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Casorso JG, DePasquale AN, Romero Morales S, Cheves Hernandez S, Lopez Navarro R, Hockings KJ, Carrigan MA, Melin AD. Seed dispersal syndrome predicts ethanol concentration of fruits in a tropical dry forest. Proc Biol Sci 2023; 290:20230804. [PMID: 37464751 DOI: 10.1098/rspb.2023.0804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 06/22/2023] [Indexed: 07/20/2023] Open
Abstract
Studying fruit traits and their interactions with seed dispersers can improve how we interpret patterns of biodiversity, ecosystem function and evolution. Mounting evidence suggests that fruit ethanol is common and variable, and may exert selective pressures on seed dispersers. To test this, we comprehensively assess fruit ethanol content in a wild ecosystem and explore sources of variation. We hypothesize that both phylogeny and seed dispersal syndrome explain variation in ethanol levels, and we predict that fruits with mammalian dispersal traits will contain higher levels of ethanol than those with bird dispersal traits. We measured ripe fruit ethanol content in species with mammal- (n = 16), bird- (n = 14) or mixed-dispersal (n = 7) syndromes in a Costa Rican tropical dry forest. Seventy-eight per cent of fruit species yielded measurable ethanol concentrations. We detected a phylogenetic signal in maximum ethanol levels (Pagel's λ = 0.82). Controlling for phylogeny, we observed greater ethanol concentrations in mammal-dispersed fruits, indicating that dispersal syndrome helps explain variation in ethanol content, and that mammals may be more exposed to ethanol in their diets than birds. Our findings further our understanding of wild fruit ethanol and its potential role as a selective pressure on frugivore sensory systems and metabolism.
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Affiliation(s)
- Julia G Casorso
- Department of Anthropology and Archaeology, University of Calgary, Calgary, Alberta, Canada
| | - Allegra N DePasquale
- Department of Anthropology and Archaeology, University of Calgary, Calgary, Alberta, Canada
| | | | | | | | | | | | - Amanda D Melin
- Department of Anthropology and Archaeology, University of Calgary, Calgary, Alberta, Canada
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Janiak MC, Pinto SL, Duytschaever G, Carrigan MA, Melin AD. Genetic evidence of widespread variation in ethanol metabolism among mammals: revisiting the 'myth' of natural intoxication. Biol Lett 2020; 16:20200070. [PMID: 32343936 DOI: 10.1098/rsbl.2020.0070] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Humans have a long evolutionary relationship with ethanol, pre-dating anthropogenic sources, and possess unusually efficient ethanol metabolism, through a mutation that evolved in our last common ancestor with African great apes. Increased exposure to dietary ethanol through fermenting fruits and nectars is hypothesized to have selected for this in our lineage. Yet, other mammals have frugivorous and nectarivorous diets, raising the possibility of natural ethanol exposure and adaptation in other taxa. We conduct a comparative genetic analysis of alcohol dehydrogenase class IV (ADH IV) across mammals to provide insight into their evolutionary history with ethanol. We find genetic variation and multiple pseudogenization events in ADH IV, indicating the ability to metabolize ethanol is variable. We suggest that ADH enzymes are evolutionarily plastic and show promise for revealing dietary adaptation. We further highlight the derived condition of humans and draw attention to problems with modelling the physiological responses of other mammals on them, a practice that has led to potentially erroneous conclusions about the likelihood of natural intoxication in wild animals. It is a fallacy to assume that other animals share our metabolic adaptations, rather than taking into consideration each species' unique physiology.
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Affiliation(s)
- Mareike C Janiak
- Department of Anthropology and Archaeology, University of Calgary, 2500 University Dr NW, Calgary AB T2N 1N4, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada
| | - Swellan L Pinto
- Department of Anthropology and Archaeology, University of Calgary, 2500 University Dr NW, Calgary AB T2N 1N4, Canada
| | - Gwen Duytschaever
- Department of Anthropology and Archaeology, University of Calgary, 2500 University Dr NW, Calgary AB T2N 1N4, Canada
| | | | - Amanda D Melin
- Department of Anthropology and Archaeology, University of Calgary, 2500 University Dr NW, Calgary AB T2N 1N4, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada.,Department of Medical Genetics, University of Calgary, AB, Canada
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Birds Drinking Alcohol: Species and Relationship with People. A Review of Information from Scientific Literature and Social Media. Animals (Basel) 2020; 10:ani10020270. [PMID: 32050472 PMCID: PMC7071081 DOI: 10.3390/ani10020270] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Revised: 02/03/2020] [Accepted: 02/03/2020] [Indexed: 12/27/2022] Open
Abstract
Ethanol is a natural by-product of the fermentation process of fruit sugars and is occasionally consumed by fruit-eating and tree sap drinking birds. Information on this form of alcohol consumption features in the scientific literature. However, as pets or as wild animals living close to humans in urban habitats, birds have increasing possibilities to consume alcohol from beverages, such as beer, wine or spirits. Some observations have been discussed in a light-hearted manner in mass media and social media, but without any generalization of why some bird species drink the beverages intentionally or unintentionally provided by humans. To check which species and in what circumstances birds drink alcohol and how this is evaluated by humans, we reviewed the scientific literature and analysed videos from YouTube. In total we found and analysed 8 scientific papers and 179 YouTube videos, from which we identified at least 55 species (in some cases not all birds were identified to species level), 11 in the scientific literature and 47 in videos. The distribution of these species over the avian phylogenetic tree suggests that the origin of this convergent behaviour is mainly by human influence. The two data sources differed in the species covered. Videos typically presented interactions of birds with human-provided alcoholic beverages, and were dominated by two groups of intelligent birds: parrots and corvids. The popularity of YouTube videos for a particular species was positively correlated with the general popularity of the species as measured by the number of hits (results listed) on Google. Human responses to the videos were generally very positive and we analysed how the responses were influenced by factors derived from viewing the videos. Moreover, YouTube videos also provide information on at least 47 new bird species not previously mentioned as using alcohol, and our results suggest that parrots in particular can be potentially good candidates for future restricted laboratory studies on the effect of ethanol on birds and their relationship with humans.
