The origin and migration of domestic cats: a genetic study

… articles about a new genetic study of domestic cats and their ancestor, Felis silvestris—an analysis published in a paper in Nature Ecology & Evolution by Claudio Ottoni et al.

The reference and free link to the paper (if you have “Unpaywall”) is at the bottom, as well as a link to the study’s supplementary material. The paper was also summarized in articles in The Guardian and in a Nature News and Views piece, and got tons of attention in the press because, well, cats.

In truth, the results can be summarized briefly; they’re a bit surprising but not earthshaking. First, if you want a video presentation and don’t want to read this whole post, just watch the 3.5-minute Nature synopsis below:

The authors looked at the mitochondrial DNA of 352 ancient cats from 30 archaeological sites, with samples taken from teeth, skin, and hair. They also looked at recent museum specimens of the five known subspecies of F. silvestris: the subspecies names are silvestris, lybica, ornata, cafra, and bieti. Here are their distributions with the numbers corresponding to the 30 archaeological sites sampled:

It’s been known from previous genetic studies that domesticated cats came from just one of these subspecies F. silvestris lybica (FSL), although modern housecats in Europe hybridize, and thus get genes from, the European subspecies F. silvestris silvestris (FSS). We also know, from remains of a cat associated with an ancient burial in Cyprus, that cats were at least semi-domesticated by 10,000 years ago, though they were probably not pets but living in association with humans and used for controlling rodents (there was agriculture by then, and stored grain needed protection). Here’s a rather skinny FSL, showing that the wild species is a striped (“mackerel”) tabby cat, but what’s shown below is a real wild species:

What the new study found, though, was that, using easily extracted mitochondrial DNA (mtDNA), there are five genetically distinct groups, or “clades”, within FSL. Using the distribution of these clades from dated cat remains from known locations showed how where cats were domesticated and how they moved about with the help of humans (probably largely on ships, which also have rodents).

 

Continue reading “The origin and migration of domestic cats: a genetic study”

Wild Woman of Cumberland Island

 

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Today we will have a rare glimpse into one of the last remaining wild places in the Eastern United States, Cumberland Island, a 18 mile long island just off the coast of Southern Georgia, a semi-tropical eden of endangered wildlife and pristine ancient forests that has been protected as a wilderness area since 1982. In addition to loggerhead turtles and wild horses, it is home to Carol Ruckdeschel, subject of the new biography Untamed: the wildest woman in America and the fight for Cumberland Island. Today we are speaking with the author of that book, Will Harlan, the editor in chief of Blue Ridge Outdoors Magazine and award-winning journalist. Will was a park ranger on Cumberland Island for nearly twenty years. He initially dreaded crossing paths with this legendary witch of the wilderness, but the real Carol Ruckdeschel turned out to be a distinguished biologist, tireless steward of Cumberland island, and one of the most wildly fascinating people in America.

Human Population Growth and extinction

We’re in the midst of the Earth’s sixth mass extinction crisis. Harvard biologist E. O. Wilson estimates that 30,000 species per year (or three species per hour) are being driven to extinction. Compare this to the natural background rate of one extinction per million species per year, and you can see why scientists refer to it as a crisis unparalleled in human history.

The current mass extinction differs from all others in being driven by a single species rather than a planetary or galactic physical process. When the human race — Homo sapiens sapiens — migrated out of Africa to the Middle East 90,000 years ago, to Europe and Australia 40,000 years ago, to North America 12,500 years ago, and to the Caribbean 8,000 years ago, waves of extinction soon followed. The colonization-followed-by-extinction pattern can be seen as recently as 2,000 years ago, when humans colonized Madagascar and quickly drove elephant birds, hippos, and large lemurs extinct [1].

Lange’s metalmark butterfly from Amy Harwood.

