Making Environmental Biology Central to a Course in Biology for Engineers

Engineers dealing with biological systems need to know how these systems interact with their physical, chemical, and biological environments when they propose solutions to problems involving living things. This awareness should start with their undergraduate education that includes an introduction to biological science. Such a course, developed and taught at the University of Maryland, is described in this paper.


Introduction
The opportunities in biology these days are vast, and all engineers should learn about and appreciate them. This extends even to all members of the general population, because there are and will be increasing numbers of ethical and societal issues involving modern biology. Engineers and other technologists, in particular, need to know how living things are and can be used to produce solutions to problems of human concern. Introductory biological science courses are, therefore, being required for all engineers at an increasing number of academic institutions.
Relying on traditional introductory biology courses taught to engineers does not generally satisfy engineering needs. This is because engineers are educated to become designers and problem solvers, and have a different outlook from traditional biologists. Especially in environmental biology, engineers are tinkerers and controllers rather than passionate observers. A different approach to teaching biology to engineers is needed.

The biological system
A main requirement for a course in biology for engineers is a comprehensive systems approach emphasizing environmental effects. Living things are influenced by, and themselves influence, their surroundings. At all hierarchical levels, hereby designated as Biological Units, or BU, these BU interact with their entire physical, chemical, and biological environments. These relationships are diagrammed simply in (Figure 1), with the arrows on the lines connecting a BU to its environmental elements pointing in both directions. This means that BU are affected by their environments, but that they also affect these environments and make them different.
This simple diagram is central to understanding of biology. Engineers and others need to realize that living things are not passive and compliant. Whenever living things are included in an engineering solution, they move, they change, and they affect the rest of the solution, sometimes so much that they may cause additional problems larger than the one that originally existed. With this appreciation, engineers can, at least, be aware of the challenges that they face when trying to fit living things into their designs.

Expectations
This brings us to the three major expectations for biological engineers [1]: 1. Possess the knowledge of biological principles and generalizations that can lead to useful products and processes.

2.
Have the ability to transfer information known about familiar living systems to those unfamiliar.
3. Know enough to avoid or mitigate the unintended consequences of dealing with any living system.
All engineers who deal with biological systems should, at least, have a level of awareness that, in biology, they are dealing with something more complex than steel, mechanical widgets, or computer programs.

Environmental components
The three environmental elements -physical, chemical, and biological -deserve explanation. All engineering is based on physics, so engineering students have always had one or more basic physics courses. In these courses are taught such things as mechanics, electricity, and optics. When considering physics as it relates to biology, however, the emphasis must be on those physical principles that apply particularly to living things. There are physical limitations due to fluidics, energetics, and mechanics that should be emphasized. Living things do not violate physical principles; they conform to them.
Chemistry courses are also a normal part of an engineering curriculum. These can include general chemistry, physical chemistry, and organic or biochemistry, depending on the engineering discipline. All of these have something to contribute to biological understanding. Knowing, for instance, that protein charges can change from positive to negative as solution pH changes can be important to know. The additional effects of temperature, ionic constitution, enzyme availability, mass action, surface configuration, toxicity, surface energy, and others must be familiar to the biological engineer.
When considering the biological environment, there is a large gap between information taught in traditional introductory biology courses and the information needed by engineers. At low hierarchical levels, there are many chemical interactions, as in quorum sensing by microbes. At higher levels, there are behavioral and psychological contributions to the biological environment. Knowledge is passed from one higher level animal to another (called memes) and changes the biological environment for them both. This range of communication types is hardly ever touched upon in traditional courses, but needs to be appreciated by the engineer designing animal confinement facilities or automobile dashboards, for instance.

Course structure
The course taught at the University of Maryland has five basic units:

Comparison between biological science and biological
engineering.

Basic sciences related to biology.
3. Biological responses to environmental stimuli.

Biological engineering applications.
In the first unit, students are introduced to differences in phylogeny, motivation, and methods used by scientists and engineers dealing with biology. The scientific method, central to science, and modeling, central to engineering, are covered. Scientific predictions are largely hypotheses, but engineering predictions are designs.
Once students appreciate that this biology course is to be different from a traditional biology course, they are taught topics in physics, chemistry, biology, mathematics, and engineering sciences that help to define the physical, chemical, and biological environments surrounding living things. This section is broad and foundational, and serves as a background for the next unit detailing typical biological responses to environmental stimuli.
The next section deals with many environmental factors, including the presence of oxygen, water, wastes, toxins, heat, mechanical stresses, and other living things. Included in this section are communications, optimization, redundancies, antagonistic actions, sensing and control, cycling, competition, cooperation, and reproduction. Death is considered in the context of product reliability, a topic all engineers should know about. It is in this unit that students are particularly primed to consider environmental factors important to biological responses.
Scaling is the ability to project the magnitude of a trait known for one type of organism to that for another unfamiliar type. It allows biological engineers to make quantitative estimates for their designs. It is, by far, the most quantitative unit for the course. Students are introduced to many allometric relationships usually based on powerlaw principles. Students are not expected to memorize these equations, but, instead, to be aware of general trends.
The last section deals with applications, from biotechnology, biomedicine, and bioenvironmental engineering. The range of applications is as comprehensive as possible so that students can see connections and discern principles among all possible applications.
Examples introduced in the course are meant not to emphasize one possible application over another so much as to be balanced among all possible application types. There are examples from environment, food, biotechnology, medicine, psychology, ecology, physiology, human factors, and imaging, as well as others. In this way, students can see biology as a wonderfully broad opportunity for engineering activity. By emphasizing the fundamental nature of environmental biological interactions, real life designs have a greater chance of success.

Textbook and teaching materials
This course is, unfortunately, unique at this time. Hence, there were no textbooks or teaching materials to support it. However, a book, Biology for Engineers [2], has been written and newly published following the course structure previously described. The book had been in development for ten years, and, as a result, has been thoroughly student-tested. Reviews of the book have been positive [3,4], and, with the availability of this textbook, courses covering biology in this way should become more common [5].
Other supporting materials are being developed. Multiple choice examination questions are available from the author, and letting students see these questions without the answers has successfully been used to help them learn the vast amount of material in this course. An extensive addendum covering recent advances in biology is available, also [6]. This addendum is being updated frequently. Power-point slides may become available from instructors teaching similar courses at other institutions.

Outcomes
Student responses have been positive. One student has remarked that is course is appropriate for those contemplating which area of biological engineering specialty to choose. Another biology student used the course to explore what biological engineering is about and decided to choose engineering as a major. All students have been made aware of the intricate interplays between living things and their