Showing posts with label Richard Fortey. Show all posts
Showing posts with label Richard Fortey. Show all posts

Thursday 27 October 2016

Murky waters: why is the aquatic ape hypothesis so popular?


Whilst not in the same class as the laughably abysmal Discovery Channel mockumentaries on the likes of mermaids and extant (rather than extinct) megalodon, the recent two-part David Attenborough BBC Radio 4 documentary The Waterside Ape has left me gritting my teeth...grrr.

The programme has confirmed something I suspected from his 2010 BBC television series and associated book, First Life: namely, that the style of his exposition takes priority over the substance of his material. I'll quickly recap on the howler he made in an episode of First Life, ironically one that featured renowned trilobite expert Richard Fortey, albeit in a different sequence. When discussing trilobites, Sir David briefly mentions that they get their name from having three segments from front to rear: head, body and pygidium (tail) - which is totally wrong!

The name is the give-away. Tri-lobe refers to the three segments across the width of the body: a central lobe and two lateral lobes. Many creatures have the head, body and tail segmentation, so it would be far from unique in trilobites. I find this example of incorrect information rather discomforting, especially from someone like Sir David who has been a fan of trilobites since childhood. You have to wonder why experts aren't invited to give BBC science and nature documentaries the once-over before broadcast, just in case any gaffes have got through to the final cut?

The issue then, is that if we non-professionals believe the content espoused by such senior figures in the field of science communication - and if such material goes without basic error-checking from professionals - how is the public to receive a half-decent science education? Of course science isn't a body of knowledge but a toolkit of investigation techniques, but few of the general public have the ability to test hypotheses themselves or access the jargon-filled original scientific papers. So relying on books and media from distinguished communicators is the primary way of increasing our STEM (Science, Technology, Engineering and Mathematics) knowledge.

Back to The Waterside Ape. The hypothesis is an old one, dating back to marine biologist - and let's face it, oddball theorist - Sir Alister Hardy's first, unpublished speculations in 1930. However, the idea didn't achieve widespread dissemination until Elaine Morgan began to publicise it in the early 1970's. Otherwise known as a fiction writer, Morgan's output on the aquatic ape hypothesis was originally considered to be a feminist critique rather than particularly serious science, bearing in mind that the author lacks professional training or experience in the field of evolutionary biology.

Whether it is thanks to dissemination via the World Wide Web, her pro-aquatic ape books have become ever more popular over the past twenty years. This is in spite of the ever-increasing number of hominin fossils and sophisticated analytical techniques that have shown little support for the idea. I'm not going to examine the evidence for and against the hypothesis, since that has been done by many others and I'm marginally less qualified to assess it than Elaine Morgan. Instead, I'm more interested in how and why the idea has maintained popular appeal when the general consensus among the specialists is that it is profoundly incorrect.

Could it be that the engaging quality of Morgan's writing obscures a lack of dry (geddit?) analysis upon a subject that could at best be deemed as controversial - and thus fool the general readership as to its validity? Or is there more to it than that? The BBC seem to have maintained an on-going interest in supporting her work over the past two decades.

Indeed, The Waterside Ape is not David Attenborough's first foray into the idea. He made another two-part BBC Radio 4 series called Scars of Evolution back in 2005, which included some of the same interviews as the recent programmes. The BBC and Discovery Channel also collaborated in 1998 on a television documentary favouring the hypothesis called surprisingly enough The Aquatic Ape, albeit without Attenborough's involvement.

A key argument that I'm sure gets public support is that the of a radical - and female - outsider being shunned by the conservative, male-dominated establishment, with Elaine Morgan pitted against the reactionary old guard of palaeontologists, biologists, etc. Her plight has been described in the same vein as meteorologist Alfred Wegener's battle with orthodox geology between the world wars, but in Wegener's case his hypothesis of continental drift lacked a mechanism until plate tectonics was formulated several decades later. As for the aquatic ape, there seems to be a suite of models describing a gamut of ideas, from the uncontroversial speculation of hominins wading for iodine- and Omega-3-rich foodstuffs (promoting brain growth) to human ancestors being Olympic-class ocean swimmers who would feel at home in a Discovery Channel mermaid mockumentary.

