a dialect rather than a universal language.

While tobacco and tomato plants might not be screaming in pain every time they are cut or lacking water, it seems that they cannot be as easily dismissed as the poorer relation to us animals. The time may be due for a complete reappraisal of their perception capabilities, although amateur researchers would do well to remember that both tomato and tobacco are from the same family as the mandrake and as any Harry Potter fan should know, you wouldn't want to hear those scream!

Printing ourselves into a corner? Mankind and additive manufacturing

One technology that has seemingly come out of nowhere in recent years is the 3D printer. More correctly called additive manufacturing, it has only taken a few years between the building of early industrial models and a thriving consumer market - unlike say, the gestation period between the invention and availability of affordable domestic video cassette recorders.

Some years ago I mentioned the similarities between the iPAD and Star Trek The Next Generation's PADD, with only several decades separating the real-world item from its science fiction equivalent. Today's 3D printers are not so much a primitive precursor of the USS Enterprise-D's replicator as a paradigm shift away in terms of their profound limitations. And yet they still have capabilities that would have seemed incredibly futuristic when I was a child. As an aside, devices such as 3D printers and tablets show just how flexible and adaptable we humans are. Although my generation would have considered them as pure sci-fi, today's children regularly use them in schools and even at home and consider the pocket calculators and digital watches of my childhood in the same way as I looked at steam engines.

But whilst it can't yet produce an instant cup of earl grey tea, additive manufacturing tools are now being tested to create organic, even biological components. Bioprinting promises custom-made organs and replacement tissue in the next few decades, meaning that organ rejection and immune system repression could become a thing of the past. Other naturally-occurring substances such as ice crystals are also being replicated, in this case for realistic testing of how aircraft wings can be designed to minimise problems caused by ice. All in all, the technology seems to find a home in practically every sector of our society and our lives.

Even our remotest of outposts such as the International Space Station are benefiting from the use of additive manufacturing in cutting-edge research as well as the more humdrum role of creating replacement parts - saving the great expense of having to ship components into space. I wouldn't be surprised if polar and underwater research bases are also planning to use 3D printers for these purposes, as well as for fabricating structures in hostile environments. The European Space Agency has even been looking into how to construct a lunar base using 3D printing, with tests involving Italian volcanic rock as a substitute for lunar regolith.

However, even such promising, paradigm-shifting technologies as additive manufacturing can have their negative aspects. In this particular case there are some obvious examples, such as home-printed handguns (originally with very short lifespans, but with the development of 3D printed projectiles instead of conventional ammunition, that is changing.) There are also subtle but more profound issues that arise from the technology, including how reliance on these systems can lead to over-confidence and the loss of ingenuity. It's easy to see the failure due to hubris around such monumental disasters as the sinking of the Titanic, but the dangers of potentially ubiquitous 3D printing technology are more elusive.

During the Apollo 13 mission in 1970, astronauts and engineers on the ground developed a way to connect the CSM's lithium hydroxide canisters to the LM's air scrubbers, literally a case of fitting a square peg into a round hole. If today's equivalents had to rely solely on a 3D printer - with its power consumption making it a less than viable option - they could very well be stuck. Might reliance on a virtual catalogue of components that can be manufactured at the push of a button sap the creativity vital to the next generation of space explorers?

I know young people who don't have some of the skills that my generation deemed fairly essential, such as map reading and basic arithmetic. But deeper than this, creative thinking is as important as analytical rigour and mathematics to the STEM disciplines. Great physicists such as Einstein and Richard Feynman stated how much new ideas in science come from daydreaming and guesswork, not by sticking to robot-like algorithmic processes. Could it be that by using unintelligent machines in so many aspects of our lives we are starting to think more like them, not vice versa?

I've previously touched on how consumerism may be decreasing our intelligence in general, but in this case might such wonder devices as 3D printers be turning us into drones, reducing our ability to problem-solve in a crisis? Yes, they are a brave new world - and bioprinting may prove to be a revolution in medicine - but we need to maintain good, old-fashioned ingenuity; what we in New Zealand call the 'Number 8 wire mentality'. Otherwise, our species risks falling into the trap that there is a wonder device for every occasion - when in actual fact the most sophisticated object in the known universe rests firmly inside our heads.

