Estimating the longer-term genetic consequences of linear
transport infrastructure.
We compared the predicted loss of genetic diversity for the two
fragmented populations (above, below) with the predicted loss of genetic
diversity for the population if the population had not been fragmented
(pre, post). This allowed us to assess the predicted long-term
consequences of linear transport infrastructure on the populations’
genetic diversity. To do this, we forecast the extent of genetic
diversity loss across generations using the following equation:
\begin{equation}
{H\mathrm{e}}^{t}=H\mathrm{e}\ {(1-\frac{1}{2N\mathrm{e}})}^{t}\nonumber \\
\end{equation}where He is Hardy-Weinberg expected heterozygosity,
Ne is effective population size and t in the number of
generations. Estimated generation time in koalas is 6 years (Phillips
2000). We adjusted Ne for the proportion of males within a population
that sire offspring (~30%) which was estimated from
Schultz et al (2020)’s study. We also generated the same analysis using
the Shannon’s diversity index (see Appendix 1, Figure S1).