Student Views on the Usefulness of IT Materials in an Integrated Curriculum

Learning Human Biology: Student Views on the
Usefulness of IT Materials in an Integrated Curriculum

Participants: Mary Peat, Sue Franklin, Alison Lewis
Mentor: Rod Sims
The University of Sydney

Abstract

This paper reports on the outcomes of a study on the use and perceived usefulness of educational multimedia resources and communications technologies within the context of a single course in a first-year biology program. A major focus of the research, as reported in this paper, was the extent to which the computer-based resources made available to the students were utilised, and the students’ perceptions of the usefulness of these resources to their learning. Data of expected and actual use and usefulness of these resources were collected from the students using surveys and focus groups within an action-research model. While the majority of students found the multimedia resources to be of use for their learning activities through providing off-campus access to supplementary and relevant materials, it is of interest that some did not find them useful and some did not use them at all. In addition the use of communications technologies was greatest for social interactions rather than course specific needs. The data indicated that these levels of use were not a function of access to computersor the Internet. These findings suggest that the provision of online resources will not necessarily generate value-added learning and reinforces the need to offer a variety of learning experiences that target different learning styles and enable a mix of off-campus and on-campus opportunities.

1. Introduction

First year science courses at The University of Sydney have high student numbers. As well as servicing many degree programs in Science, they also service other faculties such as Agriculture, Education, Arts and Engineering. This large group of students is very heterogeneous, characterised by varied educational and academic backgrounds with a broad range of incoming entry grades, and a range of incoming generic skills (writing, computer, team work, etc.). Many of the students in specialist Science degrees are highly motivated and know where they are going, but a large proportion are enrolled in the straight Science degree which allows the students a wide choice of subjects, but often means they are unsure of their future directions. In addition, many students arrive at university with an expectation of being spoonfed (McInnis, 1995), having been conditioned to using a surface approach to learning in high school, whereas, at university, they need to focus more on deep learning strategies to succeed within their chosen degree programs.

It is recognised that active involvement in the learning scenario can lead to the use of deep learning strategies (Sutcliffe, 1999). Computer-based activities offer learning experiences that are under the control of the individual learner, that may better suit individual needs and offer active involvement by way of interactivity. Increasingly the Web is being used to create a better learning environment that is more independent of teacher interaction, is sustainable in the currenteconomic climate and encourages the development of lifelong learning strategies.
To provide this type of learning environment, the School of Biological Sciences at The University of Sydney set up a virtual learning environment (VLE at http://fybio.bio.usyd.edu.au/vle/L1/), allowing students to access resources any-where/anytime. The development of this resource, and preliminary evaluations of its use by students, are discussed elsewhere (Peat, 2000b).

The current study examined one of the first year courses, Human Biology, which integrates a range of computer-based learning modules, online materials and communications strategies with more traditional learningresources such as lectures and practical sessions. The aims of the course includehelping the students develop a familiarity with foundation issues in human biology with theability to relate learning to real life and toenhance the development of those life skillsrequired of a science graduate. The teachingmethods use lectures, practical classes inwhich the students are encouraged to work insmall peer groups to foster collaborativelearning strategies and good inter-groupcommunication, and independent studyopportunities which can be done at a time to

suit the student and do not require attendance on campus. Within the teaching format educational multimedia resources, including in-house computer-based modules, have been integrated into the curriculum. It is recognised that the incorporation of information technology can change the roles of students and teachers, facilitate more student-centred learning and expand the scope and content of the curriculum (Horgan, 1998). Given the current environment, the learning paradigm is one where students are provided with a range of resources to cover the curriculum of the course and this range has been designed to cater for a variety of learning styles. The purpose of this study was to provide both a reflective and analytical assessment of a broad range of learning resources integrated through web-based technology. Three specific factors led to the adoption of this approach.

First, the students enrolling in the course constitute an heterogenous group with widely varying academic backgrounds and interests in biology, a situation that now appears to be the norm for large first year science classes. Over the last ten years the increasing heterogeneity of the student group and an increasing awareness of animal rights issues has led to potential problems with the performance of some ethnic/cultural groups with respect to some biological procedures (e.g. dissections of animals and animal parts). During this period some changes in the practical structure have been implemented to take this into account, such as replacing animal dissections with computer-based simulation (“virtual” dissections). Second, the computer-based modules used within this course have already been demonstrated as effective (Peat, 1999; Peat, 2000a; Peat, Franklin and Mackay-Wood, 1997). They have been developed over a number of years and formative evaluation enabled each resource to be enhanced as it was being integrated into the curriculum. Students (and staff) were asked such questions such as “Was it easy to use?”, “…accessible?”, “…enjoyable” and “Were there any bugs?”.

Individual resources were modified according to student and staff feedback. Many of these products were developed initially for use on the University Intranet but have now been launched on the Internet. Part of this current project is to determine the accessibility of these Internet resources to the students and when and how they are being used. Use of these resources within the learning process has been investigated by asking students for what purpose (tutorial, remedial learning, selfassessment) they are using the materials, and how the materials help them in their learning.

