Introduction

Why read this book?

Why study anything? Because the enterprise of mentally applying yourself to a particular topic is itself fulfilling. Like many journeys, study can be boring and tiresome and often you wonder if you are getting anywhere at all. But eventually you will reach a place where you not only can see how far you have gone, but a place where you can see things that you couldn’t see before, or maybe you reach a place where things that you’ ve seen before now look different and perhaps more understandable.

Fundamentally, this is a biology book. Why study biology? Living things are fascinating for a wealth of reasons—their diversity, their complexity combined with a fundamental simplicity, their functioning that begs for explanation, the multiple ways that living things exhibit organization, the multiple interrelationships between different living things. Also, there is clearly a fascination of biology that stems from the fact that people are indeed biological in nature.

Why study ‘inanimate’ (non-animal) life? This book studies a group of living things that are distinctive because they aren’t human, or mammalian or even animal in nature (hence the title). In particular, why study plants, the primary subject of the book? There are at least three basic factors that make a study of plants particularly rewarding. First, plants are familiar organisms, things that are readily and commonly encountered, so much so that their fundamental biological nature is often ignored and they are simply considered inanimate components of the environment. Secondly, plants are extremely useful to human activities, not just as food but also by providing useful materials and chemicals. Because of this, the study of plants has a connection to a host of human endeavors. Thirdly, plants are the most conspicuous members of what is considered ‘the natural world’ or ‘the outside’. Consequently, some understanding of plants can enhance the enjoyment of nature. An academic factor that makes plant study rewarding, and the reason for studying many inanimate (non-animal) organisms other than plants (e.g. fungi, bacteria), is that it enhances the understanding of other areas of biology by providing contrasting structures, development patterns, and physiologies when compared to familiar organisms.

There are many other reasons why the study of plants is rewarding, I’m confident that you will come up with additional reasons based on your own experience with the subject!

A brief history of the discipline of ‘botany’.

This book is a ‘botany book’ and the book has been used in courses that are considered  ‘botany’ courses. Most people associate ‘botany’ with plants, but this is a book studies a number of things that are not considered plants, why include them? The reason has to do with history and with classification.

Botany texts, like most of academia, have a great deal of inertia and, in terms of groups covered, this book perpetuates this. One hundred years ago, the field of biology was separated into botany and zoology, reflecting the binary taxonomy of the time that placed organisms into either the plant kingdom or the animal kingdom. Botanists studied organisms (plants, algae, some bacteria) that were green (contained chlorophyll) and also other forms of life (e.g. fungi) that weren’t green but had some ‘plant-like’ features (cell wall, apparent lack of mobility, pattern of growth). As in any classification (more on this later!) there were organisms, most of whom were generally unicellular and small in size that had both ‘animal-like’ and ‘plant-like’ characteristics.  These were often covered in both botany and zoology courses. Both textbooks and courses were ‘survey’ courses, going group by group through the members of the plant or animal kingdom.

As the 20th century progressed, more and more biological knowledge accumulated that revealed the commonality of all living things, topics like genetics, cell biology and biochemistry. Botany textbooks expanded adding  elements common to all living things in addition surveying different groups. At the same time, botany and zoology departments merged into biology departments and introductory courses and textbooks reflected this merger.

Throughout the 20th century it became increasingly clear that the dichotomous classification (plants and animals) was undesirable for multiple reasons. In 1969, Robert Whittaker proposed a five-kingdom system, with three familiar groups (‘Kingdoms’ in a taxonomic sense)—plants, animals, and fungi, and two novel Kingdoms, protists and monerans. Monerans were prokayotes, primarily unicellular organisms with cells that lacked nuclei and other organelles.  This was in contrast to the four other Kingdoms that had eukaryotic cells, ones that possessed a nucleus and membrane bound organelles.  The novel Protist Kingdom contained photosynthetic groups (algae) and non-photosynthetic groups, including many ‘problematic’ groups that weren’t obviously plants, animals or fungi. In spite of the taxonomic changes, most botany textbooks did not alter their coverage, only slightly changing how topics were organized. A few botany textbooks focused only on organisms considered to be in the plant kingdom, omitting photosynthetic protists (algae) and fungi.

With the start of the 21st century Whittaker’s classification scheme fell out of favor, primarily because neither the protist group nor the monera group was a sound phylogenetic (evolutionarily-based, more details on this later) entity. ‘Surveying’ life in an accurate phylogenetic sense became more difficult, especially for the groups formerly considered protists, whose members do not group nicely. Where you used to have one group (protists) you might now have a dozen groups, all fairly obscure. And while five kingdoms could be managed, twenty kingdoms is more challenging. In spite of this, most botany textbooks in use today still approach to the subject as they have in the past: discuss the biology common to all organisms then survey the groups, with the precise groups surveyed varying between books.

As a consequence of the expansion of cell and molecular information, the amount of coverage of plants and of ‘inanimate life’ (everything other than animals) is drastically less than it was fifty years ago. The same can be said for other taxonomic groups: birds, fish, insects; but the problem is particularly significant for ‘inanimate life’ because it is fundamentally more obscure to most biology students and instructors. Additionally, the coverage given to what you might think of as organismal biology in general, what an organism is and how it functions, is very much reduced because the discussions of various groups are often dominated by taxonomic/phylogenetic/evolutionary aspects, with primary concern placed upon where a particular group might be put with respect to other groups.

This book is both traditional and non-traditional. Although the kinds of organisms this text studies is similar to most botany texts of the last hundred years, the approach to study is very different. This book is focused organismal biology, not phylogeny/taxonomy. It considers most of the groups that were covered in traditional botany texts, that is, ‘EBA = everything but animals’: plants, fungi, bacteria/archaebacteria, and most of the organisms that used to be placed in the protist category. But the approach to these groups is ‘organismal’ and comparative. It attempts to define the organism level of life (Chapter 1) and the classification of organisms (Chapter 2). The book then comparatively examines four features that define organisms: their structure (Chapters 3-10) their means of reproduction (Chapters 11-17), their acquisition of matter and energy (Chapters 18-25), and their interactions with conditions and with other organisms (Chapters 26-31).  The approach is much more ecological (at the organism level) and much less phylogenetic/evolutionary than in botany texts or in introductory biology texts. A comparative approach, considering both the unifying features and the distinctive features of organisms, provides an enhanced perspective from which to consider the biology of plants.

This book is focused at the intersection of two biological phenomena: organisms and plants. In spite of this focus, it considers a wide area of biology — from cells to communities and from bacteria to fungi. It also considers a wide variety of organisms that are not now considered plants. Although this is intended as a botany textbook, it should be of interest to anyone interested in the scope of biology, even if they are not particularly interested in plants (something that it is hard for the author to imagine!!).