Making Eden
Page 29
possible. Our soils, the water we drink, the nature and quality of the air we
breathe, the beauty of our lives, and importantly our prospects for the future, all depend on maintaining the rich biodiversity that we have inherited, and for which are clearly responsible.’ As he points out, ‘We are but one species that grew up
here, what right do we have to destroy everything on Earth? If you were a visitor of Earth from another planet, the thing that would strike you the most is the wonder and beauty of the fantastic organisms on Earth. You wouldn’t start destroying them; you’d want to spend your whole life learning about them.’ At least that
would be the hope for most of us, but not everybody is likely to be convinced. On learning that an endangered breed of whales was being systematically turned into
soap, the writer Kingsley Amis remarked that ‘it sounds like quite a good way of
using up whales’. Obviously, we can make arguments for saving species diversity
but ‘the fact of the matter is they don’t convince people. They don’t carry the
weight of argument and I don’t know exactly why not because they sound as if
they would. Perhaps they’re too intellectual?’
Raven’s uncompromising diagnosis of the prospects for life on Earth hinges
on a clear appreciation of the stark realities of the situation.93 ‘Politically what can you say? There is nothing a politician could legitimately run on to get elected.
Every politician is elected by saying you are all going to be wealthy, that is the
196 a EdEn undEr siEgE
dream. They forget that England and America, and all these other countries, are
living in a complete bubble way above the capacity of the Earth to support them.
We can’t go on consuming more than the total productivity of the Earth. The
solution has a serious, moral underpinning. In a sense the golden rule, that really does say it all, is that if we could really love one another worldwide, I’m sure that we could solve these problems. But we are so far from that. We are wary and
looking out for ourselves and wanting to accumulate things and enrich our
lives—selfishness was highly adaptive pre-agriculture, but the more people that
adopt it the less adaptive it is. Selfishness is like a cancer. Somebody once said to Gandhi, “What do you think of Western civilization?” He said it “sounds like a
good idea, someone ought to try it”. I don’t think that ought to be given short
shrift because in a way that actually underlies everything. We need to work col-
lectively.’94
The situation recalls J.G. Ballard’s prescient missives from suburbia that have
occasionally punctuated our thinking throughout this book. Ballard repeatedly
warned of the social fallout of post-war urbanization where people become
obsessed with themselves and their security. Ballard, like Raven, was born in
Shanghai, China, but stayed far longer. In 1943, his family was interned in the
Lunghua Civilian Assembly Camp until the Hiroshima and Nagasaki atom bombs
ended the war. Environmental change features heavily in his early apocalyptic
novels (exemplified by The Drowned World and The Drought) and warning us of the need to build a better society was central to his agenda. ‘As living standards continue to rise, as they have done since the war—and I’m sure living standards will, on the whole continue to rise—people have got more to lose. You know, they’ve
packed their homes with high-tech electronic gear . . . not to mention things like jewellery. So one gets a strangely interiorized style of living where you switch off the outside world. You do this by treble-locking your front door and switching on the alarm system, and then you retreat and watch videos of the World Cup. And
that’s not a good recipe for a healthy society.’95 Or a healthy planet, we should add.
Humanity stands at a crossroads. Preserving the lush green planet we enjoy
requires protecting biodiversity and planetary climate and this ought to be a top priority for citizens, nations, and governments of the world. We are completely
dependent on plants now and will be in the future. Only with co-operation
between nations, and by taking responsibility for our own actions, can we develop
EdEn undEr siEgE a 197
global solutions for a sustainable, more equitable world. The window of opportunity is closing as the era of consequences dawns. If we make the right choices in the
coming decades, there is a chance of avoiding the sixth great wave of extinction in the history of life on Earth, one that is of our own making. If we fail to address the planetary crisis, a far worse alternative lies ahead.96 Fortunately, science tells us there is still time to take action and reject that grim alternative future of sending our emerald planet back to the drab world of the distant past.
