The term "species" was thus defined by the celebrated botanist De Candolle: "A species is a collection of all the individuals which resemble each other more than they resemble anything else, which can by mutual fecundation produce fertile individuals, and which reproduce themselves by generation, in such a manner that we may from analogy suppose them all to have sprung from one single individual." And the zoologist Swainson gives a somewhat similar definition: "A species, in the usual acceptation of the term, is an animal which, in a state of nature, is distinguished by certain peculiarities of form, size, colour, or other circumstances, from another animal. It propagates, 'after its kind,' individuals perfectly resembling the parent; its peculiarities, therefore, are permanent."
To illustrate these definitions we will take two common English birds, the rook (Corvus frugilegus) and the crow (Corvus corone). These are distinct species, because, in the first place, they always differ from each other in certain slight peculiarities of structure, form, and habits, and, in the second place, because rooks always produce rooks, and crows produce crows, and they do not interbreed. It was therefore concluded that all the rooks in the world had descended from a single pair of rooks, and the crows in like manner from a single pair of crows, while it was considered impossible that crows could have descended from rooks or vice versâ. The "origin" of the first pair of each kind was a mystery. Similar remarks may be applied to our two common plants, the sweet violet (Viola odorata) and the dog violet (Viola canina). These also produce their like and never produce each other or intermingle, and they were therefore each supposed to have sprung from a single individual whose "origin" was unknown. But besides the crow and the rook there are about thirty other kinds of birds in various parts of the world, all so much like our species that they receive the common name of crows; and some of them differ less from each other than does our crow from our rook. These are all species of the genus Corvus, and were therefore believed to have been always as distinct as they are now, neither more nor less, and to have each descended from one pair of ancestral crows of the same identical species, which themselves had an unknown "origin." Of violets there are more than a hundred different kinds in various parts of the world, all differing very slightly from each other and forming distinct species of the genus Viola. But, as these also each produce their like and do not intermingle, it was believed that every one of them had always been as distinct from all the others as it is now, that all the individuals of each kind had descended from one ancestor, but that the "origin" of these hundred slightly differing ancestors was unknown. In the words of Sir John Herschel, quoted by Mr. Darwin, the origin of such species was "the mystery of mysteries."
Great Journeys allows readers to travel both around the planet and back through the centuries – but also back into ideas and worlds frightening, ruthless and cruel in different ways from our own. Few reading experiences can begin to match that of engaging with writers who saw astounding things: Great civilisations, walls of ice, violent and implacable jungles, deserts and mountains, multitudes of birds and flowers new to science. Reading these books is to see the world afresh, to rediscover a time when many cultures were quite strange to each other, where legends and stories were treated as facts and in which so much was still to be discovered.
Among the great men of the Victorian age Wallace occupied a unique position. He was the co-discoverer of the illuminating theory of Natural Selection; he watched its struggle for recognition against prejudice, ignorance, ridicule and misrepresentation; its gradual adoption by its traditional enemies; and its final supremacy. And he lived beyond the hour of its signal triumph and witnessed the further advance into the same field of research of other patient investigators who are disclosing fresh phases of the same fundamental laws of development, and are accumulating a vast array of new facts which tell of still richer light to come to enlighten every man born into the world. To have lived through that brilliant period and into the second decade of the twentieth century; to have outlived all contemporaries, having been the co-revealer of the greatest and most far-reaching generalisation in an era which abounded in fruitful discoveries and in revolutionary [pg 003]advances in the application of science to life, is verily to have been the chosen of the gods.
Who and what manner of man was Alfred Russel Wallace? Who were his forbears? How did he obtain his insight into the closest secrets of nature? What was the extent of his contributions to our stock of human knowledge? In which directions did he most influence his age? What is known of his inner life? These are some of the questions which most present-day readers and all future readers into whose hands this book may come will ask.
The relation of the stars to the sun and moon in their respective motions was one of the earliest problems for the astronomer, and it was only solved by careful and continuous observation, which showed that the invisibility of the former during the day was wholly due to the blaze of light, and this is said to have been proved at an early period by the observed fact that from the bottom of very deep wells stars can be seen while the sun is shining. During total eclipses of the sun also the brighter stars become visible, and, taken in connection with the fixity of position of the pole-star, and the course of those circumpolar stars which never set in the latitudes of Greece, Egypt, and Chaldea, it soon became possible to frame a simple hypothesis which supposed the earth to be suspended in space, while at an unknown distance from it a crystal sphere revolved upon an axis indicated by the pole-star, and carried with it the whole host of heavenly bodies. This was the theory of Anaximander (540 B.C.), and it served as the starting-point for the more complex theory which continued to be held in various forms and with endless modifications down to the end of the sixteenth century.
It is believed that the early Greeks obtained some knowledge of astronomy from the Chaldeans, who appear to have been the first systematic observers of the heavenly bodies by means of instruments, and who are said to have discovered the cycle of eighteen years and ten days after which the sun and moon return to the same relative positions as seen from the earth. The Egyptians perhaps derived their knowledge from the same source, but there is no proof that they were great observers, and the accurate orientation, proportions, and angles of the Great Pyramid and its inner passages may perhaps indicate a Chaldean architect.
From a renowned historian comes a groundbreaking narrative of humanity’s creation and evolution—a #1 international bestseller—that explores the ways in which biology and history have defined us and enhanced our understanding of what it means to be “human.”
One hundred thousand years ago, at least six different species of humans inhabited Earth. Yet today there is only one—homo sapiens. What happened to the others? And what may happen to us?
