Metro + Piltdown = Head-desk

The Metro newspaper, which is available free to commuters in the UK, recently ran a piece on the Piltdown hoax. I recently had a rant about some of the science reporting in said newspaper, but this one was a lot better. I could quibble about some small details in the post, but those pale in comparison to some of the responses which were published in the “talk” section today. The gist of the article was that Piltdown is being desperately used as an example of scientific misconduct, as though it tarnishes the reputation of the whole field, when in reality it does nothing of the sort. I didn’t get to read the newspaper itself, but thankfully a friend of mine has sent me a photo of the ridiculous responses, which I will share below. It is notable that many of the claims being made in those responses completely ignore what has been said in the article, but some raise issues which were either not properly addressed in the article or are rather irrelevant (I hope that it is readable).

Metro responses

We can start by looking at Paul from Bristol’s diatribe. He makes the claim that Piltdown Man was forged to support evolutionary theory, but he has clearly not engaged with either the article or any of the historical data. Firstly, the article gives reasons why the Piltdown hoax may have been believed for so long and gives us part of the answer: Piltdown Man was British. National pride was key in its acceptance, but so too was the fact that very few were allowed to see the find and scrutinise it. The Bristolian critic makes the bizarre claim that nobody declared that it was a joke, so therefore it must have been perpetrated to establish evolution. It does not take much searching at all to find out that the main suspect, Charles Dawson, died decades before it was exposed as a hoax. With that little bit of searching, dear Paul would have found that Dawson had carried out many hoaxes in his time. Many of his hoaxes had nothing to do with evolution and went along with a rather simple notion: if you give people what they want to see they are less likely to question it; it is called confirmation bias. He didn’t care about establishing evolution, but he could easily trick people who were interested in providing fossil evidence, particularly if it was from the United Kingdom.

As the article notes, many did question Piltdown from the beginning, especially as it clashed with legitimate finds (which the majority of these responses ignore). When it was finally exposed as a fraud it was by the same scientific community which creationists seem to think were involved in a conspiracy. Frauds being exposed are a sign of the corrective nature of science. Perhaps Mr Fulcher should check out some of the creationist hoaxes which have been trotted out from time to time (they have a fondness for man and dinosaurs as contemporaries).

The creationist argument about “kinds” is hardly worth addressing, partly because they cannot define it consistently without having to invoke some large scale evolution (which gets brushed under the table). Fulcher has clearly never had a look into the fossil history of those groups he mentions, otherwise he would find that they blur together a fair bit, as a testament to evolution. When we trace his dog and cat families back, for example, we end up looking at miacids, which were rather primitive carnivorans, roughly the size of a weasel, which look nothing like the modern groups yet have the key features. Where do they fit into these supposed kinds?

So cute, yet there’s no “kind” for him.

But really all we need to do is help people to understand how evolution works. Paul rejects the notion of “one type of creature… turning into a completely different creature” and so do I. What evolution produces is groups within groups, with each new group remaining in its original grouping, but being sufficiently different to other members of that group to warrant its own group (do a shot every time I say “group” or “kind” if you are getting bored). The result is what is known as a nested hierarchy, something which has been recognised in nature for centuries and was the foundation of Linnaean systematics. If we arbitrarily label these groupings “kinds” then we find that evolution does not show one kind becoming another, but “kinds” become more derived and form those groups within groups. We can look at our own species, Homo sapiens, and note that we never stopped being the hominin kind, which is a group within the hominids and we still fit there, which in turn is a group within Hominoidea and we have all the defining features for that group, and you can keep going through Catarrhini, Simiiformes, Haplorhini, Primata, Primatomorpha, Euarchonta, Euarchontoglires, Boroeutheria, Epitheria, and we still fit into those groups. The next larger grouping is Eutheria, which contains all of the placental mammals; we never stopped being the placental mammal kind. Ask any creationist if we are mammals and they will be revealing that we fit into nested hierarchies if they say yes. Creationist “baraminology” ends up producing nested hierarchies (because evolution is true) but they arbitrarily draw a line and declare that it cannot be crossed, contrary to what the fossil record shows.

So anyway, onto the next response…

The second letter, which appears to be from John Clease at first glance, talks about gappiness in the fossil record. Of course the fossil record is incredibly patchy, but that does not mean that it does not support evolution. What it shows is not just consistent with evolution, but utterly inconsistent with even the most optimistic creationist ideas. The next comment along, from an S. Barber, makes some claims along similar lines, so I will address them together.

What does the fossil record show? Well, if Barber is right, then it should show a big jumble (unless they are an old earth creationist, in which case it appears that God created things to look as though they evolved, following an evolutionary logic). What we actually see is what I like to label “a gradual increase in the spread of complexity over time”. If you start from the oldest rocks containing life you find the conspicuous absence of, well, anything with a nucleus. We find only bacteria and their colonial structures for the first 2,000,000,000 years or so of Earth’s history, which then leads into very simply eukaryotes. It is not until around 600,000,000 years ago that we start seeing multicellular grades of organisation, a step up in complexity from the aforementioned early eukaryotes, which are more complex than the earlier bacteria (it should be noted that these do not appear in a strict stepwise manner, but simpler forms often persist alongside the more complex forms, comfortable exploring niches of different scales). We don’t start seeing simple mineralised parts until just before the Cambrian period (which started 542 million years ago) and those gradually become more complex. I’m sure you all know the anthropocentric story from there onwards, with fishy organisms making their début in the Cambrian, developing jaws later along the line, leading eventually into primitive tetrapods during the Devonian, going through the whole amphibian to reptile to mammals and birds sequence (can you tell that I am more interested in the earlier stuff?). At this large scale we clearly find something which practically screams evolution, showing a nested hierarchy pattern and that increase in the spread of complexity. But what if we look closer?