We shouldn't ignore the emotive aspects of the hypothesis, which the various programmes have described as a "fascinating idea" that would be "lovely to confirm". Since most people still think of dolphins as innocent, life-saving and cute (when in fact they play brutal cat-and-mouse games with live porpoises) could this be a psychological attempt to salvage something of our own rapacious species?

Elaine Morgan admitted that her first book was a response to her annoyance with the 'killer ape' theories of the 1960's, as espoused in Robert Ardrey's seminal 1961 volume African Genesis. In these post-modern, politically-correct times of gatherers first and hunters second, Raymond Dart and Robert Ardrey's once-influential machismo ape-man has fallen from favour. Unfortunately, the famous Ardrey-influenced Dawn of Man sequence in 2001: A Space Odyssey promotes just such a viewpoint, so perhaps it isn't any wonder that supporting a more tranquil aquatic ancestry might appear to be an easy way to bring 21st century sensitivities to a world reeling from constant violence.

Another possible reason for the hypothesis' widespread support is that it relies on what appears to be an impressive accumulation of facts in the Darwinian mould, without recourse to difficult mathematics or sophisticated technical jargon. For those unable to get a clear understanding of major contemporary science (Higgs boson, anyone?) the idea of aquatic ape ancestors is both romantic and easy to digest, if the supporting evidence is taken en masse and the individual alternatives for each biological feature ignored or undeclared.

Clearly, whoever thinks that science is detached from emotion should think again when considering the aquatic/waterside/paddle-boarding ape. Although on the surface a seductive idea, the collection of proofs are selective, inadequate and in some cases just plain wrong. It might be good enough for the sloppy pseudo-scientific archaeology of Graham Hancock and Erich von Daniken, but good science needs rather more to go on. Yes, there are some intriguing nuggets, but as Dr Alice Roberts said in her critique of the recent Attenborough radio series, science is about evidence, not wishful thinking. Unfortunately, the plethora of material contains rather more subtleties than trilobite nomenclature, so I can only sigh again at just how many equally poorly-concocted ideas may be swashing around the world of popular science communication. Come on, Sir David, please read past the romance and dig a bit deeper: the world needs people like you!

Tuesday 13 May 2014

Digging apart: why is archaeology a humanity and palaeontology a science?

Although my Twitter account only follows scientists and scientific organisations, every day sees the arrival of a fair few archaeology tweets, even by science-orientated sites such as Science News. As someone who has been an amateur practitioner of both archaeology and palaeontology I thought I'd like to get to grips with why they are categorised so differently. After all, the names themselves don't really help: the word 'archaeology' means "the study of everything ancient." whilst the common definition of 'palaeontology' is pretty much "the study of ancient life". I've even known people with close friends or relatives in one or the other discipline to confuse them: whilst viewing my fossil cabinet, a visitor once told me that her cousin was an archaeologist studying Maori village sites!

Even historically, both fields share many common factors. Not only were they founded by enthusiasts and amateurs, but to this day non-professionals continue to make fundamental contributions. In converse, amateurs can cause serious deficiencies in the data record by lack of rigour or deliberately putting financial gain ahead of the preservation of new information. This can be caused by a variety of methods, from crude or overly hasty preparation of fossils, to metal detectorists and site robbers who sell their finds to private collectors without recording the context, or even the material itself.

It is not immediately obvious where the dividing line between the two disciplines lies when it comes to prehistoric human remains. In the 1990s, archaeologist Mark Roberts led a team that excavated the half a million year old Boxgrove site in southern England. Finds included fragmentary remains of Homo heidelbergensis, thus crossing over to what might traditionally be deemed the territory of palaeontologists. In 2001 the multi-phase Ancient Human Occupation of Britain project started, with deliberate collaboration between both sectors, proof that their skills could overlap and reinforce each other.

By and large, neither palaeontology nor archaeology utilises repeatable laboratory experiments and therefore neither can be classified as a ‘hard’ science. Even palaeontology relies to a large extent on historical contingency, both for remains to be fossilised in the first place and then for them to be discovered and recorded using the relevant methodology. As British palaeontologist Richard Fortey has said "Physics has laboratories; systematic biology has collections." Talking of which, re-examination of old evidence in both disciplines can lead to new discoveries: how often do we see headlines pointing to a fundamental discovery...made in a museum archive?

