Evolutionary biologists believe that these flightless aquatic birds’ evolution is one of the most interesting ever studied. These birds are found mainly in the Southern Hemisphere, and they have significantly adapted for life and survival inside water bodies. However, penguins have considerably evolved over time, and it is their evolution that is the focus of this piece.
There is a debate today in the scientific community regarding the precise number of penguins’ extant species. Based on the kind of scientific conclusion that one follows, the diversity of biodiversity can be anything from 17 to around two dozen living species, and all of them are classified as part of the Spheniscinae subfamily.
There are also some other scientists that take the white-flippered penguin to belong to a different species, the Eudyptula. But on the other hand, are scientists that consider it to be another component of the little blue penguin, but there is no conclusion on this yet. Also, there is a division of opinion on the royal penguin classification as another species on its own or just a color-based variation from the macaroni penguin. The same controversy remains regarding the classification of the rockhopper penguins.
The evolution of penguins is one that researchers have exhaustively studied, and it offers a relatively detailed map of biogeography. Even though bones sourced are identified, the taxonomy for penguins is still not fully complete. Scientists seem to agree that the basal penguins existed around the era of the Cretaceous-Paleogene extinction event in the areas that are now located between Byrd Land in Antarctica and New Zealand.
As a result of plate tectonics, these regions were under 1,500 kilometers then instead of 4,000 kilometers apart in the modern era. Of all these, the most recent of all the penguins’ common ancestors and the related clade can be traced to the Campanian-Maastrichtian boundary, which places it around 70 million years ago. What is certain about this is that via the lack of direct fossil proof, the conclusion can be that the penguins’ lineage must have experienced an evolutionary distinction. However, it has to be pointed out that they had some ability to fly around that time.
The Waimanu manneringi is the most ancient known fossil of any penguin species. They existed in the initial part of the Paleocene epoch of New Zealand, which dates to around 62 million years ago. Even though they were not well-suited for life in the water like the penguins of today, they were already known to be flightless birds that had small wings perfect for deep diving. The swimming was done on the surface by making use of their feet, and the wings were mainly adapted for movement underwater. This is not the same as seen with other diving birds, including the ones living and the extinct ones.
Then there are the Perudyptes from the northern part of Peru, and the dating was to around 42 million years ago. However, by the latter parts of the Eocene and the initial part of the Oligocene, which is around 40 to 30 million years ago, several massive penguins are believed to have existed. A good example here is the New Zealand giant penguin which is likely the biggest as it tipped the scale at 80 kilograms or even more.
The convention is that a remarkable majority of penguins’ extinct species, whether big or small, have been classified under the Palaeeudyptinae. The evolution of modern penguins involves a pair of clades and a pair of other genera that have other characteristics. To assist this, genomic studies have been deployed and sequencing of extant species done. Even though penguins’ evolution is continuing almost imperceptibly, it is no doubt that these flightless rulers of the Antarctic are not done with their changes.
