Dian J. Gifford, Roger P. Harris, Stewart M. McKinnell, William T. Peterson, and Michael A. St. John
- Published in print:
- 2010
- Published Online:
- May 2010
- ISBN:
- 9780199558025
- eISBN:
- 9780191721939
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199558025.003.0004
- Subject:
- Biology, Biodiversity / Conservation Biology, Aquatic Biology
Because of GLOBEC's focus on population dynamics, species‐level research is central to the programme, and most field, retrospective and modeling studies were directed at target species defined on the ...
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Because of GLOBEC's focus on population dynamics, species‐level research is central to the programme, and most field, retrospective and modeling studies were directed at target species defined on the basis of their suitability for use in the comparative approach or their trophic role in the ecosystem. Target species may be economically significant due to their contribution to local, regional, and national economies through subsistence, commercial enterprise, and use by indigenous peoples. Target species of conservation significance may be the subjects of regional, national, or international conservation agreements. Target species of social or cultural significance have value to human communities because of their historical, aesthetic, educational, or recreational value. GLOBEC target species are heavily weighted towards marine pelagic organisms, particularly zooplankton. However, vertebrates with largely (seabirds and seals) or wholly (whales) pelagic life histories have been studied in some ecosystems, as have anadromous fish whose life history is not entirely marine. Here, this chapter reviews major groups of GLOBEC target species: Calanus and other large copepods, salmonids, cod, small pelagic fish, and large apex predators.Less
Because of GLOBEC's focus on population dynamics, species‐level research is central to the programme, and most field, retrospective and modeling studies were directed at target species defined on the basis of their suitability for use in the comparative approach or their trophic role in the ecosystem. Target species may be economically significant due to their contribution to local, regional, and national economies through subsistence, commercial enterprise, and use by indigenous peoples. Target species of conservation significance may be the subjects of regional, national, or international conservation agreements. Target species of social or cultural significance have value to human communities because of their historical, aesthetic, educational, or recreational value. GLOBEC target species are heavily weighted towards marine pelagic organisms, particularly zooplankton. However, vertebrates with largely (seabirds and seals) or wholly (whales) pelagic life histories have been studied in some ecosystems, as have anadromous fish whose life history is not entirely marine. Here, this chapter reviews major groups of GLOBEC target species: Calanus and other large copepods, salmonids, cod, small pelagic fish, and large apex predators.
LISA T. BALLANCE, ROBERT L. PITMAN, ROGER P. HEWITT, DONALD B. SINIFF, WAYNE Z. TRIVELPIECE, PHILLIP J. CLAPHAM, and ROBERT L. BROWNELL JR
- Published in print:
- 2007
- Published Online:
- March 2012
- ISBN:
- 9780520248847
- eISBN:
- 9780520933200
- Item type:
- chapter
- Publisher:
- University of California Press
- DOI:
- 10.1525/california/9780520248847.003.0017
- Subject:
- Biology, Aquatic Biology
Commercial whalers in the nineteenth and twentieth centuries exploited whales in the Southern Ocean, driving populations to extremely low levels. In a seminal paper, Laws (1977) postulated that their ...
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Commercial whalers in the nineteenth and twentieth centuries exploited whales in the Southern Ocean, driving populations to extremely low levels. In a seminal paper, Laws (1977) postulated that their removal resulted in a surplus of prey in the Southern Ocean ecosystem, with consequent increases in the numbers of other krill consumers via competitive release. This chapter provides a review of the literature published since that paper, and further investigates the effects of this massive removal of large whales and evaluate the potential ecosystem effects of this uncontrolled experiment. Nutrient cycles in the Southern Ocean ecosystem were likely altered by the loss of large whales, but little is known regarding the significance of fecal input from whales, or of the fact that krill, once removed from the system through whale predation, now remain.Less
Commercial whalers in the nineteenth and twentieth centuries exploited whales in the Southern Ocean, driving populations to extremely low levels. In a seminal paper, Laws (1977) postulated that their removal resulted in a surplus of prey in the Southern Ocean ecosystem, with consequent increases in the numbers of other krill consumers via competitive release. This chapter provides a review of the literature published since that paper, and further investigates the effects of this massive removal of large whales and evaluate the potential ecosystem effects of this uncontrolled experiment. Nutrient cycles in the Southern Ocean ecosystem were likely altered by the loss of large whales, but little is known regarding the significance of fecal input from whales, or of the fact that krill, once removed from the system through whale predation, now remain.
