Hammer and chisel: the top ten reasons why fossil hunting is so important

At a time when the constantly evolving world of consumer digital technology seems to echo the mega-budget, cutting-edge experiments of the LHC and LIGO, is there still room for such an old-fashioned, low-tech science as paleontology?

The answer is of course yes, and while non-experts might see little difference between its practice today and that of its Eighteenth and Nineteenth Century pioneers, contemporary paleontology does on occasion utilise MRI scanners among other sophisticated equipment. I've previously discussed the delights of fossil hunting as an easy way to involve children in science, yet the apparent simplicity of its core techniques mask the key role that paleontology still plays in evolutionary biology.

Since the days of Watson and Crick molecular biology has progressed in leaps and bounds, yet the contemporary proliferation of cheap DNA-testing kits and television shows devoted to gene-derived genealogy obscure just how tentatively some of their results should be accepted. The levels of accuracy quoted in non-specialist media is often far greater than what can actually be attained. For example, the data on British populations has so far failed to separate those with Danish Viking ancestry from descendants of earlier Anglo-Saxon immigration, leading to population estimates at odds with the archaeological evidence.

Here then is a list of ten reasons why fossil hunting will always be a relevant branch of science, able to supply information that cannot be supplied by other scientific disciplines:

1. Locations. Although genetic evidence can show the broad sweeps connecting extant (and occasionally, recently-extinct) species, the details of where animals, plants or fungi evolved, migrated to - and when - relies on fossil evidence.
2. Absolute dating. While gene analysis can be used to obtain the dates of a last common ancestor shared by contemporary species, the results are provisional at best for when certain key groups or features evolved. Thanks to radiometric dating from some fossiliferous locales, paleontologists are able to fill in the gaps in fossil-filled strata that don't have radioactive mineralogy.
3. Initial versus canonical. Today we think of land-living tetrapods (i.e. amphibians, reptiles, mammals and birds) as having a maximum of five digits per limb. Although these are reduced in many species – as per horse's hooves – five is considered canonical. However, fossil evidence shows that early terrestrial vertebrates had up to eight digits on some or all of their limbs. We know genetic mutation adds extra digits, but this doesn't help reconstruct the polydactyly of ancestral species; only fossils provide confirmation.
4. Extinct life. Without finding their fossils, we wouldn't know of even such long-lasting and multifarious groups as the dinosaurs: how could we guess about the existence of a parasaurolophus from looking at its closest extant cousins, such as penguins, pelicans or parrots? There are also many broken branches in the tree of life, with such large-scale dead-ends as the pre-Cambrian Ediacaran biota. These lost lifeforms teach us something about the nature of evolution yet leave no genetic evidence.
5. Individual history. Genomes show the cellular state of an organism, but thanks to fossilised tooth wear, body wounds and stomach contents (including gastroliths) we have important insights into day-to-day events in the life of ancient animals. This has led to fairly detailed biographies of some creatures, prominent examples being Sue the T-Rex and Al the Allosaurus, their remains being comprehensive enough to identify various pathologies.
6. Paleoecology. Coprolites (fossilised faeces), along with the casts of burrows, help build a detailed enviromental picture that zoology and molecular biology cannot provide. Sometimes the best source of vegetation data comes from coprolites containing plant matter, due to the differing circumstances of decomposition and mineralisation.
7. External appearance. Thanks to likes of scanning electron microscopes, fossils of naturally mummified organisms or mineralised skin can offer details that are unlikely to be discovered by any other method. A good example that has emerged in the past two decades is the colour of feathered dinosaurs obtained from the shape of their melanosomes.
8. Climate analysis. Geological investigation can provide ancient climate data but fossil evidence, such as the giant insects of the Carboniferous period, confirm the hypothesis. After all, dragonflies with seventy centimetre wingspans couldn't survive with today's level of atmospheric oxygen.
9. Stratigraphy. Paleontology can help geologists trying to sequence an isolated section of folded stratigraphy that doesn't have radioactive mineralogy. By assessing the relative order of known fossil species, the laying down of the strata can be placed in the correct sequence.
10. Evidence of evolution. Unlike the theories and complex equipment used in molecular biology, anyone without expert knowledge can visit fossils in museums or in situ. They offer a prominent resource as defence against religious fundamentalism, as their ubiquity makes them difficult to explain by alternative theories. The fact that species are never found in strata outside their era supports the scientific view of life's development rather than those found in religious texts (the Old Testament, for example, erroneously states that birds were created prior to all other land animals).

To date, no DNA has been found over about 800,000 years old. This means that many of the details of the history of life rely primarily on fossil evidence. It's therefore good to note that even in an age of high-tech science, the painstaking techniques of paleontology can shed light on biology in a way unobtainable by more recent examples of the scientific toolkit. Of course, the study is far from fool-proof: it is thought that only about ten percent of all species have ever come to light in fossil form, with the found examples heavily skewed in favour of shallow marine environments.

Nevertheless, paleontology is a discipline that constantly proves its immense value in expanding our knowledge of the past in a way no religious text could ever do. It may be easy to understand what fossils are, but they are assuredly worth their weight in gold: precious windows onto an unrecoverable past.

Hollywood's natural history hobbit hoax: did Peter Jackson create Homo floresiensis for publicity purposes?