The first wave of extinctions targeted large vertebrates hunted by hunter-gatherers. The second, larger wave began 10,000 years ago as the discovery of agriculture caused a population boom and a need to plow wildlife habitats, divert streams, and maintain large herds of domestic cattle. The third and largest wave began in 1800 with the harnessing of fossil fuels. With enormous, cheap energy at its disposal, the human population grew rapidly from 1 billion in 1800 to 2 billion in 1930, 4 billion in 1975, and over 7 billion today. If the current course is not altered, we’ll reach 8 billion by 2020 and 9 to 15 billion (likely the former) by 2050.

No population of a large vertebrate animal in the history of the planet has grown that much, that fast, or with such devastating consequences to its fellow earthlings. Humans’ impact has been so profound that scientists have proposed that the Holocene era be declared over and the current epoch (beginning in about 1900) be called the Anthropocene: the age when the “global environmental effects of increased human population and economic development” dominate planetary physical, chemical, and biological conditions [2].

  • Humans annually absorb 42 percent of the Earth’s terrestrial net primary productivity,30 percent of its marine net primary productivity, and 50 percent of its fresh water [3].
  • Forty percent of the planet’s land is devoted to human food production, up from 7 percent in 1700 [3].
  • Fifty percent of the planet’s land mass has been transformed for human use [3].
  • More atmospheric nitrogen is now fixed by humans that all other natural processes combined [3].

The authors of Human Domination of Earth’s Ecosystems, including the current director of the National Oceanic and Atmospheric Administration, concluded:

“[A]ll of these seemingly disparate phenomena trace to a single cause: the growing scale of the human enterprise. The rates, scales, kinds, and combinations of changes occurring now are fundamentally different from those at any other time in history. . . . We live on a human-dominated planet and the momentum of human population growth, together with the imperative for further economic development in most
of the world, ensures that our dominance will increase.”

Predicting local extinction rates is complex due to differences in biological diversity, species distribution, climate, vegetation, habitat threats, invasive species, consumption patterns, and enacted conservation measures. One constant, however, is human population pressure. A study of 114 nations found that human population density predicted with 88-percent accuracy the number of endangered birds and mammals as identified by the International Union for the Conservation of Nature [4]. Current population growth trends indicate that the number of threatened species will increase by 7 percent over the next 20 years and 14 percent by 2050. And that’s without the addition of global warming impacts.

Edward Humes

When the population of a species grows beyond the capacity of its environment to sustain it, it reduces that capacity below the original level, ensuring an eventual population crash.

“The density of people is a key factor in species threats,” said Jeffrey McKee, one of the study’s authors. “If other species follow the same pattern as the mammals and birds… we are facing a serious threat to global biodiversity associated with our growing human population.” [5].

So where does wildlife stand today in relation to 7 billion people? Worldwide, 12 percent of mammals, 12 percent of birds, 31 percent of reptiles, 30 percent of amphibians, and 37 percent of fish are threatened with extinction [6]. Not enough plants and invertebrates have been assessed to determine their global threat level, but it is severe.

Extinction is the most serious, utterly irreversible effect of unsustainable human population. But unfortunately, many analyses of what a sustainable human population level would look like presume that the goal is simply to keep the human race at a level where it has enough food and clean water to survive. Our notion of sustainability and ecological footprint — indeed, our notion of world worth living in — presumes that humans will allow for, and themselves enjoy, enough room and resources for all species to live.

REFERENCES CITED

  1. Eldridge, N. 2005. The Sixth Extinction. ActionBioscience.org.
  2. Crutzen, P. J. and E. F. Stoermer. 2000. The ‘Anthropocene’. Global Change Newsletter 41:17–18, 2000; Zalasiewicz, J. et al. 2008. Are We Now Living in the Anthropocene?. GSA Today (Geological Society of America) 18 (2): 4–8.
  3. Vitousek, P. M., H. A. Mooney, J. Lubchenco, and J. M. Melillo. 1997. Human Domination of Earth’s Ecosystems. Science 277 (5325): 494–499; Pimm, S. L. 2001. The World According to Pimm: a Scientist Audits the Earth. McGraw-Hill, NY; The Guardian. 2005. Earth is All Out of New Farmland. December 7, 2005.
  4. McKee, J. K., P. W. Sciulli, C. D. Fooce, and T. A. Waite. 2004. Forecasting Biodiversity Threats Due to Human Population Growth. Biological Conservation 115(1): 161–164.
  5. Ohio State University. 2003. Anthropologist Predicts Major Threat To Species Within 50 Years. ScienceDaily, June 10, 2003.
  6. International Union for the Conservation of Nature. 2009. Red List.