Roman Lunkin
- Published in print:
- 2012
- Published Online:
- January 2013
- ISBN:
- 9780199930890
- eISBN:
- 9780199980581
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199930890.003.0007
- Subject:
- Religion, Religion and Society
This chapter catalogues the torturous path of the treatment of religion in post-communist Russia. It begins with the implementation of a new legal regime of broad religious freedom during the period ...
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This chapter catalogues the torturous path of the treatment of religion in post-communist Russia. It begins with the implementation of a new legal regime of broad religious freedom during the period of Perestroika and Glasnost at the end of the Soviet era, which endured through the religious freedom of 1990 in the new Russian Federation. It then demonstrates how authorities of the Russian Orthodox Church (ROC) joined with the ruling political elite to suppress the freedom of religious competitors. New laws restricted the activities of religious minorities, but did not stem the growing religious pluralism in Russia. Thus efforts by Vladimir Putin to gain legitimacy for authoritarian measures through privileges accorded the ROC produced a backlash and forged alliances of religious minorities and the intelligentsia that reinforced religious freedom as a value in Russia. New demographic evidence shows that religious pluralism is gaining ground and fuelling hopeful democratic impulses.Less
This chapter catalogues the torturous path of the treatment of religion in post-communist Russia. It begins with the implementation of a new legal regime of broad religious freedom during the period of Perestroika and Glasnost at the end of the Soviet era, which endured through the religious freedom of 1990 in the new Russian Federation. It then demonstrates how authorities of the Russian Orthodox Church (ROC) joined with the ruling political elite to suppress the freedom of religious competitors. New laws restricted the activities of religious minorities, but did not stem the growing religious pluralism in Russia. Thus efforts by Vladimir Putin to gain legitimacy for authoritarian measures through privileges accorded the ROC produced a backlash and forged alliances of religious minorities and the intelligentsia that reinforced religious freedom as a value in Russia. New demographic evidence shows that religious pluralism is gaining ground and fuelling hopeful democratic impulses.
Caleb Gardner, Reginald A. Watson, Anes Dwi Jayanti, Suadi, Mohsen AlHusaini, and Gordon H. Kruse
- Published in print:
- 2020
- Published Online:
- April 2021
- ISBN:
- 9780190865627
- eISBN:
- 9780197517406
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/oso/9780190865627.003.0001
- Subject:
- Biology, Animal Biology, Aquatic Biology
Much of the biological and other research efforts on crustaceans have been driven by their importance to humans as a food source. Production comes from a diverse array of methods and scales of ...
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Much of the biological and other research efforts on crustaceans have been driven by their importance to humans as a food source. Production comes from a diverse array of methods and scales of extraction, from small recreational or subsistence fisheries to industrial-scale operations. Most crustacean catch comes from shrimp fisheries, with over two million tons taken in 2014, mainly by trawl. The genera Acetes, Fenneropenaeus, and Pandalus account for around three quarters of this catch. Crab, krill, and lobster are the other main crustacean products (around 600,000 t crab, 380,000 t krill, and 300,000 t lobster in 2014). Trends in crustacean fisheries are broadly similar to those of other seafood, although crustaceans often target different market segments and receive higher prices than fish. Crustacean fisheries management faces many challenges with management of bycatch from trawl gears especially significant. Fortunately, crustaceans tend to be easily handled with low discard mortality, and this has enabled widespread use of regulations based on size, maturity, or sex (e.g., male-only fisheries). Total allowable catch (TAC) limits are widely used and highly effective for ensuring sustainable harvests when set responsibly using good information. TAC systems are often combined with catch share or individual transferable quota systems, which had a mixed history in crustaceans, sometimes reducing overall community benefit. This parallels the challenge facing fisheries globally of ensuring that harvests are not only sustainable but also deliver benefits to the wider community beyond the commercial fishers; management of some crustacean fisheries is at the forefront of these developments.Less
Much of the biological and other research efforts on crustaceans have been driven by their importance to humans as a food source. Production comes from a diverse array of methods and scales of extraction, from small recreational or subsistence fisheries to industrial-scale operations. Most crustacean catch comes from shrimp fisheries, with over two million tons taken in 2014, mainly by trawl. The genera Acetes, Fenneropenaeus, and Pandalus account for around three quarters of this catch. Crab, krill, and lobster are the other main crustacean products (around 600,000 t crab, 380,000 t krill, and 300,000 t lobster in 2014). Trends in crustacean fisheries are broadly similar to those of other seafood, although crustaceans often target different market segments and receive higher prices than fish. Crustacean fisheries management faces many challenges with management of bycatch from trawl gears especially significant. Fortunately, crustaceans tend to be easily handled with low discard mortality, and this has enabled widespread use of regulations based on size, maturity, or sex (e.g., male-only fisheries). Total allowable catch (TAC) limits are widely used and highly effective for ensuring sustainable harvests when set responsibly using good information. TAC systems are often combined with catch share or individual transferable quota systems, which had a mixed history in crustaceans, sometimes reducing overall community benefit. This parallels the challenge facing fisheries globally of ensuring that harvests are not only sustainable but also deliver benefits to the wider community beyond the commercial fishers; management of some crustacean fisheries is at the forefront of these developments.