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Zungu MM, Downs CT. Effects of ethanol on fruit selection by frugivorous birds. AFRICAN ZOOLOGY 2017. [DOI: 10.1080/15627020.2016.1276856] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Manqoba M Zungu
- School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, South Africa
| | - Colleen T Downs
- School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, South Africa
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Lupfer G, Murphy ES, Merculieff Z, Radcliffe K, Duddleston KN. Adapting to alcohol: Dwarf hamster (Phodopus campbelli) ethanol consumption, sensitivity, and hoard fermentation. Behav Processes 2015; 115:19-24. [PMID: 25712038 DOI: 10.1016/j.beproc.2015.02.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Revised: 01/30/2015] [Accepted: 02/20/2015] [Indexed: 11/17/2022]
Abstract
Ethanol consumption and sensitivity in many species are influenced by the frequency with which ethanol is encountered in their niches. In Experiment 1, dwarf hamsters (Phodopus campbelli) with ad libitum access to food and water consumed high amounts of unsweetened alcohol solutions. Their consumption of 15%, but not 30%, ethanol was reduced when they were fed a high-fat diet; a high carbohydrate diet did not affect ethanol consumption. In Experiment 2, intraperitoneal injections of ethanol caused significant dose-related motor impairment. Much larger doses administered orally, however, had no effect. In Experiment 3, ryegrass seeds, a common food source for wild dwarf hamsters, supported ethanol fermentation. Results of these experiments suggest that dwarf hamsters may have adapted to consume foods in which ethanol production naturally occurs.
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Affiliation(s)
- Gwen Lupfer
- Department of Psychology, University of Alaska Anchorage, 3211 Providence Drive, Anchorage, AK 99508, USA.
| | - Eric S Murphy
- Department of Psychology, University of Alaska Anchorage, 3211 Providence Drive, Anchorage, AK 99508, USA
| | - Zoe Merculieff
- Department of Psychology, Stanford University, 450 Serra Mall, Stanford, CA 94305, USA
| | - Kori Radcliffe
- Department of Psychology, University of Alaska Anchorage, 3211 Providence Drive, Anchorage, AK 99508, USA
| | - Khrystyne N Duddleston
- Department of Biological Sciences, University of Alaska Anchorage, 3211 Providence Drive, Anchorage, AK 99508, USA
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Andrade TY, Thies W, Rogeri PK, Kalko EKV, Mello MAR. Hierarchical fruit selection by Neotropical leaf-nosed bats (Chiroptera: Phyllostomidae). J Mammal 2013. [DOI: 10.1644/12-mamm-a-244.1] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Cloning and molecular evolution of the aldehyde dehydrogenase 2 gene (Aldh2) in bats (Chiroptera). Biochem Genet 2012; 51:7-19. [PMID: 23053874 DOI: 10.1007/s10528-012-9540-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Accepted: 06/25/2012] [Indexed: 10/27/2022]
Abstract
Old World fruit bats (Pteropodidae) and New World fruit bats (Phyllostomidae) ingest significant quantities of ethanol while foraging. Mitochondrial aldehyde dehydrogenase (ALDH2, encoded by the Aldh2 gene) plays an important role in ethanol metabolism. To test whether the Aldh2 gene has undergone adaptive evolution in frugivorous and nectarivorous bats in relation to ethanol elimination, we sequenced part of the coding region of the gene (1,143 bp, ~73 % coverage) in 14 bat species, including three Old World fruit bats and two New World fruit bats. Our results showed that the Aldh2 coding sequences are highly conserved across all bat species we examined, and no evidence of positive selection was detected in the ancestral branches leading to Old World fruit bats and New World fruit bats. Further research is needed to determine whether other genes involved in ethanol metabolism have been the targets of positive selection in frugivorous and nectarivorous bats.
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Korine C, Sanchez F, Pinshow B. Effects of Ethanol on Food Consumption and Skin Temperature in the Egyptian Fruit Bat (Rousettus aegyptiacus). Integr Comp Biol 2011; 51:432-40. [DOI: 10.1093/icb/icr012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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