Keep swimming!

The somewhat fuzzy photograph above, was taken, in a rush, at the end of a rockpool survey.  Looking at it back at home it wasn’t at all obvious to me what it was, or even that its subject was organic. More geological perhaps? Some sort of crystal growth maybe?  A cluster of stars on a piece of rock at the bottom of a rockpool. 

I would normally have reached for reference books or the internet to identify a new find, but this time I didn’t know where to start, so I took the easy route and appealed to Twitter, hoping one of the several expert rockpoolers I know to be online would get back with an identification. And, within a few minutes they did1..  Not geological but biological. Animal in fact. A specie of sea-squirt commonly known as Star Ascidian.  Hence the stars, of course.

I was pleased. A new entry for my growing rollcall of species found in the pools of this little north Pembrokeshire Bay2..  I looked up Star Ascidian online to get the proper scientific name and its scientific classification:

Common name: Star Ascidian

Scientific Name: Botryllus schlosseri

Kingdom: Animalia

Phylum: Chordata

Subphylum: Tunicata

Class: Ascidiacea

Order: Stolidobranchia

Family: Styelidae

Genus: Botryllus

I like these scientific names and classifications. I enjoy the feeling of learning and arcane knowledge they project. They conjure images of ranks 18th and 19th century amateur scientists grappling to understand the world around them, at a time when the balance between knowledge and mystery left room for such intellectual curiosity and simple enthusiasm. The problem is they pique my interest.  Like tips of icebergs, they hint at more below; hidden research, information and knowledge.  I find I need to delve further, and that one thing leads to another, so that what might have started as a chance finding of something curious in a rockpool, all too easily mushrooms into a much larger, sometimes even burdensome, investigation.

Whenever I sense this process starting, I am reminded of J.R.R. Tolkien’s beautiful short story ‘Leaf, by Niggle’, in which an artist, Niggle, becomes obsessively absorbed in a particular painting which seems to take on a life of its own.

“There was one picture in particular which bothered him [Niggle]. It had begun with a leaf caught in the wind, and it became a tree; and the tree grew, sending out innumerable branches, and thrusting out the most fantastic roots. Strange birds came and settled on the twigs and had to be attended to. Then all round the Tree, and behind it, through the gaps in the leaves and boughs, a country began to open out; and there were glimpses of a forest marching over the land, and of mountains tipped with snow. Niggle lost interest in his other pictures; or else he took them and tacked them on to the edges of his great picture. Soon the canvas became so large that he had to get a ladder; and he ran up and down it, putting in a touch here, and rubbing out a patch there. When people came to call, he seemed polite enough, though he fiddled a little with the pencils on his desk. He listened to what they said, but underneath he was thinking all the time about his big canvas, in the tall shed that had been built for it out in his garden (on a plot where once he had grown potatoes). “

I particularly that last line ‘on a plot where once he had grown potatoes’, presumably illustrating how the obsessive work on the painting displaced more practically fruitful activity!

Anyway, my little sea-squirt acted, for a while, a little like Niggle’s Leaf. I have sketched one of the main branches of its tree here and will add one or two more in a second blog shortly.   

The first thing I noticed was that the sea-squirt belongs to the Phylum Chordata. The ‘chord’ in Chordata refers to a primitive nerve chord that may run along a creature and from which the spinal column and backbone evolved. Chordata is therefore the phylum to which all vertebrates, including ourselves belong. 

Two things followed this; the first was I realised that although I had recorded many different species since I started delving into these rockpools, this was the first that belonged to this group.  How different this is to the land-based animal life we are all familiar with, where Chordata seem so dominant.  For example, all the mammals, including ourselves, amphibians, reptiles, birds, fish, snakes, lizards are all Chordata. I started to wonder why this difference is so marked, which led to reading read about disparate subjects such as why insects are small and how the average density of many animal bodies, including our own is almost the same as that of sea-water, which means that marine life doesn’t feel gravity in the way land animals do enabling the wonderful strange and delicate forms of rockpool life I had been finding.

Having learned that belonging to chordata implies a primitive spinal cord or backbone, I looked again at the photograph.  It was not at all obvious how this thing, which appeared little more than a smear of patterned jelly, could have a backbone or indeed would have any use for one. Turning to the formal definition of Chordata I read,

“Chordata: A phylum of the animal kingdom comprising all the animals that have, at some stage in their life, a notochord (a hollow dorsal nerve cord), pharyngeal slits, and a muscular tail extending past the anus. Includes the subphyla Cephalochordata, Urochordata, and Vertebrata (vertebrates).3.

