Heredity & Evolution

Rules for the Inheritance of Traits – Mendel’s Contributions

  • Johann Mendel is known as "Father of Modern Genetics".
  • In human beings, the rules for inheritance of traits and characteristics are related to the fact that both the Father and the Mother equally contribute the genetic material to their child.
  • Further, each trait of an offspring is usually influenced by both paternal and maternal DNA.
  • Johann Mendel, who was an Austrian scientist, had experimented on peas and gave the “Laws of Inheritance”.
  • Mendel used a various contrasting visible characters of garden peas – round/wrinkled seeds, tall/short plants, white/violet flowers and many more to prove his law of inheritance.
  • Mendel’s law of inheritance became popular as  "The Laws of Mendelian Inheritance.”
  • The frequency of an inherited trait changes one after another generation. This happens because of change in genes (as genes control traits). eg:

Evolution – Charles Darwin

  • Darwin was an English geologist, biologist, and naturalist; and, he is best known for his contributions to the science of evolution.
  • In 1859, Darwin published his book “On the Origin of Species” explaining the theory of evolution (by natural selection).
  • Darwin’s theory of evolution describes - how life evolved from a simple to more complex forms; whereas, Mendel’s experiments explains the mechanism for the inheritance of traits from one generation to the next.
  • Evolution is basically the generation of diversity and the shaping of the diversity by the means of environmental selection.
  • Over period of time, variations in the species may advise survival advantages or merely an example of the genetic drift.
  • Further, changes in the non-reproductive tissues, are largely because of environmental factors (not by inheritance).