You don’t care about history? Well, perhaps but history cares about you. Or rather, it affects you and the world you live in, explains how you got to where you are, your successes and failures – and where you might yet go.
Of course, what I said earlier was kind of a slick answer; history doesn’t really care about you …. or about me …. or anyone else. The wind moves the trees, fills the sails, cools us or brings rain or snow – it affects us, moves us and things around us …. but is not moved by us. That is a useful metaphor because often people think they can stop some things happening by wishing strongly that they would not. Liberals and social democrats, for example …. But the metaphor breaks down – unlike our relationship with the wind, we can move things.
The shape of a tree testifies to the forces that have come to bear upon it as it was growing and its bark rings tell us of years of plenty or scarcity. To say that you don’t care about history is like, in a way, saying you don’t care about your childhood. That period of your past life and the influences that came to bear upon it and how you reacted to them have made you, to an extent, who you are today. Certainly they have hugely affected you, as any psychologist will tell.
If you really don’t care about history, you should not care whether you experience pain or pleasure. Typically, humans like to repeat pleasure and to avoid pain. But how do we know in advance what will give us pleasure or instead cause us pain? Experience. And that too is a kind of history. Which may also teach us what pleasure may be reached through pain, as for example in certain kinds of exercise – or what pleasures may end in pain, as with addictions. And we don’t only have our own experience to go on but that of many others, in their stories and in the accounts of those who have studied them. Another kind of history.
To say that you don’t care about history is to say that you don’t care about cause and effect. You don’t care about science, in other words. Science, in the sense of observation of processes and in the sense of experiment, is a kind of history. If you do this to that, in this atmosphere at that temperature, this will be the result. How do we know? It has been observed or tested, time and time again and recorded. Very like history.
Perhaps history was not taught to you in the way most suited to you at the time. Or rather, perhaps it was not introduced to you as it would best have been. A required subject to study, to gain marks and to ignore forever afterwards is hardly likely to inspire. A list of dates, of kings and queens, of prime ministers, along with their desires, though they figure in it, is not really history. “Facts” without encouragement to challenge, to interpret, to ask and to search for why and how – these drive some minds away while others learn them – but only as dogma.
Kings, Queens, Generals and Leaders of insurgents helped make history – but they didn’t really make history, though we are told they did and often say it ourselves. No king built a castle or a city though we are often told that is what happened. People build castles and cities: they dig foundations and sewers or latrines, dig wells or canals, cut timber and stone, mine and forge metal, construct buildings, grow food, settle, take up livelihoods, raise children, study nature, perform arts, record in print or orally …. History was made by people, ordinary people mostly with a few extraordinary individuals; history was made by people like you and I.
Or perhaps you acknowledge all that but think ok, as an ordinary person, there is nothing you can consciously do to alter the course of things now? Yes, our masters would like you to think that. The reality is that you can make choices: to join that organisation or movement, participate in that action or demonstration …. or not. To vote for one person or party or another – or to abstain. To treat people in this or that way.
What will help you make those choices? Well, for a start, your experience. And experience is a personal history. I did that and this happened; I didn’t agree with that outcome so now I will do something else. But we also have the experiences of millions of others upon which to draw, across thousands of years. History.
You are not an isolated individual and your people, your nation or state, is not an isolated mass. The productive forces of emerging capitalism struggled with monarchy and feudalist systems and elites and produced republicanism. Republican ideas were promoted by English and French intellectuals, for example and found receptive minds among the capitalist sons and daughters of English colonists in Ireland, bringing about the bid for a democratic parliament of all the people in Ireland. When that attempt failed, the ideas impelled some to found the United Irishmen, which hundreds of thousands of others supported because they wished for freedom from the colonial power. Less than a decade after the failure of Grattan’s Parliament to admit representation by Catholic and Dissenter, the United Irish rose in revolutionary upsurge. That was in 1798 and they looked for support from republican France, which had its revolution less than a decade earlier, in 1789. The Irish and the French republicans were encouraged by the American Revolution, which had begun in 1765 and emerged victorious in 1783.
