Royal Botanical Society of Belgium An experimentally introduced population of Brassica rapa (Brassicaceae). 2. Rapid evolution of phenotypic traits Author(s): Michael R. Sekor and Steven J. Franks Source: Plant Ecology and Evolution, 2018, Vol. 151, No. 3 (2018), pp. 293-302 Published by: Royal Botanical Society of Belgium and the Botanic Garden Meise Stable URL: https://www.jstor.org/stable/44945392 JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org. Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at https://about.jstor.org/terms Plant Ecology and Evolution 151 (3): 293-302, 2018 https://doi.org/10.5091/plecevo.2018.1401 PLANT BACOLOGY PA REGULAR PAPER An experimentally introduced population of Brassica rapa (Brassicaceae). 2. Rapid evolution of phenotypic traits Michael R. Sekor & Steven J. Franks¹2 'Louis Calder Biological Field Station, Department of Biological Sciences, Fordham University, Armonk, NY, 10504, USA Department of Biological Sciences, Fordham University, Bronx, NY, 10458, USA *Author for correspondence: msekor@fordham.edu Background and aims - Introduced populations can potentially experience strong selection and rapid evolution. While some retrospective studies have shown rapid evolution in introduced populations in the past, few have directly tested for and characterized evolution as it occurs. Here we use an experimental introduction to directly observe and quantify evolution of multiple traits in a plant population introduced to a novel environment. Methods - We experimentally introduced seeds of the annual plant Brassica rapa L. (Brassicaceae) from a location in southern California into multiple replicated plots in New York. We allowed the populations to naturally evolve for 3 years. Following the resurrection approach, we compared ancestors and descendants planted in common garden conditions in New York in multiple phenotypic traits. Key results - Within only three generations, there was significant evolution of several morphological, phenological, and fitness traits, as well as substantial variation among traits. Despite selection for larger size during the three years following introduction, there was evolution of smaller size, earlier flowering time, and shorter duration of flowering. Although there were rapid evolutionary changes in traits, descendants did not have greater fitness t n ancestors in New York, dicating a lack of ev for adaptive least over the timeframe of the study. at Conclusions - This study found rapid evolution of several morphological and phenological traits, including smaller plant size and shorter time to flowering, following introduction, confirming that evolution can rapidly occur during the early stages of colonization. Many traits evolved in the opposite direction predicted from phenotypic selection analysis, which suggests that the resurrection approach can reveal unanticipated evolutionary changes and can be very useful for studying contemporary evolution. Key words - Rapid evolution, plants, resurrection approach, morphology, flowering time, Brassica rapa, experimental introduction, introduced species. INTRODUCTION & Ian 2015). Despite these examples evolution could no INTRODUCTION While once thought to be a slow process, there is now sub- stantial evidence that rapid evolution in natural populations can occur over contemporary timescales (Thompson 2013). Evolution appears to be particularly rapid in cases where there is a mismatch between organisms and their environ- ments (Carroll et al. 2014), as can occur with anthropogen- ic environmental changes (Palumbi 2001) such as climatic changes (Levitan 2003) or pesticides (Whalon et al. 2008). Thus especially strong selection and rapid evolution is ex- pected for populations introduced to novel environments. Indeed, prior research provides evidence of rapid evolution in introduced populations of invasive species (Maron et al. 2004, Ridley & Ellstrand 2010, Novy et al. 2013, Colautti All rights reserved. © 2018 Meise Botanic Garden and Royal Botanical Society of Belgium ISSN: 2032-3913 (print)-2032-3921 (online) Pl. Ecol. Evol. 151 (3), 2018 This content downloaded from 64.106.42.43 on Tue, 23 Aug 2022 14:42:47 UTC All use subject to https://about.jstor.org/terms Table 1 -Summary of environmental variables in the source and introduced environment. Source Environment California 33.661 -117.851 State Latitude Longitude Climate type Soil type Vegetation type Growing season dates Average high/low temp in January Average high/low temp in July Average precipitation in January Average precipitation in July & Lau 2015). Despite these examples, evolution could po- tentially be limited in introduced populations due to fac- tors such as genetic bottlenecks (Barrett 1991, Van Buskirk & Willi 2006, Dlugosch & Parker 2008, Bell & Gonzalez 2009), trade-offs (Blows & Hoffmann 2005, Walsh & Blows 2009), or genetic