Life History Evolution In Plants

"The lack of discussion of the life histories of modular organisms is the weakness of this book that I most regret. . . . Modular organisms are different. " S. C. Steams: The Evolution of Life Histories (1992) Life-history theory endeavours to increase our understanding of the processe,s whereby the broad features of the life cycles of organisms, such as the timing and magnitude of reproduction, have evolved. Although reproductive traits have dominated as study objects due to their immediate importance for evolutionary success, much work has also been conducted on patterns of development, growth and senescence, as well as on the shifts in resource allocation related to these processes. The basic axiom of life-history theory is that patterns of life histories, such as reproductive traits, are subject to evolutionary explanation. This idea can be traced back at least as far as Darwin's Origin of Species (1859). In his discussion of plant domestication, Darwin wrote: "I cannot doubt that the continued selection of slight variations, either in the leaves, the flowers, or the fruit, will produce races differing from each other chiefly in these characters". Darwin was impressed by the success of plant breeders in moulding the growth and reproductive parameters of cultivated plants, and believed that natural selection could have a similar impact in natural populations.

This book reexamines patterns of relationship among plant life history traits in phylogenetic perspective. The reexamination first recognizes that because evolution is a branching process, traits are not randomly distributed across taxa and that therefore analysis of trait correlations cannot treat species as independent data points. It then discusses the use of phylogeny to reconstruct the evolutionary pathways of traits. Part 1 looks at the use of the phylogenetic perspective on trait correlation. Parts 2-4 examine traits from the reproductive phase from seed production and dispersal to recruitment and growth. The final section looks at interactions between plants and competitors, herbivores and microbial symbionts, recognizing that these interactions may have an ancient evolutionary history.

Although plants comprise more than 90% of all visible life, and land plants and algae collectively make up the most morphologically, physiologically, and ecologically diverse group of organisms on earth, books on evolution instead tend to focus on animals. This organismal bias has led to an incomplete and often erroneous understanding of evolutionary theory. Because plants grow and reproduce differently than animals, they have evolved differently, and generally accepted evolutionary views—as, for example, the standard models of speciation—often fail to hold when applied to them. Tapping such wide-ranging topics as genetics, gene regulatory networks, phenotype mapping, and multicellularity, as well as paleobotany, Karl J. Niklas’s Plant Evolution offers fresh insight into these differences. Following up on his landmark book The Evolutionary Biology of Plants—in which he drew on cutting-edge computer simulations that used plants as models to illuminate key evolutionary theories—Niklas incorporates data from more than a decade of new research in the flourishing field of molecular biology, conveying not only why the study of evolution is so important, but also why the study of plants is essential to our understanding of evolutionary processes. Niklas shows us that investigating the intricacies of plant development, the diversification of early vascular land plants, and larger patterns in plant evolution is not just a botanical pursuit: it is vital to our comprehension of the history of all life on this green planet.

Phylogenetic perspectives; Reproductive traits; Seeds; Recruitment and growth; Interactions.

Many of the characteristics that distinguish plants from other living organisms can be traced to their bacterial origin early in the history of life. These features-such as a multicellular haploid life stage, prevalent hermaphroditism, self-fertilization, and general dependence on biotic and abiotic vectors for reproduction-stem directly from the plant's ability to obtain energy from the sun. This novel mode of energy capture had far-ranging implications for plant evolution. It not only fueled the tremendous diversification of life on Earth that followed, but also had far-ranging implications for the evolution of photosynthetic microorganisms and eventually for land plants. Understanding the evolutionary processes for the proliferation and diversification of plants requires an appreciation of their unique biological features. While the processes of mutation, selection, genetic drift, and gene flow remain the same for both plants and animals, there are specific characteristics of plants that modify the way their evolution is implemented. Unique traits of plants affect everything from the fate of mutations, through exposure to selection in a haploid life phase, to the distribution of genetic variation within populations, and ultimately the rates and patterns of diversification. This book examines the origins of the unique evolutionary features of plants, as well as their implications for evolutionary processes. Author Mitchell B. Cruzan provides contemporary discussion of subjects including population genetics, phylogeography, phylogenetics, ecological genetics, and genomics. The book fills a need for modern coverage of these topics, all of which are essential to a wide range of advanced courses in plant biology.

A chronological narrative of the evolution of photosynthetic organisms, with a focus on those that led to land-based plants.

Life history theory seeks to explain the evolution of the major features of life cycles by analyzing the ecological factors that shape age-specific schedules of growth, reproduction, and survival and by investigating the trade-offs that constrain the evolution of these traits. Although life history theory has made enormous progress in explaining the diversity of life history strategies among species, it traditionally ignores the underlying proximate mechanisms. This novel book argues that many fundamental problems in life history evolution, including the nature of trade-offs, can only be fully resolved if we begin to integrate information on developmental, physiological, and genetic mechanisms into the classical life history framework. Each chapter is written by an established or up-and-coming leader in their respective field; they not only represent the state of the art but also offer fresh perspectives for future research. The text is divided into 7 sections that cover basic concepts (Part 1), the mechanisms that affect different parts of the life cycle (growth, development, and maturation; reproduction; and aging and somatic maintenance) (Parts 2-4), life history plasticity (Part 5), life history integration and trade-offs (Part 6), and concludes with a synthesis chapter written by a prominent leader in the field and an editorial postscript (Part 7).

"The lack of discussion of the life histories of modular organisms is the weakness of this book that I most regret. . . . Modular organisms are different. " S. C. Steams: The Evolution of Life Histories (1992) Life-history theory endeavours to increase our understanding of the processe,s whereby the broad features of the life cycles of organisms, such as the timing and magnitude of reproduction, have evolved. Although reproductive traits have dominated as study objects due to their immediate importance for evolutionary success, much work has also been conducted on patterns of development, growth and senescence, as well as on the shifts in resource allocation related to these processes. The basic axiom of life-history theory is that patterns of life histories, such as reproductive traits, are subject to evolutionary explanation. This idea can be traced back at least as far as Darwin's Origin of Species (1859). In his discussion of plant domestication, Darwin wrote: "I cannot doubt that the continued selection of slight variations, either in the leaves, the flowers, or the fruit, will produce races differing from each other chiefly in these characters". Darwin was impressed by the success of plant breeders in moulding the growth and reproductive parameters of cultivated plants, and believed that natural selection could have a similar impact in natural populations.