The amoeba in the room

Think of a 'living thing'. Think of 'wildlife' - or of 'our fellow creatures'.

Most images that come to mind, I guess, will be of animals, and many or most of these will be furry, or feathery, or have big eyes, and perhaps a big voice.

This is a common off-the-top image we see when we think what 'life on Earth' means to us.

Much nature conservation thinking, as well as popular TV, and - of course - motivation for science research, is geared to big, bold, and (in both senses) bright animals.

Yet "terrestrial plant life", writes David Beerling about the impact plants have had on Earth's atmosphere, "constitutes over 90% of the world's biomass, a figure reflecting [plants'] true dominance in the biosphere", and "most places on Earth which contain life are visibly plantscapes".[1]

And half of that is algae ...

Let's go back two steps: Beerling has just written that marine and freshwater phytoplankton contributes half the world's total of annually synthesised biomass.

However, this sort of thing is seldom mentioned, as though plants don't score many Brownie points, and things as small as phytoplankton are unacknowledged, or unseen, even by science.

This is roughly where Nicholas Money comes in. He wants, say his publishers, to turn our view of life upside down - or, in his own words: "We have been misled by our brains to exaggerate the importance of elephants".

One consequence he finds is that "the way we teach biology is no more sensible than evaluating all of English literature by reading nothing but a Harry Potter book." I suspect he is right.

The 'tree of life' - more convoluted than you think

There are two main aspects of The Amoeba in the room that I'd like to emphasise.

The first is that if you have not been a student of biology in recent years, or do not keep an eye open for news of major changes in the field, the chances are that your understanding of the classification of 'living things' is woefully outmoded.

Moreover the names of several parts of the classification important enough to be basic 'kingdoms' of life are (as they were to me) are surely alarmingly unfamiliar to you.

The nice simplicity of Animals, Plants, Fungi, Bacteria, Odds-&-Ends, and Not-Quite-Living Viruses, that still echoes in lay books on biology, is thoroughly misleading. The box indicates my understanding of the scheme Money uses for the eukaryotes - living things made of cells with nuclei and other structures within membranes.

This scheme is by no means universally accepted in detail, but it and similar ones represent a new orientation in biology.

Divisions of eukaryotes

• Amoebozoa - Amoeba and other protozoans that move by pseudopodia.
• Hacrobia - contains a great diversity including flagellates, amoeboids, and microalgae; some are heterotrophs.
• Stramenopila - brown algae, kelps, diatoms, and water-moulds.
• Alveolata - mostly ciliates, dinoflagellates, and the group that includes Plasmodium, the causative agent of malaria.
• Rhizaria - mostly amoeboid with pseudopodia, many form shells; includes the foraminifera, cercozoa, and radiolarians.
• Archaeplastida - red algae, green algae, and the 'plants', together with a small algal group, the glaucophytes.
• Excavata - defined by a feeding groove 'excavated' from one side; includes the euglenids and trypanosomes.
• Opisthokonta - true fungi ,the animals, and their protist relatives.

These are not the cutest, cuddliest, most photogenic foms of wildlife - and they tend to be given tongue-twister monikers. Such a scheme, of course, is not news, but it is still tentative. It is a new perspective that has yet to gain admission to the minds of many biologists, and is a long way from being general knowledge.

Not that an OUP hardback will take it far in that direction ... but if its message is read by a few more school-teachers, and lecturers, it may spread a little further: they are certainly interesting, but we exaggerate the importance of elephants.

A strong bias to big mammals

It is said that in the USSR, 95% of money for nature conservation went to saving the Siberian tiger. Here, and now, funding is not so skewed, but it is nonetheless distinctly biased.

In both the academic field of biology and the real field of conservation, size matters. Prof. Money is saying just this - and he is pointing down-scale. 

We interact with the likes of wasps and jelly-fish, and understand that we may be host to such things as tapeworms and pinworms, but we hope not to be infected by them, or by, say, the bacterium Vibrio cholerae. But we are used to interacting, often intimately, with creatures - animals - of roughly our scale: pets, domestics, and predators, for instance.

For those of us concerned with nature conservation, this scale effect is - although seldom recognised, and but rarely acknowledged - a potential problem. It draws attention away from the drivers of the fundamental systems on which we depend.

The 'elephant' is the amoeba

The second main aspect of the book, then, is that the elephant in the room is, in fact, an amoeba. Amoebae, we must keep in mind, are small.

They are not, however, nearly as small as the organisms without nuclei that greatly outnumber all others, that have, we think, been here much longer than other forms of life, can tolerate environments out of bounds to more complex beings, and appear to hold all the top jobs in Life, Inc. In the marine world, for instance, we are told "almost everything that matters is microscopic".