Oldest Fossils of Homo Sapiens Found in Morocco, Altering History of Our Species

An almost complete adult mandible discovered at the Jebel Irhoud site in Morocco. Credit Jean-Jacques Hublin/Max Planck Institute for Evolutionary Anthropology

Fossils discovered in Morocco are the oldest known remains of Homo sapiens, scientists reported on Wednesday, a finding that rewrites the story of mankind’s origins and suggests that our species evolved in multiple locations across the African continent.

“We did not evolve from a single ‘cradle of mankind’ somewhere in East Africa,” said Philipp Gunz, a paleoanthropologist at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and a co-author of two new studies on the fossils, published in the journal Nature. “We evolved on the African continent.”

Until now, the oldest known fossils of our species dated back just 195,000 years. The Moroccan fossils, by contrast, are roughly 300,000 years old. Remarkably, they indicate that early Homo sapiens had faces much like our own, although their brains differed in fundamental ways.

Today, the closest living relatives to Homo sapiens are chimpanzees and bonobos, with whom we share a common ancestor that lived over six million years ago. After the split from this ancestor, our ancient forebears evolved into many different species, known as hominins.

For millions of years, hominins remained very apelike. They were short, had small brains and could fashion only crude stone tools.

A composite reconstruction of the earliest known Homo sapiens fossils from Jebel Irhoud in Morocco based on micro computed tomographic scans of multiple original fossils. Credit Philipp Gunz/Max Planck Institute for Evolutionary Anthropology

Until now, the oldest fossils that clearly belonged to Homo sapiens were discovered in Ethiopia. In 2003, researchers working at a site called Herto discovered a skull estimated to be between 160,000 and 154,000 years old.

A pair of partial skulls from another site, Omo-Kibish, dated to around 195,000 years of age, at the time making these the oldest fossils of our species.

Findings such as these suggested that our species evolved in a small region — perhaps in Ethiopia, or nearby in East Africa. After Homo sapiens arose, researchers believed, the species spread out across the continent.

Only much later — roughly 70,000 years ago — did a small group of Africans make their way to other continents.

Continue reading “Oldest Fossils of Homo Sapiens Found in Morocco, Altering History of Our Species”

On the Origin of Extinction

Extinction has never been a purely scientific concept. When theories of extinction exploded onto the Western intellectual scene in the early 19th …

Extinction has never been a purely scientific concept. When theories of extinction exploded onto the Western intellectual scene in the early 19th century, they upended a reassuring view of nature as more or less fixed and stable. Since antiquity, it had seemed that human history might ebb and flow, that civilizations might rise and fall, but that nature, at least, always had been and always would be the same. But with the appearance of spectacular fossils—championed, most famously, by Georges Cuvier—this stability suddenly disappeared. On Cuvier’s account these were evidence of a catastrophe that had wiped out strange, monstrous creatures that once inhabited a warmer, swampier Earth. Nature itself suddenly appeared subject to the same uncertain temporality, possessed of the same self-destructive energy, as human society.

