Evolution in Modern Thought Informative Summary


This book, Evolution in Modern Thought, published in 1907, presents a series of essays exploring the impact of Darwin’s revolutionary theory of evolution on various fields of study. The essays, written by leading scientists and thinkers of the time, delve into the historical context of Darwin’s work, examine the factors that contribute to evolutionary change, and analyze the implications of Darwinism for different disciplines.

The first essays focus on the historical context of Darwin’s work, exploring the ideas of his predecessors and highlighting his unique contributions. Later essays delve into the specific impact of Darwinism on various fields. For instance, one essay explores the evolution of the human mind and its implications for understanding human behavior and moral values. Another essay examines the role of evolution in shaping history and explores the limitations of applying general evolutionary principles to the complex dynamics of human societies. The book concludes with a reflection on the ongoing debate surrounding Darwinism and its enduring influence on scientific and philosophical thought.

Key Findings:

  • Darwin’s theory of evolution, specifically natural selection, provided a powerful explanation for the diversity and adaptation of life on Earth.
  • The theory of natural selection sparked extensive debate regarding the role of evolution in shaping the human species, leading to significant advancements in anthropology and related fields.
  • The “struggle for existence” and “survival of the fittest” concepts, central to Darwinism, were applied widely to various fields, impacting social, political, and economic thought, sparking debates about human progress and the role of society.
  • The book highlights the complexities of evolutionary processes and the limitations of applying general evolutionary principles to understand specific events in history and society.


  • Understanding the History of Evolutionary Thought: Readers will gain insights into the historical development of the idea of evolution, tracing its roots back to ancient philosophers and highlighting the contributions of Darwin and his contemporaries.
  • The Power of Natural Selection: The essays provide a comprehensive overview of Darwin’s theory of natural selection, explaining its mechanisms and its role in shaping the diversity and adaptation of living organisms.
  • Debates Surrounding Darwinism: Readers will be exposed to the ongoing debates surrounding Darwinism, including the controversy regarding the inheritance of acquired characteristics and the validity of applying evolutionary principles to human society.
  • The Impact of Evolution on Various Fields: The essays showcase the wide-ranging influence of Darwinism on diverse disciplines, including anthropology, history, philosophy, and religion. This provides a multi-faceted perspective on the transformative power of Darwin’s theory.

Historical Context:

The essays were written in 1907, a time of significant scientific and societal upheaval. The theory of evolution was still hotly debated, particularly in relation to the human species. The essays reflect the growing acceptance of Darwinism among the scientific community, but also the ongoing resistance from religious and philosophical quarters. The world was undergoing rapid industrial and technological advancements, and the rise of social Darwinist thinking influenced political and economic discourse.


  • Darwin’s theory of evolution emphasizes the idea that species change over time through a process of natural selection.
  • Natural selection favors individuals with advantageous traits, allowing them to survive and reproduce more successfully.
  • Darwin’s work revolutionized our understanding of the natural world and sparked a major shift in scientific thinking.
  • The concept of “struggle for existence” became a central tenet of Darwinism, influencing various fields, including sociology, economics, and politics.
  • Darwin’s theory of evolution helped to dismantle the long-held belief in the fixity of species, promoting the concept of continuous change and adaptation.
  • Darwin’s work was controversial, leading to intense debate within the scientific community and sparking conflict between science and religion.
  • The theory of natural selection provided a plausible explanation for the diversity and complexity of life on Earth, reducing the need for a supernatural creator.
  • The book explores the evolution of the human species, examining the anatomical and physiological similarities between humans and other primates.
  • The book highlights the importance of understanding the historical context in which Darwin’s work emerged and the significant contributions of his predecessors.
  • The book emphasizes the importance of careful observation and evidence-based research in understanding evolutionary processes.
  • Darwin’s work continues to be a source of inspiration and debate, influencing various fields of study and shaping our understanding of the natural world.
  • The book examines the debate surrounding the inheritance of acquired characteristics, highlighting the complexities of heredity and the role of environmental factors in shaping traits.
  • Darwin’s theory of evolution challenged the traditional view of human exceptionalism, prompting a reassessment of the relationship between humans and the natural world.
  • The book explores the emergence of social Darwinism, a controversial application of Darwinian principles to human societies, and its impact on social and political thought.
  • The book highlights the importance of considering the psychological and social factors in understanding human evolution, beyond the purely biological.
  • The book emphasizes the ongoing debate about the nature of evolution, particularly the relative importance of gradual change and sudden mutations.


