Modified overview

Author: mtomasini

docs/source/overview.md

@@ -18,11 +18,11 @@ Currently, each individual's culture is represented by a set of {math}`N` featur
 
 ### Neutral model
 
-The Neutral model follows loosely the set up selected by other authors working on the spread of cultural traits (_e.g._ *Patterns in space and time: simulating cultural transmission in archaeology*, Marko Porčić). While in most works the Neutral Model assumes some sort of mutation rate in the traits, in the form of errors in the process of copying traits, we assume no copying error and instead use the simplest model where one focal individual at random in each subpopulation and each generation copies one trait at random from another individual in the same subpopulation. Because of the absence of mutations, given enough time, this process is expected to lead to uniformity in an isolated subpopulation. 
+The Neutral model follows loosely the set up selected by other authors working on the spread of cultural traits (_e.g._ *Patterns in space and time: simulating cultural transmission in archaeology*, Marko Porčić). We use the simplest model where one focal individual at random in each subpopulation and each time-step copies one trait at random from another individual in the same subpopulation. The model allows for copying errors with rate {math}`\mu`: if a copying error occurs, instead of copying a trait from another individual, the focal individual changes the trait at the feature in focus with a random trait between the available ones. 
 
 ### Axelrod model
 
-While we plan on adding several different ways for individuals to interact and change their traits, as of July 2024 the only such way to interact is shaped upon the **Axelrod model of culture dissemination** (*The Dissemination of Culture: A Model with Local Convergence and Global Polarization*, Robert Axelrod (1997), The Journal of Conflict Resolution, vol. 41, no. 2). In this model, at each generation an individual is chosen at random to copy a trait from a neighboring source on a lattice; the copy occurs with a probability proportional to the total similarity of the two random individuals. This mimicks homophily - the principle by which two individuals that resemble each other have a higher chance of having an exchange than two individuals that are completely different. In the metapopulation model that I developed, for each subpopulation we pick two random individuals that will act as target and source of the copy.
+While we plan on adding several different ways for individuals to interact and change their traits, as of July 2024 the only such way to interact is shaped upon the **Axelrod model of culture dissemination** (*The Dissemination of Culture: A Model with Local Convergence and Global Polarization*, Robert Axelrod (1997), The Journal of Conflict Resolution, vol. 41, no. 2). In this model, at each generation an individual is chosen at random to copy a trait from a neighboring source on a lattice; the copy occurs with a probability proportional to the total similarity of the two random individuals. This mimicks homophily - the principle by which two individuals that resemble each other have a higher chance of having an exchange than two individuals that are completely different. In the metapopulation model that I developed, for each subpopulation we pick two random individuals that will act as target and source of the copy. Here too, copying errors occur with rate {math}`\mu`.
 
 ### Diversity measures