---
title: "Genetic drift"
output: html_notebook
---

This notebook shows a simple, one-locus, two allele simulation of genetic drift 

```{r}
options(tidyverse.quiet = TRUE)
library(tidyverse)
library(ggplot2)

## These are the parameters you can play with
##
n_gen <- 100
n_e <- 100

## This is the simulation
##
p <- numeric(n_gen)
p[1] <- 0.5
for (i in 2:n_gen) {
  k <- rbinom(1, 2*n_e, p[i-1])
  p[i] <- k/(2*n_e)
}

## This is the code to plot the results
##
dat <- tibble(generation = seq(1:n_gen),
              p = p)
p <- ggplot(dat, aes(x = generation, y = p)) +
  geom_point() +
  geom_line() +
  theme_bw() +
  xlab("Generation") +
  ylab("p") +
  ylim(0, 1)
p
```