  • The ratio of elimination in species is often very high. For example, only two out of six elephant offspring survive in a given area.
  • The average number of descendants that survive to reproduce in a species is only two per pair, highlighting the intensity of the struggle for existence.
  • In some species of Mayflies (Ephemerids), the females are in the minority, with a ratio of 1:100 compared to males, indicating the high level of competition among males.
  • Over 90% of the pupae of the “tortoise-shell butterfly” were killed in one experiment, emphasizing the high rate of elimination by predators.
  • In tropical trees, the number of leaves that have evolved to be thick and leathery as protection against heavy rain is significant.
  • In the single genus of butterflies, Anaea, there are over 100 species with a deceptive leaf-like appearance.
  • In some cases, the same species of butterfly exhibits different patterns of color and markings, showcasing the wide range of variation.


  • Adaptation: A process by which an organism becomes better suited to its environment.
  • Coadaptation: The harmonious development of different parts of an organism, each contributing to a specific function.
  • Darwinism: The theory of evolution by natural selection, proposed by Charles Darwin.
  • Degeneration: The process of a species losing or reducing its complexity or function over time.
  • Germinal Selection: A process of selection operating at the level of the germ cells, influencing the characteristics of future generations.
  • Mimicry: A phenomenon where one species evolves to resemble another species, often for protection from predators.
  • Mutation: A sudden change in an organism’s genetic material, potentially leading to the emergence of new traits.
  • Natural Selection: The process by which individuals with advantageous traits are more likely to survive and reproduce, leading to the evolution of species.
  • Sexual Selection: A process where individuals with desirable traits are more likely to attract mates, resulting in the development of secondary sexual characteristics.
  • Species: A group of organisms that can interbreed and produce fertile offspring.


  • The Woodpecker: The specialized beak and claws of woodpeckers are adaptations for climbing and foraging for insects in trees.
  • The Leaf-Butterfly: Butterflies like Kallima inachis have evolved a leaf-like appearance on their wings, providing camouflage and protection from predators.
  • The Praying Mantis: The green and brown variations of the praying mantis (Mantis religiosa) illustrate the role of protective coloration in nature.
  • The Yucca Moth: The relationship between the Yucca moth (Pronuba yuccasella) and the Yucca plant exemplifies the mutualistic interdependence of species, showcasing coadaptation.
  • The Irish Elk: The Giant Stag of the Irish peat, with its massive antlers, is a striking example of coadaptation, where the development of one trait (antlers) led to a cascade of related changes in other body parts.
  • The Driver Ants: The distinct castes of workers in driver ants, with their specialized functions, demonstrate the complexity of social organization in insects.
  • The Whale: The many adaptations of whales to aquatic life, including their streamlined body shape, flippers, and blowhole, illustrate the transformative power of natural selection.
  • The Moth Shark: The “shark” moth Xylina vetusta has evolved a remarkable instinct to feign death when threatened, illustrating the close link between behavior and adaptation.
  • The Duckling: The instinctive swimming behavior of a duckling, emerging soon after birth, highlights the role of heredity in shaping behavior.
  • The Peacock: The elaborate plumage and courtship displays of the male peacock demonstrate the influence of sexual selection in shaping species.


Evolution in Modern Thought offers a captivating and thought-provoking exploration of Darwin’s lasting impact on scientific and philosophical thought. The essays demonstrate the power of Darwin’s theory of evolution in explaining the diversity and adaptation of life and the subsequent debates surrounding its applications to human society. The book emphasizes the importance of acknowledging the complexity of evolutionary processes, recognizing both the role of natural selection and the significant influence of psychological and social factors. Ultimately, Evolution in Modern Thought serves as a reminder of the ongoing scientific inquiry into the mysteries of life and the transformative power of Darwin’s ideas.

Learn more

What is the best quiz for you business?

Quizzes are super effective for lead generation and selling products. Find the best quiz for your business by answering a few questions.

Take the quiz