Your Essential Assignments. 1. Give the biological meaning of evolution.

I. Quick check:

1. Give the biological meaning of evolution.

2. How does neo-Darwinism differ from Darwin’s original theory of evolution?

II. Fill in the missing words:

III. Use monolingual English dictionary and write down what could the words given below mean:

change, naturalist, complex, to escape, to collect, humans.

IV. Match these words with their definitions:

V. Find English equivalents to the following word combinations:

VI. Give Russian equivalents to the following English terms:

VII. Find synonyms among the pool of words:

VIII. Answer the following questions. Use all information given before:

1. How does the evolution usually take place?

2. What led Charles Darwin to develop his theory of evolution?

3. What did Darwin mean by “natural selection”?

4. What are three main observations of Darwin’s theory?

5. What does “struggle for existence” mean?

6. What book has been called the most important biology book ever written?

7. Do the majority of biologists accept Darwin’s theory?

8. What is called neo-Darwinism?

IX. Match the sentence halves. Make complete sentences:

X. Read and translate the short text without any dictionary:

Fact of life: Highly sensitive dating techniques tell us that the Earth is between 4.5 and 5.0 thousand million years old. It is generally agreed by scientists that the Earth was originally devoid of life, and that the first living organisms arose by biochemical evolution from complex organic chemicals formed in the atmosphere and seas of early Earth. These first forms of life gave rise to countless millions of species. Most have become extinct, but some have evolved into organisms found today. According to the latest estimates, 20-30 million species share our planet.

XI. Food for thought:

In 1809 Jean-Baptiste de Lamark suggested that the driving force behind evolution was the need for organisms to adapt to changing environmental conditions. His theory became known as the theory of evolution by the inheritance of acquired characteristics. He believed that adaptations developed by an organism during its lifetime could be passed on to its offspring. According to Lamark, modern giraffes might have evolved from a short-necked ancestors in the following way. Giraffes feed on leaves ripped off the branches of trees. When leaves on the lower branches were removed, or when the trees became taller, the ancestral giraffe needed to stretch to reach leaves on higher branches. By continually stretching, their necks lengthened and the ability to grow a slightly longer neck was inherited by the next generation which carried on stretching, and so on.

We know that this explanation of the evolution of the giraffe’s neck is untrue because activities such as stretching to feed do not affect the gametes. Therefore, this type of characteristic acquired during the life of an organism is not inherited by its offspring. Expressed in modern terms, Lamarckism would mean that changes in phenotype could determine the genotype of future generations. This does not agree with modern genetics, and there are no generally accepted examples of acquired characteristics being inherited. Suggest a neo-Darwinian explanation for the evolution of the modern long-necked giraffe from a short-necked ancestor.