The loss of Flight
The Kakapo`s evolved from a type of bird that could fly millions of years ago. When Gwanaland broke up 100 million years ago the Proto-kaka/kakapo species developed from adaptive radiation, as there are so many various types of Parrots today. A homologous trait among the parrots is their curved beaks. The Proto-kaka/kakapo type of parrot seperated from the others into what is now New Zealand.
Isolation caused this species to diverge into two different species, the Proto-Kaka (Nestor) and the Kakapo (Strigops) sixty to eighty million years ago. The Proto-kaka or commonly called kaka birds have strong flight, these birds are currently classified as a vulnerable species. During isolation because of the geographic position these birds were each in, they evolved to fit their environment. The Kakapo beaks and size are ancestrial traits while their lack of flight is a derived trait. The plummage of the Kakapo is a phenotype, the colour green matching the forest floor for camoflouge, a result of the Kakapo losing it`s ability to fly.
While the Kakapo evolved because of its environment and the lack of mammal predators on the forest floor it became nocturnal and an excellent climber/hiker. The Kakapos that flew less, and were present during times that their predators were increased their fitness, which is why the Kakapo are as they are today. The kakapo has two predators that are both birds, hawks and eagles that flew and hunted during the day.
This adaptation to be flightless is vestigial, the environment in which the kakapo evolved to fit changed, being flightless now has turned to be a detriment to the bird. Especially when the Kakapo climbs to escape, get food or for whatever reason climbs to a higher height, and forgets it can`t fly. Although the Kakapo is a fast runner, it is unable to outrun or escape land mammals like dogs, cats, rats, ferrets, weasles and stoats, all animals that helped to decimate the Kakapo population rapidly. If the kakapo still had the ability to fly, these predators would be much more easily avoided. Another bird that had adapted this trait is a popular one, but not for a good reason, the extinct dodo bird.
This is microevolution because the change is happening within the species of parrots, and specifically Kakapo.
Isolation caused this species to diverge into two different species, the Proto-Kaka (Nestor) and the Kakapo (Strigops) sixty to eighty million years ago. The Proto-kaka or commonly called kaka birds have strong flight, these birds are currently classified as a vulnerable species. During isolation because of the geographic position these birds were each in, they evolved to fit their environment. The Kakapo beaks and size are ancestrial traits while their lack of flight is a derived trait. The plummage of the Kakapo is a phenotype, the colour green matching the forest floor for camoflouge, a result of the Kakapo losing it`s ability to fly.
While the Kakapo evolved because of its environment and the lack of mammal predators on the forest floor it became nocturnal and an excellent climber/hiker. The Kakapos that flew less, and were present during times that their predators were increased their fitness, which is why the Kakapo are as they are today. The kakapo has two predators that are both birds, hawks and eagles that flew and hunted during the day.
This adaptation to be flightless is vestigial, the environment in which the kakapo evolved to fit changed, being flightless now has turned to be a detriment to the bird. Especially when the Kakapo climbs to escape, get food or for whatever reason climbs to a higher height, and forgets it can`t fly. Although the Kakapo is a fast runner, it is unable to outrun or escape land mammals like dogs, cats, rats, ferrets, weasles and stoats, all animals that helped to decimate the Kakapo population rapidly. If the kakapo still had the ability to fly, these predators would be much more easily avoided. Another bird that had adapted this trait is a popular one, but not for a good reason, the extinct dodo bird.
This is microevolution because the change is happening within the species of parrots, and specifically Kakapo.
The Ugly Truth
The Kakapo were not a species that were built to live as long as they have. From subfossils we are able to tell that the Kakapo bird`s population was decreasing before Europeans or humans at all had any contact with these birds. A hypothesis to why this was occuring was because of a climatic change, other explanations to why the population started to decrease drastically have been discussed but have not had any absolute proof. This species would be extinct without humans first speeding up the decrease of its population, and then saving it. People are what are keeping this population from reaching its extinction.