Question

a) What are the primary steps involved in the scientific method?

b) Define the term "paradigm shift". Describe the paradigm shift regarding the solar system from the fourth-century B.C. to the 1600s.

c) Jean-Baptiste Lamarck (1744-1829) provided the first statement of evolution as a scientific theory. a. Give the name of Lamarck's theory b. Explain the Lamarck's notion of inheritance of acquired characteristics.

Answer 1

Paradigm Shift is any fundamental change in basic concepts & experimental practices of a scientific discipline.

Copernican Revolution was the paradigm shift from Ptolemaic model or geocentric model ( which cosidered earth as the centre of universe & planets,moon,sun & stars were revolving around earth) to the Heliocentric model (which argued that sun is the central body of solar system & everything else revolved around it ).

C) i) ans - According to Lamarck's theory of evolution any physical change in organism during its lifespan such as development of any organ/part/tissue due to its increased use is being passed on to next generation.

ii) Lamarck explained his theory by giving numerous examples such as

1) In Giraffe - ancestors used to have small neck & fore-limbs but since they were living in places with no surface vegetation ,they had to stretch their neck to reach out food which resulted in slight elongation of these body parts & this was transmitted to future generations.

2) In whales - hind limb was lost over a period of time because of its disuse.

3) Aquatic birds like ducks have been evolved from terrestial ancestors Since there was shortage of food on land they developed some structures like web between toes.Since there was no use of wings in water they got reduced over a period of time.

4) In Jacana (bird) long legs were developed through generations of consistent streching to keep themselves above water level.

Lamarck's theory of inheritance of acquired characteristics was simply based on the hypothesis that any body part which an organism use or misuse decides it's evolution or extinction in future generations.