Linnaean Society Meeting Minutes—November 14, 2023

At 7:00 p.m., President Debbie Mullins called the Society meeting to order.

For those birders who list their sightings, there are some new lumps and splits to announce. The AmericanOrnithological Society (AOS) has re-lumped Pacific-slope and Cordilleran Flycatchers into one species, the Western Flycatcher. The Northern Goshawk has been split into two species, the American and Eur-asian goshawks. President Mullins recommended a podcast about these developments published by the American Birding Association (ABA).

The American Ornithological Society (AOS) announced that they are committed to changing all bird namesderived from people and assembling a diverse group to oversee the renaming process, which it said would include input from the general public. More than 100 avian species across the Americas will be given new names.

President Mullins reminded all LSNY members to renew their annual membership online or by mailing a check.

Motion 1: President Mullins then announced the result of the online vote to approve the October 2023 members’ meeting minutes. The vote passed with 136 votes in favor, none opposed, and three abstaining.

Motion 2: The Society welcomed the following seven new members, with 139 members voting in favor and none opposed.

Gouri Nanjangud, Active, sponsored by Mary Beth Kooper
Malcolm Fenton, Active, sponsored by Deborah Shapiro
Neti Bauta, Active, sponsored by Amanda Bielskas
Barry Elkins, Active, sponsored by Joe DiCostanzo
Kerri Howland Kruse, Active, sponsored by Richard Davis and Shannon Kelly
Kacie Rettig, Active, sponsored by Elise Boeger
Arabella Pajoohi, Associate, sponsored by Mary Beth Kooper

At 7:05 p.m., President Mullins introduced the speaker, Dr. Michael Donoghue.

Dr. Michael Donoghue
Michael Donoghue joined Yale in 2000 as the G. Evelyn Hutchinson Professor of Ecology and Evolutionary Biology. He served as chair of the Ecology and Evolutionary Biology Department in 2001–02 and as the Peabody Museum of Natural History director from 2003-08. From 2008– 10, he served as Yale’s inaugural vice president for West Campus Planning and Program Development, and in 2011, he was named Sterling Professor of Ecology and Evolutionary Biology. He served as director of Yale’s Marsh Botanical Garden from 2015–2018 and as director of the Yale Institute for Biospheric Studies from 2019–2021. Until his retirement in 2022, he served as a botany and paleobotany curator atthe Peabody Museum of Natural History.

Donoghue earned his undergraduate degree from Michigan State University (1976) and his Ph.D. in Biology from Harvard University (1982). He served on the faculty of San Diego State University (1982–85), the University of Arizona (1985–92), and Harvard University (1992– 2000), where he was the director of the Harvard University Herbaria from 1995–99. He is a fellow of the American Association for the Advancement of Science (1997), a member of the National Academy of Sciences (2005), and a fellow of the American Academy of Arts and Sciences (2008). His research concerns plants’ diversity, evolutionary history, and connections between phylogeny,biogeography, and ecology. He has been active in movements to reconstruct the tree of life and to link evolution to ecology and biodiversity conservation. He has published over 290 scientific papers and two books and mentored over 50 postdoctoral associates and graduate students.

Donoghue is continuing his research as a research professor at Yale. He currently resides in Tucson, Arizona, where he is an adjunct professor in the Department of Ecology and Evolutionary Biology at the University of Arizona.

Fleshy Fruits and their Dispersal
Dr. Donoghue is the world’s expert on viburnum, a genus comprising 163 species in the moschatel family Adoxaceae. The species are mostly evergreen, with some deciduous shrubs, and are native primarily throughout the temperateNorthern Hemisphere. They have fleshy fruits and are almost entirely pollinated by animals and insects.

The plants began around sixty to seventy million years ago in tropical biomes, and as they adapted and moved north, the leaves evolved from rounded to toothed edges. The fruits are known as droops, evidenced by fleshy fruiton the outside and a single seed on the inside. An endocarp covers the seed, and the evolution can be traced from a “Batman” shape to a flat, grooved shape that looks similar to a horseshoe and then to a round seed.

Miranda Synod Armstrong, a graduate student from Yale, conducted multiple studies of viburnum fruits that have illuminated many exciting traits of this species. Her first study measured wavelengths to understand the variation infruit color among the different species. Another study revealed the differences in lipid content in the fruit, an essential aspect of the nutritional value to birds and other species. She found that blue fruits are lipid-rich with low moisture and round endocarps, while red fruits are carbohydrate-rich and juicy with flat endocarps. She named this phenomenon the blue syndrome and the red syndrome.

These findings led scientists to hypothesize that the different species might have co-evolved with different sets ofbirds dispersing the seeds. However, it turns out that multiple bird species eat the same fruit, and there is a one-to-many relationship. There is a diffuse co-evolutionary trajectory with the two fruit syndromes and numerous species of birds that eat them.

Typically, a fruit’s color comes from pigmentation, a chemical process. However, some fruits have a different physical nano-structure that causes the eye to see the color as iridescent or metallic. The outside layer of the fruit isthe epidermis, with a waxy layer composed of cellulose called a cuticle. The epidermis keeps the water inside thefruit and reduces cell damage. Inside is a cell wall containing the cytoplasm, where structural differences occur. Within the cytoplasm is a novel layer of structures that have not been previously reported in any other plant or animal.

These structures proved to be lipid droplets that work as a multi-layer reflector that reflects different wavelengthsto increase the brightness and intensity of the color. The more ordered the structures are, the more intense the coloris, resulting in iridescent blue fruit. Miranda conducted further investigations and has proven that this phenomenon occurs in multiple species that evolved independently in distantly related groups of plants.

How does this relate to birds? One hypothesis is that the intense color evolved to signal the high lipid content to birds as an evolutionary strategy for seed dispersal. Although many bird species eat the seeds, the European Robin is considered a key species because their large population is the primary dispersal agent for the seeds. In the United States, it is dispersed by a number of birds, and it is commonly visited and dispersed by the American Robin.

Another critical factor in the plant’s value to birds is that the Viburnum displays sequential fruiting. The fruits mature at different rates, offering food over a more extended time than with plants that fruit all at once. Some fruitsremain on the tree all through the winter, allowing birds such as Cedar Waxwings to have food available duringMarch and April when not much else is available.

Another study revealed more fruit color variation in the tropics than towards the poles. Red fruits are more common at higher latitudes, while the regions closer to the equator are covered with plants producing green, orange, and yellow fruits. The plants closer to the equator also tend to have larger fruits than the red, blue, and black fruits in higher latitudes.

The evening concluded with a fascinating Q&A session hosted by Vice President Douglas Futuyma. Dr. Donoghue noted many interesting and unresolved problems would benefit from better collaboration and communication betweenornithologists and botanists. At the close of the evening, The Linnaean Society expressed its appreciation to Dr. Donaghue for sharing his lifelong passion for evolutionary biology and his essential study of the viburnum.