Falling off the edge: in search of a flat Earth

It's just possible that future historians will label the 21st century as the Era of Extreme Stupidity. In addition to the 'Big Four' of climate change denial, disbelief in evolution by natural selection, young Earth creationism and the anti-vaxxers, there are groups whose oddball ideas have rather less impact on our ecosystem and ourselves. One segment of people that I place in the same camp as UFO abductees and their probing fixation are believers in a flat Earth.

Although on the surface this - admittedly tiny - percentage of people appear to be more amusing than harmful, their media visibility makes them a microcosm of the appalling state of science education and critical thinking in general. In addition, their belief in an immense, long-running, global conspiracy adds ammunition to those with similar paranoid delusions, such as the moon landing deniers. One example of how intense those beliefs can be (at times there's just a whiff of religious fanaticism), the American inventor and stuntman 'Mad' Mike Hughes was killed recently flying a self-built rocket intended to prove that the Earth is a disc.

I won't bother to describe exactly what the flat Earthers take to be true, except that their current beliefs resemble a description of the late, great Terry Pratchett's fantasy Discworld - albeit without the waterfall around the edge of the disc. For anyone who wants to test the hypothesis themselves rather than rely on authority (the mark of a true scientist) there are plenty of observational methods to try. These include:

1. Viewing the Earth's shadow on the Moon during a lunar eclipse
2. Noticing that a sailing ship's mast disappears/reappears on the horizon after/before the hull
3. How certain stars are only visible at particular latitudes

For anyone with a sense of adventure, you can also build a high-altitude balloon or undertake a HAHO skydive to photograph the Earth's curvature - from any point on the planet!

It's easy to suggest that perhaps our brains just aren't up to the task of deciphering the intricacies of a 13.7 billion old universe, but basic experiments and observations made several thousand years ago were enough for Greek scientists to confirm both the shape and size of our planet. So what has changed in the past century or so to turn back the clock, geophysically-speaking?

The modern take on a flat Earth seems to have begun in the late 19th century, with an attempt - similar to contemporary mid-Western creationists - to ignore scientific discoveries that disagree with a literal interpretation of the Old Testament. Indeed, the forerunners of today's flat Earthers were anti-science in many respects, also denying that prominent enemy of today's Biblical literalists, evolution by natural selection. However, many of the 21st century' s leading adherents to a disc-shaped Earth have more sympathy and interest in scientific discoveries, even supporting such politically contentious issues as rapid, human-induced, climate change.

This topic is laden with ironies, few greater than the fact that a large proportion of the evidence for global warming is supplied by space agencies such as NASA. The latter has long been claimed by the Flat Earth Society as a leading conspirator and purveyor of faked imagery in the promotion of a spherical earth (yes to all pedants, I know that strictly speaking our planet is an oblate spheroid, not purely spherical).

Today's flat Earth societies follow the typical pseudo-scientific / fringe approach, analysing the latest science theories for material they can cherry pick and cannibalise to support their ideas. In recent years they've even tackled key new developments such as dark energy; in fact, about the only area they are lagging behind in is the incorporation of elements involving quantum mechanics.

But for anyone with an understanding of parsimony or Occam's Razor, the physics for a flat Earth have about as much likelihood as Aristotle's crystalline spheres. It isn't just the special pleading for localised astrophysics (since the other planets are deemed spherical); isn't it obviously absurd that there could be a global conspiracy involving rival nations and potentially hundreds of thousands of people - with no obvious explanation of what the conspirators gain from the deception?

Even for the vast majority of the public with little interest or understanding of the physics, most people considering the flat Earth hypothesis are presumably puzzled by this apparent lack of motivation. In a nutshell, what's in it for the conspirators? Until recently, NASA (nick-named 'Never A Straight Answer,') was the main enemy, but with numerous other nations and private corporations building space vehicles, there is now a plethora of conspiracy partners. Going back half a century to the height of the Cold War why, for example, would the USA and Soviet Union have agreed to conspire? As yet, there hasn't been anything approaching a satisfactory answer; but ask Carl Sagan said: "Extraordinary claims require extraordinary evidence."

Unlike most fringe groups, flat Earthers don't appear to favour other, popular conspiracy theories above scientific evidence. Yet somehow, their ability to support ludicrous ideas whilst denying fundamental observations and the laws of physics in the light of so much material evidence is astonishing.  Of course our species doesn't have a mental architecture geared solely towards rational, methodical thought processes, but the STEM advances that Homo sapiens has made over the millennia prove we are capable of suppressing the chaotic, emotional states we usually associate with young children.

