- What is evolution?
Why do penguins can’t fly? Have they evolved from flying birds or their ancestors were non flying birds? How did they evolve? Have they forgotten to fly? When did penguins start to diverge into their lineages?
In biology, evolution is the change in the characteristics of a species over several generations and relies on the process of natural selection. The theory of evolution is based on the idea that all species are related and gradually change over time. The change in characteristics of animals and birds is gradual and takes place over successive generations.
There are four principles at work in evolution—variation, inheritance, selection and time. These are considered the components of the evolutionary mechanism of natural selection.
The theory of evolution by natural selection, first formulated in Darwin’s book “On the Origin of Species” in 1859, is the process by which organisms change over time as a result of changes in heritable physical or behavioral traits.
Penguins are flightless marine birds. They had uncountable species and most of them are extinct now.
One of the authentic ways to find their evolutionary history is the deep study of their fossils. Fossils resembling penguins are nearly 62 million years old. The oldest penguin is called Waimanu manneringi. Although it was quite different from modern penguins, it was unable to fly. Its wings were adapted for flying. It was the cretaceous period.
Then the question arises that what happened to the older fossils? Where have they gone? Were they lost due to some disaster or climatic change? It is observed by the paleontologists that a climatic change occurred in Antarctica approximately 12 million years ago.
Initially, the penguins are thought to have evolved from an ancient flying bird called Archaeopteryx. According to some ornithologists, their closest living relatives are very graceful and beautiful birds called albatrosses. They are very attractive, large and white seabirds. Present penguins are the members of Spheniscidae family.
There are three major groups of birds that resemble closely to modern penguins. So we can assume that these all groups and penguins share some common ancestor. These groups include albatrosses and petrels, frigate birds and loons.
Penguins are also thought to be closely related to the Alcidae family but this relationship is not too close. This is due to the reason that species of Alcidae and Spheniscidae evolve in a similar way, despite the fact that they evolve independently. So these are the cases of convergent evolution.
In order to study the evolutionary history of penguins and molecular changes related to the Antarctic environment., scientists made a deep study of penguins in 2014. It was named Genomes of two Antarctic Penguins. The outcome of this study suggested that penguins are brothers of the birds of the order Procellariiformes, which includes albatrosses, petrels, and storm petrels.It is assumed that first ancestors of the penguins were flying birds but this is not true. Facts are totally against this perception, that is, penguins evolved from non-flying birds. The masses of land, that are now called Australia, New Zealand, Antarctica and parts of South America, are considered to be the habitats of basal penguin. At that time, these masses were in the form of a single mass called Gondwana. Apparently, it seems that evolution of penguins occurred in Antarctica, but this is contrary to the actual fact. Examination of fossils revealed that first true penguins developed on the east coast of the South Island of New Zealand, in an area called Waipara. This conclusion was derived because of the fact that the precise location of oldest fossil fuels is New Zealand.
Being birds, penguins should fly but why did their ancestors not adapt themselves for flying?
The simple reasons are their habitats, living conditions and mode of nutrition. They actually didn’t need to fly. Nature has created everything with a purpose. Then what is the need for wings if penguins can’t fly? I tell you the reason. Penguins do fly in water. They swim and dive very effortlessly in water due to their heavy wings. Wings are developed in the form of flippers and they help in underwater movements. Flying birds have lighter wings and hollow bones but penguins have heavier wings and slightly bulky bones. Mode of nutrition is another factor. Penguins adapted themselves for the marine environment where they could find food abundantly. They no longer need to fly for food, so they learned to swim and dive. Their wings got the shape of flaps and became shortened as a result of evolution. This is one of the most accepted hypotheses which gives the reason why penguins can’t fly? Fossil study revealed that even about 55 million years ago, penguins were completely adapted to marine life. This evolution of penguins took over 3 million years to complete. Penguin one is one of the descendents of basal penguin that exists even today in slightly modified form. In other words, penguin one is the ancestor of all the penguins that now exist in the world.This ancestor of modern penguins lived some 34.2-47.6 million years ago.
- Who was penguin A?
The penguin, which gave rise to the formation of biggest species of the modern penguins: the emperor penguin and the king penguin, is called Penguin A and it appeared about 40 million years ago. An interesting fact about Penguin A is that this penguin is only one member of the genus because it’s other species didn’t evolve in the same way. This penguin was classified in the genus Aptenodytes.
- Who was Penguin B?
Penguin B is the father of the present day Gentoo penguins, Adelie and Chinstrap penguins. It shows that these three species of penguins share close ancestral relationships. This penguin was classified as the member of genus Pygoscelis.
- Who was Penguin C?
Now we are going to discuss the father of some more species of penguins. This penguin gave birth to the Galápagos, Humboldt, Magellanic and African penguins. So these three species share the same father.
Now the question may arise:
Who was the father of the remaining species of penguins?
The answer is quite simple. One more ancestor appeared, who was considered to be the father of the remaining species of penguins. About 40-25 million years ago, penguins were warm-blooded and used to feed upon fish, krill and squid. So penguins have marine mode of nutrition even millions of years ago. Formerly, there were a lot of species, but many species became extinct with the passage of time because they were not able to survive in changing climatic conditions, severe competition for survival and other reasons. Among the extinct species, the Miocene species was huge and gigantic. But after this, reduction and extinction of huge penguins occurred and their predators like seals and whales began to proliferate on earth. The penguins of Miocene species were even larger than modern emperor penguins. They were called monster birds having lengths up to two metres. It shows that they were bigger than human males and a bit heavier as well. With the passage of time, they start dying. Perhaps, due to the reason that their predators began to grow on earth which ate them and as a result, they all died and got extinct.
By using genetic information of modern as well as extinct penguins, it is revealed that they soon evolved after the formation of the islands they inhabit. It means young and modern penguin species are associated with young islands which includes the Galapagos and the Chathams.
Otago University PhD candidate Theresa Cole, says: “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.”
The scientists are now trying to sequence the whole genomes in order to extend the study and to explore more about penguins. By examining hundreds of prehistoric bones across New Zealand, scientists confirmed the existence of a special kind of species on Chatham Islands until a few centuries ago. All of them are extinct now.
This was all about penguins and their evolution. Evolution is the gradual process that takes time. Best traits are selected by nature and organisms with most favourite traits survive. The organisms, with high ability to adapt themselves, survive without any kind of danger. Evolutionary history of penguins is very interesting.
Evolution helps us to find the origin of species, its ancestral background and gradual changes that occurred in it with the passage of time. Evolutionary history of penguins is a bit complicated because their ancestors were very adaptive in nature. Penguins’ characteristics resemble closely to birds, mammals as well as fish. Darwin was the first to study the details of the evolutionary background of animals and birds.
I m going to quote the most famous words of Darwin:
It is not the strongest of the species that survives, nor the most intelligent, but the one most responsive to change.