Although bacteria were first observed by Antonie van Leeuwenhoek in 1676, still, in the early 1890s, bacteria - germs - were "scarcely heard of outside scientific circles": a few years later, though, when some of their implications for us were becoming clearer, "they were almost household words". [2]

They are prokaryotes - cells-without-nuclear-membranes - and were separated from the eukaryotids in the 1930s. Then, in 1977, it was acknowledged that in their biochemistry and genetics some of these prokaryotids are, as Money phrases it, "as different from bacteria as you are".

These are now commonly known as the Archaea. This distinct but obscure group includes some 'ordinary' creatures, but also some Guinness record-breakers.

There are archaea that thrive in deep-sea vents in water over 110°C (c. 230°F), in corrosively alkaline or acid waters, in oxygen-starved mud, in petroleum deposits, and in animals' guts.

What exactly are the archaea?

Between them, archaea reach places intolerable to (most) mere multicellular beings. There are, certainly, multicellular organisms, for instance the fungi that thrive in Chernobyl's sarcophagi, and a red alga from nearly 270 metres down in the Bahamas, that we class as extremomorphs, but this is not the norm.

The hardy prokaryotes have given biology and ecology a problem. This involves two weaselly words, 'biodiversity' and 'species'. The first, a measure of the number of different varieties amongst living things, invokes the second to explain variety and variation.

Even when the diversity is measured as variation in the RNA and DNA represented in a sample (say of seawater), it is usually envisaged that it can be allocated to particular species. We cannot count most microbes as individuals: that is like counting sandgrains on the beach.

And many seem more or less to refuse to be pigeonholed as particular species. That would be stretching the idea of species beyond its elastic limit. Our sense of 'species' is of reproduction more or less kept to and requiring alike individuals, with more-or-less continent genomes.

But some types of organism are so leaky they do not play this game. We are only just beginning to learn how un-personal a personal genome is. Yours, for example, or mine.

And what exactly are we?

Frank Ryan, author of Virolution [3], comments that in the human genome, virus-like components make up nearly half of 'our' DNA, and in many 'species' that have been examined, where some of the genes and sequences came from is very uncertain.

Nicholas Money is probably right to say that our view of ourselves is soon going to be very different. We are going to have to get used to being thought of as mobile ecosystems, as well as members of a species.

Evidence is accumulating, that Homo sapiens by itself is dead. Only as part of a process do 'our' bodies live and reproduce; and 'we' have colonised most of Earth, and use its resources, only with the help - and hindrance - of micros.

We live together having evolved together, though the micros were here first, and as it were invented the rules: they have, for example, "dominion over the planet's nutrient cycles".

Intimate relationships

It looks as though life is far more intimate than that. Endosymbiosis was mooted in 1905, though when I was a student, it was still only becoming fashionable to speak of chloroplasts and mitochondria as "very like" microorganisms that had somehow survived becoming engulfed in other things' cells.

Now we read things like "Plants do photosynthesis like cyanobacteria because the chloroplasts in plants are cyanobacteria".

I remember being intrigued by the thought of algae living in the bodies of Hydra, or sting-cells of hydrozoids being commandeered by seaslugs. Now, the very idea of 'self' is clouded, and whatever we are we are made of cells made of useful pieces of others' cells.

I am not sure the book's structure and style are the best for turning its readers' lives upside-down. However, they work quite well. Money covers a lot of ground, made fairly easy to take in by relaxed, clear English that is frequently colloquial for punch-lines.

'Fascinating, amazing, and thoroughly enthusiastic'

I wish, though, that there was a glossary, and more informative diagrams. A number of taxonomic names are dropped as though readers will know things about the organisms. This reader went to the web to check.

Although interesting, some of the detail of the development of microscopes is rather tangential, as perhaps is some of the chapter on extremomorphs.

In several places, Money's meaning is somewhat cryptic, and needs more detail. Particular sections, looking at water, air, soil, and the human body are not intended to be complete pictures, but would have benefited from succinct overviews.

Nonetheless, this is a fascinating, amazing, and thoroughly enthusiastic sketch of a subject sure to increase in importance, about which we know little and will want to know a lot more. The book helps orient us to new biological horizons - and new philosophic ones.

As Prof. Money says, four hundred years after Descartes "mainstream philosophy clings to the illusion of human magnificence. Biology has been saying something very different recently."

The book: The Amoeba in the Room: lives of the microbes by Nicholas P. Money is published by Oxford University Press. It is due for release on 24th April 2014 at £16.99 (hardback).

References

1. David Beerling (2007) The emerald planet, Oxford University Press.
2. H.W. Conn (1897) The story of germ life. Bacteria, Newnes, London.
3. Frank Ryan (2009) Virolution, Collins, London.

Martin Spray is an editor and writer for Ecos - A review of conservation.

He retired early from the University of Gloucestershire, England, because of Parkinson's disease. He taught aspects of ecology, landscape architecture, environmental philosophy, and professional ethics, and has contributed to a wide variety of conservation, landscape, gardening and education magazines and journals.