Thursday, 6 December 2012

Tread lightly on the fossil record

The view from my Southend hotel room on Wednesday morning
On Tuesday and Wednesday I spent two days in Southend, giving talks at the High School for Boys. Perhaps as karmic revenge for my referring to the town as 'sunny Southend' I woke up on Wednesday to a surprise snowfall, which was rather fun.

The talks went well (I think) but a useful bonus was a chance to attend a little symposium the school was running for a group of students. Said students were entering a competition to write a piece about science and religion, so the school put together a panel of five of their teachers, who each gave their personal opinion on science v religion, from an out-and-out atheist perspective to one that put the two on very much equal footing and could see no conflict between them.

The students were then given the chance to ask questions of the teachers. One, rather daringly, questioned a statement from the head teacher that while he had no problem with evolution, we need to recognize that as a theory it has some big problems. Would the head like to identify one of these problems, asked the bold student.

The head responded that the fossil record does not provide good evidence for evolution.  Not that it counters evolution, but is not sufficient to support it. With the thoughts of what my friend Henry Gee would say, who gets rather hot under the collar when the fossil record is waved around in a dangerous fashion, I waded in and pointed out that the fossil record is inherently incomplete in a big way, and any attempt to use it to cast doubt on evolution was dubious at best.

Ah yes, said the head, but the fact remains that there are not, for example, enough dead-end fossils. We should expect many more fossils of creatures that were evolutionary errors, the outcome of random variation gone wrong.

A breakfast view that morning
Now this, I admit, is where I chickened out. Bear in mind that this was the head of the school that was employing me and (I hope!) may do so again in the future. So rather than come back on that remark, I let it lie. (I also thought it was wrong to hog the debate, when it was supposed to be for the students to ask questions.)

However, it's not going to stop me responding now. I know very little of palaeontology and the likes of Dr Gee are welcome to correct me on this, but my response would have been 'So what?' I'm not at all surprised there aren't many dead-ends for three reasons. One is that by definition many dead-ends would be, well dead-ends. They'd be one-offs. Chances of being fossilized? Vanishingly small.

Then what I always feel is the most amazing aspect of evolution, something that isn't made enough of. This is that every individual creature throughout history has been the same species as its parent. Even though if you follow back through our parental history you will eventually get back to bacteria-like ancestors, you will never see a species change from one generation to the next. It's a glorious paradox. So inevitably the first step down a dead-end will be indistinguishable from a non dead-end fossil.

Finally, I very much doubt how well we can deduce whether or not many fossils are dead-ends, bearing in mind what a fossil is. There may be some where it's pretty obvious but surely there will be many where it won't. To use a breeding rather than evolutionary analogy, I doubt if anyone looking at a fossilized mule would say 'that's a dead-end animal. It won't continue the line.' But the fact is a mule is just that.

As for the religion v science debate it was inevitably open ended. But it was fun trying and much kudos to the school for trying it.

4 comments:

  1. John the Plumber6 December 2012 at 23:09

    You pointed out in a recent post that dark matter may be a convenient way to explain away what might be a fault in the science requiring dark matter to exist –like 'the ether' was once used as a means to explain the propagation of light waves - that correcting the fault in the science might do away with need to find a possibly non existent answer.

    It seems to me that missing links in the fossil record might fall into the same category.

    The fossil record is certainly clear evidence that the complex lifeforms of today evolved from simple lifeforms of the past. - What it fails to provide is evidence of joined-up change from one species to the next. - There are gaps between species. - Science would dearly love to find missing links, and for one simple reason. Science has only Darwin's one mechanism to evolution which is essentially a joined-up change mechanism – and so must deny the gaps – regardless that the gaps in the fossil record seem undoubtedly to be there. - If that was not so there would have been no need for any search for any missing links.

    This is not rocket science. It is simple stuff. Yet science seems unable to deal with this problem of gaps – particularly when it is used as a reason for the whole of the theory to be wrong by the religious faction.

    I am quite happy that Darwin was as good as right about most of what he proposed – and that science has done a fair job of tying up his loose ends. - It is just that so far, there is no answer to the fact of gaps.

    The fossil record is made by the finding of a particular type of fossil in a particular geological layer. If the same type is found in a different layer then we can say the species of that type lived for that length of geological time.

    The fossil record then is one of separate time-lines with gaps between each.

    It tells us little of the variety contained within species.

    The study of extant life tells little of evolution. – Without the fossil record we would struggle to know that evolution had ever happened – but extant life tells us much about the width of variety contained within individual species – and there seems little doubt that in extant life, there are individual species – like the docks and nettles in my garden. - In Darwinian terms, they are the twigs on the current ends of the branches of evolution's 'tree'.

    What we have then is two sources of evidence. - The fossil record shows straight time lines - of how long individual species have remained the same - whilst the study of extant life shows the width of variety. - In effect, these are two lines at right angles to each other.

    In extant life, it is clear that the width of variety does not extend to cross the gaps between species. - Yet to explain speciation, science would have it that in extinct life, the width of variety did cross the gaps between the time lines of individual species. - Hence the search for missing links.

    It appears to me that this contradiction is responsible for the current situation of 26 different definitions of the word species - The Species Problem as it is known. - Look it up in Wikipedia if you want your brain nicely scrambled.

    If only there was a second mechanism – an adjunct to Darwin's survival of the fittest joined-up change – a mechanism to leap gaps on occasion – then the fabled missing links could become a quaint old historical contrivance – as maybe dark matter might, one day in the future.

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  2. Thanks, John. I'm not a palaeontologist - you would have to look to Henry for a sensible comment on your comment! One point you make that I don't think is well enough appreciated is that species is, in some regards, not really a scientific term, and so it probably isn't worth spending too much effort on looking for speciation and the like, because it's such an arbitrary concept.

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  3. I've come across this argument before from those closet creationists hoping to wave a straw in favour of God....if we had a perfect fossil record of all species/creatures that had ever inhabited the earth then it's possible that you might be able to identify the last in the line. However we don't have such a thing; in fact the amount of fossils we do have is an incredibly small percentage of all life to date....which does makes Darwin's postulate seem retrospectively like an act of faith.

    In fact it's hard to identify today in real life when a species has died out - merely not seeing something for a while doesn't mean that it's gone forever, it might be hiding in the hedges or the mountains etc ....

    I think I'd have been ruder towards your headmaster but I expect you had a big hole in your tongue where you bit long and hard before saying anything!

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  4. Ian - you have to bear in mind a) I was being employed by that headmaster's school and b) there was a room full of his students, and I don't think it's good to undermine the headmaster in front of the students. To be fair to him, I don't think he was a closet creationist, he was just trying to illustrate some of the limitations of science, which is fair enough.

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