Author
August Weismann
1834-1914
August Weismann (1834-1914) is a public-domain author available on Rivro. Read free books, explore subjects, and discover related classics.
Subjects
Books by August Weismann
The Evolution Theory, Vol. 1 of 2
"The Evolution Theory, Vol. 1 of 2" by August Weismann is a scientific publication written in the early 20th century. This work builds upon the foundations of evolutionary thought established by Darwin and others, delving into the intricacies of heredity, descent, and the processes that govern the transformation of life forms over time. Weismann aims to present a coherent theory of evolution, countering criticisms and integrating newly observed facts within a broader context. The opening of the book introduces the author's motivation for compiling these lectures, which encompass his lifelong research and advocacy for the Theory of Descent. Weismann argues that the diversity of life has evolved through a series of transformations from simpler forms, linking the concepts of heredity, reproduction, and evolution. He emphasizes the importance of grounding theories in observable facts and acknowledges the evolving nature of understanding within biological science. Through a historical lens, he sets the stage for discussing the various theories of evolution while identifying his own views and the significant contributions of earlier naturalists.
Essays Upon Heredity and Kindred Biological Problems Authorised Translation
"Essays Upon Heredity and Kindred Biological Problems" by August Weismann is a scientific publication written in the late 19th century. The work is a compilation of essays that delve into the biological concepts surrounding heredity, particularly examining the duration of life and various related biological phenomena. Weismann's ideas are influential in the field of evolutionary biology, where he discusses the implications of heredity and the processes that underpin the life cycle of organisms. At the start of the work, the author introduces his essay titled "The Duration of Life," which he had previously presented at a naturalists' meeting. Weismann reflects on the variability in life spans among different species, arguing that while structural and chemical factors contribute to an organism's longevity, the causes of life duration also have roots in natural selection and adaptation to environmental conditions. He raises questions surrounding the limits of life, considers the interplay between size and longevity, and challenges conventional reasoning about how external factors might not solely dictate life span but rather, a complex interplay of internal and external mechanisms governs it. The opening sets the stage for a rigorous exploration of these biological principles throughout the subsequent essays.
Studies in the Theory of Descent, Volume II
"Studies in the Theory of Descent, Volume II" by August Weismann is a scientific publication written in the late 19th century. This work delves into the concepts of biological development, focusing particularly on the independence and variability of the different stages of metamorphosis in insects. Weismann explores the relationship between larva and imago, or the adult stage, presenting various cases that demonstrate how these stages can exhibit independent variations despite being part of the same organism. At the start of the volume, Weismann introduces the idea that the physical structure of the larva and its corresponding imago can vary independently of each other. He discusses how these variations can manifest differently across species and stages of development, addressing questions about the influences that cause such differences—whether they arise from inherent biological factors or external environmental conditions. Through examples from Lepidoptera, he argues that changes in one developmental stage do not necessarily affect the others, setting the foundation for a deeper investigation into the nature of organismal development and the mechanics of evolutionary change. This opening establishes a framework for understanding variability and adaptation in the context of evolutionary theory, aiming to link morphological changes with environmental interactions.
The Evolution Theory, Vol. 2 of 2
"The Evolution Theory, Vol. 2 of 2" by August Weismann is a scientific publication written in the early 20th century. This work is focused on biological evolution, particularly exploring concepts related to regeneration, inheritance, and the mechanisms of evolution as understood in that era. The book elaborates on the principles of heritable traits and how they are transmitted across generations, contributing to a foundational understanding of evolutionary biology. At the start of the volume, Weismann introduces the topic of regeneration, discussing the various forms it takes in different organisms and the underlying biological principles. He emphasizes that regeneration is an adaptive phenomenon, varying widely between species based on their exposure to injuries and environmental conditions. He argues that regeneration is not a universal trait but rather a complex capacity that has evolved as a response to specific survival needs. Through a detailed examination of examples such as hydra, newts, and earthworms, Weismann sets the stage for an in-depth exploration of the processes that govern regeneration and heredity, laying the groundwork for the subsequent chapters in the book.
Studies in the Theory of Descent, Volume I
"Studies in the Theory of Descent, Volume I" by August Weismann is a scientific publication written in the late 19th century. This work extensively explores the principles of evolution, specifically focusing on the origins and significance of seasonal dimorphism in butterflies and how variations in external conditions influence these phenomena. The content provides insights into Weismann's theories on inheritance, variation, and the impact of climate on species adaptation. The opening of this volume introduces the concept of seasonal dimorphism, exemplified by the butterfly species "Araschnia Levana", which appears in distinct winter and summer forms. Weismann discusses his experimental findings that suggest these variations are not merely superficial but are influenced by direct external conditions such as temperature and the duration of the developmental stages. He details a series of experiments and observations aimed at understanding whether these differences arise from adaptation via natural selection or from underlying biological processes, ultimately leading toward a deeper investigation of the mechanisms behind evolutionary change.
Studies in the Theory of Descent (Volumes 1 and 2)
"Studies in the Theory of Descent" by August Weismann is a scientific publication written in the late 19th century. This work delves into the principles of evolution, focusing significantly on the mechanisms of inheritance and variability in species, particularly in insects. It aims to investigate the interactions between environmental factors and biological development, thereby exploring the complexities and implications of evolutionary theory. At the start of this work, Weismann introduces the concept of seasonal dimorphism in butterflies, where different forms of a species appear at different times of the year, as exemplified by the species "Araschnia Levana". He describes experiments that reveal how environmental influences, such as temperature, can affect the development and characteristics of butterflies, offering insights into the origin of their markings. Weismann challenges existing views on adaptation and establishes a basis for further investigation into how species may evolve and adapt over time, highlighting the significance of both inherited traits and external conditions in shaping biological forms.
On Germinal Selection as a Source of Definite Variation
"On Germinal Selection as a Source of Definite Variation" by August Weismann is a scientific publication written in the late 19th century. The work discusses the theory of germinal selection as a mechanism of evolution, aiming to clarify and expand upon the principles of natural selection originally proposed by Darwin and Wallace. Weismann seeks to argue that variation and adaptation arise not purely from random chance but through underlying processes connected to the germinal elements of organisms, which can direct the course of evolution. The opening of this work presents the author's preliminary arguments and the context for his theory. Weismann introduces the concept of germinal selection, which posits an internal mechanism that influences the direction of variation in response to external environmental pressures. He discusses the criticisms of conventional selection theories and emphasizes the importance of exploring deeper biological mechanisms, arguing that understanding the role of germs and determinants is essential for explaining how useful variations arise and how organisms adapt to their environments over generations. The preface sets the stage for a detailed analysis of heredity, variation, and selection, showcasing Weismann's ambition to enhance the discourse on evolutionary biology.