Evolution is not such a straight-forward process to analyse. It is all about species adapting to their environments and the survival of the fittest to live in a particular environment. However, the environment itself is always changing.
Now, researchers from Australia, New Zealand, USA, UK, and China analysed genetic data from all 20 living penguin species and found links between their evolution and island formation.
Scientists were able to reconstruct the timescale for the evolution of the penguins, which revealed that new penguin species arose at the same time as the islands they breed on. All penguins breed on land, even though almost entire time when they are not breeding they spend at sea.
Scientists calculate 20 species of penguins in total and they range in size from 1.5 kg fairy penguins to 45 kilogram emperor penguin. Scientists analysed genetic makeup of these species and found that their evolution is closely related to the formation of the islands. For example, the northern rockhopper penguin came about around that time when Gough Island emerged from the Atlantic Ocean.
But why evolution of species would be so closely related to island formation? Well, new breeding grounds could’ve created new isolated colonies of existing penguins, which evolved into new species over the course of hundreds of thousands of years. However, scientists say that the biggest surprise in the study was the discovery of two new species of penguins.
Scientists analysed DNA from prehistoric penguin bones and revealed the existence of two previously unknown penguins: a new species of crested penguin (Eudyptes warhami) and a new dwarf subspecies of yellow-eyed penguin (Megadyptes antipodes richdalei). Both of these species became extinct when people moved into these Chatham Islands east of New Zealand.
Even though both of these newly discovered species are extinct, their discovery helped scientists prove that evolution of penguins and island formation were closely linked. Theresa Cole, lead author of the study, said: “From an evolutionary perspective, it’s fascinating to understand how and why species evolve. We were able to provide a comprehensive framework for exploring these questions about penguins, and demonstrated for the first time that islands may have played a key role in penguin evolution”.
Species were formed by their environment. Animals had to learn to adapt and those who failed to do so didn’t survive. However, this environment is altered by human activity. Several penguin species went extinct due to arrival of humans. That is why scientists have to understand evolution better to be able to predict what is going to happen in the future.
Source: University of Adelaide