Extinction, then, first came into being as a problem of human meaning. For Alfred Tennyson, fossils were nature’s way of mocking the poet’s grief at his friend’s death: “From scarped cliff and quarried stone / She cries ‘A thousand types are gone: / I care for nothing, all shall go.’”1 Tennyson is left grasping at dust. H. G. Wells later employed the horror of extinction spectacularly in The Time Machine’s chilling ending; elsewhere, he reminded readers that “the long roll of palaeontology is half filled with the records of extermination.”2

But should we be horrified by extinction? Charles Darwin didn’t think so. In On theOrigin of Species, he mocked the catastrophist view of extinction as scientific illiteracy: “So profound is our ignorance, and so high our presumption, that we marvel when we hear of the extinction of an organic being; and as we do not see the cause, we invoke cataclysms to desolate the world!”3 Extinction was no cataclysm. Without it, the human species—along with all other life—would never have evolved.

We remain just as conflicted as 19th-century writers about what to make of extinction. Anthropogenic climate change is the first major development in the cultural story of extinction since Cuvier’s fossils and Darwin’s Origin. Tennyson and company were divided about whether to anthropomorphize nature as a callous fate or as a wise selective breeder. But none of them could imagine that humans themselves would become capable of causing planetary extinction. In recent years, however, the lethal combination of habitat destruction and global warming has elevated extinction rates to anywhere from 50 to 10,000 times the normal level. Most scientists believe that we are on the cusp of a mass extinction—only the sixth to take place in the three and a half billion years that Earth has existed.

Ursula Heise’s Imagining Extinction: The Cultural Meanings of Endangered Species and Ashley Dawson’s Extinction: A Radical History each wrest the extinction concept away from scientists. For Dawson, extinction must be understood as an internal feature of imperialist and capitalist attitudes toward nature that can be traced to antiquity. And for Heise it is a cultural narrative whose ethical implications are most explored in art, literature, digital media, and the law. But Heise and Dawson arrive at positions whose divergence reflects the persistent challenge of coming to terms with the human meaning of extinction.

Dawson is a catastrophist, like Cuvier and Tennyson. In Dawson’s judgment, extinction is properly understood as a cataclysmic effect of capitalism and imperialism, which depend on ever-increasing global expansion and resource expropriation. The solution is therefore obvious. Radicals must seize the assets of fossil fuel companies and initiate a transition to a postcapitalist steady-state economy in which there is no more imperative toward endless growth. This may seem extreme, but it is in fact a proportional response to the present scale of ecological crisis.

Expansion and exploitation are the threads of Dawson’s history, which takes a very long view of human responsibility for ecological degradation, or “ecocide.” Some historians have criticized the Anthropocene narrative propounded by scientists for presupposing a happy relation between humanity and nature prior to the industrial revolution. Dawson avoids this assumption, telling a story of humanity as a species that has been invasive for the past 30,000 years. The earliest moments of anthropogenic extinction include a “late Pleistocene wave of megadeath” in the wake of megafauna hunting and the Sumerian deforestation. The Roman Empire’s unsustainable agricultural practices and recreational killing of large animals like lions and elephants speak to “the exploitative attitude towards nature that accompanies empire.”

From prehistory and antiquity, we leap forward to early modern capitalism, where the exploitation of nature is perhaps more obviously endemic. The North American fur trade, which eroded beaver populations to the point that trapping itself became unprofitable, testifies to capitalism’s propensity to cause extinctions. The accumulation of capital depends on an endless extraction of natural resources, but limitations imposed by dwindling populations or resource exhaustion mean that at some point extraction must move elsewhere. “Capital’s logic is consequently that of a cancer cell, growing uncontrollably until it destroys the body that hosts it.” It is for this reason that Dawson takes a dim view of solutions to the present crisis that would be housed within the existing economic system of global capitalism.

Dawson asserts a direct causal link between political formations and attitudes toward nature. Empire entails extinction. “Capitalism is responsible” for most of the current extinctions. This perspective shapes the prescriptions offered in the second half of the book. De-extinction, the genetic recreation of extinct species, is cast as problematic because it enables a commodification of nature. More promising is a guaranteed income for the mostly poor inhabitants of biodiverse regions, which will discourage poaching and land clearing. Extinction ought to be understood as a symptom of the “terminal crisis of capitalism,” and so the tools to counteract it will be the same tools used to fight imperialism and capitalism.

