Until 1953, scientists used statistics and presumed mechanisms to make predictions about inheritance. Nobody knew what exactly was the mechanism behind it. But in 1953 Watson and Crick, using research results from Wilkins and Franklin, discovered the double helix structure of DNA and together they won the Nobel prize for their discovery.
Since the discovery of the DNA structure a lot has happened. In the beginning studying the DNA was very labor intensive and very costly. In the beginning of the 21th century robots performed large scale genotyping e.g. of more than 60,000 genetic markers, specific and identifiable sequences of DNA, on thousands of individuals within very limited amounts of time. The location of a marker and its composition is known. These genetic markers, called Single Nucleotide Polymorphisms (SNPs) can be used to compare animals based on the composition of the various markers. Nowadays, the genome can be characterized in full detail, very preciously, by Whole Genome Sequencing (WGS). The genome of an individual consists of approximately 3 billion base pairs. Storage of genomic information requires comprehensive databases and analysis requires appropriate complicated statistical models.