For this investigation it was considered more important to focus on the overall teaching and learning process rather than the effectiveness of individual resources. Third, the research agenda within instructional technology has gone beyond that of comparing resources to one of making them work better (Reeves, 1999). Over the past 25 years a vast quantity of research has been conducted to assess the comparative benefits of computerbased learning, with ambivalent results (cf Reeves, 1993; Russell, 1999). For this project the focus was not on the individual resources as effective learning tools, but on the perceptions of both students and teaching staff as to their importance in the overall teaching and learning process; this is particularly significant with the increased emphasis by tertiary institutions on online learning. Within this context, the project emphasised the student perceptions of their learning experiences as advocated by (Prosser, 2000) and so the focus was on the ways in which resources, based on
information and communications technologies (email, discussion groups, computer-based learning), had been effectively integrated into the curriculum.

Given the amount of time and money that had been spent on the development of all the teaching and learning resources and within the context of the three issues identified (increased heterogeneity of users, accepted mature materials, and making the resources work better), the aim of this project was to determine how the computer-based modules and information and communications technologies influence the learning process. The resources in question are being sustained within the curriculum and have been used by more than800 students each year for several years, and while this has been accepted as cost effective, the effectiveness of the materials has not beensufficiently demonstrated with respect to student learning outcomes.

This paper examines the role of computerbased modules and communications technologies on the learning opportunities for a large group of first year students as viewed from the student perspective. In general terms it was found that a substantial proportion of students used the computer-based resources and reported that they were useful in their learning, although some resources were not actually used as much as students themselves expected to use them.

2. Available Online Resources

Since 1992 computer-based modules have been introduced into all the first year biology courses at The University of Sydney. There is a suite of modules used for a variety of teaching and learning scenarios: modules to be completed pre-lecture and pre-practical class; modules to be used within a practical class; and modules enabling revision, and selfassessment.

Students are directed to particular modules at given times during the course and many of these are accompanied by paper-based resources. Some of these modules are primary or core resources for the students, replacing other materials, whilst some modules are additional to help support the students in the absence of extensive face-to-face contact.

Tutorial modules provide a large amount of information for students to explore, at a variety of depths, to complete projects and laboratory exercises, and contain a quiz section for students to assess their understanding of the material. Tutorial modules enable biological processes to be illustrated in an animated manner not otherwise available. Pre-lab modules are introductions to the use of laboratory equipment and they allow the students to gain an understanding about how
the equipment works before meeting up with it in the laboratory session. This has proved an
effective way to help students learn to use equipment and one that is now used extensively in Chemistry classes around the higher education sector (Wilson, 1996; Wilson and Cavallari, 1995). Self-assessment modules allow students to take a series of formative tests and exercises aimed at helping them monitor their level of understanding of major biological concepts. Further descriptions of design and evaluations of all the modules can be found at http://fybio.bio.usyd.edu.au/SOBSFYB/fyb/tdg/FYBTDGhome.html and in Peat (2000a), and
Franklin & Peat (2001). It is considered that the use of these resources will possibly vary depending on the students’ perceptions of the usefulness of each resource.

In 1997, communications technologies in the form of email and chat were introduced as a resource for learning, enabling asynchronous electronic student/staff and student/student contact. These resources are available via the CyberTutor and discussion links from the first year biology Virtual Learning Environment (VLE ). The use of communications technologies as a resource was enhanced in 1999 when The University of Sydney provided all students with a free email account. The current communications links available via CyberTutor, CyberAdmin and
CyberTechSupport through the VLE allow students to contact staff about academic, administrative and technical matters.

3. The Students

The target population of students (n=800) is typically recent high school leavers enrolled in science-based degree programs. As noted earlier, the student body has become increasingly diverse over the years, with respect to academic achievements, literacy and science backgrounds and extra-curricular activities such as paid employment. A recent survey (Peat and Franklin, 2000) indicates that the majority of first year biology (full-time) students are undertaking a significant amount of paid casual employment to support their lifestyle (67% are in paid employment from 5-15 hours a week). For many students this increasing demand by part-time work is making it difficult for them to fulfil on-campus course expectations and is one of our reasons for developing online resources available anytime, anywhere. McInnis, et al. (2000)
indicate that this is common to all first year students Australia-wide.

4. Method
The research model used was based on the more recent arguments of Reeves (1993) and Alexander and Hedberg (1994) which have led to a model involving a mixed approach to data production and analysis, with both quantitative and qualitative information obtained in the evaluation process. Described as the Eclectic-Mixed Methods-Pragmatic Paradigm (Phillips, et al 2000) this approach is considered more capable of handling the complexity of modern society and technology with a focus on practical problems rather than on issues, whilst acknowledging the weaknesses of current evaluation tools.

The overall study was based on the dynamic state of the perceptions of the major stakeholders involved in the course, but this paper focuses on the students’ perceptions of their use of computer-based modules and communications technologies within an integrated curriculum. Data were collected from all stakeholders at four separate intervals, using surveys, interviews and/or focus groups.