The clue is in the second line; “at some stage in their life”.  It turns out that the sea-squirt starts out as a free-swimming larva, somewhat like a little tadpole, complete with a primitive, eye, tail and notochord and importantly, a very rudimentary brain, designated to controlling it’s motion.

After a brief free swimming (pelagic) period the tadpole attaches itself to a suitable substrate and metamorphoses into the attached (sessile) jelly form I found. 

This life-cycle, of pelagic larva to sessile sea-squirt, turned out to be more significant than it at first seemed. 

Evolutionarily speaking the story goes like this; Once Upon a Time (roughly 550 million years ago) there was a specie of tiny tadpole like creatures that spent their days swimming in the sea. Some of these tadpoles found that it took much less effort to cling to the rocks and wait for the food to come to them than to actively seek it out by swimming, while the others stuck with the original swimming about plan.  Each group became somewhat set in their ways and slowly evolved to become more suited to their adopted lifestyles.   

The group that stuck with the swimming, we could call them the pelagic group, went on to great things, or, even if we eschew this somewhat subject value judgement, at least went on to great variety and experimentation, as it is now believed, that these little free swimming tadpoles evolved to give rise to all the vertebrate life on earth, including, of course, ourselves. 

Things did not go as well for the sessile group. Nature discovered (through the usual method of ruthless experimentation no doubt) that once attached to its rock the organism no longer needed its tail, eye, embryonic spinal cord and backbone, or, for that matter its brain. These organs the sea-squirt evolved, in a process known as regressive evolution, to digest for the sake their protean content!

The element of black humour in this coupling of an organism ‘settling down’ with the loss of its mental faculties, has not been missed. The philosopher of mind, Daniel Dennett, draws a parallel to the process of a university professor obtaining tenure!

“ The juvenile sea squirt wanders through the sea searching for a suitable rock or hunk of coral to cling to and make its home for life. For this task, it has a rudimentary nervous system. When it finds its spot and takes root, it doesn’t need its brain anymore so it eats it! (It’s rather like getting tenure.) ” 4.

Professor Sea Squirt5

Different lines of investigation, including modern genetic analysis, indicate that the sea-squirt is the immediate ancestor of all vertebrates and therefore is considerably closer to humans than many other forms of equally unlikely looking life.  For this reason, among others, the sea-squirt has become the model organism for studying the evolution of vertebrates, including the origin and development of human hormone, nervous and immune systems.  The latter, among other things, providing a new range of chemo-therapy drugs6..

The above is a tiny sample of what investigations of the humble sea-squirt have revealed and are still revealing, but already I somehow felt the need to shake its hand, if only it had one.

Evolution of chordates showing the sea-squirt (Tunicates) as the ancestor of the vertibrates.7.

  1. Thanks to:
  3. For example:
  4. MLA (7th ed.) Dennett, D C. Consciousness Explained. Boston: Little, Brown and Co, 1991.
  5. Drawing by Paul Jackson. ©Randel McCraw Helms, 2018

Just one of those days

(I wouldn’t have bothered to blog this, but I have decided to be more inclusive and curate less. It is best treated as an observation in ‘over thinking’ and maybe an exercise in self-mockery! There maybe however one or two things perhaps worth picking up at a later date.)

Pt 1.  (Carpark on the Preseli hills)

I have written several times below about the wonders of this place. The way the light transforms, the calm and the wildlife, the sculptural rocks and soft air.  But, of course, it is not always like this.  Grey days exist everywhere and for everyone and it is grey today. Today also the landscape matches the mood.   I feel grey; my head frozen, locked up and useless.  This is my least favourite state. Joy comes from freedom and freedom from thinking. But, for the last week or so, my head has been having none of it. In this frame of mind all the bad things seem real and the good things illusory, which is, of course, as it should be in a meaningless, random and uncaring universe!

Some of this mood is, I would say, objectively justifiable. I find myself obsessively typing ‘Ukraine news’ into Google, searching for reassurance, while scouring social media for a sense of contact and warmth. The first is nowhere to be found and the second scarce.