correlations that oppose selection (Etterson & Shaw 2001). Thus it remains unclear to what extent rapid adaptive evolution occurs in introduced populations. Detailed information on the rates of evolution of differ- ent traits in introduced populations is scarce because much of the prior research in this area has been indirect, coming from populations that have already been introduced and established. Previous studies have used techniques such as population genetic analyses (Dlugosch et al. 2015), quantita- Mediterranean Clay loam Mediterranean Coastal Scrub December-April 18°C/9°C 26°C/19°C 7 cm 0.6 cm tive genetic analyses (Franks et al. 2008b, 2012), or recipro- cal transplants (Maron et al. 2004, Ridley & Ellstrand 2010, Novy et al. 2013, Colautti & Lau 2015) to retrospectively indirectly infer past evolution, rather than directly capturing evolution in action. In contrast, experimental introductions provide the opportunity to directly observe evolution as it occurs (Walsh & Reznick 2011), and allow a focus on the early stages of introduction and colonization not possible in studies where the introduced species is already established. Experimental introductions of taxa to a new environment have been used to study evolution and colonization success in a variety of animals (Reznick et al. 1997, Herrel et al. 2008, Forsman et al. 2012, Gotanda & Hendry 2014, Stuart et al. 2014, Gordon et al. 2015), but examples of experimen- tal introductions to examine evolution in plants appears to be surprisingly lacking (Campbell et al. 2006, Hovick et al. 2012). Experimental introductions are particularly powerful for studying evolution in introduced species when combined with the resurrection approach (Franks et al. 2008a). In the parumaction cannonch ancestor obtained from stored neon Introduced Environment New York 41.127 -73.731 Temperate Loam Eastern Deciduous Forest April-September 4°C/-5°C 28°C/19°C 5 cm 10 cm mizuna) and artificially selected lines (e.g. Fast Plants) of B. rapa, and populations have become feral or naturalized. This species was chosen due to its demonstrated ability to rapidly evolve in response to artificial (Williams & Hill 1986, Agren & Schemske 1994) and natural (Franks et al. 2007) selection. Franks et al. (2007) documented the evolution of earlier flowering time in populations of B. rapa following a five-year drought in southern California. The derived pheno- types were able to flower at a smaller size, demonstrating a flexible relationship between size and flowering (Franks & Weis 2008). This study examines evolution directly following coloni- zation in an experimentally introduced population of Bras- sica rapa. In May 2011, seeds from a population in Southern California were introduced to ten replicated plots in Armonk, New York. These sites are separated by 4500 km from their locality of origin and differ from this in many characteristics, including climate, soil type and species composition (table 1). We thus expect that the introduced population would ex- marianna strona calactiva anacon The intenduoad monula

Royal Botanical Society of Belgium An experimentally introduced population of Brassica rapa (Brassicaceae). 2. Rapid evolution of phenotypic traits Author(s): Michael R. Sekor and Steven J. Franks Source: Plant Ecology and Evolution, 2018, Vol. 151, No. 3 (2018), pp. 293-302 Published by: Royal Botanical Society of Belgium and the Botanic Garden Meise Stable URL: https://www.jstor.org/stable/44945392 JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org. Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at https://about.jstor.org/terms Plant Ecology and Evolution 151 (3): 293-302, 2018 https://doi.org/10.5091/plecevo.2018.1401 PLANT BACOLOGY PA REGULAR PAPER An experimentally introduced population of Brassica rapa (Brassicaceae). 2. Rapid evolution of phenotypic traits Michael R. Sekor & Steven J. Franks¹2 'Louis Calder Biological Field Station, Department of Biological Sciences, Fordham University, Armonk, NY, 10504, USA Department of Biological Sciences, Fordham University, Bronx, NY, 10458, USA *Author for correspondence: msekor@fordham.edu Background and aims - Introduced populations can potentially experience strong selection and rapid evolution. While some retrospective studies have shown rapid evolution in introduced populations in the past, few have directly tested for and characterized evolution as it occurs. Here we use an experimental introduction to directly observe and quantify evolution of multiple traits in a plant population introduced to a novel environment. Methods - We experimentally introduced seeds of the annual plant Brassica rapa L. (Brassicaceae) from a location in southern California into multiple replicated plots in New York. We allowed the populations to naturally evolve for 3 years. Following the resurrection approach, we compared ancestors and descendants