The republican revolutions were carried out by the ordinary mass of people but it was the capitalist class that they brought to power; today the working class struggle to overcome them and come into power themselves, for the first time a majority class taking power and holding up the possibility of the end of classes and therefore of class exploitation. “The history of all hitherto existing society is the history of class struggles”, wrote Karly Marx and Frederick Engels in the Communist Manifesto, published in 1848.
You are in history. You are a product of history. What you do now affects the historical outcome to some degree at least – to one degree or another you are making history. You might as well study its process and use its lessons to illuminate your way: the distilled and concentrated experiences of millions of human beings like you.
They are all around us; they live but they are not animals. Nor are they micro-organisms – we see them clearly all in many places. They can grow on organic and none-organic surfaces. We might think they are plants – algae, moss or fungus but they are none of those — they are lichens. There are about 20,000 known species1 and they cover an estimated 6% of the Earth’s surface, able to exist in environments as different as beneath Artic snow, on salt spray-showered seashores and windswept mountain rocks and in tropical rainforest. An estimated 6% of the Earth’s land surface is covered by lichen species.2 Some are long-lived and include the longest-living things on Earth. There are species that require nothing to cling to while others can live inside rock, in the spaces between grains.3In Ireland, 1,134 separate species of lichen have been recognised, according to the National Biodiversity Data Centre – i.e over 5% of Earth’s estimated total species right here on this little island.4
When we look at some growing on tree bark or rock, we are tempted to think of them as fungus, algae or even moss. Mosses are ancient enough life-forms and are plants, which algae are too and almost certainly much older. Fungi used to be considered plants but are so no longer and in their structure and digestion and also genes, are more akin and more closely related to animals. This will not be good news to vegetarians or vegans but the evidence is difficult to deny.5 Indeed there are some feoilséantóirí (word in Irish for a vegetarian and more apt in the context of this sentence) who already dislike eating many fungi because the texture reminds them of meat.
But lichens are neitherfungi nor plants.
So if lichens are not plant or fungus, what are they? Another kind of life-form? Well yes … and no. They are a combination of both, fungus and plant. At some point in the evolution of life on earth, logically after plants and after fungi had evolved, somehow some species of fungi combined with some species of alga and/or cyanobacteria6 and produced a symbiont or biont: lichen. Scientists maintain that the 20,000 estimated species did not evolve from one common ancestor but that different species appeared separately at different times during the history of the Earth.
Plants draw their nutrients from sun and elements in the soil (or in some cases, in the water). Fungi, like animals, cannot get their nutrients straight from sun or soil and need to break down their alimentation materials, whether flesh or plant, in order to feed on them. In doing so, fungi are important decomposing agents – in fact, the principal ones.
Vascular plants need roots not just to cling to soil but even more importantly, to draw up water and nutrients but algae don’t; when they have any kind of roots, it is to cling to a surface and that is exactly what the lichen needs too. Fungi extend and feed through root-like growths usually under the surface of what they are feeding upon, extending from the tips; they are not roots, however and break off easily.What we see of fungi is usually the spore-bearing parts above the surface, often much the smaller part of the organism.
Plants seem to grow above ground also by elongating their tips but in fact are extending from further back, adding cells to cells to lengthen the body. All plants need a constant supply of water (cacti and succulents store water but still need to draw on the supply to live). Fungi need damp conditions. But when combined into lichens, the new species can live without water for a considerable time. So, a marriage, as they say, “made in Heaven” … or perhaps in a Hell, an environment of very dry and hot conditions alternating with the very wet and cold , where the newly-wedded ancient algae and fungi set out to build their homes.
Some lichens contain not only algae combined with a fungus but also a cyanobacterium; this partner is capable of fixing nitrogen extracted from the air and is a valuable addition to the menage-a-trois.