Extinction first came into being as a problem of human meaning.

Continue reading “On the Origin of Extinction”

eternally wild

July 15, 2017

My Man-Boy,

Your life is an intuitive energy from the start. When you were born the first thing you did with all your being was search the unfamiliar place. You homed in on the body whose world you just left, fervently reconnected with this suddenly disconnected mother, and in that moment forged an eternal bond. That was your first innate endeavor after birth.

As with most humans born today, your early life senses were drenched in the artificial. But as you grew I watched you navigate around civilization’s apparatuses. You saw straight to the heart of what remains of forms and ways of nature. That is the remnant realm in which you chose to be. You went from gypsy meanderings awakening your instinctive senses, into overflowing awe and entire involvement with wildest wonders. You did not cave to the man-made limits of science or technology. You followed your born calling to be a naturalist, to be a part of nature, and be nature itself. Despite worldly troubles, you celebrated not merely the existence of nature, but your connection to nature, your bond with nature, your self as nature.

In your travels to deep wilds, you’ve honed an adaptive response to diverse environments. Your abilities to adapt and connect are who you are, lingering as lifelong requisites. You are a freeness of perceiving, of being, de-mediated through civilization. No matter how fragmented civilization becomes, you partake in the profound continuity of earth. As you did from birth, you search and connect and bond. You seek relations with human and nonhuman, with indigenous prodigy, to thrive and to be untampered by civilization.

Your calling to wildness evolved you into your present person. Your feral experiences have become you. You remain constantly aware of earth’s essence. Through humility, awe and nurturing deeds, you are one with wild earth, from forested mountains to seashores. You perceive that all life is a celebration of being in connection in organic form. As you return from adventures to settle with a partner into places already been, your life will be a celebration of increasingly diverse and deepening reconnections.

Now you have a ritual to present this union with your mate. There are many rituals of all life. Do not be uncomfortable participating in rituals. All animals not only indulge in them, but require them. All are nourished by them. In civilization, wild rituals have become formalized. But you can give natural meaning to your wedding. This ceremony marks the quenching of thirsts for life partners. It is civilization’s institutional ways that detract from the purity of the ritual. Your wedding, your union ritual, is yet another opportunity to discover and recover the way of wild, which you have done lifelong.

The way of wild is simply striving to thrive in earth communities, to continue melding your authentic self with authentic others. Domesticated culture cannot lame or tame or eliminate your essence. For the man-boy who has become nature, who retains the ability to hold nature identity into adulthood, be assured that wounding by civilization is an impossibility. For to be silenced or assaulted only increases the drive. It is the civilized who accept defeat and comply. Living civilized is virtual opposite living wild. You have chosen the way of wild. That is the mindset and striving of origins that cannot be crushed.

Don’t let yourself be distracted by civilization’s formalities. Your union ritual is a primal celebration of your bond together. Your connections revel in Liliana and your union, and that elation is energizing. Feel the boundless energy. Take it in and channel it into life. Your union is an earthly endeavor of your truest beings. A forging of another eternal bond. In this you are nature raw and pure.

Eternally,

Your Tiger-Mamma

decivilized:

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In the explorer’s journal by Thomas Farnham, “Travels In The Far Northwest 1839-1846”, Farnham writes of an anonymous Delaware trapper he encountered on his journeys, who had been educated at Dartmouth prior to traveling west. (Originally Dartmouth was commissioned by the Crown of England to educate Indians in the civilized ways.) Farnham’s account goes as follows:

“I inquired the reason of his leaving civilized life for a precarious livelihood in the wilderness. ‘For reasons found in the nature of my race’, he replied. ‘The Indian’s eye cannot be satisfied with a description of things, how beautiful soever may be the style, or the harmonies of verse in which it is conveyed. For neither the periods of burning eloquence, nor the mighty and beautiful creations of the imagination, can unbosom the treasures and realities as they live in their own native magnificence on the eternal mountains, and in the secret, untrodden vale.