SIMPLIFIED GEOLOGIC TIMESCALE
FROM THE CAMBRIAN
CENOZOIC
MESOZOIC
PALEOZOIC
AGE
AGE
AGE
(Mya) PERIOD
EPOCH
(Mya)
PERIOD
(Mya)
PERIOD
QUATER-
HOLOCENE
NARY
PLEISTOCENE
70
260
PLIOCENE
5
80
PERMIAN
280
NEOGENE
90
10
300
100
C
MIOCENE
ARBON
15
CRETACEOUS
PENNSYLVANIAN
110
320
IFER
20
120
340
OU
MISSISSIPPIAN
S
130
25
360
140
OLIGOCENE
30
380
150
DEVONIAN
160
400
35
170
JURASSIC
420
40
PA
180
LEOGEN
SILURIAN
440
190
45
EOCENE
E
200
460
ORDOVICIAN
50
210
480
55
220
500
TRIASSIC
230
60
CAMBRIAN
PALEOCENE
520
240
65
250
540
Based on the 2018 version of the Geological Society of America’s time
PRECAMBRIAN
scale. ‘Mya’ = millions of years ago
ENDNOTES
1. All flesh is grass
1. Christopher, J. (1956) The Death of Grass. Penguin, London.
2. Ballard, J.G. (1965) The Drought. Fourth Estate, London.
3. McCarthy, C. (2006) The Road. Picador, London.
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6. Although we know little about the earliest form of life, we are no longer tied to the intriguing yet ultimately untenable suggestion of the evolutionary biologist J.B.S. Haldane (1892–1964) that a primordial soup may have provided the basis for the origin of life, as given in Haldane, J.B.S. (1929) The origin of life. Rationalist Annual, 3, 3–10.
8. Früh-Green, G. L. et al. (2003) 30,000 years of hydrothermal vent activity at the Lost City vent field. Science, 301, 495–8.
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11. Vermeij, G.J. & Grosberg, R.K. (2010) The great divergence: when did diversity on land exceed that in the sea? Integrative and Comparative Biology, 50, 675–82. May, R.M. (1994) Biological diversity: differences between land and sea. Philosophical Transactions of the Royal Society, B343, 105–11. Grosberg, R.K., Vermeij, G.J. & Wainwright, P.C. (2004) Biodiversity in water and on land. Current Biology, 22, R900–3.
12. Labandeira, C.C. (2005) Invasion of the continents: cyanobacterial crusts to tree-inhabiting arthropods. Trends in Ecology and Evolution, 20, 253–62.
13. Clack, J.A. (2007) Devonian climate change, breathing, and the origin of the tetrapod stem group. Integrative and Comparative Biology, 47, 510–23. For a popular treatment dealing with all aspects of vertebrates coming ashore, see Clack, J.A. (2012) Gaining Ground: The Origin and Evolution of Tetrapods (Life of the Past) (2nd edn). Indiana University Press, USA.
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14. Seward, A. C. (1914) Antarctic Fossil Plants. British Antarctic (‘Terra Nova’) Expedition, 1910. British Museum Natural History Report. Geology, 1, 1–49.
15. Wandersee, J.H. & Schussler, E.E. (1999) Preventing plant blindness. American Biology Teacher, 61, 82–6. Wandersee, J.H. & Schussler, E.E. (2001) Toward a theory of plant blindness. Plant Science Bulletin, 47, 2–9.
16. In an effort to combat humanity’s appalling plant blindness, and win the battle for young minds, Wandersee and Schussler produced a poster, endorsed by the Botanical Society of America and distributed to more than 20 000 schools, with the hope of
recruiting the next generation into the exciting science of botany. They maintain an exciting website for their visual cognition research development laboratory (http://
www.15degreelab.com). The laboratory takes its name from the observation that most people typically view objects that lie between 0° and 15° below eye level. We really do need to look up more to overcome plant blindness.
17. In a fascinating North American study, university botany students were shown 14
pairs of animal and plant images, and their recall of each image was determined after undertaking a distracting task. The results showed that they consistently recalled the images of animals more accurately, and more often, than those of plants. See Schussler, E.E. & Olzak, L.A. (2008) It’s not easy being green: student recall of plant and animal images. Journal of Biological Education, 42, 112–18.
18. New, J., Comsides, L. & Tooby, J. (2007) Category-specific attention for animals reflects ancestral priorities, not expertise. Proceedings of the National Academy of Sciences, USA, 104, 16598–603. See also the commentary: Ohman, A. (2007) Has evolution primed humans
to ‘beware the beast’? Proceedings of the National Academy of Sciences, USA, 104, 16396–7.
19. Gee, H., Howlett, R. & Campbell, P. (2009) 15 Evolutionary Gems. Nature, 457, doi: 10.1038/nature07740. Available at http:// www.nature.com/evolutiongems.
20. Bower was following original research by the Czech botanist Ladislav Josef Celakovsky (1834–1902). Sadly, we know little about Celakovsky’s life.
