Final answer:
Inheritance of acquired characteristics is an outdated theory proposed by Jean Baptiste Lamarck, suggesting that traits developed in an organism's lifetime can be passed on to offspring. It is discredited because genetic traits, not acquired ones, are inherited according to alleles on chromosomes.
Step-by-step explanation:
Inheritance of Acquired Characteristics
The concept of inheritance of acquired characteristics was a theory proposed by the scientist Jean Baptiste Lamarck. According to this theory, traits developed by an organism during its lifetime due to environmental influences or usage of organs could be passed down to its offspring, ultimately bringing about evolutionary changes. However, this idea has been proven incorrect because most characteristics of organisms are controlled by genes and the inheritance of traits does not work through acquiring traits during an organism's life.
Problems with Lamarckian Inheritance
Lamarckian inheritance faces a couple of significant issues. Firstly, desires or changes in behavior during one's life do not alter genetic characteristics. For instance, dyeing your hair blue does not affect your DNA, hence your children will not inherit blue hair. Instead, characteristics that are passed on to offspring are determined by the genetic information contained in the parents' egg and sperm cells.
Modern understanding of genetics has thoroughly disproved Lamarck's theory, showing that traits are inherited according to the alleles present at the same locus on homologous chromosomes, a principle solidified by Gregor Mendel and observable in complex organisms like humans. Characteristics that are encoded in DNA, also called genetic traits, follow Mendelian inheritance patterns, some simple, some complex, but not acquired characteristics.