So Kawaguchi and Stephen Nicol
- Published in print:
- 2020
- Published Online:
- April 2021
- ISBN:
- 9780190865627
- eISBN:
- 9780197517406
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/oso/9780190865627.003.0006
- Subject:
- Biology, Animal Biology, Aquatic Biology
Antarctic krill is a key species in the Southern Ocean ecosystem as well as the target for the largest fishery in the Southern Ocean, which has been operating continuously since the early 1970s. The ...
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Antarctic krill is a key species in the Southern Ocean ecosystem as well as the target for the largest fishery in the Southern Ocean, which has been operating continuously since the early 1970s. The krill fishery began by operating all around the continent but gradually contracted to the West Antarctica in the 1990s, where it is currently concentrated on a few fishing grounds in the Southwest Atlantic sector. This fishery has regained some commercial attraction because of recent technological developments in harvesting and processing. These developments permit the production of high-value products, and the total annual catch has increased to nearly 400,000 t over the last decade. Climate change has already affected the krill fishery, with the reduced winter sea ice in the South Atlantic allowing current fishery operations farther south than what was previously possible. The Antarctic krill fishery is managed by the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR). Its management system is unique in taking into account the state of the ecosystem as well as that of the harvested stock. The establishment of a feedback management approach for this fishery has been the major task for the Scientific Committee of CCAMLR to realize this ecosystem-based management objective. This chapter provides a general introduction to krill biology and ecology, followed by a narrative of the forces that prompted the development of a krill fishery and the current issues that surround its management.Less
Antarctic krill is a key species in the Southern Ocean ecosystem as well as the target for the largest fishery in the Southern Ocean, which has been operating continuously since the early 1970s. The krill fishery began by operating all around the continent but gradually contracted to the West Antarctica in the 1990s, where it is currently concentrated on a few fishing grounds in the Southwest Atlantic sector. This fishery has regained some commercial attraction because of recent technological developments in harvesting and processing. These developments permit the production of high-value products, and the total annual catch has increased to nearly 400,000 t over the last decade. Climate change has already affected the krill fishery, with the reduced winter sea ice in the South Atlantic allowing current fishery operations farther south than what was previously possible. The Antarctic krill fishery is managed by the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR). Its management system is unique in taking into account the state of the ecosystem as well as that of the harvested stock. The establishment of a feedback management approach for this fishery has been the major task for the Scientific Committee of CCAMLR to realize this ecosystem-based management objective. This chapter provides a general introduction to krill biology and ecology, followed by a narrative of the forces that prompted the development of a krill fishery and the current issues that surround its management.
Alistair J. Lindley
- Published in print:
- 2017
- Published Online:
- October 2017
- ISBN:
- 9780199233267
- eISBN:
- 9780191835698
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/oso/9780199233267.003.0030
- Subject:
- Biology, Aquatic Biology, Ecology
This chapter describes the taxonomy of Euphausiacea, exclusively marine holoplanktonic crustaceans commonly known as krill. Although not highly diverse, with only two families and ~ 86 species ...
