Characteristics like height and weight can be examined in this way because they are easily measured. It is more difficult to analyse differences between individuals when the characteristic is not so easy to measure. Fig. 14 shows eight individuals from the same species of ladybird. They are all different sizes. It is easy to measure the size. The ladybirds all have different patterns of spots. Variations like this are more difficult to analyse because they are not easy to measure. Scientists often record these types of variation using diagrams or photographs. Computer programmes can also be used to analyse the variety of patterns.
Fig. 14 Eight individual ladybirds from the same species of ladybird showing variation in their pattern of spots.
Nature of Science
The idea that traits are controlled by genes was first proposed by a German monk, Gregor Mendel, in 1866. The structure of DNA was discovered by two British scientists in 1953, Watson and Crick. In 2003 the Human Genome Project revealed the precise detail of human DNA. The Human Genome Project involved teams of scientists from all around the world. Since 2003 information from the Human Genome Project has been used by scientists throughout the world for a variety of purposes, including the identification of genes which cause disease. In the future it is hoped that this information may help with the prevention and cure of genetic diseases. 1. What do these discoveries in genetics tell you about the process of science? 2. What do these discoveries tell you about the way that scientists work? 3. What do these discoveries tell you about the importance of scientific research to society?