The first data collection point (DC1) was at the commencement of the course and consisted of surveys of students and laboratory teaching staff, and interviews of lecturers, courseware developers and technical staff. This established a benchmark of understanding and perceptions prior to any teaching and learning influences. A separate instrument was designed for each of the stakeholder groups such that the questions focused on similar course delivery issues and all stakeholder perceptions of learning resources and how they would be used. This will enable alignment of responses and the derivation of common themes in terms of the understanding, potential and use of learning resources within the program. It asked all stakeholders for their
expectations of the use of different learning resources (including educational multimedia).

Figure 14.1 shows the relationship between the data gathering activities from DC1 to DC4 associated with investigating the students’ views of the computer-based modules and communications technologies.

Student surveys, using both qualitative and quantitative instruments, were conducted at
each of the data collection points (DC1-DC4). Student survey S1 provided benchmark information about the student cohort, including demographic data and learning style, as well as
students’ expectations of learning resource usage. At S1 all students were surveyed, during the fourteen laboratory sessions of one week that accommodate this large group of students and the data collected are from this entire stakeholder group. Subsequent datacollection by survey was of a subset of this stakeholder group with S2, S3 and S4 each surveying half the total number of students but chosen at random. The information from S1 helped inform both S2 and the focus group. In particular students were asked further questions in S2 about their use of email and the
Internet in their learning, and ease of access to first year online modules. In addition S2 targeted their perceptions of the use of virtual versus real dissections in enhancing learning.

The focus group questions, relevant to this paper, concentrated on the use of online tutorial material. On the basis of the focus group material the third survey (S3) revisited some of the material from the second survey as it was felt that some of the S2 questions had been ambiguous and the data collected were not easy to interpret. It also focused specifically on students’ perceptions of the usefulness of the resources to their learning and understanding. Whilst survey S4 repeated much of the ground covered in the initial survey (S1), it did so by asking students what resources they had actually used and how useful they had found these resources. A focus
group was asked to comment specifically on the use of the self-assessment modules.

5. Results and Discussion
This section reports on the major factors emerging from this research process and examines student:

• demographics;
• use and perceptions of the Internet;
• access to online materials;
• views of communications technologies; and
• perceptions about using online tutorials in general.

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Ecology Connections

Adapted Primary Literature:

An Untapped Resource for
High School Biology Education


www.ecologyconnections.ca
© 2006 University of Calgary Kananaskis Field Stations
Alberta Innovation & Science ISRIP Science Awareness & Promotion Program

Adapted Primary Literature

Introduction

It is often assumed that textbooks present the agreed upon and current facts within the scientific community. However, how did these ‘facts’ come to be and where did they come from? The scientific process is often not made explicit in many textbooks and there is little debate or criticism of the content that is presented. Textbooks do provide a reader with the foundations upon which science education is based; however, to really understand the nature of science we need to delve into the primary literature.

Primary literature is written by scientists for other scientists and will often contain technical methods and jargon beyond the understanding of anyone not involved in that specific field. Nevertheless, there are ways in which students can be introduced to the primary literature. A number of high school biology educators and researchers at the undergraduate level have investigated the use of adapted primary literature in their classes (Baram-Tsabari et al. 2005, Brill et al. 2004, Camill 2000, Herman 1999, Kuldell 2003, Levine 2001, Smith 2001, Yarden et al. 2001).

The articles presented in the Ecology Connections Research Connections sections of this website provide access to adapted primary literature; articles that have been adapted from primary literature by science writers and reviewed by leading scientists. They serve as a starting point to introduce students to reading primary literature, or as a way to enhance high school biology education with real examples of peer-reviewed literature.

The benefits of having students read primary literature have been well documented. Skills gained include:

• increased understanding of how science works and the process of inquiry
(Baram-Tsabari 2005, Levine 2001);
• improved science writing (Herman 1999, Kuldell 2003, Muench 2000);
• increased creative and effective data presentation (Kuldell 2003);
• placing knowledge from labs and lectures into the broader scientific
community (Kuldell 2003);
• improved understanding of lecture material (Smith 2001);
• increased confidence reading and interpreting graphs, figures, and tables
(Smith 2001);
• Increased active learning, question asking, and ‘authentic’ scientific thinking
(Brill and Yarden 2003, Gillen et al. 2004, Gillen 2006).

Secondary, or popular-scientific literature, is what you read in magazines and newspapers. These authors take the primary literature and fit it into a format that the ‘non-scientist’ is more comfortable reading. Much of the same information is passed on; but it is easier to read and understand. If the information is the same, why not give students the popular, more readable article? Baram-Tsabari et al. (2005) conducted a study that had high school students read both primary and secondary articles coveringthe same information. They found that students that read the primary article had abetter understanding of the nature of scientific inquiry than students who read thesecondary article. However, it is important to note that the student who read thesecondary article had a better comprehension of the content and less negative views

towards the activity.