Whether we can transform science education into a cornerstone topic, as daily-relevant as reading, writing and arithmetic, remains to be seen. Meanwhile, the quest continues for funding a voyage to find the Antarctic ice wall that prevents the oceans falling over the edge of the world. Monty Python, anyone?

Wildfires and woeful thinking: why have Australians ignored global warming?

In a curious example of serendipity, I was thinking about a quote from the end of Carl Sagan's novel Contact ("For small creatures such as we the vastness is bearable only through love") just a few minutes before discovering his daughter Sasha Sagan's book For Small Creatures Such as We. Okay, so I didn't buy the book - due to the usual post-Christmas funds shortage - and cannot provide a review, but this indication of our place in the scale of creation is something that resonates deep within me.

I've often discussed how biased we are due to our physical size, especially when compared to other species we share the planet with. However, I've never really considered that other fundamental dimension, time. Another Carl Sagan quote echoes many a poet's rumination on our comparatively brief lifespan: "We are like butterflies who flutter for a day and think it is forever."

There's more to this than just fairly familiar poetic conceit. Earlier this month I was given a brief taste of what it might be like to live on Mars, thanks to high-altitude dust and ash transported across the Tasman Sea from the Australian bush fires. By three o'clock in the afternoon a New Zealand summer's day was turned into an eerie orange twilight, with birds and nocturnal insects starting their evening routine some five hours early. There was even a faint powdery, acrid taste in the air, adding to the sense of other-worldliness.

Apart from the obvious fact that this an example of how climate change in one nation can affect another, there is a more disturbing element to all this. Why is it that despite the reports and general consensus of the global climate science community Australians have shown a woeful lack of interest, or indeed, negativity, towards climate change?

Could it be that our society is now centred upon such short increments of time (competing businesses trying to out-do each other, which comes down to working at the ever-increasing speed our technology dictates) that we have replaced analysis with unthinking acceptance of the simplest and most aggressive opinions? Research shows that compared to even twenty years' ago, children read far less non-school literature and rely on the almost useless 'celebrity' shouters of social media for much of their information; there's not much chance of learning about informed, considered arguments via these sources!

After all, it's difficult for most of us to remember exact details of the weather a year ago, but understanding climate change relies on acceptance of directional trends over at least decades. How much easier is it to accept the opinions of those who preserve the status quo and claim we can maintain our current lifestyle with impunity? When combined with the Western capitalist notion of continuous growth and self-regulation, we see a not-so-subtle indoctrination that describes action to prevent climate change as disruptive to the fundamental aspects of the society that has arisen since the Industrial Revolution.

There is an old French saying that we get the government we deserve, which in Australia's case, implies a widespread desire to ignore or even deny global warming. Yet the irony is that of all developed nations, Australia has been at the receiving end of some of its worst effects, thanks to an average increase in daily temperature of several degrees over past century. It takes little cognition to understand how this can lead to the drier conditions that have caused the horrific bush fires; even though some have been deliberately started, their scale has been exacerbated by the change of climate. So what until now has prevented Australians from tying the cause to the effects?

It's not as if there isn't plenty of real-world evidence. However, with computer technology able to generate 'deep fakes', which implies a level of sophistication that only experts can detect, is the public becoming mistrustful of the multitude of videos and photographs of melting polar caps and shrinking glaciers? When combined with the decreased trust in authority figures, scientists and their technical graphs and diagrams don't stand much of a chance of acceptance without a fair amount of suspicion. As mentioned, it's difficult to understand the subtleties inherent in much of science when you are running at breakneck speed just to stand still; slogans and comforting platitudes are much more acceptable - unless of course people become caught up in the outcome themselves.

However, this doesn't explain why it is the key phrases such as 'climate change' and 'global warming' generate such negative sentiment, even from those Australian farmers who admit to hotter, drier conditions than those experienced by their parents' and grandparents' generations. Somehow, these sober terms have become tainted as political slogans rather than scientifically-derived representations of reality. That this negativity has been achieved by deniers seems incredible, when you consider that not only does it run counter to the vast majority of report data but that it comes from many with vested interests in maintaining current industrial practices and levels of fossil fuel usage.

Could it simply be a question of semantics, with much-used labels deemed unacceptable at the same time as the causes of directly-experienced effects accepted as valid? If so, it would suggest that our contemporary technological society differs little from the mindset of pre-industrial civilisation, in which leaders were believed to have at very least a divine right to rule, or even a divine bloodline. In which case, is it appalling to suggest that the terrible bush fires have occurred not a minute too soon?

