Reading

1. Read the text and answer the questions: What is evolution? Do you agree or disagree with the definitions in the text?

WHAT IS EVOLUTION?

“Evolution” really has two different meanings to biologists. The term can refer to either as a process or an organizing principle, that is, a theory. Generally, the word evolution means change, and the process of biological evolution is derived from this definition. That is, biological evolution is a change in the features of individuals in a biological population that occurs in the course of generations.

For example, consider the species of organism commonly known as head lice. A species (Latin, meaning “kind”) consists of a group of individuals that can regularly breed together and is generally distinct from other species in appearance or behavior. Most species are physically subdivided into smaller groups, populations, that are somewhat independent of other, populations – that is, most individuals in a population breed with other individuals in the same population. As some parents of small children have discovered some populations of head lice in the United States have become immune to the pesticide permethrin, found in over-the-counter delousing shampoos. Initially, lice infections were readily controlled through treatment with these products; however, over time, populations of lice changed to become less susceptible to the effects of these chemicals. The evolution of resistance can occur rapidly – a study in Israel demonstrated that population of head lice were four times less susceptible to permethrin only 30 months (40 lice generations) after it came into widespread use in that country.

Note that in this example, individual head lice did not “evolve” or change; each individual louse is either susceptible to, or resistant to permethrin. Instead the population in a whole changed from one in which most lice were susceptible to one in which most lice were resistant to the pesticide. This change in the characteristics of the population took many generations. According to the definition above, the lice have evolved.

In general, the fact that the process of evolution occurs is not questioned. Evolutionary change in biological populations, such is the development of pesticide resistance in insects and antibiotic resistance in bacteria, has been observed multiple times. Changes that occur in the characteristics of population are referred to as microevolution.

Few members of the Kansas state school board, or their supporters, disagree that populations of organisms can change over time. The theory of evolution is much more controversial in society than the process.

The scientific theory is a body of scientifically acceptable general principles that help explain how the world works.Scientific theories are supported by numerous lines of evidence and have stood up to repeated experimental tests. So the theory of evolution is an organizing principle for understanding how species originate and why they have the characteristics they exhibit. The theory of evolution can thus be stated:

All organisms present on Earth today are descendants of a single common ancestor, and all organisms represent the product of millions of years of microevolution.

In other words, modern animals, plants, fungi, bacteria, and other living things are related to each other and have been diverging from their common ancestor by various processes since the origin of life on this planet. The origin of modern species from a common ancestor is what most nonscientists think of when they hear the word evolution. However, most biologists conceive of the theory of evolution as encompassing both the theory of common decent and the processes by which evolutionary change occurs.

2. Reproduce in your own words:

Микробиология – наука о мельчайших, невидимых невооруженным глазом живых существах – микробах. Эта наука изучает внешнюю организацию микроорганизмов, проявления их жизнедеятельности, систематику, изменчивость, наследственность и экологию микробов. Термин «микроб» был предложен в 1878 году Сидийо (Ch.E.Sedillot) для обозначения всех невидимых простым глазом живых существ. Название «микробиология» впервые применено Дюкло (E.P.Duclaux) и теперь является общепринятым.

Мир микроорганизмов весьма обширен и разнообразен. В его состав входят одноклеточные (unicellular) и некоторые многоклеточные (multicellular), а также микробы неклеточной природы – риккетсии (Rickettsias) и вирусы. Эти различные группы микроорганизмов составляют объект изучения соответствующих разделов микробиологии, которые в процессе исторического развития дифференцировались в самостоятельные дисциплины, а именно: бактериология, микология, вирусология и протистология. Микробиология как отрасль биологических знаний объединяет эти дисциплины, создавая цельное представление о мире микроорганизмов.

Основоположниками микробиологи в России являются И.И.Мечников и С.Н.Виноградский. Идеи этих великих ученых надолго определили направление развития отечественной микробиологии. За последние годы наблюдается новый расцвет микробиологии, причина которого состоит в том, что в микробиологии стали применять новые, точные методы исследования, разработанные физикой, химией, биологией. Знания о морфологии клетки, структуре вирусов значительно расширились благодаря применению электронного микроскопа, использованию современных методов органической, физической и биологической химии.