Most books about the history of humanity pursue either a historical or a biological approach, but Dr. Yuval Noah Harari breaks the mold with this highly original book that begins about 70,000 years ago with the appearance of modern cognition. From examining the role evolving humans have played in the global ecosystem to charting the rise of empires, Sapiens integrates history and science to reconsider accepted narratives, connect past developments with contemporary concerns, and examine specific events within the context of larger ideas.
Dr. Harari also compels us to look ahead, because over the last few decades humans have begun to bend laws of natural selection that have governed life for the past four billion years. We are acquiring the ability to design not only the world around us, but also ourselves. Where is this leading us, and what do we want to become?
Featuring 27 photographs, 6 maps, and 25 illustrations/diagrams, this provocative and insightful work is sure to spark debate and is essential reading for aficionados of Jared Diamond, James Gleick, Matt Ridley, Robert Wright, and Sharon Moalem.
A major book about the future of the world, blending intellectual and natural history and field reporting into a powerful account of the mass extinction unfolding before our eyes
Over the last half a billion years, there have been five mass extinctions, when the diversity of life on earth suddenly and dramatically contracted. Scientists around the world are currently monitoring the sixth extinction, predicted to be the most devastating extinction event since the asteroid impact that wiped out the dinosaurs. This time around, the cataclysm is us. In The Sixth Extinction, two-time winner of the National Magazine Award and New Yorker writer Elizabeth Kolbert draws on the work of scores of researchers in half a dozen disciplines, accompanying many of them into the field: geologists who study deep ocean cores, botanists who follow the tree line as it climbs up the Andes, marine biologists who dive off the Great Barrier Reef. She introduces us to a dozen species, some already gone, others facing extinction, including the Panamian golden frog, staghorn coral, the great auk, and the Sumatran rhino. Through these stories, Kolbert provides a moving account of the disappearances occurring all around us and traces the evolution of extinction as concept, from its first articulation by Georges Cuvier in revolutionary Paris up through the present day. The sixth extinction is likely to be mankind's most lasting legacy; as Kolbert observes, it compels us to rethink the fundamental question of what it means to be human.
In the current debate about creationism and intelligent design, there is an element of the controversy that is rarely mentioned-the evidence. Yet the proof of evolution by natural selection is vast, varied, and magnificent. In this succinct and accessible summary of the facts supporting the theory of natural selection, Jerry A. Coyne dispels common misunderstandings and fears about evolution and clearly confirms the scientific truth that supports this amazing process of change. Weaving together the many threads of modern work in genetics, paleontology, geology, molecular biology, and anatomy that demonstrate the "indelible stamp" of the processes first proposed by Darwin, Why Evolution Is True does not aim to prove creationism wrong. Rather, by using irrefutable evidence, it sets out to prove evolution right.
Sparked by a controversial debate in February 2014, Bill Nye has set off on an energetic campaign to spread awareness of evolution and the powerful way it shapes our lives. In Undeniable: Evolution and the Science of Creation, he explains why race does not really exist; evaluates the true promise and peril of genetically modified food; reveals how new species are born, in a dog kennel and in a London subway; takes a stroll through 4.5 billion years of time; and explores the new search for alien life, including aliens right here on Earth.
With infectious enthusiasm, Bill Nye shows that evolution is much more than a rebuttal to creationism; it is an essential way to understand how nature works—and to change the world. It might also help you get a date on a Saturday night.
"Intelligent Design" is being taught in our schools; educators are being asked to "teach the controversy" behind evolutionary theory. There is no controversy. Dawkins sifts through rich layers of scientific evidence—from living examples of natural selection to clues in the fossil record; from natural clocks that mark the vast epochs wherein evolution ran its course to the intricacies of developing embryos; from plate tectonics to molecular genetics—to make the airtight case that "we find ourselves perched on one tiny twig in the midst of a blossoming and flourishing tree of life and it is no accident, but the direct consequence of evolution by non-random selection." His unjaded passion for the natural world turns what might have been a negative argument, exposing the absurdities of the creationist position, into a positive offering to the reader: nothing less than a master’s vision of life, in all its splendor.
By examining fossils and DNA, he shows us that our hands actually resemble fish fins, our heads are organized like long-extinct jawless fish, and major parts of our genomes look and function like those of worms and bacteria. Your Inner Fish makes us look at ourselves and our world in an illuminating new light. This is science writing at its finest—enlightening, accessible and told with irresistible enthusiasm.
Publication of The Souls of Black Folk was a dramatic event that helped to polarize black leaders into two groups: the more conservative followers of Washington and the more radical supporters of aggressive protest. Its influence cannot be overstated. It is essential reading for everyone interested in African-American history and the struggle for civil rights in America.
The Story of the Human Body brilliantly illuminates as never before the major transformations that contributed key adaptations to the body: the rise of bipedalism; the shift to a non-fruit-based diet; the advent of hunting and gathering, leading to our superlative endurance athleticism; the development of a very large brain; and the incipience of cultural proficiencies. Lieberman also elucidates how cultural evolution differs from biological evolution, and how our bodies were further transformed during the Agricultural and Industrial Revolutions.
While these ongoing changes have brought about many benefits, they have also created conditions to which our bodies are not entirely adapted, Lieberman argues, resulting in the growing incidence of obesity and new but avoidable diseases, such as type 2 diabetes. Lieberman proposes that many of these chronic illnesses persist and in some cases are intensifying because of “dysevolution,” a pernicious dynamic whereby only the symptoms rather than the causes of these maladies are treated. And finally—provocatively—he advocates the use of evolutionary information to help nudge, push, and sometimes even compel us to create a more salubrious environment.
(With charts and line drawings throughout.)