It is when we start looking closer that creationists like to claim that gaps exist, and some really do (we find transitional bat forms, but not for their origins). But gaps are constantly being filled and not all grab the headlines. People want to see gaps between major groups, they want to see human ancestral forms, they want to see whale transitions, fish giving rise to tetrapods, dinosaurs giving rise to birds, and we have examples for all of those. Many of these forms have been found relatively recently too, but some are as old as Darwin’s seminal work. Creationist like to criticise Archaeopteryx yet they have to ignore that all of the supposedly bird features have now been found in dinosaurs (not least feathers) or that working out where these things fit on their family tree is difficult precisely because of their transitional nature; it comes out either nestling with the more familiar birds or being more closely related to dinosaurs such as Velociraptor. (I intend to do a detailed post on all of this relatively soon, so I must apologise for any brevity.) So we find that when we zoom in a bit we end up finding transitional forms, though we still have many more to find. But what if we look closer?

These must not exist…

Looking even closer is difficult, not least because it requires a lot of effort to collect samples and study them for hours on end, taking lots of measurements etc. But this sort of work has been done for decades, with palaeontologists going into a lot of detail, particularly with microfossils, and elucidating different modes of evolution. What this requires is a deposit which covers a large stretch of unbroken geological time and is chock full of fossils. Naturally such deposits are rare, so the fossil record can only show us so much. What we do see is that evolution, over geological time, follows a number of patterns. Amongst these is the gradualism which anti-evolutionists like to claim is absent, but the main pattern appears to be a jerky one, where species often change little, then change rather rapidly (on a geological time scale, and when these “rapid” changes can be found in the fossil record they tend to last tens to hundreds of thousands of years, which is practically nothing to a geologist). Darwin actually did predict such patterns of evolution, so it can hardly be claimed as evidence against his ideas. (Again, expect more on this in the near future.) Clease mentioned Dawkins explaining away gaps in the fossil record as migrationary events, yet it is this very fine-scale evolution where this can be applied. Species migrate, this is undeniable, yet the fossil sequences we require for this sort of study have to be from the same locality. What will migration look like in the fossil record? Well, if you cannot trace the migration through other localities then it will look like an abrupt appearance or disappearance.

So what we see, at all scales, is consistent with evolution. Patchiness is no excuse to ignore the fossils, as what we do have is highly informative. Barber goes on to mention that evolution cannot explain abiogenesis, but that is not what evolution is meant to explain. It applies only to life which already exists and they are separate fields of study. The appearance of design is precisely one of the things which evolution does explain, that’s part of what made Darwin’s ideas so brilliant (although I surmise that they would baulk at my choice of authors, they could do with reading Dawkins’ The Blind Watchmaker).

Finally onto the last one. I could have lumped Jeremy Craxford’s claims in with the last two, but he raises a couple of other issues. He makes the statement that “Tens of millions of fossils have been dug up and still there is not a single clear, undisputed case of a ‘missing link’ between species.” Well, I have already briefly touched on there being transitional forms at multiple levels, but there are two points I want to make. First is that the term “missing link” is a pointless tautology which really should never be used; a missing link is, by definition, missing, so when it is found it simply creates a couple more gaps which need links. We instead tend to refer to transitional forms, of which many are known and are undisputed (note that any disputes come from those who a priori deny evolution).

The second point I want to make is that we currently know of around 8.7 million species of living eukaryotes. The fossil record for eukaryotes shows that they have existed for roughly two billion years, yet the last estimate I saw of known fossil diversity was around 250,000 identified species. That’s close to 3% of the diversity we see around us, spread out over two billion years. If we conservatively start at the first unequivocal bilaterians in the Cambrian period, then we have 542 million years that these fossil species are spread out over. If we calculated it so that each species was, for its duration, the only species on the planet, they would each have 2,168 years alone. I mention that just to give insight into how little we do have. Naturally species tend to last millions of years and it is difficult to estimate how many there are due to difficulties with classification. When each of these species was living there were likely millions more which we will never get to see, particularly those which have soft bodies, or live in environments which are not conducive to preservation. Anyone who thinks we should have a fossil record which perfectly shows evolutionary history is talking out of ignorance. What we do have shows, rather clearly, that evolution is the name of the game and has been for nearly four billion years.

This was a bit of an off the cuff rant (blame Dean Lomax if you found it tedious, or the Metro for publishing those inane ramblings). It saddens me that the public seriously does not understand what the fossil record shows. Someone needs to buy them each a copy of Donald Prothero’s Evolution: What the Fossils Say and Why it Matters. I will be expanding on many of these points in detail in the future, so if I left you unsatisfied you can always come back for more, I promise it will be better.



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Filed under Evolution, Palaeontology

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