Which format should you choose? As with anything, you choose the appropriate tool to accomplish the goals of the lesson. An interesting assignment conducted by Pall (2000) was to have students compare and contrast a primary article with its secondary companion. This may be a way to introduce students to the primary literature as well as familiarizing them with secondary sources that they may access as adults.

Why do ecologists read primary literature?

Communicating your findings and results is part of belonging to a scientific community. Primary literature allows ecologists to share their results and learn about advances in their field. The following list provides reasons why scientists read primary literature (Adapted from: http://biology.kenyon.edu/Bio_InfoLit/index.html):

• This research sounds interesting; I wonder if we can incorporate any of the new
insights or methods into our research.
• I am trying to stay current with our field of study; I wonder what new work has
been published.
• I am having trouble to get our experiments to work; I had better check to see
what other researchers have done.
• These researchers have been working on the same question as us; I wonder
whether their work supports or contradicts ours.
• These research results contradict our work; I need to look closer at our data and
analysis to see we have made any mistakes.

Peer Review Process

All primary ecological articles published in reputable journals go through a peer review process, wherein experts in the field review, recommend, or reject the article for publishing. The peer review process ensures that the methods employed by the authors adhere to the standards set for that field of research. Science is an exciting and constantly changing field. Scientists cannot possibly stay on top off all the research occurring in all the labs around the world. Peer review acts as a screening process for that scientific community, presenting them with sound, relevant research upon which they can build. The following websites provide further background and debate on the peer review process:

• Article: Wikipedia [http://en.wikipedia.org/wiki/Peer_review]
This article offers an overview of the peer review process.

• Article: Nature http://www.nature.com/nature/peerreview/debate/index.html
Structure of a primary article
Before reading an article, the purpose of each section should be understood.
Here are some sites that review the structure of primary articles.

• Tutorial: Kenyon College [http://biology.kenyon.edu/Bio_InfoLit/index.html]
This website introduces students to the parts of a scientific paper and the
different reasons for reading them. A short quiz and questions about a
specific paper are included in the website.

• Tutorial: Purdue University
[http://www.lib.purdue.edu/phys/inst/scipaper.html#mainmenu]
This flash tutorial provides an easy to follow guide to reading scientific
papers.
• Hand-out and Guide: Hampshire College
[http://helios.hampshire.edu/~apmNS/research/papers.html]
This website has a lesson on using scientific papers in class, along with a four
step students’ guide to reading scientific papers.

Reading figures and graphs

Gillen (2006) calls the methods and results the “central information portion of an article” and scientists often start by looking at the graphs and figures to draw their own conclusions before reading the author’s interpretation of the results. Therefore, an essential skill to successfully understanding an article is the ability to interpret figures and graphs, but it is a skill ecology students at all levels have difficulty with (Bowen et al. 1999, Bowen & Roth 2002, Roth et al. 1999). The following website resources provide suggestions for helping students interpret graphs and tables:

• Article: Ecological Society of America
[http://tiee.ecoed.net/teach/essays/students_interpreting_graphs.html]
This article discusses some of the problems students have with graphs.
• Article: Ecological Society of America
[http://tiee.ecoed.net/teach/essays/figs_tables.html]
A short article on helping students read graphs and tables.

Technical Terms

Students are not experts in the field of ecology and like all disciplines, there are terms and methods that will be beyond the level of your students. Teachers that have used primary literature in their classes emphasize that students need some level of background information in the field before tackling a primary article (Janick-Buckner 1997, Yarden et al 2001, Gillen 2006). To support this approach, the authors and editors of Ecology Connections have strived to ensure that the concepts explained in the articles are accessible to all readers. Technical terms in the Research Connections are also highlighted and hyperlinked to a glossary of terms.

Research Literature Connection

Baram-Tsabari, A., and Yarden, A. 2005. Text genre as a factor in the formation of scientific literacy. Journal of Research in Science Teaching 42 (4): 403-428.

Bowen, G.M. and Roth, W-M. 2002. Why students may not learn to interpret scientific inscriptions. Research in Science Education 32: 303-327.

Bowen, G.M., Roth, W-M., and McGinn, M.K. 1999. Interpretations of graphs by university biology students and practicing scientists: Toward a social practice view of scientific representation practices. Journal of Research in Science Education 36 (9): 1020-1043.

Brill, G., and Yarden, A. 2003. Learning biology through research papers: A stimulus for question asking by high school students. Cell Biology Education 2(4): 266-274.

Brill, G., Falk, H, and Yarden, A. 2004. The learning processes of two high-school biology students when reading primary literature. International Journal of Science Education 26 (4): 497-512.

Camill, P. 2000. Using journal articles in an environmental biology course: Wetland ecosystems: valuable natural habitat or real estate goldmine? Journal of College Science Teaching 30 (1): 38-43.

Gillen, C.M. 2006 Criticism and interpretation: Teaching the persuasive aspects of research articles. Cell Biology Education – Life Sciences Education 5: 34-38.

