Question

Why are the traits acquired during the life time of an individual not inherited? Explain.

Answer 1

Acquired traits (like muscle built by exercise or a scar) arise from environmental effects on an individual’s somatic cells and do not change the DNA of gametes. Because inheritance depends on alterations in the germ line, somatic modifications are not passed to offspring, this is the Weismann barrier separating soma and germ line. Lamarck’s idea that acquired characters are inherited was thus disproved; only genetic changes (mutations) or stable germ-line epigenetic marks can be inherited, and these are rare. Therefore, traits acquired during life are generally not transmitted to the next generation.