- Author: Kathy Keatley Garvey
The ant world on Twitter is crawling with congratulatory comments and how "awesome" the work is. Wrote one: "Congratulations! Lasius is a familiar genus in Japan, so I will let the Japanese entomologists know about it."
The story behind the story? It all began in the Ward lab. "The Three Ant Men" are now scattered from Idaho to Arizona to Germany.
- Borowiec, who received his doctorate at UC Davis in 2016, is an assistant professor at the University of Idaho.
- Prebus, who received his doctorate at UC Davis in 2018, is a postdoctoral scholar at Arizona State University.
- Boudinot, who received his doctorate at UC Davis in 2020, is in Jena, Germany on a two-year Alexander von Humboldt Research Fellowship to research evolutionary and comparative anatomy.
"Within the Formicidae, the higher classification of nearly all subfamilies has been recently revised given the findings of molecular phylogenetics," the co-authors wrote in their abstract. "Here, we integrate morphology and molecular data to holistically address the evolution, classification, and identification of the ant genus Lasius, its tribe Lasiini, and their subfamily Formicinae. We find that the crown Lasiini originated around the end of the Cretaceous on the Eurasian continent and is divisible into four morphologically distinct clades: Cladomyrma, the Lasius genus group, the Prenolepis genus group, and a previously undetected lineage we name Metalasius gen.nov., with one extant species M. myrmidon comb. nov. and one fossil species, †M. pumilus comb. nov. " (See more.)
Looking back, Prebus and Borowiec said that they were both interested in Lasius atopus "due to its strange morphology and lack of phylogenetic data despite the amount of attention paid to the genus, and planned a collecting trip to the type locality in Mendocino County in 2013."
The collecting trip to Mendocino proved unsuccessful. "But because of Phil's extensive collections. we knew of a population of a closely related species in Gates Canyon near the city of Vacaville," Prebus said. This time the trio collected specimens from several colonies at Gates Canyon, which is located off Pleasants Valley Road.
"For all of us, this was a collaborative side project, so after the study was presented, submitted, and rejected, it took the back-burner while people finished their dissertations, got jobs, got married, had kids, and so on," Prebus recalled. "Speaking personally, the pandemic put quite a few of my postdoc projects on hold after the Arizona State University campus closed, but the small upside amongst the inundation of downsides was that I was able to focus on getting some long-haul projects into shape for publication, including the Lasius study. This involved a huge amount of reanalysis of data that we had already collected, but thankfully didn't require generating any new data."
"In my opinion, one of the really cool aspects of this study is the method of evaluating the placement of fossil taxa in the phylogeny of the subfamily Formicinae," Prebus shared. "Because DNA data aren't available for fossil taxa, the assignment of fossils to ranks higher than species relies on the interpretation of their morphology, and historically that interpretation has relied heavily on expert opinion--and all of the biases that said experts hold. By collecting morphological data from all extant and fossil taxa in our dataset, we were able to unite the DNA data--from extant taxa--and the morphological data--from extant and fossil species--and formalize fossil placement, and evaluate the uncertainty of those placements, in model-based analyses. I think that this study joins a growing trend in systematics in general, in which we are increasingly moving away from expert opinion toward approaches that are testable and repeatable."
Follow the myrmecologists on Twitter:
- Matthew Prebus at @mmprebus
- B. E. Boudinot at @BoudAnt1
- Marek Borowiec at @mareklborowiec
![This is the species (Lasius nr. atopus) that inspired the initial stages of the project. (Photo by Matthew Prebus) This is the species (Lasius nr. atopus) that inspired the initial stages of the project. (Photo by Matthew Prebus)](/blogs/blogcore/blogfiles/88604.jpg)
![Brendon Boudinot's pinned post on his Twitter account spotlights the research that he, Marek Borowiec and Matthew Prebus did. Brendon Boudinot's pinned post on his Twitter account spotlights the research that he, Marek Borowiec and Matthew Prebus did.](/blogs/blogcore/blogfiles/88622.jpg)
- Author: Whitney Brim-DeForest
- Posted by: Gale Perez
We talk about herbicide resistance all of the time in California rice, but how does it evolve in a field? Understanding how herbicide management selects for resistant populations is an important part of preventing the problem from occurring in your fields.
We have many weed species in CA rice that are confirmed to be herbicide resistant. The major herbicide-resistant species are late watergrass, early watergrass, barnyardgrass, smallflower umbrella sedge, ricefield bulrush (roughseed), sprangletop, and redstem. For this illustration of how herbicide resistance evolves in a field, we use redstem as our example.
Year 1, Beginning of season: A population of redstem is found in a field and are emerging at the beginning of the season. In this illustration, the plants with the blue background are naturally susceptible to an herbicide (Granite SC). The plants with the yellow background are naturally herbicide resistant to Granite SC. There is nothing that the grower has done at this point to select for resistance. The genes that make the plant resistant are naturally found in the redstem population in the field.