My project to write a book feels already dead. Killed by just the demons I suspected it would be killed by, but which I hoped to exorcise by calling out and naming. But no, they know me too well and are too clever and wily.

Of course, there is probably never a ‘right time’ to try and write a book, just as there is never a right-time to have children or move house, but this time, with global conflagration appearing a distinct possibility, makes even starting seem pointless.   

The fact that I am not alone in this gloom is some comfort. Talking to a neighbour the other day black humour welled up when she said, ‘well I’m not buying any ripen-at-home fruit, or long-playing records for that matter at the moment!’  Not easy times for a perfectionist obsessional who wants everything to be just right, while simultaneously searching, with the aid of a very proficient imagination, for reasons for them not to be.

I have found retirement also brings challenges. The working week, with its cycle of pressure-relax-pressure-relax, used to at least act like a simple pump, keeping the stuff of life moving.  Take that away and you can be left with stagnation and the opportunity for a real sharp-toothed-long-clawed existential crisis. I have always had a propensity for such crises, but with little to distract me, this talent can truly blossom.

I remember I chose science, specifically physics, as a career because I realised, I needed something challenging but, most importantly, something external and objective, to engage with. I knew, even by then, that if I didn’t distract the beast with some red meat, it would surely eat me alive.

I fancy others have felt similarly. Was Einstein referring to something similar when he said:

“Strenuous intellectual work and the study of God’s Nature are the angels that will lead me through all the troubles of this life with consolation, strength, and uncompromising rigor.”

Not many of us have the strength to forge our sense of meaning, Nietzsche-like, out of nothing, with just our bare hands. In any case, is it possible to hang meaning from something we have constructed ourselves? What other choice do we have? To hang meaning off God or Nature. But both of these it seems can be pulled down relatively easily. Perhaps recognition of our common human plight and compassion for other sufferers is at least a starting point, but this too can be picked apart philosophically if one really chooses to do so.

Philosophical ideas, particularly those around free-will, determinism and reductionism have always had the power to empty life of meaning. This is one of the difficulties I have with writing; everything that doesn’t tackle at least one of the three or four major philosophical questions of life and existence can seem like so much padding!  Ridiculous to feel like this, I am sure.  Maybe the answer is simply stop thinking about such things and accept that, to quote Kirkegard; “Life Is Not A Problem To Be Solved, But A Reality To Be Experienced.”

Who knows! I am tired of swinging between imagined possibilities. I drove out here to write, but can’t and the weather does not inspire walking, so I am heading back home.

Pt 2. (Two hours later)

I dropped a hundred feet or so, from the relatively flat top of the hill, down the steep sided valley and the world changed.  The mist thinned, making it to appear luminous rather than flat grey. The bluebells began to faintly glow from the verge and birds (pipits and a wheatear I think) could be seen moving along the banks on either side of the road. I was struck by the warmth of the air blowing gently through the van window.

The usual order of things was reversed.  Usually, I love to get out of the valley. To the more open uplands.  But not today. The terrain matched the mood. Enough of the bleak.  Why would we choose to live on the colder, windier uplands when the shelter of the warm folded valley is nearby.  To profess love of such bleakness, be it mountain or sea, is, it seems to me now, to not really know these places.  We are not designed to live in such inhospitable environments, however good the views.

These thoughts and feelings recalled something I had read recently on twitter. An author I follow1. and who I suspect experiences similar days, had tweeted a quote from the writing of the Scottish philosopher David Hume;

[1] “The intense view of these manifold contradictions and imperfections in human reason has so wrought upon me, and heated my brain, that I am ready to reject all belief and reasoning, and can look upon no opinion even as more probable or likely than another. Where am I, or what? From what causes do I derive my existence, and to what condition shall I return? Whose favour shall I court, and whose anger must I dread? What beings surround me? and on whom have, I any influence, or who have any influence on me? I am confounded with all these questions, and begin to fancy myself in the most deplorable condition imaginable, invironed with the deepest darkness, and utterly deprived of the use of every member and faculty.

[2] Most fortunately it happens, that since reason is incapable of dispelling these clouds, nature herself suffices to that purpose, and cures me of this philosophical melancholy and delirium, either by relaxing this bent of mind, or by some avocation, and lively impression of my senses, which obliterate all these chimeras. I dine, I play a game of backgammon, I converse, and am merry with my friends; and when after three- or four-hours amusement, I would return to these speculations, they appear so cold, and strained, and ridiculous, that I cannot find in my heart to enter into them any farther.”2.