Judging by the limited ingredients of contemporary blockbusters, cinema audiences are fairly easy to please. Or are they? Peter Jackson's magnum opus The Lord of the Rings trilogy made an absolute mint at the box office and garnered seventeen Oscar wins besides critical acclaim. In contrast, The Hobbit trilogy received but a single Oscar accompanying some rather lukewarm reviews.

The reason for the critical indifference and lack of awards has been put down to franchise fatigue, although to be fair stretching a children's book over three long movies whilst partly improvising the script at a late stage couldn't have helped. So if you are a world-renowned film maker well aware that you are judged by many of your fans and much of your peer group on the success - and possibly the quality - of your latest film, it wouldn't be surprising if you go to great lengths to maximise that success. Just how far Peter Jackson went for The Hobbit trilogy is astounding...so read on...

It's been some years since I visited Weta Cave in Wellington, where close-up views of various costumes and props from movies including the LOTR trilogy leaves you in no doubt about the superb workmanship the effects house is capable of. Some of the exhibits and merchandise included non-human characters from Middle Earth and District 9, the quality of which got me thinking. Peter Jackson is known to have visited the Natural History Museum when in London recording the soundtrack for The Lord of the Rings. This in itself is not suspect, except that the museum was at the time hosting an exhibition about the infamous Piltdown Man.

For anyone who knows anything about science scandals, Piltdown Man has to be among the most notorious. The 1908 discovery in southern England of a hominin skull of unknown species was rapidly followed by numerous associated finds, all touted as genuine by professional scientists. In fact, by 1913 some palaeontologists had already suggested what was finally confirmed forty years later: the entire assemblage was a fraud, the skull itself including an orang utan jawbone with filed-down teeth! The fact that so many specialists authenticated the remains is bizarre, although it may be that patriotic wishful thinking (to confirm prehistoric hominins had lived in Britain) overrode any semblance of impartiality.

Back to Peter Jackson and his hobbit conundrum. Although LOTR trilogy did the bums-on-seats business (that's an industry term, in case you were wondering), Jackson's next film was the 2005 King Kong remake. Included in the record-breaking US$207 million production costs was a $32 million overspend which the director himself was personally responsible for. Having already been put into turnaround (that's cold feet in Hollywoodese) in the previous decade, Jackson was determined to complete the film to his own exacting standards, thus resulting in the financial woes surrounding the production.

So just how do you get the massive budget to make a prequel trilogy that's got a less involved storyline (sound vaguely familiar, Star Wars fans?) directly after you've made the most expensive film in history, which is not even a remake but a second remake? How about generating tie-in publicity to transfer from the real world to Middle Earth?

Around the time that Peter Jackson's production company Three Foot Six was being renamed (or if you prefer, upgraded) to Three Foot Seven, worldwide headlines announced the discovery of a small stature hominin of just this height. The first of the initial nine specimens found on the island of Flores, labelled LB1, would have been a mere 1.06 metres tall when alive, which is three feet six inches give or take a few millimetres.

Coincidence? When in doubt, adherents of scientific methods should follow the principle of parsimony, A.K.A. Occam's razor. Which in this case has led to me putting my conspiracy hat on.

Consider this: the new species rapidly became far better known by its nickname the 'hobbit people' than as Homo floresiensis. Which was handy for anyone about to spend US$225 million on three films involving hobbits. In addition, it was discovered at the perfect time for Jackson to get maximum publicity (admittedly not the release of the first hobbit film, but for purposes of convincing his American backers of the audience anticipation).

The smoking gun evidence for me is the almost comical resemblance the remains bear to Tolkien's creations. For example, the feet are said to be far longer and flatter than any other known hominin species. Remind you of anything you've seen at the movies? It's just a shame that hair doesn't survive as long as the alleged age of the specimens - which based on the stratigraphy has been estimated from 94,000 to 13,000 years ago.

In addition, how could such creatures have built the bamboo rafts or dug-out boats necessary to reach the island in the first place? When sea levels dropped during glaciation periods Flores was still convincingly isolated from the mainland. Braincase analysis shows that Homo floresiensis had an orange-sized brain. Since the tools found with the semi-petrified organic remains were simple stone implements, the idea of real-life hobbits sailing the high seas appears absurd in the extreme.

Several teams have attempted to extract DNA from the water-logged and delicate material but after a decade's effort none have been successful. This seems surprising, considering the quality of contemporary genetic replication techniques, but perhaps not if the material consists of skilfully crafted fakes courtesy of Weta Workshop. Some of the fragments appear similar to chimpanzee anatomy, but then Peter Jackson has always tried to make his creatures as realistic as possible. Indeed, he even hired a zoologist to ensure that his King Kong was anatomically correct (I recall hearing that some of his over-sized gorilla's behind needed reworking to gain accuracy. Now that's dedication!)

There has also been some rather unscientific behaviour concerning the Homo floresiensis remains which appears counter to the great care usually associated with such precious relics. At one point, the majority of material was hidden for three months by one of the Indonesian paleoanthropologists, only for what was returned to include damaged material missing several pieces. All in all, there is much about the finds to fuel speculation as to their origin.

In summary, if you wanted to promote worldwide interest in anything hobbit-wise what could be better yet not too obvious? Just how the much the joint Australian-Indonesian archaeology and palaeontology team were in the know is perhaps the largest mystery still remaining. I've little doubt that one day the entire venture will be exposed, perhaps in a documentary made by Peter Jackson himself. Now that would definitely be worth watching!

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?