Plants can sometimes share such strong similarities that the identification techniques established by 18th century scientist Carl Linnaeus fall short. A recent study from the University of Gothenburg has revealed entirely new species of daisies, uncovered through advanced DNA analysis.
It is estimated that there are around 8.7 million species on our planet, with roughly 2.2 million found under the sea. While many species can be classified based on their physical traits, known as morphology, botanists and zoologists have been increasingly employing DNA sequencing over the past decade to identify species more precisely. Traditionally, scientists have focused on a specific location in the DNA that typifies the species, although this approach can occasionally lead to inaccuracies.
“There are occasions when it is challenging to distinguish different plant species from a short DNA sequence. However, advancements in DNA sequencing have enabled us to analyze larger portions of the genome, allowing for the identification of completely new species,” explains Zaynab Shaik, the author of a doctoral thesis from the University of Gothenburg.
Daisies in South Africa
Zaynab Shaik concentrated her research on a group of 66 officially recognized species of daisies found in the Cape Province of her home country, South Africa. Although these daisies are well-regarded and the first species was documented in 1753, a cluster of daisies in this region has posed identification challenges for botanists. These plants are considered ‘cryptic’ because they appear very similar, sharing identical leaves and flowers, as well as resembling each other in their growth habits and distribution, yet they exhibit notable genetic differences.
“Understanding plant relationships and the biodiversity on our planet is crucial. Imagine the potential consequences if we were to discover that a specific plant is useful for drug production, only to mistakenly select a similar-looking species that does not have the same beneficial qualities,” Zaynab Shaik warns.
Mistaken for Other Species
Zaynab’s DNA examinations of these cryptic species have led to the revelation of four new species.
“When I discuss this, there’s a bit of an anticlimactic feeling when I clarify that I haven’t discovered a new daisy in a remote region that no one has encountered before. These daisies have been appreciated for a long time but were misidentified as another species,” she explains.
The approach employed by Zaynab Shaik for species identification is known as integrative taxonomy. This method combines traditional observations regarding plant appearance and growth characteristics with laboratory-based DNA sequencing. By merging these techniques, researchers gain a clearer insight into the distinctions among different species and can expect to identify new species more frequently than in the past.
“In the Cape region, it has been assumed that merely 1 percent of biodiversity remains undiscovered. My findings indicate that the actual number could be significantly higher. This trend is likely applicable to other regions around the world,” concludes Zaynab Shaik.