Although archaeologist were not previously known for conducting experiments,  the New Archaeology/Processual archaeology that arose in the 1960s included an emphasis on testing hypotheses, one result of which is that archaeology now uses experiments to interpret site data. This includes attempts to recreate artefacts, structures, boats, or even food recipes, based on finds from one or more sites. It may not be laboratory conditions, but it is still a method of analysis that can reinforce or disprove an idea in a close equivalent of the scientific hypothesis.

Attempts to improve the quality of data gleaned from the archaeological record have led to the utilisation of an enormous variety of scientific techniques collectively labelled archaeometry. These include microwear analysis, artefact conservation, numerous physical and chemical dating methods such as the well-known radio carbon dating and dendrochronology; geophysical remote sensing techniques involving radar, magnetometry and resistivity; and DNA analysis, pathology and osteo-archaeology.

Teeth of a sand tiger shark
(possibly Odontaspis winkleri)
I found in a wood in Surrey, UK

But there are some major differences between archaeology and palaeontology as well. Although both appear to involve excavation, this is only somewhat true. Not only does archaeology include standing structures such as buildings or ancient monuments, but a project can be restricted to non-invasive techniques such as the geophysical methods mentioned above; excavating a site is the last resort to glean information unobtainable by any other way, especially important if the site is due to be destroyed by development. In contrast, fossils are no use to science by remaining buried. Having said that, I often fossils by sifting through pebbles rather than concerted digging. I have occasionally split rocks or dug through soft sand, but a lot of the time fossils can be found scattered on the surface or prised out of exposed chalk via finger nails. The best way to spot even large finds is to have them already partially exposed through weathering, whilst some archaeology cannot be directly seen from the site but only identified via aerial photography or geophysics.

Archaeological sites can prove extremely complex due to what is known as context: for example, digging a hole is a context, back filling it is another, and any finds contained therein are yet more. Repeated occupation of a site is likely to cause great difficulty in unravelling the sequence, especially if building material has been robbed out. This is substantially different to palaeontology, where even folded stratigraphy caused by geophysical phenomena can be relatively easily understood.

Perhaps the most fundamental difference between the disciplines is that of data analysis. As anyone who has spent time on a site excavation knows, there are often as many theories as there are archaeologists. There are obviously far less fixed data points than that provided by Linnaean taxonomy and so there is a reliance on subjectivity, the keyword being 'interpretation'. Even the prior experience of the excavator with sites of a similar period/location/culture can prove crucial in gaining a correct (as far as we can ever be correct) assessment. In lieu of similarity to previously excavated sites, an archaeologist may turn to anthropology, extrapolating elements of a contemporary culture to a vanished one, such as British prehistorian Mike Parker-Pearson's comparison between the symbolic use of materials in contemporary Madagascar and Bronze Age Britain. In stark contrast, once a fossil has been identified it is unlikely for its taxonomy to be substantially revised - not that this doesn’t still occur from time to time.

As can be seen, not all science proceeds from the hypothesis-mathematical framework-laboratory experiment axis. After all, most of the accounts of string theory that I have read discuss how unlikely it can ever be subject to experiment. The British Quality Assurance Agency Benchmark Statement for Archaeology perhaps comes closest to the true status of the discipline when it lists 'scientific' as one of the four key contexts for higher level archaeological training. In addition, every edition since 2000 has stated "Where possible, thinking scientifically should be part of the armoury of every archaeologist."

So part historical science, part humanity, archaeology is an interesting combination of methodologies and practice, with more resemblances than differences to palaeontology. As the Ancient Human Occupation of Britain project shows, sometimes the practitioners can even work in (hopefully) perfect harmony. Another nail in the coffin for C.P. Snow's 'Two Cultures', perhaps?

Sunday 22 September 2013

Going, going, gone: how do you decide which endangered species are worth saving?