It has been remarked by some that the marriage of plant and fungus is not an equal one, is not true symbiosis, since the fungal partner or symbiote benefits more than does the algal. The algal symbiote produces sugar through photosynthesis and the fungus only chitin, or ‘hard‘ structure, it is argued. However, if both partners (or three) are content with the arrangement, is that not a happy marriage? More seriously, the fungal partner may contribute other factors to the symbiosis of which scientists are only just becoming aware – for example, chemicals to repel organisms attempting to graze on them and protection from the sun.
And scientists do not treat them equally either, since the species of lichen is always determined and named by them according to the species of fungus, not of the alga or bacterium.
COLOURS IN THE RAIN
So, if the claim is that we see them all around us, where are they? They may be seen on slate roof-tops, in patches of roughly circular white (not to be confused with pigeon or seagull excrement, which may also be in evidence). Yellow or orange patches are typically seen on stone, as is a black or dark brown one by the seaside. A bright yellow-green one may be seen on fallen twigs or on tree-bark, as may also a tufted-form green one growing on rock or tree.
The colours tend to be particularly vivid during or soon after rain when the cortex becomes translucent and, if there were no other reason to be grateful for the precipitation levels usual in Ireland, that would be reason enough, perhaps, should we take the time to admire the little things of beauty. Of course there are other reasons and as a Basque once said to me about the green of his native country and could perhaps even more accurately said about colour associated with the “Emerald Isle” — “It’s not green because we paint it.”
Some of the bright colours in lichens, produced by the fungus, are thought to be of use in protection from the rays of the sun and become more vivid after rain due to rapid absorption of water by the chlorophyl-holding part of the symbiont (or biont).
PIONEERS AND SURVIVORS
Lichens are considered “pioneer organisms” by botanists and geologists, i.e organisms that set out to colonise new territories. These maybe new territories in the sense that a geological change has exposed them to air, e.g from the seabed or from under ice, or from inside the earth by volcanic action or by tectonic plate collision.
Pioneer organisms need to be tough and adaptable and they often create footholds for other species, not quite so tough or adaptable, to follow after. However, given that logic dictates that algae and fungi existed before some of them combined to form lichens, the latter could not have been among the earliest colonisers of the Earth’s crust. On Earth then, they are later pioneers of newly-created inhospitable terrain.
May they be used to help create habitable environments elsewhere? It’s perhaps worth quoting these two paragraphs from Wikipedia in their entirety:
In tests, lichen survived and showed remarkable results on the adaptation capacity of photosynthetic activity with the simulation time of 34 days under Martian conditions in the Mars Simulation Laboratory (MSL) maintained by the German Aerospace Center (DLR).
The European Space Agency has discovered that lichens can survive unprotected in space. In an experiment led by Leopoldo Sancho from the Complutense University of Madrid, two species of lichen — Rhizocarpon geographicum7 and Xanthoria elegans — were sealed in a capsule and launched on a Russian Soyuz rocket 31 May 2005. Once in orbit, the capsules were opened and the lichens were directly exposed to the vacuum of space with its widely fluctuating temperatures and cosmic radiation. After 15 days, the lichens were brought back to earth and were found to be in full health with no discernible damage from their time in orbit.
In some areas, soil lichens help to bind the sand-crust or soil-crust together but lichens have also been shown to chemically attack stone, thereby helping to create soil. Lichens can also help create little environments where soil may be retained and seeds of plants germinate. However, like all species, lichens are out to help themselves and some produce chemicals to restrict the march of mosses (another pioneer species but more water-reliant), with which lichens would have to compete in many areas).
When growing on tree bark, lichens do not parasitise on the tree nor harm it in any way, merely using it as a secure base. Older trees are often covered with lichen and dead trees or branches more so, associating in some people’s minds the ill-health in a tree with the growth of lichen upon it. Circumstantial evidence may suggest the guilt of the lichen but it is completely a case of coincidence: lichen is slow-growing and the older the tree, the more time lichen has had to grow and extend upon it; the tree dies because it grows old.
