- Author: Kathy Keatley Garvey
Whiteman, UC Berkeley professor of genetics, genomics, evolution and development, and director of the Essig Museum of Entomology, writes with a passion bestowed on him by his late father, a naturalist. “....he was a used car salesman, and later, a furniture salesman, but in his heart, he was a naturalist.”
The 336-page book is captivating, transparent, and fascinating--an “I-didn't-know-that-tell-me-more!” read.
Take monarchs.
Whiteman recalls a scene from his childhood. He and his father are in a patch of milkweed. His father tears a leaf in half. As "white latex" drips from the leaf, his father tells him: "That's why they call it milkweed. Don't ever eat it. Heart poisons are in that sap.”
The toxins are terpenoids called cardiac glycosides. “One of the principal toxins in the common milkweeds that my dad and I encountered is aspecioside,” Whiteman wrote. "The monarchs obtained these heart poisons during their caterpillar stage. But the caterpillars did something even more extraordinary—they concentrated the toxin to levels even high than those found in the milkweed itself.”
“The butterflies were poisonous, my dad explained, because as caterpillars, they had eaten toxins from the milkweed leaves. The insects then stored the toxins in their bodies all the way through metamorphosis, from a zebra-striped caterpillar to a chrysalis encircled at the top by a golden diadem, to the familiar brightly colored butterfly.”
Whiteman points out that monarch butterflies "evolved to become brightly colored to warn predatory birds and other predators of the bitter and emetic cardiac glycosides within." When a bird eats a monarch, it vomits, associating "the butterfly with danger, just as Pavlov's dogs learned to associate the ring of a bell with food.”
That led Whiteman to the question “How do animals that sequester these toxins, as the monarch does, resist them?”
Whiteman researched cardiac glycosides with evolutionary ecologist Anurag Agrawal of Cornell University, who received his doctorate in population biology in 1999 from UC Davis, studying with major professor Richard "Rick" Karban, Department of Entomology and Nematology.
You'll have to read Chapter 4, "Dogbane and Digitalis," to learn what Whiteman, Agrawal and their colleagues discovered.
All 13 chapters of “Most Delicious Poison” are deliciously intriguing and inviting, from “Deadly Daisies,” “Hijacked Hormones,” “Caffeine and Nicotine” to “Devil's Breath and Silent Death” to “Opicoid Overloads” to “The Spice of Life.” And more.
His father's death in 2017 from a substance use disorder (alcohol) pushed him to write the book. "His long struggle with nature's toxins came to a head just as my collaborators and I uncovered how the monarch butterfly caterpillar resists the deadly toxins made by the milkweed host plant.”
Toxins are why the monarch can migrate thousands of miles to overwintering spots without getting eaten by predatory birds.
Nature's chemicals are not a side show, as Whiteside emphasizes. They're "the main event."
(Editor's Note: The Bohart Museum of Entomology, UC Davis, displayed Whiteman's book at its Nov. 4th open house on monarchs. Whiteman plans to deliver a presentation on the UC Davis campus sometime next spring.)
- Author: Kathy Keatley Garvey
The seminar will take place at 4:10 p.m., in 122 Briggs Hall and also will be virtual. The Zoom link:
https://ucdavis.zoom.us/j/95882849672.
"Flowers are more than just a source of food for bees; they can also act as hubs of microbial transmission," McFrederick says in his abstract. "Some pathogenic microbes can spillover from social bees into solitary species and move through plant-pollinator networks, while others have more restricted host ranges. We use a combination of fieldwork, laboratory assays, molecular ecology, and genomics to understand the evolution and ecology of these microbes. In this talk I will discuss how plant-pollinator networks can help us understand relationships between bee hosts and pathogens and other microbes."
"I will then explore the evolution of pathogenicity in the fungal genus Ascosphaera. While Ascosphaera is best known as the causative agent of chalkbrood disease, the genus is ancestrally commensal and pathogenicity has evolved independently several times. I will finish by discussing the microbiomes of bees that have reverted to a carnivorous lifestyle, the so-called bee vulture. Our ultimate goal is to leverage these symbionts to improve bee health, and we are just beginning to understand many of these weird and wonderful relationships."
