Genetic memory

Genetic memory is the controversial theory that the memories of one's ancestors are genetically passed on to subsequent generations. In the Assassin's Creed universe, genetic memory exists, and plays a critical role in the plot.

The Theory
"What if I told you the human body not only housed an individual's memories, but the memories of his ancestors as well? Genetic memory, if you will. Migration, hibernation, reproduction. How do animals know when and where to go? What to do?"

- Dr. Warren Vidic

The theory is controversial. Proponents point out examples of what seem to be genetic memory happening in reality, such as birds knowing where to migrate in the winter, and other forms of instinct. However, the mechanism for the preservation of memories in DNA has not been found.

There are still many flaws in this theory, such as if the memory continues after the ancestor's child is born, or if it abruptly stops there.

The Animus
In the world of Assassin's Creed, genetic memory exists. The Animus is a machine developed to read a subject's genetic memory, and, from it, create a simulation of the ancestor's life that the subject can interact with, "playing" as the ancestor.

In Assassin's Creed, the Animus is used by Abstergo Industries on Desmond Miles to decode the memories of his ancestor, Altaïr Ibn-La'Ahad, who lived during the Third Crusade. In Assassin's Creed II, it is again used upon Desmond, this time to learn about his later ancestor Ezio Auditore da Firenze, who lived during the Renaissance. Before Desmond Miles, Abstergo had already used the Animus on 16 different subjects.

In the second game, Desmond's dream of Altaïr explains that the point in which the genetic memories of an ancestor are passed on is the moment of conception of the next descendant. Naturally, as is the moment where all genetic traits are then passed.

In "Assassin's Creed Brotherhood", Desmond is using an Animus at the Assassin's Hideout in the Mountains to view the last few moments of Ezio's Life.