It doesn't, but the article doesn't go into this detail, so people unfamiliar with the field wouldn't understand why. The keyword is epigenetics. I.e. how certain genes become activated or deactivated through behaviour and/or environmental influences. But the DNA sequence itself remains unaltered. So no evolution necessary. There are basically a bunch of molecules than sit on top of your DNA that regulate gene expression. They don't just tell a cell to behave like a skin cell or a brain cell, they also regulate the entire cellular metabolism. The discovery that male sperm can also transmit this epigenetic information to offspring is relatively new, but now that we know that, it makes total sense that these gene-expression-modifying behaviours in fathers could affect their children. After all, they simply get to start with a good (or bad) bunch of epigenetic markers. They will not persist across many generations though, so it has no real long term effect on evolution. It may even be an evolved mechanism that allows organisms to respond to environmental changes on timeframes that would be prohibited by evolution.