Gillen, C.M., Vaughan, J., and Lye, B.R. 2004. An online tutorial for helping nonscience majors read primary literature in biology. Advances in Physiology Education 28: 95- 99.

Herman, C. 1999. Reading the literature in the jargon-intensive field of molecular genetics: Making molecular genetics accessible to undergraduates using a processcentered curriculum. Journal of College Science Teaching 28 (4): 252-253.

Janick-Buckner, D. 1997. Getting undergraduates to critically read and discuss primary literature. Journal of College Science Teaching 27 (1): 29-32.

Kuldell, N. 2003. Reading like a scientist to write like a scientist: Using authentic literature in the classroom. Journal of College Science Teaching 33 (2): 32-35.

Levine, E. 2001. Reading your way to scientific literacy: Interpreting scientific articles through small group discussions. Journal of College Science Teaching 31 (2): 122- 125.

Muench, S.B. 2000. Choosing primary literature in biology to achieve specific educational goals: Some guidelines for identifying the strengths and weaknesses of prospective research articles. Journal of College Science Teaching 29 (4): 255-260.

Roth, W-M., Bowen, G.M., and McGinn, M.K. 1999. Differences in graph-related practices between high school biology textbooks and scientific ecology journals. Journal of Research in Science Teaching 36 (9): 977-1019.

Pall, M. 2000. The value of scientific peer-reviewed literature in a general education science course. The American Biology Teacher 62 (4): 256-258.

Smith, G. 2001. Guided literature explorations: Introducing students to the primary literature. Journal of College Science Teaching 30 (7): 465-469.

Yarden, A., Brill, G., and Falk, H. 2001. Primary literature as a basis for a high-school biology curriculum. Journal of Biological Education 35 (4): 190-195.

Education Connections
Christina Pickles, Kananaskis Field Stations
Michael J. Mappin, Kananaskis Field Stations
Website Design:
Diane Laflamme, Laflamme Designs

Educational exsiccatae:

Educational exsiccatae:

Ferdinand von Mueller’s botanical lessons in colonial Victoria
by Sara Maroske

Abstract

In 1872, Ferdinand von Mueller seized a moment when the Victorian government was intensely interested in education, to put a proposal regarding his own specialty of botany. Based on the idea that the best way to learn about plants was from plants, he sought to distribute sets of dried specimens, or exsiccatae, throughout the colony.
Although hampered by his own troubled relationship with government, he was nevertheless able to place three fascicles in about 50 institutions not previously seen as repositories of this kind of material.

Introduction
In August 1872, Ferdinand von Mueller (Fig. 1), Victoria’s illustrious Government Botanist and director of the Melbourne Botanic Garden, put an educational proposition to his ministerial chief, James Casey.1 As later explained by Mueller, it was to issue here [i.e. in Victoria,] as in many European countries[,] collections of indigenous plants for public instruction ... in connection with ... works under publication, as the best means to diffuse information on the native vegetation.2
This was a proposal that seemed certain to appeal to a member of the ministry that was about to pass legislation providing ‘free, compulsory and secular schooling’, the first such Act in Australia.3 Nevertheless, Mueller was not well-regarded by Casey, who had just commissioned a report into the management of the Botanic Garden.4 In this context, Mueller could not really be sure how anything he said would be received. Botanical specimens The main idea behind Mueller’s educational proposal in 1872 was to use plants, or rather ‘collections of plants’, to impart basic information about the names of, and relationships between, plants. In the nineteenth century, such ‘collections’ were also known as ‘exsiccatae’, a term that referred to the fact that they consisted of dried specimens. Typically an exsiccata comprised multiple copies of the same set of plants, that had been collected from areas in which they were regarded as ‘indigenous’, or ‘native’, in contrast to plants that were ‘introduced’, or ‘exotic’. Each copy usually
began with a printed page, as in a book, which included a title, date and place of issue, followed by a series of specimens, each one occupying a single page with a printed label bearing the specimen’s scientific name, and information on where and when it was collected. The compilers of exsiccatae usually sold them in parts, by subscription,to private collectors, or to public institutionssuch as museums.5

Mueller believed that the educational value of exsiccatae was well known in ‘many European countries’. This was a fact to which he could testify personally.6 As a young pharmacy-apprentice in Schleswig-Holstein in the 1840s, he was required to construct his own ‘herbarium’, or collection of dried plants, in order to learn how to identify the suite of plants that, at the time, was the source of most medicines.7

Mueller not only did this, but also formed a herbarium of most of the plants in his area. He also obtained specimens from collectors in other areas, including Lars Hansen, a teacher in northern Schleswig who, in exchange, used some of Mueller’s specimens in an exsiccata.8Mueller also gained knowledge of plants by visiting the herbaria of other collectors, and the one at Kiel University, which institution he attended from 1845 to 1847.

The Kiel University herbarium would have contained tens of thousands of specimens, including exsiccatae.9

In 1848, only a year after his arrival in South Australia, Mueller attempted to introduce his knowledge of exsiccatae into his new home by advertising sets of ‘mostly indigenous’ plants for sale in the South Australian Register. This may well have been the first such advertisement in Australia.

