A SCIENTIST at a Scottish university has discovered a flower which sheds new light on our understanding of evolution.

Dr Mario Vallejo-Marin, a Plant Evolutionary Biologist at Stirling University, unearthed a new species of monkeyflower which indicates the way species originate can be repeated.

He first found the flower on the bank of a stream in South Lanarkshire, in 2012, but was unable to locate it anywhere else.

But during an expedition two years later Dr Vallejo-Marin uncovered a second batch of the yellow plant growing 350 miles to the north north near Stromness on the Orkney Islands.

"Orkney was a missing region which hadn't been sampled," said Dr Vallejo-Marin, Senior Lecturer in the School of Natural Sciences. "There were different varieties of monkey flower on the island, but when we spotted this population I knew it was unusual as after looking at hundreds of plants, you get to recognise the subtle differences.

"Usually a species forms once in a particular location then spreads to other regions. In this case, the opposite has occurred as the same species has evolved multiple times in different places. It shows that when the conditions are right, the origin of species is a repeatable phenomenon."

Dr Vallejo-Marin named the species Mimulus peregrinus, which translates as 'the foreigner', in recognition of its origins from two invasive species first brought to the UK from the USA and South America in the 1800s.

Hybrid plants of its kind are normally infertile, but this one spread by doubling the amount of DNA in its cells and evolving to form a new species in a process known as polyploidisation, the same mechanism by which Wheat, Cotton and Tobacco originated.

Dr Vallejo-Marin added: "It is impossible to say whether Mimulus peregrinus evolved first in the south or in the north of Scotland, but our discovery of a very young species of this kind has allowed us to study evolution as it happens.

"We only know of a handful of other plant species as young as Mimulus peregrinus and so in this respect it is like looking at the big bang in the first milliseconds of its occurrence.

"The process of evolution it has followed is particularly interesting and adds complexity to our conception of the tree of life. Instead of branching out as it grows, Mimulus peregrinus is an example of how some branches can come back together again and spawn new species that are in part the combination of their ancestors."