1865 – Mendel Develops his First Theories of Inheritance

Gregor Johann Mendel, a nineteenth-century Austrian monk, developed the first theories of inheritance by experimenting on pea plants which grew in the garden of his monastery.

He wanted to see what would happen if he took a ‘male’ pea plant with red petals and used it to fertilize a ‘female’ pea plant with white petals.

After doing this he took it a step further and used the plants that had grown as a result of his original experiment (the offspring of the first test, if you like) and repeated the fertilization process to see what colour petals the second generation would have.

Mendel’s Law of Inheritance

Mendel went on to test 5,000 plants and as a result developed his theories which became known as Mendel’s Principles of Heredity or Madeline Inheritance. From these principles came the three laws of inheritance (these were supported by further study, but more on that later):

• Law of Segregation (first law) – During gamete formation, the alleles for each gene segregate from each other so that each gamete carries only one allele for each gene

• Law of Independent assortment (second law) – Genes for different traits can segregate independently during the formation of gametes

• Law of Dominance (third law) – Some alleles are dominant while others are recessive; an organism with at least one dominant allele will display the effect of the dominant allele.*

So did fame and fortune await Mendel?

Not exactly, the principles were mostly ignored to start with as it was not felt that they applied in general, even Mendel himself struggled to see the importance of his work. As a result it wasn’t until 1900 when three European scientists ‘re-discovered’ Mendel’s work and undertook further investigation into his three laws, allowing them to add to the findings and therefore create a much more robust argument. However even with further results this work was still considered to be controversial.

Due to further investigation by many other scientists and the meticulous nature of Mendel’s work, it was finally seen as the Law of Inheritance and granted Mendel his rightful position in the history books.

If this has left you feeling curiouser and curiouser then join us next week when we’ll be sticking in 1865 when Lewis Carroll publishes Alice’s Adventures in Wonderland.

*Source: Mendel’s law of inheritance