My elder daughter recently adopted a Sumatran tiger. Not literally of course, but an Auckland Zoo package bought as a birthday present, with the tiger chosen above the seven other species on offer because - at least according to my daughter's claim - it was the most endangered one. In fact, the estimate for the number of Sumatran tigers left in the wild varies between four hundred and seven hundred individuals, so the lack of accuracy is only countered by the fact that both extremes are so low. With countless other species similarly close to the edge, if not worse off, a key question has arisen in recent years: are some species more worthy of conserving than others?

Presumably the choice on offer in the zoo's Adopt an Animal programme is intended to increase awareness of the plight of these particular animals. But can there be many people at least in the developed world who are not aware of some of the ever-increasing roster of endangered species? Indeed, there are now widespread claims that we may be living through a mass extinction event, the sixth known. Interestingly, it's only been in the last few years that some sort of quantitative definition of a mass extinction has gained popularity over the earlier, somewhat vague ‘one hundred to a thousand times the background rate' designation, with a rapid (at least on a geological timescale) 75% loss of species deemed the minimum number. However, this figure appears somewhat arbitrary, yet is quoted in various general readership articles as the number of species currently headed for extinction! Evolutionary biologist Richard Dawkins has much to say on the subject of fundamentally meaningless statistics: for example, how is 74% so much less worthy of the term ‘mass extinction' than a mere one per cent more? Granted, there may just be too many unknowns for a consensus in expert opinion, but deciding on a one per cent cut-off line for such an event is surely creating a label for its own sake, useful for lazy journalists but little else.

The International Union for Conservation of Nature (IUCN) Red List makes for depressing reading, with around 7000 species listed between the three worst categories: critically endangered; extinct in the wild; and species that have recently become totally extinct. Even worse, it appears to be out of date, if the example of the Yangtze River dolphin is anything to go by. It appears on the first of these lists, as opposed to the third, where most experts agree it should now sit. The fact that no single organisation seems to have enough resources to compile definitive current data doesn't help. After all, if you cannot identify the species most in need, how do governments and agencies decide which ones to save (and, unfortunately, which to doom to near-future extinction)?

The environmental movement of the past half century has long capitalised on photogenic ‘poster' species such as whales, apes and the giant panda, which add a wow factor that has had the side-effect of concentrating much of the funding on them. This has regrettably deprived many less aesthetic species of publicity, and probably in the case of some species such as the Yangtze River dolphin, their existence.

There are strong arguments both for and against the continuation of this policy, although things have recently got slightly better as regards recognition for non-figurehead species. Late last year the BBC television series Dara O Briain's Science Club made a foray into this area with the question - covered at the programme's usual break-neck speed -  are pandas worth all the money spent on them? Palaeontologist Richard Fortey and zoologist Lucy Cooke presented arguments seemingly against the high level of resources accorded the giant panda. Indeed, the latter emphasised the decline of one third of amphibian species worldwide. The time has finally come to appreciate that non-cute species deserve much greater attention than hitherto gained. To this end, the decidedly unpleasing looks of the deep-sea blobfish have recently seen it voted World's Ugliest Animal in a concerted effort to improve awareness of all the species that are least likely to appear on any fundraising poster.

So considering how many species, including plants and fungi, are currently endangered, is it worth spending millions of dollars each year to preserve, say, giant pandas? After all, aren't the latter just a wee bit useless? With a diet that is 99% bamboo and a seeming lack of reproductive drive, couldn't they be viewed as an over-specialised, evolutionary dead end, doomed regardless of loss of habitat and poaching? However, it isn't as simple as that. The popular description isn't completely accurate, with panda libido in captivity seemingly less than in the wild, although admittedly females are apparently only able to conceive for a few days each year. Even so, is it worthwhile to spend millions on captive breeding programmes (involving artificial insemination) for these cute creatures when the money could be split amongst many other species?

Auckland Zoo's adopt an animal scheme

Awww, cute...but is it worth it?