Mueller predicted his sets of plants would be ‘a valuable acquisition to public institutions, or an agreeable object of private curiosity at home’, and if taken up by the public would also encourage his own further scientific enquiries ‘into the riches of the Botany of our adopted country’. Each set of plants was to consist of 100 specimens, arranged......

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Botany Cryptogamae

Diversity of Seed Plants and Their Systematics

Angiosperms II (Nomenclature, Classification with emphasis on Bentam and Hooker and Engler and Prantl, Taxonomic evidence – Role of Cytology, Phytochemistry and Taximetrics)


M.P. Sharma
Reader
Department of Botany
Jamia Hamdard
Hamdard Nagar
New Delhi - 110062


Date of submission: February 14, 2006
Significant keywords: Taxonomy, Angiosperms, Classification, Systematics, Nomenclature, Taxonomic evidence.

Classification Of Angiosperms

Keeping the things arranged is a basic human instinct. Laboratories, libraries workshops, shops etc are easier to work in if there is a system to keep track of things. Biology is no exception. It is lot easier to study living things if we have a system that keep something apart from other things. Biologists called this system as classification or taxonomy. Typically, classification can be defined as the systematic arrangement of similar organisms into categories on the basis of their structural or evolutionary relationships.
The naming and classification of plants undoubtedly began in the earliest stages of civilization. Our own observations show that plants are of many kinds, and we immediately seek for a name to apply to a plant of interest. The primitive people and tribal communities of today, as well in the past, apply common names to those plants that are peculiar or that affect their life in any way. Early classification systems were utilitarian; plants were grouped as to whether they were beneficial or harmful.
With increasing civilization, especially as knowledge grew concerning the uses of plants in food and medicine, the necessity of plant names became even greater. And ultimately, as the number of known plants increased and as botanists collected plants from far corners of the earth, it became necessary to group plants into large categories following rational principles. The collection, naming and classification of plants nowadays are carried out mainly with the objective of showing their origins and relationship, and also to provide positive identification for the hundreds of thousands of different kinds of plants.

Kinds of Classification

According to the principle employed, mainly three kinds of classifications are recognized. They are: Artificial, Natural and Phylogenetic. In practice, these may overlap.
Artificial Classification is based on convenient or conspicuous diagnostic characters without attention to characters indicating relationship; often a classification based on a single arbitrarily chosen character such as flower colour, habit, habitat, time of flowering or arrangement of leaves, rather than an evaluation of the totality of characters. The earlier pre-Darwinian systems of classification were largely artificial. Linnaeus’ sexual system, which is based on the number of stamen and pistils, falls in this category since unrelated plants can have same number of stamen and pistils in their flowers.
Natural Classification is one which is based on over-all resemblances in external morphology, and unlike artificial systems, involved as many characters as possible. It is presumed that the larger the number of characters shared by different plants, more closely are they related to each other. Overall gathering data from diverse disciplines like palynology, embryology, anatomy, phytochemistry, cytology etc, and not the morphology alone nowadays ascertain similarity. Later pre-Darwinian systems, which were based on over-all resemblances in gross morphology, were mostly natural.
Phylogenetic Classification is based on hypothesized evolutionary relationship. In the years, following Darwin’s Origin of Species (1859) the theory of evolution gradually replaced the concept of special creation of species. It was found that species are not fixed or unchanging, but have evolved from pre-existing species during geological time. It is now considered that, in general, similarities in structure are evidences of evolutionary relationship. Thus have arisen modern phylogenetic systems of classification based on relationship by descent. Such systems utilize previously determined natural groups, and categories – genera, family, orders – of the natural systems are arranged in scheme that presumably reflects evolutionary relationships. Since 1980’s phylogenetic classification has been made much more facile by using molecular data. Data from many sources are used to determine relationship. Thus any phylogenetic scheme of plant classification is subject to change as our knowledge of the various groups increased.
History and Development of Plant Classification
In order to understand the field of taxonomy or classification at the present day, it is necessary to have some knowledge of the history of the subject and the development of the ideas associated with it. The observations made by the earlier workers were never wasted; subsequent workers with some modifications incorporated them into classifications. Scientists have struggled to find correct classification systems to use. They have eventually agreed on the systems we use today.

The discipline of plant classification has extremely deep cultural roots in all parts of the world. Ancient men who made their living by gathering food from the wild were probably much more familiar with the local plants, in terms of species recognition, than most people today. Though several cultural groups like African, Asian and Native American carried a wealth of botanical information into modern times, present systems of angiosperm classification have been derived from a European base. Historical development of classification is briefly reviewed here.