As soon as you thrust the ploughshare under the earth, it teems with worms and useless weeds. It increases population to an unnatural extent; creates the necessity of penal enactments, builds the jail, erects the gallows, spreads over the human face a mask of deception and selfishness, and substitutes villany, love of wealth and power, and the slaughter of millions for the gratification of some individual instead of the single-minded honesty, the hospitality, the honour and the purity of the natural state. Hence, wherever Agriculture appears, the increase of moral and physical wretchedness induces the thousands of necessities, as they are termed, for abridging human liberty; for fettering down the mind to the principles of right, derived, not from nature, but from a restrained and forced condition of existence. And hence my race, with mental and physical habits as free as the waters which flow from the hills, become restive under the rules of civilized life; dwindle to their graves under the control of laws, customs, and forms, which have grown out of the endless vices, and the factitious virtue of another race. Red men often acquire and love the Sciences. But with the nature which the Great Spirit has given them, what are all their truths to them? Would an Indian ever measure the height of a mountain that he could climb? No, never. The legends of his tribe tell him nothing about quadrants, and base lines and angles. Their old braves, however, have for ages watched from the cliffs, the green life in the spring, and the yellow death in the autumn, of their holy forests. Why should he ever calculate an eclipse? He always knew such occurrences to be the doings of the Great Spirit. Science, it is true, can tell the times and seasons of their coming; but the Indian, when they do occur, looks through nature, without the aid of science, up to its cause. Of what use is a Lunar to him? His swift canoe has the green embowered shores, and well-known headlands, to guide its course. In fine, what are the arts of peace, of war, of agriculture, or any thing civilized, to him? His nature and its elements, like the pine which shadows its wigwam, are too mighty, too grand, of too strong a fibre, to form a stock on which to engraft the rose or the violet of polished life. No. I must range the hills, I must always be able to out-travel my horses, I must always be able to strip my own wardrobe from the backs of the deer and buffalo, and to feed upon their rich loins; I must always be able to punish my enemy with my own hand, or I am no longer an Indian. And if I am anything else, I am a mere imitation of an ape.’

The enthusiasm with which these sentiments were uttered impressed me with an awe I had never previously felt for the unborrowed dignity and independence of the genuine, original character of the American Indians. Enfeebled, and reduced to a state of dependence by disease and the crowding hosts of civilized men, we find among them still, too much of their own, to adopt the character of another race, too much bravery to feel like a conquered people, and a preference of annihilation to the abandonment of that course of life, consecrated by a thousand generations of venerated ancestors.

This Indian has been trapping among the Rocky Mountains for seventeen years. During that time, he has been often employed as an express to carry news from one trading post to another, and from the mountains to Missouri. In these journeys he has been remarkable for the directness of his courses, and the exceedingly short space of time required to accomplish them. Mountains which neither Indian nor white man dared attempt to scale, if opposing his right-line track, he has crossed. Angry streams, heavy and cold from the snows, and plunging and roaring among the girding caverns of the hills, he has swum; he has met the tempest as it groaned over the plains, and hung upon the trembling towers of the everlasting hills; and without a horse, or even a dog, traversed often the terrible and boundless wastes of mountains, and plains, and desert valleys, through which I am travelling; and the ruder the blast, the larger the bolts, and the louder the peals of the dreadful tempest, when the earth and the sky seem joined by a moving cataract of flood and flame driven by the wind, the more was it like himself, a free, unmarred manifestation of the sublime energies of nature.

He says that he never intends again to visit the States, or any other part of the earth ‘which has been torn and spoiled by the slaves of agriculture.’ ‘I shall live,’ said he, ‘and die in the wilderness.’ And assuredly he should thus live and die. The music of the rushing waters should be his requiem, and the Great Wilderness his tomb.” -Thomas Farnham, Travels in the Far Northwest, 1839-1846