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This chapter describes the taxonomy of Euphausiacea, exclusively marine holoplanktonic crustaceans commonly known as krill. Although not highly diverse, with only two families and ~ 86 species worldwide, they are often a major component of the biomass of the plankton and micronekton of the world's oceans. This chapter covers their life cycle, ecology, and general morphology. It includes a section that indicates the systematic placement of the taxon described within the tree of life, and lists the key marine representative illustrated in the chapter (usually to genus or family level). This section also provides information on the taxonomic authorities responsible for the classification adopted, recent changes which might have occurred, and lists relevant taxonomic sources.Less
This chapter describes the taxonomy of Euphausiacea, exclusively marine holoplanktonic crustaceans commonly known as krill. Although not highly diverse, with only two families and ~ 86 species worldwide, they are often a major component of the biomass of the plankton and micronekton of the world's oceans. This chapter covers their life cycle, ecology, and general morphology. It includes a section that indicates the systematic placement of the taxon described within the tree of life, and lists the key marine representative illustrated in the chapter (usually to genus or family level). This section also provides information on the taxonomic authorities responsible for the classification adopted, recent changes which might have occurred, and lists relevant taxonomic sources.
James P. Barry and Stephen Widdicombe
- Published in print:
- 2011
- Published Online:
- November 2020
- ISBN:
- 9780199591091
- eISBN:
- 9780191918001
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/oso/9780199591091.003.0015
- Subject:
- Earth Sciences and Geography, Oceanography and Hydrology
The biodiversity of the oceans, including the striking variation in life forms from microbes to whales and ranging from surface waters to hadal trenches, forms a dynamic biological framework ...
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The biodiversity of the oceans, including the striking variation in life forms from microbes to whales and ranging from surface waters to hadal trenches, forms a dynamic biological framework enabling the flow of energy that shapes and sustains marine ecosystems. Society relies upon the biodiversity and function of marine systems for a wide range of services as basic as producing the seafood we consume or as essential as generating much of the oxygen we breathe. Perhaps most obvious is the global seafood harvest totalling over 100 Mt yr–1 (82 and 20 Mt in 2008 for capture and aquaculture, respectively; FAO 2009) from fishing effort that expands more broadly and deeper each year as fishery stocks are depleted (Pauly et al. 2003). Less apparent ecosystem services linked closely to biodiversity and ecosystem function are waste processing and improved water quality, elemental cycling, shoreline protection, recreational opportunities, and aesthetic or educational experiences (Cooley et al. 2009). There is growing concern that ocean acidification caused by fossil fuel emissions, in concert with the effects of other human activities, will cause significant changes in the biodiversity and function of marine ecosystems, with important consequences for resources and services that are important to society. Will the effects of ocean acidification on ecosystems be similar to those arising from other environmental perturbations observed during human or earth history? Although changes in biodiversity and ecosystem function due to ocean acidification have not yet been widely observed, their onset may be difficult to detect amidst the variability associated with other human and non-human factors, and the greatest impacts are expected to occur as acidification intensifies through this century. In theory, large and rapid environmental changes are expected to decrease the stability and productivity of ecosystems due to a reduction in biodiversity caused by the loss of sensitive species that play important roles in energy flow (i.e. food web function) or other processes (e.g. ecosystem engineers; Cardinale et al. 2006). In practice, however, most research concerning the biological effects of ocean acidification has focused on aspects of the performance and survival of individual species during short-term studies, assuming that a change in individual performance will influence ecosystem function.