If it is only by becoming victims at the tip of the impending (melted) iceberg that global warming is deemed genuine, then so be it. When scientists are mistrusted and activists labelled as everything from misguided to corrupt and scheming manipulators, this might only leaves a taste of what lies ahead to convince a majority who would otherwise rather keep doing as they always have done and trust politicians to do the thinking for them. I can think of nothing more apt to end on than another Carl Sagan quote: "For me, it is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring."

Our family and other animals: do we deliberately downplay other species' intelligence?

I recently heard about a project investigating canine intelligence, the results being that man's best friend can distinguish similar-sounding words, even if spoken by strangers. Yet again, it appears there is a less and less that makes our species unique: from the problem-solving skills of birds to social insects' use of farming techniques we find ourselves part of a continuum of life rather than standing alone at the apex.

Reading the Swedish philosopher Nick Bostrom's thought-provoking book Superintelligence, I was struck by his description of the variation of human intellect (from as he put it, Einstein to the village idiot) as being startling narrow when compared to the potential range of possible intelligences, both biological and artificial.

The complexity of animal brains has been analysed by both quantitive and qualititive methods, the former dealing with such measurements as the number of neurons while the latter looks at behaviour of members of a species, both in the wild and under laboratory conditions. However, a comparison of these two doesn't necessarily provide any neat correlation.

For example, although mammals are generally - and totally incorrectly - often described as the pinnacle of creation due to their complex behaviour and birth-to-adult learning curve, the quantitive differences in neural architecture within mammals are far greater than those between amphibians and some mammalian families. In addition, there are many birds, mostly in the Psittacidae (parrot) and Corvidae (crow) families, that are both quantitatively and qualitatively superior to most mammals with the exception of some primates.

I think it was the essays of evolutionary biologist Stephen Jay Gould that introduced me to the concept of EQ or encephalisation quotient, which is a label for the brain-mass to body-mass ratio. On these terms, the human brain is far larger than nearly all other species with a similar sized body, the exception (perhaps not surprisingly) being dolphins.

However, it's difficult to draw accurate conclusions just from examination of this general trend: both the absolute size of the brain and neuron density play a fundamental role in cognitive powers. For example, gorillas have a lower EQ that some monkeys, but being a large ape have a far greater brain mass. It could be said then, that perhaps beyond a certain mass the absolute brain size renders the EQ scale of little use. A 2009 study found that different rules for scaling come into play, with humans also having a highly optimal use of the volume available with the cranium, in addition to the economical architecture common among primates.

As historian and philosopher Yuval Noah Harari has pointed out, the development of farming, at least in Eurasia, went hand in hand with the evolution of sophisticated religious beliefs. This led to a change in human attitudes towards the other animals, with a downplay of the latter's emotional needs and their categorisation as inferior, vassal species in a pre-ordained (read: divinely-given) chain of being.

By directly connecting intelligence - or a lack thereof - to empathy and emotions, it is easy to claim that domesticated animal species don't mind their ruthless treatment. It isn't just industrial agriculture that makes the most of this lack of empathy today; I've seen small sharks kept in a Far Eastern jewellery store (i.e. as decoration, not as future food) in tanks barely longer than the creature's own body length.

Although the problem-solving antics of birds such as crows are starting to redress this, most people still consider animal intelligence strictly ordered by vertebrate classes, which leads to such inaccuracies as the 'three second goldfish memory'. I first noticed how incorrect this was when keeping freshwater invertebrates, namely shield shrimp A.K.A. triops, almost a decade ago. Even these tiny creatures appear to have a range of personalities, or perhaps I should say - in an effort to avoid blatant anthropomorphizing - a wide variety of behaviour.

Now on the verge of setting up a tropical aquarium for one of my children, I've been researching what is required to keep fish in fairly small tanks. I've spoken to various aquarium store owners and consulted numerous online resources, learning in the process that the tank environment needs to fulfill certain criteria. There's nothing in usual in this you might think, except that the psychological requirements need to be considered alongside the physical ones.

