Introduction to Life

This chapter introduces what life is and what characterises it, discusses its diversity, then introduces the theory of evolution. It ends with a section discussing how scientists investigate research problems called the “Process of Science.” Living organisms share very defined characteristics—the sum of which make the “wholeness” we call life. Carl Linnaeus proposed a binomial system of classification where each organism's scientific name has two distinct parts: the genus and the species. Charles Darwin formulated the theory of natural selection which explains how evolution works. Humans share a lot in common with other living organisms, but there are features that make us distinctly human not shared with any other living organisms. The practice of science uses a carefully formulated series of steps in investigating problems. Science cannot explain everything especially philosophical questions that involve issues of right and wrong.

2019 ◽  
Vol 25 ◽  
pp. 344-347
Author(s):  
H. B. Humeniuk ◽  
I. B. Chen ◽  
O. S. Voloshyn

Charles Robert Darwin is an English naturalist, geologist and biologist. He was one of the first to realize and clearly demonstrated that all living organisms evolved over time from common ancestors. The main driving force of evolution was called natural selection and uncertain variability. The existence of evolution was recognized by most scientists during the life of Charles Darwin, while his theory of natural selection, as the main explanation of evolution, became universally recognized only in the 30’s of the XX century. The ideas and discoveries of Charles Darwin, in a revised form, form the foundation of a modern synthetic theory of evolution and form the basis of biology, providing a logical explanation for biodiversity. Orthodox followers of Darwin’s teachings develop the direction of the evolutionary thought bearing his name Darwinism. Keywords: evolution, natural selection, uncertain variability, theory, biodiversity.


Author(s):  
Samir Okasha

In 1859 Charles Darwin published On the Origin of Species, in which he set out his theory of evolution. The book marked a turning point in our understanding of the natural world and revolutionized biology. ‘Evolution and natural selection’ outlines the theory of evolution by natural selection, explaining its unique status in biology and its philosophical significance. It considers how Darwin’s theory undermined the ‘argument from design’, a traditional philosophical argument for the existence of God; how the integration of Darwin’s theory with genetics, in the early 20th century, gave rise to neo-Darwinism; and why, despite evolutionary theory being a mainstay of modern biology, in society at large there is a marked reluctance to believe in evolution.


Author(s):  
Michael Ruse

The modern usage of the term Darwinism dates from the publication of On the Origin of Species, by Charles Darwin, in which he argued for evolution through natural selection. Very soon after the appearance of the Origin (in 1859), Darwin’s great supporter Thomas Henry Huxley introduced the term Darwinism. The term—together with the related terms Darwinian and Darwinist—took root. The codiscoverer of natural selection, Alfred Russel Wallace, used the term as the title of a book expounding evolution: Darwinism: An Exposition of the Theory of Natural Selection, with Some of Its Applications. Note that there seems to be a fuzziness about the term. Some identify Darwinism with evolution through natural selection. Others suggest that the essence of Darwinism is not selection per se but change or variation. Late in the 19th century, George Romanes coined the term neo-Darwinism to cover those for whom natural selection is basically the only significant cause of change. In 1930 Ronald A. Fisher, in his Genetical Theory of Natural Selection, argued that the newly developed theory of Mendelian genetics offered the required foundation for a perspective that made natural selection the central force of evolutionary change. Although the British were happy to call the Darwin-Mendel synthesis neo-Darwinism, in America the synthesis was known as the synthetic theory of evolution. This reflects that in the New World it was Sewall Wright who did the foundational work in bringing Mendelian genetics into the evolutionary picture and that he never thought of natural selection as being the force that Fisher took it to be. For Wright and his followers, especially Theodosius Dobzhansky, genetic drift was always a major component of the evolutionary picture, and as Fisher pointed out nonstop, this is about as non-Darwinian a notion as it is possible to have. By 1959 professional evolutionists (on both sides of the Atlantic) agreed that Darwin had been right about natural selection: it is the major cause of evolutionary change. Neo-Darwinism fell into disuse, as everyone now used the term Darwinism for evolution through natural selection. Mention should also be made of so-called social Darwinism, the application of Darwinism to persons and groups within society. The earliest use apparently was during Darwin’s own lifetime, by a historian discussing land tenure in Ireland. However, it was not a popular or general term, coming into widespread use only in the 1940s, with the publication of the American historian Richard Hofstadter’s book Social Darwinism in American Thought.


Joseph Dalton Hooker was eight years the junior of Charles Darwin (1809-82) and lived twenty-nine years after Darwin’s death. He was, for a long period, the personal friend of Darwin and the frank critic of many of Darwin’s researches and of the botanical aspects of Darwinian theories. Hooker was a botanist and, since he had an extensive first-hand experience of many branches of botany, above all of plant taxonomy and phytogeography, it was naturally the botanical aspects of evolutionary problems which both interested him and concerning which he was best able to help Darwin. Such help was gratefully and fully acknowledged by Darwin, as is shown by published correspondence. Numerous letters passed between Darwin and Hooker and the latter visited his friend at Down and stayed there for periods of varying length. A considerable amount of living material was obviously supplied from Kew for the later botanical experiments Darwin carried out at Down. The assistance given by Hooker in the accumulation of facts and in criticism of theories preparatory to the publication of the Origin of species and later works of Darwin, his presenting (with Lyell) and reading Darwin’s communication to the Linnean Society of London on 1 July 1858 introducing the theory of natural selection, and his influence in gaining the speedy general acceptance of the theory of evolution are well known and it is not necessary to consider them here in much detail. It is proposed, instead, to outline very briefly the salient facts in the life of J.D. Hooker and then to devote the major part of this essay to a consideration of the development of his views on the problems of species, phytogeography, and evolution. In part at least, this means considering the influence of Darwin on Hooker but, from a wider viewpoint, it is possible to form some conception of the clarifying and unifying effects of the acceptance of the general theory of evolution on biological thought.


