What do we know about animal evolution in the early twenty-first century? How much more do we know today than Darwin did? What are the most exciting discoveries that have been made in the last few decades? Covering all the main animal groups, from jellyfish to mammals, this book considers all of these questions and more. Its 30 short chapters, each written in a conversational, nontechnical style and accompanied by numerous original illustrations, deal equally with the pattern and the process of evolution - with both evolutionary trees and evolutionary mechanisms. They cover diverse evolutionary themes, including: the animal toolkit, natural selection, embryos and larvae, animal consciousness, fossils, human evolution, and even the possibility of animal life existing elsewhere than on Earth. This unique text will make an excellent introduction for undergraduates and others with an interest in the subject.

What determines the direction of evolutionary change? This book provides a revolutionary answer to this question. Many biologists, from Darwin's day to our own, have been satisfied with the answer 'natural selection'. Professor Wallace Arthur is not. He takes the controversial view that biases in the ways that embryos can be altered are just as important as natural selection in determining the directions that evolution has taken, including the one that led to the origin of humans. This argument forms the core of the book. However, in addition, the book summarizes other important issues relating to how embryonic (and post-embryonic) development evolves. Written in an easy, conversational style, this is the first book for students and the general reader that provides an account of the exciting new field of Evolutionary Developmental Biology ('Evo-Devo' to its proponents).

All humans share three origins: the beginning of our individual lives, the appearance of life on Earth, and the formation of our planetary home. Life through Time and Space brings together the latest discoveries in both biology and astronomy to examine our deepest questions about where we came from, where we are going, and whether we are alone in the cosmos. A distinctive voice in the growing field of astrobiology, Wallace Arthur combines embryological, evolutionary, and cosmological perspectives to tell the story of life on Earth and its potential to exist elsewhere in the universe. He guides us on a journey through the myriad events that started with the big bang and led to the universe we inhabit today. Along the way, readers learn about the evolution of life from a primordial soup of organic molecules to complex plants and animals, about Earth's geological transformation from barren rock to diverse ecosystems, and about human development from embryo to infant to adult. Arthur looks closely at the history of mass extinctions and the prospects for humanity's future on our precious planet. Do intelligent aliens exist on a distant planet in the Milky Way, sharing the three origins that characterize all life on Earth? In addressing this question, Life through Time and Space tackles the many riddles of our place and fate in the universe that have intrigued human beings since they first gazed in wonder at the nighttime sky.

The two most fascinating questions about extraterrestrial life are where it is found and what it is like. In particular, from our Earth-based vantage point, we are keen to know where the closest life to us is, and how similar it might be to life on our home planet. This book deals with both of these key issues. It considers possible homes for life, with a focus on Earth-like exoplanets. And it examines the possibility that life elsewhere might be similar to life here, due to the existence of parallel environments, which may result in Darwinian selection producing parallel trees of life between one planet and another. Understanding Life in the Universe provides an engaging and myth-busting overview for any reader interested in the existence and nature of extraterrestrial life, and the realistic possibility of discovering credible evidence for it in the near future.

Why do the best-known examples of evolutionary change involve the alteration of one kind of animal into another very similar one, like the evolution of a bigger beak in a bird? Wouldn't it be much more interesting to understand how beaks originated? Most people would agree, but until recently we didn't know much about such origins. That is now changing, with the growth of the interdisciplinary field evo-devo, which deals with the relationship between how embryos develop in the short term and how they (and the adults they grow into) evolve in the long term. One of the key questions is: can the origins of structures such as beaks, eyes, and shells be explained within a Darwinian framework? The answer seems to be yes, but only by expanding that framework. This book discusses the required expansion, and the current state of play regarding our understanding of evolutionary and developmental origins.

The most important aspect of evolution, from a philosophical viewpoint, is the rise of complex, advanced creatures from simple, primitive ones. This "vertical" dimension of evolution has been downplayed in both the specialist and popular literature on evolution, in large part because it was in the past associated with unsavory political views. The avoidance of evolution's vertical dimension has, however, left evolutionary biology open to the perception, from outside, that it deals merely with the diversification of rather similar creatures, all at the same level of "advancedness" from a common ancestor--for example, the classic case studies of finches with different beaks or moths of different colors.
The latest incarnation of creationism, dubbed intelligent design (or ID), has taken advantage of this situation. It portrays an evolutionary process that is constantly guided--especially in its upward direction--by the hand of an unseen Creator, who is able to ensure that it ends up producing humans. "Creatures of Accident" attacks the antiscience ID worldview, mainly by building a persuasive picture of how "unaided" evolution produces advanced creatures from simple ones by an essentially accidental process. Having built this picture, in the final chapter the book reflects on its religious implications.

Are we alone in the universe, or are there other life forms 'out there'? This is one of the most scientifically and philosophically important questions that humanity can ask. Now, in the early 2020s, we are tantalizingly close to an answer. As this book shows, the answer will almost certainly be that life forms are to be found across the Milky Way and beyond. They will be thinly spread, to be sure. Yet the number of inhabited planets probably runs into the trillions. Some are close enough for us to detect evidence of life by analysing their atmospheres. This evidence may be found within a couple of decades. Its arrival will be momentous. But even before it arrives we can anticipate what life elsewhere will be like by examining the ecology and evolution of life on Earth. This book considers the current state of play in relation to these titanic issues.

Why do the best-known examples of evolutionary change involve the alteration of one kind of animal into another very similar one, like the evolution of a bigger beak in a bird? Wouldn't it be much more interesting to understand how beaks originated? Most people would agree, but until recently we didn't know much about such origins. That is now changing, with the growth of the interdisciplinary field evo-devo, which deals with the relationship between how embryos develop in the short term and how they (and the adults they grow into) evolve in the long term. One of the key questions is: can the origins of structures such as beaks, eyes, and shells be explained within a Darwinian framework? The answer seems to be yes, but only by expanding that framework. This book discusses the required expansion, and the current state of play regarding our understanding of evolutionary and developmental origins.

What determines the direction of evolutionary change? This book provides a revolutionary answer to this question. Many biologists, from Darwin's day to our own, have been satisfied with the answer 'natural selection'. Professor Wallace Arthur is not. He takes the controversial view that biases in the ways that embryos can be altered are just as important as natural selection in determining the directions that evolution has taken, including the one that led to the origin of humans. This argument forms the core of the book. However, in addition, the book summarizes other important issues relating to how embryonic (and post-embryonic) development evolves. Written in an easy, conversational style, this is the first book for students and the general reader that provides an account of the exciting new field of Evolutionary Developmental Biology ('Evo-Devo' to its proponents).

While neo-Darwinism has considerable explanatory power, it is widely recognized as lacking a component dealing with individual development, or ontogeny. This lack is particularly conspicuous when attempting to explain the evolutionary origin of the thirty-five or so animal body plans, and of the developmental trajectories that generate them. This significant work examines both the origin of body plans in particular and the evolution of animal development in general. Wallace Arthur ranges widely in his treatment, covering topics as diverse as comparative developmental genetics, selection theory, and Vendian/Cambrian fossils. He places particular emphasis on gene duplication, changes in spatio-temporal gene-expression patterns, internal selection, coevolution of interacting genes, and coadaptation. The book will be of particular interest to students and researchers in evolutionary biology, genetics, paleontology, and developmental biology.