Suppose those chicks eventually grow, mate and have chicks that follow them via the short path to food. Furthermore, let's suppose the common food source is not very plentiful. Consequently, there will me more of these on the shores. Eventually, they will dominate the scene. The theory of evolution can be an interesting topic when one considers penguins, so let's talk about where penguins came from.
Penguins are birds, and they obviously came from birds.
Look at the following geological timeline. An Introduction to Behavioural Ecology. The Discovery of Evolution.