Lecture 01
Nature & Scope of Biological Science
What is Biology? A brief history. Biology today. Group of organisms being studied. Approach taken to the study of organisms. New definition of Biology. Why study Biology?

Aspects of Science
Science has two aspects. It is both (1) a body of knowledge and (2) a method used for discovering new knowledge.

What is biology?
The word biology comes from the Greek words bios, which means life, and logos, which means thought. Thus, biology is the science that deals with the study of life.

Origin of Life
|According to this theory, about 15 billion years ago (15,000,000,000) the Universe was nothing more than a very small speck of mass. This speck|
|was probably no bigger than the head of a pin. Everything in the Universe, all the galaxies, stars, planets, and even the matter making up your|
|body, was squished up tightly in this tiny space. |
|Eventually, after a very long time, this speck exploded. All of a sudden, in a giant flash of unimaginable heat and power, the Universe was |
|born. Over a period of billions and billions of years, the Universe became what we see today. Slowly stars began to form, and around these |
|stars planets formed. |
|About 4.6 billion years ago our Earth looked very different than it does today. Instead of the beautiful blues, greens and whites of today, it |
|would have looked red and orange. The surface of our planet was covered in oceans of hot lava. Instead of breathable oxygen, the atmosphere |
|contained a mix of deadly poisons. |
|Still, there was no life. No fishes to fill these oceans, no plants to cover the rocky surface, no animals to graze the wilderness. Just a |
|barren wet rock, orbiting the Sun. The Earth's atmosphere now contained a mix of very poisonous gases, including carbon monoxide, carbon |
|dioxide, nitrogen oxides, hydrogen sulfide, methane, and cyanide. Breathing this air would cause death to most life forms as we know them. |
|What forces changed this barren wasteland into the beautiful garden that it is today? Biologists believe that the process that created life is |
|something called evolution. Earth's ancient oceans while lifeless, were filled with the chemicals needed for life. These chemicals were not |
|alive, but they were there sloshing around. They call these chemicals “primordial soup”, this soup was filled with amino acids, proteins, |
|lipids, and other basic components that are commonly found in life forms today. |
| |
|What is a cell? |
|A cell is a basic unit of life. They are tiny packets, or bags, of organelles, or tools, needed for the cell to survive. A cell can eat, move |
|around, and reproduce. These cells took the chemicals of life found in the soup and put them together inside protective sacks. These first |
|cells were very simple and because there was little or no oxygen available, they probably did not need it to survive. |
|From very simple cells, to multi-cellular human beings, life had a long way to go. A number of very important advances in evolution allowed |
|life to become what it is today. The first important advancement was the development of cells that use oxygen. Remember, the first cells could |
|not use oxygen because there was not enough of it in the air. However, as these first cells carried out the business of living, they released |
|oxygen into the atmosphere. Over a very long period of time, our atmosphere changed from a poisonous and deadly mix of gases to the atmosphere |
|we know and love today. |

A Brief History of Biology
Biology is a very old science. In fact, it probably began in prehistoric times.

Over thirty thousand years age, cave dwellers in France and Spain decorated the walls and ceilings of their caves with paintings of animals. These paintings show that the cave dwellers had closely observed the structure and behaviour of many animals.

When humans were mainly hunters of animals and gathers of edible plants, they studied biology at a simple level. They had to know the behaviour of their prey and, of course, the behaviour of animals that might prey on them. They also had to observe the growing conditions required by the various plants as they collected them for food.

When human began an agricultural way of life about ten thousand years ago, they had to know much more about plants and animals. For example, they had to know when to collect seeds for their next year’s crop, when to plants seeds, and how much moisture the various types pf plants needs. They also had to know what to feed their animals, how long the animals would live, and what might kill the animals. In a sense then, they were biologists because the studied living things. From such early beginnings came the science of biology.

Prehistoric humans had to rely on their senses alone to make observations. They had no laboratories, microscopes, dissecting kits, or other equipment.

What other living things is it like? While seeking answers to such questions, they probably discovered that the wide variety of living things had much in common, as well as many differences. They probably grouped similar living things and named each group. For example, they might have noted that all flying animals with feathers had much in common. They may have grouped them under one name such as birds. This process of grouping similar things is called classification.

These early Biologists also would have observed other patterns in nature, such as regular migration of birds and life cycles of plants and animals.
As century passed, humans became more knowledgeable and curious. They began to ask more complex questions such as: What is it made of? and, How is it put together?

Modern Biology
Modern biology began during the 17th century when humans finally had the knowledge, skill, and equipment to seek answers to such questions. During that century Robert Hooke (1635-1703) and Anton van Leeuwenhoek (1632-1723) introduced a new tool, the microscope, to the scientific world. Another pioneer of modern biology was William Harvey (1578-1657), an English physician. He showed the importance in biological studies of well-designed experiments and careful observations. He traced the pattern of circulation of blood in humans, and showed that it travelled in one direction through the arteries and veins in a circular path.

The search for still more knowledge by curious scientists led them to ask even more complex question: What do the parts of a living thing do? How do the parts work? With the asking of such questions, biology truly came of age.

Biology Today
Modern biology is vast science. Over 1,500,000 different kinds or species of organisms have been identified and new ones are still being discovered. Biologists think that there may be over 2,000,000 different species on earth. They range in size and complexity from tiny bacteria to trees and humans. Because biology is such a large field, it is broken down into several subdivisions for easier study. These observations are formed according to the group of organisms being studied or the approach taken to the study of the organisms.

Group of Organisms Being Studied
Examples of some of the main fields of biology formed using this method of subdivision are:
Botany The study of plants.
Zoology The study of animals.
Microbiology The study of microscopic organisms.
Bacteriology The study of bacteria.
Virology The study of viruses.
Mycology The study of fungi.
Entomology The study of insects.
Ornithology The study of birds.

Approaches taken to the Study of organisms
Examples of some of the main fields of biology formed using this second method of subdivision are:
Taxonomy The classification of organisms.
Morphology The study of the external form and structure of organisms.
Anatomy The study of the internal structure of organisms.
Physiology The study of the function of organisms.
Cytology The study of cells.
Ecology The study of the relationship of organisms to their environment.
Genetics The study of inheritance
Pathology The study of diseases.
A New Definition of Biology
Biology was first defined as the science that deals with the study of life. However, as we learn more, we see that biology involves many other things. It is also a study of all those things that affect life. Thus the following is a more accurate definition of biology:
Biology is the study of living things and the things that were once alive, together with the matter and energy that surround them.

Review Questions 1. State the two main aspects of every science. 2. Explain the origin of life. 3. Explain the origin of the word Biology. 4. Give a simple definition of biology. 5. State the modern definition of biology. 6. Name, with definition and example, five subdivisions of biology formed according to the group of organisms being studied. 7. Name, with definition and example, five subdivisions of biology formed according to the approach taken to the study of the organisms.