The Ancients

Theophrastus (370 – 285 B.C.). He was a Greek philosopher and is regarded as the “Father of Botany”. He was born in the city of Eresus. A people of Plato, and later a people and assistant to Aristotle, he embodied to the full extent the culture and learning of ancient Greece. For most of his life he lived in the midst of Lyceum botanical garden, established by Aristotle at Athens, and there he taught and wrote books representing many fields of knowledge. Theophrastus covered most aspects of botany: description of plants, distribution, classification, propagation, germination and cultivation. He is accredited with more than 200 publications; only few of his writings survive today. His two important botanical works “Inquiry into Plants” and “The causes of Plants” provided a systematic treatment of over 500 species according to habit (herbs, under-shrubs, shrubs and trees) and separated according to flowering and non-flowering. He recognized and described families among flowering plants, such as carrot family, known today as Umbelliferae (Apiaceae). He recognized genera, in the sense of a group of species, and applied to them Greek names then in use. A few generic names currently in use, such as Daucas, Asperagus, Anemone, and Narcissus, originated during his time.

Dioscorides ( Ist century A.D. ) was a Greek physician in Roman army. His most famous work was De Materia Medica, which discussed the medicinal qualities of 600 plants. This included natural grouping of species that represent well-defined modern families (Apiaceae, Fabaceae, Lamiaceae). The plant descriptions in his De Materia Medica were adequate for identification, including methods of preparation, medicinal uses, and doses. His work was used in various translations and editions for next 1000 years.

The Middle Or Dark Ages
The period from the fall of the Rome to the Renaissance is often called dark ages because of intellectual stagnation. Very little original botanical work was done during this period. Most workers copied and translated the ancient work of Greeks and Roman.
Alburtus Magnus (1193-1280 A.D.) was only botanist of note during this period. His contemporaries popularly called him “Doctor Universalis”. In his work De Vegetabilis he is believed to have first differentiated monocots from dicots.

RENAISSANCE, THE HERBALISTS AND TRANSITION PERIOD

The renaissance in Europe that started in the 14th century marked the beginning of an active period in which artistic, social, scientific, and political thoughts turned into new directions. Two major technological innovations – printing press and science of navigation – contributed to renaissance and especially to plant taxonomy. With the invention of printing press in 1440, many large volumes about plants and their medicinal uses, known as herbals, were produced throughout Europe. The authors of these books (herbals) are known as ‘herbalists’. It helped making knowledge available about the practical uses of plants, primarily from medicinal standpoint, to all. Herbalists did not propose any original systems of classification but marked the period of original work rather than copying the ancient work. Navigation made explorations easy and the collection of new species from ongoing explorations forced the herbalist to extend the initial efforts of the ancients to structure and order flowering plant diversity. Many natural and well-defined genera and families were established during this period. Prominent herbalists and their works are:

Otto Brunfels (1464-1534). German Herbalist. Herbarium Vivae Eicones.
Gerome Bock (1469-1554). German. Neu Kreuterbuch.
Leonhard Fuchs(1501-1556). German. De Historia Stirpiu, New Kreuterbuch.
John Gerard (1542-1612). English. The Herball,or, Generall Historie of Plantes.
Rombert Dodoens (1517-1585). Flemish. Cruydeboeck.

Herbalists advanced science of botany but systems adopted by herbalists although commendable in their own way, had very little systematic basis. It was from the sixteenth and seventeenth century onwards that attempts were made to study more and plants and a large number of characters in order to arrive at a satisfactory classification. Some of the 16th and 17th century botanists are:

Andrea Caesalpino (1519-1603), an Italian, tried to base his classification on logic rather than utilitarian concept. He published De Plantis in 1583, which contain description of about 1500 plants. This was the first methodical classification of plants based on definite morphological criteria. Caesalpino recognized the usefulness of fruits and seeds in classification. His views influenced the later botanists like Tournefort, John Ray and Linnaeus.
Casper Bauhin (1560-1624). A Swiss botanist; published Pinax theatri botnici in which he listed 6000 plants. He also provided synonymy i.e. the other names used for a species by earlier workers and binomials for many plants that he named. Bauhin is credited with modern concept of genera and species.

John Ray (1628-1705), a British botanist and philosopher formulated the principle that all parts of the plant should be used for classification- a principle now recognized as the corner stone of a natural system. His system of classification is presented in his Methodus Plantarum (1703), which contain description of 18000 species of plants. He grouped plants by their resemblance to one another and divided the plant kingdom into herbs and trees and further divided herbs into imperpectae (flowerless) and perfactae (flowering plants). Flowering plants and trees were further divided into dicotyledons and monocotyledons.

J.P. de Tournefort (1656-1708). French botanist produced a classification that was purely artificial (based on few features). He is regarded as the “father of genus concept”. In his publication Institutiones Rei Herbarie (1700) he provided descriptions for 698 genera. He differentiated genera on the basis of floral and vegetative characters. Linnaeus later adopted most of the Tournefort’s genera that were distinguished by floral characters.
The systems based on habit and the pre-Linnaean era ends with the system of Tournefort.