21. Walton, J. (1948) Obituaries. Prof F.O. Bower, F.R.S. Nature, 161, 753–4.
22. Gribbin, J. (2003) Science: A History 1543–2001. Penguin Books, London.
23. YouTube is currently offering a memorable reading by David Horovitch of this haunting tale: http://www.youtube.com/watch?v=gjeEaviwUYQ
24. Frank’s botanical and mycological colleague Anton de Bary (1831–1888) devoted much of his life to studying fungi and greatly expanded the concept; see de Bary, H. (1879) Die Erscheinung der Symbiose. Strasberg, Germany. As one of a new breed of active continental botanists using advanced experimental techniques to understand how nature works, de Bary attracted many scientific visitors eager to learn his approach. Bower spent a full academic year with him in Strasburg in 1879, where he mastered German and attended the great professor’s lectures to improve his mind, and general education in botany; see Lang, W.H. (1949) Fredrick Orpen Bower. Obituary Notices of the Royal Society, 6, 347–74.
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202 a EndnotEs
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2. Fifty shades of green
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2. Death Valley in the Mojave Desert is the hottest place in North America—summer temperatures regularly soar above 120°F (49°C).
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2001. Penguin, London.
6. Before the molecular sequencing revolution, classification was undertaken by looking for features that are similar or different, the principle of inheritance by which, for example, we share similar characteristics to our parents or grandparents. The fact is that today almost all evolutionary trees are based entirely on ‘features’ observed by DNA sequencing, and for good reason. The morphological characters of organisms,
like those studied by Linnaeus and Darwin, were often confused by confounding
issues of convergent evolution. Convergent evolution is the process by which natural selection favours similar adaptations (or characters) in different species not because they are closely related to each other, but because they equip those species similarly for survival in particular habitats. Chapter and verse on convergent evolution can be found in Conway-Morris, S. (2003) Life’s Solutions. Cambridge University Press, Cambridge.
7. Cheng, C., Bowman, J.L. & Meyerowitz, E.M. (2016) Field guide to model plant systems.
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10. Margulis, L. (1981) Symbiosis in cell evolution. F.H. Freeman, New York. Sadly, Margulis died in 2011. For a concise overview of her revolutionary contribution to cell biology and evolution, see Lake, J.A. (2011) Obituary. Lynn Margulis (1938–2011). Nature, 480, 458.
11. Mereschkowsky, C. (1905) Über Natur und Ursprung der Chromatophoren im
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13. The classic paper is: Schwartz, R.M. & Dayhoff, M.O. (1978) Ori
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EndnotEs a 203
15. If you think this seems far-fetched, consider the strange case of the herbivorous saco-glossan sea-slugs, minuscule molluscs that dwell on the Great Barrier Reef and elsewhere in the world’s oceans. These solar-powered sea-slugs have a distinctive bright green appearance that comes from the chloroplasts of the green algae they eat but fail to fully digest, see Händeler, K. et al. (2009) Functional chloroplasts in metazoan cells—a unique evolutionary strategy in animal life. Frontiers in Zoology, 6, 28. In other words, these little green molluscs are kleptoplasts, ‘stealing’ and retaining chloroplasts from their algal food to camouflage themselves and avoid predation. The chloroplasts also provide the slugs with additional energy in the form of sugars manufactured by photosynthesis, a function that seems to be especially important for enhancing their survival when times are hard and the algae they feed on scarce. Many components in the complex photosynthetic machinery of algal chloroplasts need replacing every few hours, yet the slugs maintain their captive collections of chloroplast hostages active for weeks or months until they die. Quite how they manage this feat is not clear, but it has led to the suspicion that the genes used by algae to run chloroplasts have somehow been transferred into the slugs’ genome, the slugs having recruited them to build essential proteins for light harvesting and synthesizing chlorophyll (Rumpho, M.E.
et al. (2008) Horizontal gene transfer of the algal nuclear gene psbO to the photosynthetic sea slug Elysia chlorotica. Proceedings of the National Academy of Sciences, USA, 105, 17867–71). It’s an exciting, if controversial, proposition for explaining the photosynthetic longevity of these startling lime-green creatures. The following paper, for example, reports evidence against the idea: Wägele, H. et al. (2011) Transcriptomic evidence that longevity of acquired plastids in the photosynthetic slugs Elysia timida and Plakobranchus ocellatus does not entail lateral transfer of algal nuclear genes. Molecular Biology and Evolution, 28, 699–706. In contrast, this paper reports evidence supporting it: Schwartz, J.A., Curtis, N.E. & Pierce, S.K. (2010) Using algal transcriptome sequences to identify transferred genes in the sea slug, Elysia chlorotica. Evolutionary Biology, 37, 29–37.