Examples of Evolution: Plants and Birds

My AP Biology Thoughts Unit 7 Natural Selection EPISODE TITLE: Babiana ringens

Welcome to My AP Biology Thoughts podcast, my name is Raelynn and my name is Samiyah and we are your hosts for Unit 7: Examples of Evolution - Plants and Birds. In episode 118, we will be discussing the plant Babiana ringens and how it has evolved to attract sunbirds.

Segment 1: Overview of Babiana ringens and evolution to attract birds

• The Babiana ringens plant in South Africa evolved in such a way that increases the chance of Nectarine famosa, or the malachite sunbird - their main pollinators- to stop by and drink nectar out of their flowers. In the certain region that these plants reside, most sunbirds avoid predators by staying away from the ground- as such, the Babiana ringens evolved to create a small perch, making it easier for birds to drink their nectar, and thus pollinate them, which in turn increased their evolutionary fitness.

Segment 2: Evidence that supports the evolution of Babiana ringens to attract pollinators

• Through a study conducted by botanist Spencer Barrett from the University of Toronto Canada, along with a team of researchers, they found that the sunbirds in the specific region of South Africa in which the plants with the perches reside used the perches to pollinate the plants, and were their main pollinators.
• They went on to study other Babiana ringens plants across South Africa and found that they didn’t have the perches, and after studying them for some time, realized that their main pollinators weren’t the sunbirds that require the perches to make pollination easier. As such, the perch was an adaptation to the environmental pressures (of their main pollinators having been sunbirds).

Segment 3: Connection to the Course

• The interactions between Babiana ringens and sunbirds demonstrate the concept of evolution and natural selection. The flowers with the perch were more “fit” for the environment since it encouraged the birds to perch on them and pollinate the flower. As a result, the Babiana ringens with the genes for the perch were able to both outlive and outpopulate those without perches. Over time, the gene for flowers without this stem faded away from the gene pool, and it became characteristic of Babiana ringens