McKendrick studies studies symbionts (pathogens, commensals, and mutualists) of wild and solitary bees, with the goal of leveraging these symbionts to protect bee populations and communities. His research includes a stingless species of bee in Costa Rica. He and fellow researchers "set up baits — fresh pieces of raw chicken suspended from branches and smeared with petroleum jelly to deter ants," according to a UC Riverside news story. published Nov. 23, 2021.
"The baits successfully attracted vulture bees and related species that opportunistically feed on meat for their protein," wrote Jules Bernstein. "Normally, stingless bees have baskets on their hind legs for collecting pollen. However, the team observed carrion-feeding bees using those same structures to collect the bait." McFrederick called them "little chicken baskets."
“The vulture bee microbiome is enriched in acid-loving bacteria, which are novel bacteria that their relatives don't have,” McFrederick related. “These bacteria are similar to ones found in actual vultures, as well as hyenas and other carrion-feeders, presumably to help protect them from pathogens that show up on carrion.”
The article noted that "One of the bacteria present in vulture bees is Lactobacillus, which is in a lot of humans' fermented food, like sourdough. They were also found to harbor Carnobacterium, which is associated with flesh digestion."
McFrederick and his colleagues published their research, "Why Did the Bee Eat the Chicken? Symbiont Gain, Loss, and Retention in the Vulture Bee Microbiome?" in the Nov. 21, 2021 edition of the American Society for Microbiology.
McFrederick holds a bachelor's degree in integrative biology (1992) from UC Berkeley, and a master's degree in conservation biology (2004) from San Francisco State University, where he studied with advisor Gretchen LeBuhn. He went on to receive his doctorate in biology in 2010 from the University of Virginia, where he was advised by Douglas Taylor.
Among his awards:
- 2017: Hellman Fellowship
- 2016: Outstanding Faculty Award from the UCR Entomology Graduate Student Association.
- 2010: Award for Excellence in Scholarship in the Sciences from the Vice-President for Research, University of Virginia. The award recognizes “excellence in original scholarship by Ph.D. students at the University”
- 2010: Graduate Teaching Assistant Award from the Department of Biology, University of Virginia
The UC Davis Department of Entomology seminars, coordinated by urban landscape entomologist Emily Meineke, assistant professor, are held on Wednesdays through March 15. (See schedule.) Eight of the 10 will be in-person in 122 Briggs Hall, and all will be virtual.
- Author: Kathy Keatley Garvey
The research paper, “Introduced Herbivores Restore Late Pleistocene Ecological Functions” is the work of an 11-member international team led by Australian ecologist Erick Lundgren of the University of Technology, Sydney.
The authors pored over scientific literature; created a list of living and extinct herbivores over the last 126,000 years; and categorized them by their body size, anatomy, habitat, diet, and how their bodies digested the vegetation. Then they compared their lifestyles in overlapping regions.
Carroll, affiliated with the UC Davis Department of Entomology and Nematology, said one of the studies dealt with the abandoned hippos of Colombian drug lord Pablo Escobar (1949-1993), who purchased a male and three females in the 1980s from a California zoo and kept them in fields along the Magdalena River, northwestern Colombia. Without humans and other predators decimating them, the population today is 80 and is expected to reach 800 to 5000 by 2050.
The out-of-place hippos may be filling the exotic roles of extinct massive animals, such as giant llamas and rhinoceros-sized relatives, the ecologists said.
Said Carroll: “That paleontological analysis found that, amazingly, introduced herbivores– including Pablo Escobar's escaped Colombian hippos– often match the functional traits of extinct natives better than do those missing species' closest living native relatives. In this way, the ‘out-of-place' make the world more similar to the pre-extinction past. The ‘shoot-first- and-ask-questions later' approach as a maxim is as reckless as it sounds, and it's not going to sustain our life-saving drugs, nor the species we revere or ecosystems we rely on, into the future.”
