A scientist called Lamarck proposed a mechanism for evolution. The passage gives Lamarck’s explanation of the evolution of the long legs of wading birds.
‘Change occurs because an animal passes on to its offspring changes it acquires during its lifetime. The long legs of wading birds arose when those animals’ ancestors responded to a need to feed on fish. In their attempt to get into deeper water, but still keep their bodies dry, they would stretch their legs to the full extent, making them slightly longer in the process. This trait would be passed on to the next generation, who would in turn stretch their legs. Over many generations the wading birds’ legs became much longer.’
Darwin’s proposal of natural selection would give a different explanation for the evolution of the long legs of wading birds. Describe the differences between Lamarck’s and Darwin’s explanations of the evolution of the long legs of wading birds.
Lamarck's theory of evolution, often referred to as the theory of inheritance of acquired characteristics, suggests that changes in an organism's traits during its lifetime can be passed on to its offspring. According to Lamarck, the long legs of wading birds evolved as a result of the birds' ancestors stretching their legs in an attempt to feed on fish in deeper water while keeping their bodies dry. These stretched legs then became slightly longer and were inherited by the next generation. Over time, this process continued and resulted in the wading birds' legs becoming significantly longer.
On the other hand, Charles Darwin proposed a different explanation for the evolution of the long legs of wading birds based on his theory of natural selection. According to Darwin, variation exists naturally within a population. In the case of wading birds, there might have been variations in leg length among individuals. Darwin's theory states that certain variations, such as longer legs, can give some individuals an advantage in their environment. For example, wading birds with longer legs would be better equipped to wade through deeper water and catch fish. As a result, they would have a higher chance of surviving and reproducing, passing on their advantageous traits to the next generation. Over time, this process of natural selection would lead to an increase in the prevalence of longer-legged wading birds within the population.
The key difference between Lamarck's and Darwin's explanations lies in the mechanism of evolution. Lamarck proposed that changes in an individual organism's traits during its lifetime are inherited by its offspring, while Darwin's theory suggests that advantageous traits are selected for through natural selection and then passed on to the next generation. Lamarck's theory focuses on an individual's experiences and adaptations during its lifetime, whereas Darwin's theory emphasizes the role of the environment in selecting advantageous traits and the accumulation of these traits over generations through the process of natural selection.