Mutation Changes – Basic Mechanism for Augmentation of the Gene Fund and Diversity of Living Organisms
Section 2.9. Variability is at the root of the very essence of nature. It is inherent in the
living, as well as in the non-living nature. Different are only the modes and
mechanisms of its realization. The changes in the living nature can be
temporary and persistent. Let pause on some of their characteristic features.
Temporary changes exist only during of the individual development of the
cells and organisms. After eliminating the reasons, caused their appearance,
they recover its initial form. Such changes are called modifications. They
have a temporary character and are not inherited.
Persistent changes are inherited. Because of that they are called
inheritable. They can arise as a result of genetic recombinations in case of
fusion of generative cells (fertilization), exchange of hereditary material
(transformation, transduction and conjugation), the influence of different
mutagenic factors, and others still unknown reasons. Sudden hereditary
changes are called mutations.
Prerequisites for the Generation of Idea of Mutation Changes
Sudden changes in the morphology and qualitative properties of naturally
existed plant and animal organisms are observed by people for ages. In
1590 the German pharmacist Sprenger from Heidelberg has noticed a
new form among the sown fields of the plant snake milk (Chelidonium
majus) different from the other plants. Unlike the normal plants whose
leaves have had round lobes the new form has possessed cut leaves and
petals. He has called it Ch. laciniatum. In 1851, among usual strawberry
plants with trilobate leaves (Fragaria vesca), the French gardener A.
Duchesne has found a plant with unilobar leaves. He has called it F.
monophila. The Chinese emperor Kang-Xi (1654—1722) has discovered
an early rice of better regarding grain qualities, become known as
“emperor’s”. Similar uneven changes are also observed in animals. In the
ranch of Ankon (Massachusetts, USA) a lamb with a long backbone and
short legs has appeared, originating Ankon breed of sheep (see
Rukmansky et al., 1984).
These is only a part of the curious cases of sudden hereditary changes
described in the literature. At that time it has been impossible to find a
scientific explanation. Their number is great and continues to increase.
Everybody knows that it is possible in a flock of white sheep a black lamb to
be born, in a flight of black swallows to meet one white for “luck”, in a
collection of Drosophila with red eyes to observe an appearance of one
with white (the case in the Laboratory of T. Morgan), a transformation of
antennae in some insects into legs, a change of the morphology in bacterial
colonies and loss or acquisiton of virulence by some cells in them, or