“Many introduced herbivores restore trait combinations that have the capacity to influence ecosystem processes, such as wildfire and shrub expansion in drylands,” the team wrote.
As for feral hogs in North America, Carroll said their rooting increases tree growth and attracts bird flocks, like the ecological work of their extinct ancestors. Likewise, the feral horses and burros, known for their well-digging behavior, are replacing the original American horses, which went extinct 12,000 years ago.
In their abstract, the authors pointed out that humans “have caused extinctions of large-bodied mammalian herbivores over the past 100,000 years, leading to cascading changes in ecosystems. Conversely, introductions of herbivores have, in part, numerically compensated for extinction losses. However, the net outcome of the twin anthropogenic forces of extinction and introduction on herbivore assemblages has remained unknown. We found that a primary outcome of introductions has been the reintroduction of key ecological functions, making herbivore assemblages with nonnative species more similar to preextinction ones than native-only assemblages are. Our findings support calls for renewed research on introduced herbivore ecologies in light of paleoecological change and suggest that shifting focus from eradication to landscape and predator protection may have broader biodiversity benefits.”
Carroll, who also co-led an author group of the newly published “Coevolutionary Governance of Antibiotic and Pesticide Resistance” in the journal Trends in Ecology, said that the publications together “address both sides of the human-environment co-existence issue.”
“Reading the titles, you might not expect these two studies are two sides of the same coin,” Carroll said, “but for me they address both sides of the human-environment issue that most compels me: How can we create more workable, productive and respectful long-term relationships with other species? To help think about this as an evolutionary biologist, I divide the key challenges of human interactions with Nature into those that arise from competitor and parasite species that adapt too quickly for us to control, and those that arise in in our efforts to protect more valued species– like endangered large mammals– that adapt too slowly to survive human impacts.”
“Pesticide and drug resistance are nature's predictable resilience to our reliance on an escalating war of toxic eradication,” Carroll commented. “A broader understanding shows how we can develop our own behavior to instead cultivate susceptibility to control in species we fight, using both new and known practices for improved sanitation, locally diversified agriculture, and eating lower on the food chain to inflect their evolution in a positive direction. Similarly, after millennia of driving much of the Earth's giant mammal community to extinction, we need to step back from our reflex to extinguish the errant survivors to preserve a modern sense of what's natural, without stopping to consider how these new neighbors (commonly fading from their native lands) may restore ancient ecological functions our own ancestors extinguished not so long ago.”
Carroll emphasized that “neither of these studies dismisses the serious problems irruptive populations can cause for meeting our food, health and environmental needs, nor seeks to oversimplify complex challenges. But it's actually important to work against being limited by prejudicial generalizations that lead us to sort other species into ‘good' versus ‘bad' bins. This is a sensibility that ecologists in particular should strive to cultivate. To continue to feed and shelter ourselves and remain healthy while sharing the Earth with other species, we need to develop methods that respect the tremendous information and know-how inherent in each species. I want us to do a much better job of working with that intrinsic functional diversity and adaptive potential as our best resource for advancing resilient and biodiverse ecological systems into the future.”
Carroll and his wife, UC Davis ecologist Jenella Loye, own Carroll-Loye Biological Research, Davis. They engage in public health and environmental entomology and natural product development.
(Editor's Note: The lead author of Coevolutionary Governance of Antibiotic and Pesticide Resistance is Peter Søgaard Jørgensen, who during his University of Copenhagen graduate work, spent a year at Davis studying soapberry bug host adaptation in California with Scott Carroll. The duo led the multi-year international "Living with Resistance" pursuit at the National Science Foundation's National Socio-Environmental Synthesis Center. Carroll served as the senior author.)
- Author: Kathy Keatley Garvey
Evolutionary biology techniques can and must be used to help solve global challenges in agriculture, medicine and environmental sciences, they said.