One of the key arguments in favour of figurehead species is that the publicity gained is then disseminated to other species in the same habitat, such as by keeping those environments as free of development as possible.  Preservation of entire ecosystems is a major element to the notion that for purely selfish reasons we should maintain as much biodiversity as possible. This is in order to preserve unique genomes that may one day prove useful in agriculture or as pharmaceuticals. After all, only about 5% of plant species have so far been studied for their medicinal properties, whilst the DNA of many species remains almost entirely unexamined. A good case can be seen with the Pacific yew, a conifer in severe decline that proved to be the source of an important chemotherapy drug. In a similar vein, loss of one species may cause the rise of another that is rather less neutral from a human viewpoint, whether it is an agricultural pest or a dangerous predator such as the aggressive Humboldt squid, which has largely superseded over-fished sharks around the Mexican Pacific coast.

So even without invoking a moral argument, there are plenty of good reasons why preserving as many types of organisms as possible may be important to our future.  Whether this can be achieved most efficiently via publicity-raising poster species is more difficult to ascertain. There are claims that we should support evolutionary-distinct species or those with a definitively viable breeding/cultivatable population, but this is hampered by the lack of detailed information mentioned above. For example, several population bottlenecks in the history of cheetahs have reduced their genetic diversity to such an extent that even a relatively comfortable population size - at least compared to some endangered species - is no guarantee of future salvation. In other words, the minimum viable population for a species is probably unique for each.

In addition, there aren't complete lists of members in each ecosystem for even relatively large creatures: it was only last month that the Olinguito, a Central American omnivorous mammal new to science, was formally described. With this lack of definitive information, it's little wonder there is a multitude of problems concerning even knowing where to begin conservation measures. Of course, spending funds on this sort of research, which has no immediate benefit to endangered species, would presumably take crucial funding away from vital preservation measures in the here and now. But since the research hasn't been done many factors remain little more than guestimates, thus creating a vicious circle as to which species require the most support.

This doesn't of course mean that dedicated ecologists are likely to be swayed from their labours of love by any amount of hard data. Whether the enormous efforts to save those species with miniscule populations is worthwhile in the long run remains to be seen. New Zealand's flightless parrot the kakapo, with less than one hundred breeding individuals left, is a prominent example. There are now so few that almost every bird has been named; but would it have been better to try saving multiple species with more likelihood of long-term survival? It's difficult to attempt objectivity when you are fighting for the survival of creatures that have been anthropomorphised even to the minimum level of naming them. Then again, it's often been the devotion of small groups of committed conservationists that pioneered the techniques now widespread, including the methods for publicising the plight of endangered species.

So it doesn't look like there are any easy answers in what has to be, if it is to succeed, a rapidly developing field. After all, it's only been a century since we stopped wiping out species for fun in the name of sport. Unlike the Higgs Bosun, some of the subjects involved in this area - the species themselves - aren't going to be hanging around for solutions at some indeterminate point in the future. As Gandhi put succinctly: "Earth provides enough to satisfy every man's needs, but not every man's greed." The problem is knowing where to begin on the mammoth task of fixing a planet-wide ecosystem. All I can say is good luck, because like it or not, we're all participants in this one!

Wednesday 26 September 2012

Moulds, mildew and mushrooms: living cheek by jowl with fungi

There is a form of life that probably exists in every house, office and workplace on the planet (operating theatres and clinical laboratories largely excepted) that is so ubiquitous that it goes chiefly unnoticed. The organisms are stationary yet spread rapidly, are composed of numerous species - some of which include common foodstuffs - and are neither animal nor plant. In other words they belong to the third great kingdom of macroscopic life: fungi. But what are these poor relations of the other two groups, seen as both friend and foe?

Having moved last year from a one hundred and thirty year old, centrally-heated and double-glazed terrace house in the UK to a single-glazed, largely unheated detached house less than a quarter that age in New Zealand, I've been able to conduct a comparative domestic mycology experiment. Without sounding  too much like a mould-and-spores collector out of a P.G. Wodehouse story, the subject has proved interesting and reasonably conclusive: a family of four moving to an annual climate on average four degrees warmer but with twice the rainfall has not substantially changed the amount or placement of mould in the home; if anything, it has slightly decreased. But then the amount of bathing, laundry and pans on the hob hasn't changed, so perhaps it's not too surprising. The more humid climate has been tempered by having more windows and doors to open, not to mention being able to dry more of the laundry outside. Mind you, one big plus of the move has been not having to use electric dehumidifiers or salt crystal moisture traps, so a few degrees warmth seems to be making a difference after all.

