A new study has found that mammals and birds evolve more rapidly in mountainous regions.
The authors, from the University of Cambridge, claim that the rise and fall of the Earth’s surface in the last three million years shaped the evolution of birds and mammals.
Surprisingly, this elevation has more of an effect on the formation of new species, known as “speciation,” than temperature and historical climate change.
Topographic changes in the form of growing mountain ranges can create “new habitats and niches where new species evolve and diversify,” experts say.
Examples of unique new species evolving in the mountains include the kea, a large parrot found in the alpine regions of New Zealand and bighorn sheep in the Rocky Mountains.
The kea (Nestor notabilis), a large parrot found in the alpine regions of New Zealand, is an example of a unique new species that has evolved in the mountain ranges. Keas are known for their olive green bodies and orange feathers under their wings. They also have a long, narrow curved gray beak
It extends along alpine regions of the southern island of the country, including Mount Cook National Park.
“Often on the tops of the mountains there are many more unique species that are not found anywhere else,” said Dr. Andrew Tanentzap, lead author.
“While it was previously believed that the formation of new species was climate-driven, we have found that change in elevation has a greater effect on a global scale.”
The effect of increased elevation on this rate of new species formation over time was more pronounced for mammals than for birds, the team found.
But this is probably because birds can fly through barriers to find mates in other areas. Birds were more affected by current temperatures than mammals.
Dr. Tanentzap said two important factors may help explain why land augmentation equates to faster evolution.
“First, it creates new habitats where different types of species can adapt,” he told MailOnline.
“A great example of this is the iconic maps by Victorian naturalist Alexander von Humboldt that show how habitats change as it rises.
“Therefore, this greater diversity and complexity of habitats allows populations of organisms to differentiate more rapidly into new species.”
Pictured is a map by Victorian naturalist Alexander von Humboldt showing how habitats change as it rises.
Second, Dr. Tanentzap said, the increase in land creates barriers to movement that prevent populations from growing.
“If a population of an organism moves along separate mountain slopes, it is possible that these two populations cannot mix because they are separated at great distances,” he said.
“We believe this is the reason why the effect of land magnification was stronger in mammals than in birds, because birds are able to travel greater distances.”
Kea is found along the alpine regions of the south island of the country, including Mount Cook National Park (pictured)
For the study, researchers combined reconstructions of the Earth’s changing surface heights over the past three million years with data on climate change over the same period of time and with the location of bird species. and mammals.
As the elevation of the terrain increases, the temperature generally decreases and the complexity of the habitat increases.
In some cases, for example, where mountains are formed, increasing elevation creates a barrier that prevents the movement and mixing of species, so that populations are left isolated.
This is the first step towards the formation of new species, according to experts.
The graph of the document shows the cause and effect between speciation rates and climatic and geological variables
In birds, such as kea, a variation in temperature creates differences in the timing and extent of mating, with the risk of reproducing isolation from populations of the same species elsewhere.
Reproductive isolation is the prevention of two or more populations growing together.
An interesting exception to the general findings is the Amazon rainforest, which has a rich diversity of species but is not too high.
But, according to the university, the results reveal how species evolved into new ones as terrain elevation changed and “unlinked the effects of elevation from the effects of climate.”
“It is amazing the great effect that the historical change of elevation had on the generation of global biodiversity: it has been much more important than variables traditionally studied such as temperature,” said the first author, Dr. Javier Igea, in the Department of Plant Sciences, University of Cambridge.
“The speed with which species evolved in different parts of the Earth is closely linked to changes in topography over millions of years.
In the picture, the bighorn sheep (Ovis canadensis), named for its impressive horns, native to North America
The Amazon rainforest (pictured) has a rich diversity of species but does not have much elevation
“This work highlights important areas for evolution to develop. From a conservation perspective, these are the places we might want to protect, especially given climate change.
“While climate change has been occurring for decades, not millions of years, our study points to areas that may be home to species with the greatest potential for evolution.”
Researchers say that as the Earth’s surface continues to rise and fall, topography will continue to be a major driver of evolutionary change.
The results have been published in the journal Nature Ecology and Evolution.