The lichen will survive the dead tree for a period but it is not the killer. Now come decomposers: insects, snails, slugs and especially, distant relatives of the lichens: fungi. Without concern for their relatives, the fungi, along with the other decomposers, will reduce the tree to soil ingredients and thereby deprive the lichens of their base but, in time, providing more soil for more trees to grow and for new generation of lichens to attach themselves to the bark.
The fungus is not too discriminating and a particular species may combine with different algae species; the resultant lichens may appear to be different species but (since 2014) will be classified as the same lichen species, i.e containing the samespecies of fungus.8
The alga can also exist independently in nature but the fungi cannot. Two species in two genera of green algae are found in over 35% of all lichens, but can only rarely be found living on their own outside of a lichen.9
Sex and Reproduction
It is only the fungal part of the symbiote that reproduces sexually. When doing so, it produces spores (as do ferns and mosses) which must find a compatible alga in order to produce a new lichen, a symbiote of the fungus of the parent fungus and a new alga.
Some lichens reproduce or extend asexually, advancing across a surface and merging with another of the same species.
Uses of lichens:
When we discuss “the use” of some thing we generally mean its use for humans; lichens no doubt have many uses for other organisms, whether as food for reindeer during non-growing seasons or as micro-environments for tiny creatures. But for humans, the uses are mostly in the areas of
geological age indicators
Dyes and Pigments:
Dyes were made from the orange Xanthoria Parietina and the grey-green branched Parmelia Saxitillis to dye wools used in traditional tweed (Harris) weaving in the Scottish Highlands10and I myself have had the second of the two pointed out to me by an Aran Islander woman as the source for the rarely-used green wool knitted into a geansaí (pullover or jumper). Material for other natural dyes exist for example in Ireland but the issues are how easily they are obtained, how true they dye and how long they remain the desired colour and shade.
“There are reports dating almost 2000 years old of lichens being used to make purple and red dyes. Of great historical and commercial significance are lichens belonging to the family Roccellaceae, commonly called “orchella weed” or “orchil”. Orcein and other lichen dyes have largely been replaced by synthetic versions.”11
We know that red and purple dyes were much sought after and in some medieval civilisations the wearing of those colours was restricted to certain social classes and even to one individual (e.g the purple for the Emperor). Once Europeans had gained familiarity with indigenous civilisations of Central and South America, the red dye obtained from the parasitic cochineal insect Dactylopius coccusbecame an important export product to Europe until the late 19th Century, when synthetic pigments and dyes were invented. Despite this development, traditional hand-made textile producers, for example in regions of Mexico, continued to use cochineal dyeing. However, health concerns associated with some or all of those synthetic colourings in food have once again created a demand for cochineal and cultivation of the insect is once again economically viable, with Peru being currently the main exporter.12
Drugs and Medicine:
There is reason to believe that metabolites produced by lichens may have antibiotic effects and usnic acid, the most commonly-studied metabolite produced by lichens, is being investigated as a possible bactericide, in particular against Staphylococcus and E.coli.13
Lichens were also used in European traditional medicine, in particular based on the theory that plants that resembled human organs would be efficacious in treatment of illness of those organs. Some American Indigenous people also used them in traditional medicine treatment.
Lichens as Indicators of Geological Age and of Pollution Levels:
The science of lichenometry is a relatively new one in which measuring the type and size of lichen is used to indicate the age of exposed rock. It takes the known slow growth-rate of different lichens to arrive at an estimate of how long the rock in question has been exposed. This can be used on rock formations, landslides, stone buildings and statuary.
The tolerance (or lack of tolerance) of different species of lichen to certain types of air and rain pollutant can be used as bio-indicators. In general the “frond” or “bushy” types are less resistant to some air pollutants and the flat or “crusty” types more so. Lichens take their water from the surfaces to which they are attached and from the air and are therefore quickly affected by the water quality in rain and air.
Readers may find it worthwhile to take some time to examine the lichens growing around us, to think about their unusual ‘domestic arrangements’ and their pioneering habits. Or to inventory them as indicators of the level and content of pollution in a specific area.
And in particular, to put on rainproof or resistant clothing and to view lichens during rainfall or at least very soon afterwards.