For example, tank keepers use words such as 'unhappy' and 'depression' to describe what happens when schooling fish are kept in too small a group, active swimmers in too little space and timid species housed in an aquarium without hiding places. We do not consider this fish infraclass - i.e. teleosts - to be Einsteins (there's that label again) of the animal kingdom, but it would appear we just haven't been observing them with enough rigour. They may have minute brains, but there is a complexity that suggests a certain level of emotional intelligence in response to their environment.

So where does all this leave us Homo sapiens, masters of all we survey? Neanderthal research is increasingly espousing the notion that in many ways these extinct cousins/partial ancestors could give us modern humans a run for our money. Perhaps our success is down to one particular component of uniqueness, namely our story-telling ability, a product of our vivid imagination.

Simply because other species lack this skill doesn't mean that they don't have any form of intellectual ability; they may indeed have a far richer sense of their universe than we would like to believe. If our greatest gift is our intelligence, don't we owe it to all other creatures we raise and hold captive to make their lives as pleasant as possible? Whether it's battery farming or keeping goldfish in a bowl, there's plenty we could do to improve things if we consider just what might be going on in the heads of our companion critters.

Ocean acidification: climate change at the sour end

A few weeks ago, I overheard a 58 year old man telling a 12 year old boy that the most dire of scientists' warnings concerning global warming over the past 30 years had failed to materialise - and that what the boy needed to learn was to be able to separate facts from propaganda.

Although it is no doubt next to impossible to be able to change such entrenched mindsets as those of this particular baby boomer, there is still extremely limited public understanding of the insidious changes currently taking place in our oceans. In addition to the rise in both sea temperature and sea level (approaching a centimetre every two-to-three years) a rapid increase in ocean acidity is now on course to profoundly disrupt marine life.

With the USA pulling out of the Paris Agreement, will the rest of world manage to pull together in order to prevent another tipping point? After all, increasing ocean acidification isn't something us non-marine scientists can directly observe. One key point that is immediately obvious is that it isn't a localised issue: as a third of atmospheric carbon dioxide is absorbed into the oceans, all the planet's seas will be affected. The decrease of 0.1pH unit in the past few centuries equates to an astonishing 26-29% increase in acidity. What's more, this change is predicted to have doubled by the end of this century. Clearly, the effect on marine life is set to be substantial.

So what is being done to assess the probable issues? Various projects around the world are using mesocosms - transparent cylinders up to ten metres long - to understand the effects of current and predicted near-future acidity levels on marine life. Coral bleaching is possibly the one condition people will have heard of (although there appear to be an astonishing number of people who think that coral is a plant rather than invertebrate animal) but sea temperature changes are as much a cause as increased acidity. Apart from causing stress to some marine organisms, leading to such conditions as lowered immune systems and so the spread of disease, acidification reduces the material available for shell and carapace formation, especially for juveniles and nauplii.

The problem isn't so much the change itself as the rate of change, which is far faster than normal geophysical processes. Indeed, one report states that over the past 20 million years, changes in oceanic acidification have been barely one percent of the current rate. Obviously, there is minimal chance of the non-directed mechanism of natural selection keeping pace with adaptations to the new conditions.

While many organisms will suffer, some such as jellyfish and toxic algae may benefit, with the latter leading to the poisoning of key fishing industry species. This in turn could lead to toxins entering the human food chain, on top of the economic issues from the decline in fish and shellfish stocks. Indeed, the US Pacific coast aquaculture industry is already experiencing a reduction in the shellfish populations. This will be in addition to the pollution of fresh waterways already explored in a post last year.

Of the various experiments aiming to understand the impact of the rapid increase, the largest project is the pan-European Biological Impacts of Ocean Acidification (BIOACID) scheme. Giant mesocosms sunk in a Swedish fjord have been sealed with local ocean water (and associated organisms) and half of them modified with the projected pH level.

Similar but small projects are underway in New Zealand and the Canary Islands, with preservation of edible stocks a key priority. Another problem with a decline in shellfish species destined for human consumption would be the loss of the raw material for chitosan, which may prove to be an ecologically-friendly replacement for plastic packaging.

Clearly, there could be numerous - and some as yet unknown - knock-on effects from the ocean acidification. Unlike the rise in atmospheric temperature, it is much more difficult to see the results of this fundamental change and for the public to understand the consequences. Yet again, the life forms affected are far from the cute poster species usually paraded to jump-start the public's environmental consciousness. Unfortunately, these may prove to be far more critical to the future of humanity and the wider world than say, giant pandas or Amur leopards. It's time for some serious sci-comm to spread the warning message!