Less
The biodiversity of the oceans, including the striking variation in life forms from microbes to whales and ranging from surface waters to hadal trenches, forms a dynamic biological framework enabling the flow of energy that shapes and sustains marine ecosystems. Society relies upon the biodiversity and function of marine systems for a wide range of services as basic as producing the seafood we consume or as essential as generating much of the oxygen we breathe. Perhaps most obvious is the global seafood harvest totalling over 100 Mt yr–1 (82 and 20 Mt in 2008 for capture and aquaculture, respectively; FAO 2009) from fishing effort that expands more broadly and deeper each year as fishery stocks are depleted (Pauly et al. 2003). Less apparent ecosystem services linked closely to biodiversity and ecosystem function are waste processing and improved water quality, elemental cycling, shoreline protection, recreational opportunities, and aesthetic or educational experiences (Cooley et al. 2009). There is growing concern that ocean acidification caused by fossil fuel emissions, in concert with the effects of other human activities, will cause significant changes in the biodiversity and function of marine ecosystems, with important consequences for resources and services that are important to society. Will the effects of ocean acidification on ecosystems be similar to those arising from other environmental perturbations observed during human or earth history? Although changes in biodiversity and ecosystem function due to ocean acidification have not yet been widely observed, their onset may be difficult to detect amidst the variability associated with other human and non-human factors, and the greatest impacts are expected to occur as acidification intensifies through this century. In theory, large and rapid environmental changes are expected to decrease the stability and productivity of ecosystems due to a reduction in biodiversity caused by the loss of sensitive species that play important roles in energy flow (i.e. food web function) or other processes (e.g. ecosystem engineers; Cardinale et al. 2006). In practice, however, most research concerning the biological effects of ocean acidification has focused on aspects of the performance and survival of individual species during short-term studies, assuming that a change in individual performance will influence ecosystem function.
Jan Zalasiewicz
- Published in print:
- 2010
- Published Online:
- November 2020
- ISBN:
- 9780199569700
- eISBN:
- 9780191918216
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/oso/9780199569700.003.0013
- Subject:
- Earth Sciences and Geography, Historical Geology
One of the books that changed my perception of the world is The Open Sea, Part 1, by the marine biologist Sir Alister Hardy. He had set out to write one book about the sea, but found that there was ...
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One of the books that changed my perception of the world is The Open Sea, Part 1, by the marine biologist Sir Alister Hardy. He had set out to write one book about the sea, but found that there was so much to say about the world of the plankton that it took up a whole book (he then had to write another book about everything else). It’s now more than half a century old, and yet this hidden world remains marvellously evoked by his words, and by the antique black and white photographs and line drawings. Coming to this as a palaeontologist, it was eye-opening. I was aware that in the strata, one normally only finds the remains of those forms of life that had some hard parts to fossilize. Bones, teeth, shells—and in the case of the acritarchs, chitinozoa and graptolites, their tough organic casings and homes. I knew that there had been other soft-bodied things out there of course, but alas these don’t register often enough on the radar of the geologically programmed. So the sheer variety and exuberance of this world, revealed in those pages, took me by surprise. The remains of some of this life, within the pebble, lie somewhere within the amorphous black carbon that gives this object its dark colour, and in some of the subtle chemical signals of the rock itself. Parts of the hidden Silurian sea are beginning to be decoded from this unpromising material, and the stories emerging—fragmentary, ambiguous, tantalizing— sometimes have surprising uses. Tow a fine-mesh net behind a ship for a few minutes, as Hardy did as a working scientist, and then examine its contents with a microscope, and a small fraction of this world is revealed—enough to reveal its almost boundless diversity. There are microscopic plants, the base of the food chain: the diatoms, for instance, single-celled algae with a silica skeleton that looks like a tiny ornate hatbox; the coccolithophores, even smaller algae with a bizarre calcium carbonate skeleton made of overlapping shield-like discs, and the dinoflagellates, too.
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One of the books that changed my perception of the world is The Open Sea, Part 1, by the marine biologist Sir Alister Hardy. He had set out to write one book about the sea, but found that there was so much to say about the world of the plankton that it took up a whole book (he then had to write another book about everything else). It’s now more than half a century old, and yet this hidden world remains marvellously evoked by his words, and by the antique black and white photographs and line drawings. Coming to this as a palaeontologist, it was eye-opening. I was aware that in the strata, one normally only finds the remains of those forms of life that had some hard parts to fossilize. Bones, teeth, shells—and in the case of the acritarchs, chitinozoa and graptolites, their tough organic casings and homes. I knew that there had been other soft-bodied things out there of course, but alas these don’t register often enough on the radar of the geologically programmed. So the sheer variety and exuberance of this world, revealed in those pages, took me by surprise. The remains of some of this life, within the pebble, lie somewhere within the amorphous black carbon that gives this object its dark colour, and in some of the subtle chemical signals of the rock itself. Parts of the hidden Silurian sea are beginning to be decoded from this unpromising material, and the stories emerging—fragmentary, ambiguous, tantalizing— sometimes have surprising uses. Tow a fine-mesh net behind a ship for a few minutes, as Hardy did as a working scientist, and then examine its contents with a microscope, and a small fraction of this world is revealed—enough to reveal its almost boundless diversity. There are microscopic plants, the base of the food chain: the diatoms, for instance, single-celled algae with a silica skeleton that looks like a tiny ornate hatbox; the coccolithophores, even smaller algae with a bizarre calcium carbonate skeleton made of overlapping shield-like discs, and the dinoflagellates, too.
