Home \ Online Books \ The Creation Explanation

Living Things Are Classified³

The differences between the various kinds of living things form the basis for the system of classification used by biologists to name and distinguish them. Classification promotes organization, clarity, and communication in scientific investigations. To classify means to arrange things in logical groups according to their properties and give them appropriate, systematic names.

Living things are usually classified by their structure according to obvious external differences in structure, hidden internal differences, or even subtle differences in cell structure. Taxonomists supply Latin names for each organism because Latin as a language is not used in everyday speech and therefore does not change. The meaning of the Latin terms afford the precision necessary in scientific communication and investigation.

The modern system of zoological classification stems from the eighteenth century work of the Swedish scientist Linnaeus. He believed that all organisms were designed and created by God, and that his system of classification was simply a logical means whereby man could better know and understand the Creator's handiwork. With the increase of knowledge Linnaeus' system has been greatly modified and enlarged. Cells are classified into two types: prokaryotic cells, which have no nuclear membrane, and eukaryotic cells, which have nuclei enclosed by membranes. All living things are then classified into five kingdoms:

1. Kingdom Monera: Prokaryotic single-cell organisms including the bacteria and blue-green algae.

2. Kingdom Protista: Eukarotic single-cell organisms including protozoans, algae, diatoms, and non-cellular slime molds.

3. Kingdom Fungi: Eukaryotic unicellular organisms which sometimes exist as continuous, non-cellular organisms which sometimes exist as continuous, non-cellular filaments containing many nuclei.

4. Kingdom Plantae: Eukaryotic many-cell and unicelled forms using photosynthesis as their main source of nutrition.

5. Kingdom Animalia: Eukaryotic many-cell organisms which are not capable of photosynthesis, including marine invertebrates, fish, reptiles, mammals, birds, insects, spiders, etc.

A kingdom is divided generally into two or more major groups, these into smaller groups, and so on. The names, then, of the ranks of classification from larger to smaller groupings are kingdom, phylum, class, order, family, genus, and species. Most biologists consider that the correct or "natural" system of classification is a consequence of and evidence for a real historical process by which all creatures evolved by chance from one or a few original single-cell organisms. As was indicated earlier, however, an arrangement of animals in a graded series of bodily forms or internal structures does not establish genetic relationship. Only actual breeding experiments or eyewitness observation of the evolutionary history could provide scientific verification for evolution, but this kind of evidence is not available to evolutionary theorists. On the other hand, creationists consider that the fact that all living organisms can be fitted into a classification system is to be expected in a created world.

For example, the fact that living things can be put into groups and classified establishes distinct differences between one kind and another. The created kinds are distinct, but limited variation is one of the best established facts of biology, and there is no question that processes of diversification have produced a vast number of new species since the original creation and also since the global flood of Noah. Each species can undergo limited variation in order to adapt to changing environments. For example, the one or more related species composing an originally created kind of bird may have diversified into a larger number of different species which are adapted to different environments and life types. The changes were limited within the boundaries of the created kind. A Creator who created plants and animals without adaptability and placed them in a changing world could expect most or all created species finally to become extinct.

The extent of variation within kinds and the boundaries of the created kinds are reasonable and useful subjects for scientific research by biologists who believe in creation. A massive body of genetic evidence exists for the reality of impassable genetic boundaries. Furthermore, although there was undoubtedly a number of different original kinds of birds, and although there must have been much diversification into many new varieties and species within each kind, all birds, both extinct and living species, are readily classified as birds.

If all organisms had come from one common ancestor by evolutionary change and descent, one would expect to find one continuous chain of life forms connecting the beginning to the end. It would not be possible so readily to classify species and genera, either of living species of extinct fossilized species. There would be species starting to change into other kinds of plants and animals, and proto-organs just beginning to take on their role as genuine organs. But this is not observed. Furthermore, the various kinds of living plants and animals are separated by impassable boundaries. For example, one cannot discover living reptiles starting to change their scales into feathers and attempting to fly, nor is there fossil evidence that this ever happened in the past.

The beautiful manner in which each creature is adapted to its place in nature is strong evidence for intelligent, purposeful design. In the creationist view, similarities between different creatures are the result of a plan for each creature which provides it with the organs and capabilities required for life in its possible range of environments. As an example, each organism requiring vision possesses the type of eye which is adapted to give vision of just the correct kind for that creature.

References

3. Curtis, Helena, ibid., pp. 205-254; Moore and Slusher, ref. 1, pp. 141-149.