There appears to be a wide range of dubious stories, old wives' tales and assorted urban myths regarding fungi, no doubt being due to the lack of knowledge: after all, if you ask most people about the kingdom they will probably think of edible mushrooms followed by poisonous toadstools. Yet of the postulated 1.5 million species of fungi, only about 70,000 have so far been described. They are fundamentally closer to animals than they are to plants, but as they live off dead organic matter (and some inorganic substances too), thriving in darkness as unlike plants they do not photosynthesise, their reputation is more than a little sinister. The fact they will grow on just about any damp surface, hence the kitchen and bathroom mould populations, reinforces the opinion of them as being unwelcome visitors. So just how bad are they?

Firstly, fungi play a vital role in the nitrogen cycle, supplying nutrients to the roots of vegetation. The familiar fruiting bodies are, as Richard Dawkins describes them, pretty much the tip of iceberg compared to the enormous network of fungal material under the soil. Even so, they are given short shrift in popular natural history and science books: for example, they only warrant five pages in Richard Fortey's Life: An Unauthorised Biography, whilst Bill Bryson's A Short History of Nearly Everything spends much of its four pages on the subject concerned with the lack of knowledge about the number of species. Of my five Stephen Jay Gould volumes totalling over two thousand pages, there are just several, short paragraphs. And at least one of my books even refers to fungi as a simple form of plant life! Yet we rely on fungi for so many of our staple foodstuffs; it's just that they are so well hidden we don't consider them if they're not labelled as mushrooms.  But if you eat leavened bread, yoghurt, cheese or soy sauce, or drink beer or wine, fungi such as yeast will have been involved somewhere along the line. On another tack, fungi are party to yet another knife in the coffin of human uniqueness, since both ants and termites cultivate fungi: so much for Man the Farmer.

As this point I could start listing their uses in health cures, from traditional Chinese medicine to Penicillin, but my intention has been to look at fungi in the home. Anyone who has seen the fantastic BBC television series Planet Earth might recall the parasitical attack of the genus Cordyceps upon insects, but our much larger species is far from immune to attack. Minor ailments include Athlete's Foot and Ringworm whilst more serious conditions such as Candidemia, arising from the common Candida yeast, can be life- threatening . The spores are so small that there is no way to prevent them entering buildings, with commonly found species including Cladosporium, Aspergillus, and our old friend Penicillium.

Once they have a presence, moulds and mildew are almost impossible to eradicate. They are extremely resilient, with the poison in Amanita species such as the death cap failing to be destroyed by heat. An increasingly well-known example is the toxin of the cereal-infecting ergot, capable of surviving the bread-making process, even the baking. Indeed, ergot has seemingly become a major star of the fungi world, being used in pharmaceuticals at the same time as being nominated the culprit behind many an historic riddle, from the Salem witch trials to the abandonment of the Marie Celeste. Again, lack of knowledge of much of the fungal world means just about anything can be claimed with only dubious evidence to support it.

Varieties of domestic mould
A rogue's gallery of household fungi

Although we are vulnerable to many forms of fungus, an at least equally wide range attack our buildings. Whether the material is plaster, timber or fabrics, moulds and mildew can rapidly spread across most surfaces containing even a hint of dampness, often smelt before they are seen. At the very least, occupants of a heavily infested property can suffer allergies, sinus problems and breathing problems. As an asthmatic I should perhaps be more concerned, but other than keeping windows and doors open as much as possible there doesn't seem much that can be done to counter these diminutive foes.  As it is, vinegar is a favourite weapon, particularly on shower curtains and the children's plastic bath toys. Even so, constant vigilance is the watchword, as can be seen by the assorted examples from around the house above. For any mycophobes wondering how large fungi can get indoors, I once worked on a feature film shot in a dilapidated Edwardian hotel in central London about to be demolished which had fungal growths on the top floor (saturated with damp thanks to holes in the roof) which were the size of dinner plates.

So whether you've played with puffballs or like to dine on truffles, remember there's no escape: fungi are a fundamental element of our homes, our diet, and if we're unlucky, us too. Seemingly humble they may be, but even in our age of advanced technology, there's just no escape...