The start of the Mendelian Era of genetics is when Charles Darwin publishes his book “On the Origin of Species” in 1895. The book is a result of his studies from his voyage to South America on the Beagle. The basis of the book is that the organisms that are best adapted to their environments are the most likely ones to breed successfully, and while doing that, also passing on their beneficial traits to their future generations of offspring.
The next major progression to happen was when Gregor Mendel published his paper “Experiments in plant hybridization”, which encompasses his theory of inheritance. The paper was a result of his several of studying and breeding pea plants. Over the years of study he bred together pea plants that exhibited different characteristics such as pea pod color and pea texture. His discovery was that in most cases, the characteristics did not blend, which went against the current idea of heredity.
Friedrich Miescher made the next big discovery in 1871. That discovery being of what he called ‘nuclein’. This compound that he isolated was acidic and phosphorus-rich part from the nuclei of white cells. The name nuclein did not stay, instead it was renamed nucleic acid, which we know today makes up DNA.
In 1882 a man by the name of Walther Flemming discovered the process of mitosis and chromosomes, which is the following great discovery. Walther had stained cells and examined the structure inside their nuclei. He saw the complete process of cell division, which he named mitosis. The highlights of it were the thread-like structures formed and separated to the two poles of the cell. He named those structures observed chromatin. The name chromosome wasn’t used until 1888.
The last work of significance was Francis Galton’s law of ancestral inheritance. That law simply proposed that an offspring obtained half of their inherited characteristics from each parent, a fourth from each grandparent, and so on. This law provided a model for the reappearing of characteristics in offspring that weren’t seen directly in their parents.