Of course, it is interesting that despite the healthier and more natural feelings Hume described in the second part of this excerpt, whatever it is that drives philosophers and others to ponder the sorts of questions they ponder, drove him, sooner or later, back to the ‘hills’!

  1. Caspar Henderson

Time to try

I have been blathering away to myself, for quite a long time now, about trying to produce a larger piece of writing, maybe even a book. I realise that if I don’t do it now it will never happen. Of course, it probably wont happen anyway. More than likely I will get bogged down in the usual feelings of shifting perspectives and fractal complexity that tend to assail me whenever I try to focus on a specific objective. But at least I will have tried, and the next time the thought; ‘it would be fun to write a book’ occurs to me I will be able to say, ‘remember, you tried that once and couldn’t do it’, so shut up and get on with something useful’.

So I intend to try. I don’t know what the usual or best approach is, but, given a rough direction, I intend to just start to write and simply see what happens. Sometimes thoughts breed thoughts in a way that makes planning too far ahead pointless.

So, I have put the first draft of a few paragraphs below, as a merest toe in the water and indication of intent! I may occasionally add little bits as things go along, if they go along, as I feel it will help me to put something ‘out there’. If anybody reads this and has comments, please feel free!


The rockpool is about a metre long, half metre wide and thirty centimetres deep.  A small depression in dark rock lying at the eastern end of a small sandy bay on the north Pembrokeshire coast. I have arrived at nearly the lowest point of a low Spring tide. The sea is less than a meter above what is known to sailors as LAT or the ‘lowest astronomical tide’ and at such a tide much more foreshore is accessible than is usually the case.

It is cold and grey. The sea is rough from a recent storm, and a residual swell is washing round the headland that defines this side of the bay.  Despite this cold greyness I can already feel the calming and soothing effect of this place working on me.

I have been visiting this Bay, and the particular area around this rockpool for a year or so now. I started coming here as part of a citizen science project designed to monitor species of shore life, but unfortunately, despite having worked in science for many years I found I lacked the discipline to do the science properly. I could not focus. So, instead of conducting proper timed searches I just potter about seeing what I can find and thinking and dreaming about the sort of things being near the sea makes you think and dream about.

There is much to inspire here.  In terms of the wildlife alone it can feel like living inside one of those iconic ladybird books of the 1950s and 60s. A new edition maybe; ‘What to look for in Pembrokeshire’ whose cover would show an anemone filled rock pool and behind which dolphins would swim in a blue sea whith black fingered, red beaked Choughs displaying above. In these days of constant reporting of ecological disaster, I am drawn to this place as an iron filing to a magnet.

But it is not just the wildlife. The folded cliffs and the rocky outcrops that crest the nearby Preseli hills speak of geological drama and even the night sky appears clearer than usual, revealing worlds beyond.

Just wandering and experiencing is enjoyable here. Walking along the cliffs, or on the hills, is often dramatically beautiful. There is a quality to the light which, combined with the juxtaposition of sea, cliffs and hills produces something which is nearly always special and sometimes feels transformational.

Unfortunately, for me, it is never quite enough to just be in a place and enjoy it. I always want to do something more with it. Sometimes it is just to use it as inspiration for trying to paint or draw, or write poetry, but more often it acts as a spur to think about what I suppose might be thought of as the bigger questions of life, science and philosophy.

And so today I am sat here, on these rocks looking out to sea, with a coffee in hand wondering where to start.

But then I realise, it doesn’t matter too much where one starts. It is all connected. The sea is boundless. Wherever you jump in is, in some sense, the same as everywhere else. So, as I am in the fortunate position of having no plan to work to, no deadline and no one to please, I will probably just wander and see what turns up.

Short walk

I wanted to do a blog with no (or very few) words. Words can be so difficult; always limited or limiting in some way.

So here it is; a short walk in my favourite area of the Preselis – to share.

(The music is me attempting to play Roy Harper’s lovely instrumental ‘Blackpool’).

There is a little lyric with this song which I wasn’t up to singing:

"The rain falls like diamonds
pin-pricks the still water
spreadeagles it's laughter
across the green sheet
of the sleeping sea."

Roy Harper - Blackpool, (from 'The Sophisticated beggar').
(Lots of good songs on this album, but maybe an acquired taste!)