Year 1, Mid-season: The grower applies Granite SC.
Year 1, End of season: One herbicide resistant plant survives. This plant goes on to produce seed, and the seeds are deposited onto the soil surface, where they are tilled into the soil seedbank at the end of the season.
Year 2, Beginning of season: The redstem population emerges from the soil at the beginning of the season. Because there are more seeds in the soil seedbank from the resistant plants, more of the emerged plants are resistant to Granite SC this year (yellow background = herbicide resistant).
Year 2, Mid-season: The grower again applies Granite SC or another herbicide with the same mode of action (Regiment, Halomax/Sandea or Londax).
Year 2, End of season: All of the herbicide resistant plants again survive the herbicide application. Again, they go on to produce seed, and the seeds are deposited onto the soil surface, where they are tilled into the soil seedbank.
Year 3, Beginning of season: The redstem population emerges from the soil at the beginning of the season. There are even more herbicide resistant plants than the previous 2 years, as the proportion of herbicide resistant seed in the soil has increased.
Year 3, Mid-season: For the third year,the grower applies Granite SC or another herbicide with the same mode of action (Regiment, Halomax/Sandea or Londax).
Year 3, End of season: All of the herbicide resistant plants again survive the herbicide application. Again, they go on to produce seed, and the seeds are deposited onto the soil surface, where they are tilled into the soil seedbank.
Year 4, Beginning of season: The redstem population emerges from the soil at the beginning of the season. This year, all of the plants are herbicide resistant, as the soil seedbank contains mostly herbicide resistant redstem seed.
The illustrations above are an example of how herbicide resistance evolves and is selected for in a field. A grower may not notice during the first year or two, as there are just a few plants that survive the herbicide applications. However, if the grower continues to use the same herbicide year after year, or the same herbicide mode of action, eventually, the population of redstem (or another weed species) will shift to become composed of only plants that are herbicide resistant.
The best way to prevent the development of herbicide resistance is to rotate herbicide modes of action, both between seasons and within seasons. Refer to the UC Herbicide Susceptibility Chart for CA rice when planning an herbicide program.
2016 CA RICE WEED HERBICIDE SUSCEPTIBILITY CHART
- Author: Whitney Brim-DeForest
Whitney Brim-DeForest, UCCE Rice Advisor
We talk about herbicide resistance all of the time in California rice. But how does it evolve in a field? Understanding how herbicide management selects for resistant populations is an important part of preventing the problem from occuring in your fields.
We have many weed species in CA rice that are confirmed to be herbicide resistant. The major herbicide-resistant species are: late watergrass, early watergrass, barnyardgrass, smallflower umbrella sedge, ricefield bulrush (roughseed), sprangletop, and redstem. For this illustration of how herbicide resistance evolves in a field, we use redstem as our example.
Year 1, Beginning of season: A population of redstem is found in a field and are emerging at the beginning of the season. In this illustration, the plants with the blue background are naturally susceptible to an herbicide (Granite SC). The plants with the yellow background are naturally herbicide resistant to Granite SC. There is nothing that the grower has done at thispoint to select for resistance. The genes that make the plant resistant are naturally found in the redstem population in the field.
Year 1, Mid-season: The grower applies Granite SC.
Year 1, End of season: One herbicide resistant plant survives. This plant goes on to produce seed, and the seeds are deposited onto the soil surface, where they are tilled into the soil seedbank at the end of the season.
Year 2, Beginning of season: The redstem population emerges from the soil at the beginning of the season. Because there are more seeds in the soil seedbank from the resistant plants, more of the emerged plants are resistant to Granite SC this year (yellow background = herbicide resistant).
Year 2, Mid-season: The grower again applies Granite SC or another herbicide with the same mode of action (Regiment, Halomax/Sandea or Londax).
Year 2, End of season: All of the herbicide resistant plants again survive the herbicide application. Again, they go on to produce seed, and the seeds are deposited onto the soil surface, where they are tilled into the soil seedbank.
Year 3, Beginning of season: The redstem population emerges from the soil at the beginning of the season. There are even more herbicide resistant plants than the previous 2 years, as the proportion of herbicide resistant seed in the soil has increased.
Year 3, Mid-season: For the third year,the grower applies Granite SC or another herbicide with the same mode of action (Regiment, Halomax/Sandea or Londax).
Year 3, End of season: All of the herbicide resistant plants again survive the herbicide application. Again, they go on to produce seed, and the seeds are deposited onto the soil surface, where they are tilled into the soil seedbank.