The Sexual Or Artificial System
The botanical research on the European flora and subsequent explorations resulted in the collection of more and more plants by the eighteenth century that required a simple and efficient system of naming and classification. This demand produced several purely artificial systems of which Linnaeus’ sexual system is most important

Carolus Linnaeus (1707-1778). It is to Swedish botanist, Carolous Linnaeus, that we owe the modern methods of naming plants. He is considered as “Father of Taxonomy”. Before the time of Linnaeus it was the general custom to name plants with a single name followed by a set of descriptive nouns and adjectives (polynomials). Linnaeus established what has come to known as ‘binomial system’ of nomenclature, which involves naming of plants by two names – one for the genus and one for the species. In addition to establishing the practice of binomial nomenclature, Linnaeus also set up a system of classification that was more comprehensive than any previously devised. This system is usually called as ‘sexual system’ or ‘artificial system’, because Linnaeus based his classification on number of stamens and their relation to one another and to other floral parts. Linnaeus divided plants into 24 classes, of which 23 were of flowering plants and the 24th class includes non-flowering plants i.e. ferns, mosses, fungi and algae. While the artificial approach allowed quick sorting and identification, its application produced unnatural grouping. The important publications of Linnaeus are: Syatema Naturae(1735), Genera Plantarum(1737) and Species Plantarum(1753). Because of the consistent use of binomial nomenclature, the date of publication of his Species Plantarum (Ist May, 1753) is considered as a starting point of the modern botanical nomenclature.

The system of Linnaeus was very simple and convenient and remained in force until the beginning of the 19th century.

Natural Systems Of Classification (systems based on form relationship)
The wealth of plant material collected by the botanist world over during eighteenth century could not be satisfactorily identified with the help of Linnaeus’ sexual system and a need was realized for a more objective classification. This resulted in the development of still better systems (based on overall resemblance in external morphology), which, unlike artificial systems, involved as many characters as possible.

Michel Adanson (1727-1806), a French botanist, published a two volume work Familles des Plantes (1763). He recognized 58 natural orders according the their natural affinities. He based his classification on using as many characters as possible and giving equal weightage to all the observable characters. This is precursor of modern computer aided Numerical Taxonomy, which is often called Adansonian Taxonomy.

Antonie Laurent de Jussieu (1748-1836), a French botanist published his system in Genera Plantarum (1789) incorporating his uncle’s (Bernard de Jussieu, 1669-1776) work along with his own. He laid emphasis on number of cotyledons, presence or absence of petals and position of the stamens with respect to the ovary.

Augustin Pyrame de Candolle (1778-1841), a Swiss botanist, published his views on classification in his work Theorie Elementaire de la Botanique(1813) and introduced the term Taxonomy do designate the theory of plant classification. He was first to use the characteristics of vascular tissues in the classification of plants and recognized two major groups - Vasculares (Vascular bundle present) and Cellulares (no vascular bundle).

George Bentham (1800-1884) and Sir J.D. Hooker (1817-1911). These two English botanists associated with Royal Botanic Gardens, Kew, presented the most elaborate natural system of classification in their three-volume work Genera Plantarum (1862-83). This was a major landmark in botany, for its system as well as for its quality. All genera of seed plants then known were very carefully and accurately described in Latin observing living specimens or dissected herbarium material. The geographical distribution of each genus was given. They followed de Candolle’s system with some modifications. The Genera Plantarum provided the classification of seed plants, including gymnosperms, describing 200 orders (equivalent to present day families) and 7569 genera. The larger genera were further divided into subgenera and sections. They estimated the seed plant to include 97,205 species. This was the last great work produced on the assumption that angiosperm taxa are fixed entities, unchanging through time and placed on earth by God. British and Indian herbaria are still arranged following the system of Bentham and Hooker.

Bentham and Hooker divided seed plants into three classes (Dicotyledones, Gymnosperms and Monocotyledones), three sub-classes, 21 series, 25 cohorts and 202 orders (initially 200 orders). Orders Vochysiaceae and Cyrillae were incorporated later.

OUTLINE OF SYSTEM OF BENTHAM AND HOOKER, 1862-1883

I. CLASS: DICOTYLEDONES (two cotyledones, exogenous growth)

Sub class 1. POLYPETALAE (petals separate)

Series I. Thalamiflorae (Petals and stamens hypogynous and usually many)

Cohort 1. Ranales (Gynoecium apocarpus)

Orders: 1, Ranunculaceae; 2, Dilleniaceae; 3, Calycanthaceae; 4, Magnoliaceae;
5, Annonaceae; 6, Menispermaceae; 7, Berbaridaceae; 8, Nymphaeaceae

Cohort 2. Parietales (Parietal placentation)

Orders: 9, Sarraceniaceae; 10, Papavaraceae; 11, Cruciferae; 12, Capparideae; 13,
Resedaceae; 14, Cistineae; 15, Violarieae; 16, Canellaceae; 17, Bixineae

Cohort 3. Polygalineae (Calyx and corolla 5, ovary 2 locular)
Orders: 18, Pittosporaceae; 19, Tremendreae; 20, Polygaleae; 20a, Vochysiaceae

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