Jan Zalasiewicz
- Published in print:
- 2008
- Published Online:
- November 2020
- ISBN:
- 9780199214976
- eISBN:
- 9780191917387
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/oso/9780199214976.003.0008
- Subject:
- Earth Sciences and Geography, Geology and the Lithosphere
History is bunk—or so Henry Ford is reputed to have said. Folk memory, though, simplifies recorded statements. What Henry Ford actually told the Chicago Tribune was ...
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History is bunk—or so Henry Ford is reputed to have said. Folk memory, though, simplifies recorded statements. What Henry Ford actually told the Chicago Tribune was ‘History is more or less bunk. It’s tradition. We don’t want tradition. We want to live in the present, and the only tradition that is worth a tinker’s damn is the history that we make today.’ So folk memory, in this case, did pretty well reflect the kernel of his views. Henry Ford also said that ‘Exercise is bunk. If you are healthy, you don’t need it; if you are sick, you shouldn’t take it.’ Henry Ford was a very powerful, very rich man of strongly expressed views. And he was quite wrong on both counts. Not having known Henry Ford, interplanetary explorers may have their own view of history. As, perhaps, an indispensable means of understanding the present and of predicting the future. As a way of deducing how the various phenomena—physical, chemical, and biological—on any planet operate. And as a means of avoiding the kind of mistake—such as resource exhaustion or intra-species war—that could terminate the ambitions of any promising and newly emerged intelligent life-form. On Earth, and everywhere else, things are as they are because they have developed that way. The history of that development must be worked out from tangible evidence: chiefly the objects and traces of past events and processes preserved on this planet itself. The surface of the Earth is no place to preserve deep history. This is in spite of—and in large part because of—the many events that have taken place on it. The surface of the future Earth, one hundred million years from now, will not have preserved evidence of contemporary human activity. One can be quite categorical about this. Whatever arrangement of oceans and continents, or whatever state of cool or warmth will exist then, the Earth’s surface will have been wiped clean of human traces. For the Earth is active. It is not just an inert mass of rock, an enormous sphere of silicates and metals to be mined by its freight of organisms, much as caterpillars chew through leaves.
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History is bunk—or so Henry Ford is reputed to have said. Folk memory, though, simplifies recorded statements. What Henry Ford actually told the Chicago Tribune was ‘History is more or less bunk. It’s tradition. We don’t want tradition. We want to live in the present, and the only tradition that is worth a tinker’s damn is the history that we make today.’ So folk memory, in this case, did pretty well reflect the kernel of his views. Henry Ford also said that ‘Exercise is bunk. If you are healthy, you don’t need it; if you are sick, you shouldn’t take it.’ Henry Ford was a very powerful, very rich man of strongly expressed views. And he was quite wrong on both counts. Not having known Henry Ford, interplanetary explorers may have their own view of history. As, perhaps, an indispensable means of understanding the present and of predicting the future. As a way of deducing how the various phenomena—physical, chemical, and biological—on any planet operate. And as a means of avoiding the kind of mistake—such as resource exhaustion or intra-species war—that could terminate the ambitions of any promising and newly emerged intelligent life-form. On Earth, and everywhere else, things are as they are because they have developed that way. The history of that development must be worked out from tangible evidence: chiefly the objects and traces of past events and processes preserved on this planet itself. The surface of the Earth is no place to preserve deep history. This is in spite of—and in large part because of—the many events that have taken place on it. The surface of the future Earth, one hundred million years from now, will not have preserved evidence of contemporary human activity. One can be quite categorical about this. Whatever arrangement of oceans and continents, or whatever state of cool or warmth will exist then, the Earth’s surface will have been wiped clean of human traces. For the Earth is active. It is not just an inert mass of rock, an enormous sphere of silicates and metals to be mined by its freight of organisms, much as caterpillars chew through leaves.