Year 4, Beginning of season: The redstem population emerges from the soil at the beginning of the season. This year, all of the plants are herbicide resistant, as the soil seedbank contains mostly herbicide resistant redstem seed.
The illustrations above are an example of how herbicide resistance evolves and is selected for in a field. A grower may not notice during the first year or two, as there are just a few plants that survive the herbicide applications. However, if the grower continues to use the same herbicide year after year, or the same herbicide mode of action, eventually, the population of redstem (or another weed species) will shift to become composed of only plants that are herbicide resistant.
The best way to prevent the development of herbicide resistance is to rotate herbicide modes of action, both between seasons and within seasons. Refer to the UC Herbicide Susceptibility Chart for CA rice when planning an herbicide program.
- Author: Kathy Keatley Garvey
![Florian Schiestl Florian Schiestl](http://ucanr.edu/blogs/entomology/blogfiles/35775.jpg)
- Evolution of floral signals and flower morphology
- Pollinator-drive speciation
- Evolution of floral mimicry
Related Link:
Scholar.google.com
For upcoming seminars, download this PDF
- Author: Lynn M. Sosnoskie
This blog was originally supposed to be an interesting article on Thanksgiving foods; specifically, a discussion about crops (i.e. squashes, onion, corn, carrots, parsnips, etc...) that traditionally accompany our Thursday turkey, as well as their weedy relatives.
However, I stumbled upon more thought-provoking article that I've chosen to share, instead.
The paper, 'Crops gone wild: evolution of weeds and invasives from domesticated ancestors', which was published in the journal 'Evolutionary Applications' (Norman C. Ellstrand (UC-Riverside) et al., 3:494-504) in 2010, can be accessed here.
The authors, who are interested in the development of weediness and invasiveness, chose to examine pest plants that had purportedly descended, either directly or through hybridization, from cultivated crops. They reasoned that the evolutionary changes correlated with weed development might be best studied by comparing problematic species to their more well-characterized (i.e. genetically, physiologically, morphologically, etc...) progenitors. To quote the authors: "Our original motivation was to understand how natural selection works on the descendants of domesticated species so that they are able to become weedy or invasive."
With this intention in mind, Ellstrand et al. (2010) conducted a literature search to identify weedy descendants of domesticated species. They considered four criteria when choosing examples to explore further:
1. "...cases involving ancestors that are well-domesticated taxa" (At least 100 years)
2. "...required genetic or historical evidence that the problematic lineage has evolved from a domesticated taxon"
3. "...asked whether evidence existed that the feral lineage is indeed problematic"
4. "...required evidence that the lineage is more problematic than its crop progenitor (in the case of endoferals) or each of its progenitors (in the case of exoferals)"
As a result, 13 species were determined to have evolved from domesticated species (in italics), including: artichoke thistle (Cynara cardunculus var. scolymus), semi-wild wheat (Triticum aestivum), weedy finger millet (Eleusine coracana subsp. coracana), Johnsongrass (Sorghum bicolor), Columbus grass (Sorghum bicolor), forrageira (Raphanus sativus), California wild radish (Raphanus sativus), weedy rice (Oryza sativa japonica, Oryza sativa japonica x Oryza sativa indica), 'blackhull' weedy rice (Oryza sativa indica), 'strawhull' weedy rice (Oryza sativa indica), weedy rye (Secale cereale), and weedy beet (Beta vulgaris subsp. vulgaris).
Important results highlighted in the article with respect to de-domestication include: the involvement of at least one parent that is primarily outcrossing; the most common adaptations were related to increased seed production and easier seed dispersal (i.e.shattering), relative to the crop progenitors; increased seed dormancy, relative to ancestors, was observed in only three cases; other traits associated with the evolution of a weedy pest from a domesticate included the production of rhizomes, woody roots, the transition to an annual life-cycle, and the development of resistance to the ALS-inhibiting herbicides.
Ellstrand et al. (2010) point out that crops and weeds are both adapted to growth and development in disturbed habitats and are often grown/grow in dense monoculture (or else very simple communities); as such, crops and weeds are not ecologically dissimilar. The authors conclude their manuscript with several intriguing questions, including:
"...with regard to crops and their weedy derivatives, we note that both grow in exactly the same location, but they are subjected to different selection regimes. How do weedy crop derivatives end up perceiving different selection pressures so that diverge in sympatry?"
"...how do [weedy descendants] diverge given that they are likely to be swamped by gene flow from the initially more abundant crop?
"If humans select crops that grow densely in monospecific stands, are those plants only a few allele changes away from becoming invasives or weeds?"
To quote the authors: "Genetic and genomic approaches, often used in concert with ethnobotanical data, have been successful in illuminating the evolution of crops from wild species under domestication.... These approaches may prove to be equally powerful in investigating evolution in the other direction, the evolution of sustainable feral populations from domesticated species."