Monkeyflowers are a diverse species known for their unique shapes and vibrant colors. However, around 5 million years ago, one species of monkeyflower lost its yellow pigments and gained pink, which attracted bees for pollination.
Later, a descendant species accumulated mutations in a gene called YUP, which recovered the yellow pigments and led to the production of red flowers. This change caused the species to stop attracting bees and become pollinated by hummingbirds, leading to the creation of a new species.
Understanding the Genetics of the Monkeyflower
Botanists from the University of Connecticut, along with researchers from four other institutions, have discovered which gene changed to prevent the monkeyflower from producing yellow. The YUP gene in question is found at a specific region of the monkeyflower genome that contains three new genes. These genes are not found in other species, and they are duplicates of other genes from other parts of the monkeyflower genome.
Surprising Discoveries about Taxon Specific Genes
Researchers initially believed that idiosyncratic genes were unlikely to be important. However, the uniqueness of these three genes found only in a few closely related monkeyflowers is an important clue as to how new species evolve. These „taxon specific” genes are keys to the creation of new species, and this research highlights the importance of studying them.
The Importance of Challenging Conventional Wisdom
This research also teaches the importance of not constraining oneself with „conventional wisdom.” While it was unlikely that the partial duplicate genes found in the monkeyflower genome would affect an unrelated gene, postdoctoral researcher Mei Liang decided to investigate them anyway.
Her persistence paid off, as she discovered that the YUP gene suppressed the carotenoid gene, which is the master regulator of carotenoids that make monkeyflowers and other plants yellow. There are very few examples of genes that produce small RNAs affecting traits important to the creation of a new species.
Evolution is Unpredictable
This research reveals that evolution is unpredictable and that we still have much to learn about it. While many evolutionary biologists and geneticists thought that changes in the expression of common genes shared by many different species differentiated them, this research shows that idiosyncratic genes may be more important than previously believed.
Exploring the Monkeyflower Genome
The UConn botanists’ lab is now investigating how the monkeyflower genome controls the production of pigment spatially. They want to know how the plants suppress pigment in certain parts of the flower, such as upper petals that are entirely white, but lower petals with color.
In conclusion, the study of the monkeyflower genome has provided insight into how a single-gene change can lead to the creation of a new species. This research highlights the importance of studying taxon specific genes and challenges conventional wisdom about the importance of idiosyncratic genes in the evolution of species.
It also reminds us that evolution is unpredictable and that we still have much to learn about it.