2008 ◽  
Vol 28 (2) ◽  
Author(s):  
Steven A. Gelb

When Charles Darwin turned his attention to writing about human descent in 1871 he attempted to narrow the fossil gap between human beings and higher primates by presenting persons with intellectual disabilities — "idiots" in the language of the day — as evidence in support of the theory of evolution. This paper explores the four ways that Darwin used persons with intellectual disabilities in The Descent of Man: 1) as intermediate rung on the evolutionary ladder connecting humans and primates; 2) as exemplars of the inevitable waste and loss produced by natural selection acting upon variability; 3) as the floor of a scale representing the "lowest", most unfit variety of any species when individuals were rank ordered by intelligence; and 4) as atavistic reversions to extinct forms whose study would reveal the characteristics of earlier stages of human evolution. Darwin's strategic use of intellectual disability is brought to bear on the controversy regarding the mental state of Darwin's last child.


Author(s):  
Keith Stewart Thomson

All of science is fundamentally about cause. It is about explanations of the reasons things are the way they are and the mechanisms that produce them. It is now commonplace to observe that Charles Darwin brought evolution and all of organismal biology into line as a truly scientific subject by discussing evolutionary phenomena in terms of cause, and thus in the same testable, quantifiable frame of reference that applies to other science. Darwin's theory of natural selection as a causal agency for evolutionary change was only the beginning of our problems, not the end. For more than a hundred years, we have sought to find all the layers and intersecting lines of causality that produce natural selection as well as to discover other mechanisms for change that are nonselective in nature—genetic drift or neutral mutations, for example. Natural selection is basically a mechanism that involves two components: the introduction of variants into a system and the subsequent sorting of these variants (Vrba and Eldredge, 1984) so that, over generations, there is a differential contribution of these variants to higher levels such as populations and species. Up to the present time, most attention of evolutionists has concentrated upon two aspects of the problem: the genetic basis of phenotypic variation and the dynamic properties of populations containing the individual variants. The present book is concerned with the mechanisms affecting the expression of variation among individual phenotypes. It has been a surprisingly neglected subject. The New Synthetic theory of evolution and its later modifications have largely been pursued as if the intrinsic mechanisms by which variation is caused among individual organismal phenotypes are less important to the processes of evolution than the extrinsic mechanisms of sorting. If only by default, variation introduced at the level of the individual phenotypes is commonly treated as if it were a simple mapping of variation at the genetic level, or at least were only a very simple function of that. It has seemed not only necessary but sufficient to study genetics in order to understand phenotypic variation.


Polar Record ◽  
1985 ◽  
Vol 22 (139) ◽  
pp. 413-420 ◽  
Author(s):  
Richard Grove

AbstractCharles Darwin's notes, diary entries and letters covering visits to southern South America and the Falkland Islands in 1833 and 1834 throw light on the revolutionary events of the time. His notes also contain the first indication of an evolutionary concept, suggested by the endemic flora and fauna of the Falklands, which guided his later observations on the Galapagos Islands and lead ultimately to his theory of evolution by natural selection.


Religions ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 124
Author(s):  
Michael Ruse

Does God exist? If he does, what is the evidence for this? Can one arrive at God through reason (natural theology), or is it faith or nothing (revealed theology)? I write of my lifetime of wrestling with this question. Raised a Quaker, I lost my faith at the age of 20. As an academic, I became an expert on Charles Darwin and his theory of evolution through natural selection. How can I make sense of—and how can I reconcile—these two hugely important things in my life? At the age of 80, I find myself a long-standing agnostic. This is not, as Francis Collins claims, a “cop out.” Showing my debt to my Quaker heritage, I am theologically apophatic. I can say only what I do not know. I find this quite-out-of-character modesty hugely exciting. It gives my life great meaning.


Author(s):  
J. Arvid Ågren

To many evolutionary biologists, the central challenge of their discipline is to explain adaptation, the appearance of design in the living world. With the theory of evolution by natural selection, Charles Darwin elegantly showed how a purely mechanistic process can achieve this striking feature of nature. Since Darwin, the way many biologists think about evolution and natural selection is as a theory about individual organisms. Over a century later, a subtle but radical shift in perspective emerged with the gene’s-eye view of evolution in which natural selection was conceptualized as a struggle between genes for replication and transmission to the next generation. This viewpoint culminated with the publication of The Selfish Gene by Richard Dawkins (Oxford University Press, 1976) and is now commonly referred to as selfish gene thinking. The gene’s-eye view has subsequently played a central role in evolutionary biology, although it continues to attract controversy. The central aim of this accessible book is to show how the gene’s-eye view differs from the traditional organismal account of evolution, trace its historical origins, clarify typical misunderstandings and, by using examples from contemporary experimental work, show why so many evolutionary biologists still consider it an indispensable heuristic. The book concludes by discussing how selfish gene thinking fits into ongoing debates in evolutionary biology, and what they tell us about the future of the gene’s-eye view of evolution. The Gene’s-Eye View of Evolution is suitable for graduate-level students taking courses in evolutionary biology, behavioural ecology, and evolutionary genetics, as well as professional researchers in these fields. It will also appeal to a broader, interdisciplinary audience from the social sciences and humanities including philosophers and historians of science


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