Science Express makes important papers available to readers before they appear in the journal Science. The first-of-its-kind study will appear in a November edition of the journal.
“Evolutionary biology is often overlooked in the study of global challenges,” said lead author Scott, with the UC Davis Department of Entomology and Nematology and the Institute for Contemporary Evolution, also in Davis. “By looking at humanity's problems across the domains of nature conservation, food production and human health, it is clear that we need to strengthen evolutionary biology throughout the disciplines and develop a shared language among them.”
The study calls attention to how evolutionary biology techniques can be used to address challenges in agriculture, medicine and environmental sciences, said Carroll, noting that these techniques, although seemingly unrelated, work within a similar set of evolutionary processes.
“These techniques range from limiting the use of antibiotics to avoid resistant bacteria and breeding crops with desired benefits such as flood tolerant rice, to less commonly implemented strategies such as gene therapy to treat human disease, and planting non-native plants to anticipate climate change,” Carroll said.
“A particular worry is the unaddressed need for management of evolution that spans multiple sectors, such as occurs in the spread of new infectious diseases and antimicrobial resistance genes between natural, human health and agricultural systems.”
In their paper, the nine researchers—two from UC Davis, one from UCLA and six from universities in Denmark, New Zealand, Maine, Minnesota, Washington state and Arizona--crafted a graphic wheel divided into three sectors, food, health and environment and cited the challenges that link them together, including rapid revolution and phenotype environment mismatch in more slowly reproducing or threatened species.
Carroll said the underlying causes of societal challenges such as food security, emerging disease and biodiversity loss “have more in common than we think.”
“Humans, pathogens and all other life on earth adapt to their environment through evolution, but some adaptation happens too quickly and some too slowly to benefit human society,” Carroll said. “Current efforts to overcome societal challenges are likely only to create larger problems if evolutionary biology is not swiftly and widely implementedto achieve sustainable development.”
Society faces two sorts of challenges from evolution, the research team said. “The first occurs when pests and pathogens we try to kill or control persist or even prosper because the survivors and their offspring can resist our actions,” Carroll said. “The second challenge arises when species we value adapt too slowly, including humans.”
Although practices in health, agriculture and environmental conservation differ, each field can better target challenges using the same applications of evolutionary biology, they said.
For example, when a farmer plants a crop that is susceptible to pests, he might actually help the agricultural community as a whole by slowing down evolution of pesticide resistance, the authors said, citing an applied evolutionary biology tactic used in agriculture.
Planting pest-friendly crops has been used in the United States with good results, the team said. Farmers planting these crops slow the evolution of resistance to genetically modified corn and other crops. Pests then reproduce in abundance eating the susceptible plants, and when a rare resistant mutant matures on a toxic diet, it is most likely to mate with a susceptible partner, keeping susceptibility alive. This approach works to suppress the unwanted evolution on the whole, but farmers will have sacrificed a short-term gain for the long-term good.
Similar innovative solutions exist across the fields of medicine and environmental conservation, they said.
“This is an example of how implementing applied evolutionary biology without a plan for regulatory measures may come at short-term costs to some individuals that others may avoid.” Jorgensen said. “By using regulatory tools, decision makers such as local communities and governments play a crucial role in ensuring that everybody gains from the benefits of using evolutionary biology to realize the long-term goals of increasing food security, protecting biodiversity and improving human health and well-being.”
Other co-authors are Michael T. Kinnison, University of Maine; Carl Bergstrom, University of Washington; R. Ford Denison, University of Minnesota; Peter Gluckman, University of Auckland, New Zealand; Thomas B. Smith, UCLA; Sharon Strauss, UC Davis Department of Evolution and Ecology and Center for Population Biology, and Bruce Tabashnik, University of Arizona.
Carroll is an affiliate of the Sharon Lawler lab, UC Davis Entomology and Nematology. The research was funded in part by the National Science Foundation and the Australian-American Fulbright Commission.
(See PDF at http://www.sciencemag.org/content/early/2014/09/10/science.1245993.full.pdf)