planted in common garden conditions in New York in multiple phenotypic traits. Key results - Within only three generations, there was significant evolution of several morphological, phenological, and fitness traits, as well as substantial variation among traits. Despite selection for larger size during the three years following introduction, there was evolution of smaller size, earlier flowering time, and shorter duration of flowering. Although there were rapid evolutionary changes in traits, descendants did not have greater fitness t n ancestors in New York, dicating a lack of ev for adaptive least over the timeframe of the study. at Conclusions - This study found rapid evolution of several morphological and phenological traits, including smaller plant size and shorter time to flowering, following introduction, confirming that evolution can rapidly occur during the early stages of colonization. Many traits evolved in the opposite direction predicted from phenotypic selection analysis, which suggests that the resurrection approach can reveal unanticipated evolutionary changes and can be very useful for studying contemporary evolution. Key words - Rapid evolution, plants, resurrection approach, morphology, flowering time, Brassica rapa, experimental introduction, introduced species. INTRODUCTION & Ian 2015). Despite these examples evolution could no INTRODUCTION While once thought to be a slow process, there is now sub- stantial evidence that rapid evolution in natural populations can occur over contemporary timescales (Thompson 2013). Evolution appears to be particularly rapid in cases where there is a mismatch between organisms and their environ- ments (Carroll et al. 2014), as can occur with anthropogen- ic environmental changes (Palumbi 2001) such as climatic changes (Levitan 2003) or pesticides (Whalon et al. 2008). Thus especially strong selection and rapid evolution is ex- pected for populations introduced to novel environments. Indeed, prior research provides evidence of rapid evolution in introduced populations of invasive species (Maron et al. 2004, Ridley & Ellstrand 2010, Novy et al. 2013, Colautti All rights reserved. © 2018 Meise Botanic Garden and Royal Botanical Society of Belgium ISSN: 2032-3913 (print)-2032-3921 (online) Pl. Ecol. Evol. 151 (3), 2018 This content downloaded from 64.106.42.43 on Tue, 23 Aug 2022 14:42:47 UTC All use subject to https://about.jstor.org/terms Table 1 -Summary of environmental variables in the source and introduced environment. Source Environment California 33.661 -117.851 State Latitude Longitude Climate type Soil type Vegetation type Growing season dates Average high/low temp in January Average high/low temp in July Average precipitation in January Average precipitation in July & Lau 2015). Despite these examples, evolution could po- tentially be limited in introduced populations due to fac- tors such as genetic bottlenecks (Barrett 1991, Van Buskirk & Willi 2006, Dlugosch & Parker 2008, Bell & Gonzalez 2009), trade-offs (Blows & Hoffmann 2005, Walsh & Blows 2009), or genetic correlations that oppose selection (Etterson & Shaw 2001). Thus it remains unclear to what extent rapid adaptive evolution occurs in introduced populations. Detailed information on the rates of evolution of differ- ent traits in introduced populations is scarce because much of the prior research in this area has been indirect, coming from populations that have already been introduced and established. Previous studies have used techniques such as population genetic analyses (Dlugosch et al. 2015), quantita- Mediterranean Clay loam Mediterranean Coastal Scrub December-April 18°C/9°C 26°C/19°C 7 cm 0.6 cm tive genetic analyses (Franks et al. 2008b, 2012), or recipro- cal transplants (Maron et al. 2004, Ridley & Ellstrand 2010, Novy et al. 2013, Colautti & Lau 2015) to retrospectively indirectly infer past evolution, rather than directly capturing evolution in action. In contrast, experimental introductions provide the opportunity to directly observe evolution as it occurs (Walsh & Reznick 2011), and allow a focus on the early stages of introduction and colonization not possible in studies where the introduced species is already established. Experimental introductions of taxa to a new environment have been used to study evolution and colonization success in a variety of animals (Reznick et al. 1997, Herrel et al. 2008, Forsman et al. 2012, Gotanda & Hendry 2014, Stuart et al. 2014, Gordon et al. 2015), but examples of experimen- tal introductions to examine evolution in plants appears to be surprisingly lacking (Campbell et al. 2006, Hovick et al. 2012). Experimental introductions are particularly powerful for studying evolution in introduced species when combined with the resurrection approach (Franks et al. 2008a). In the parumaction cannonch ancestor obtained from stored neon Introduced Environment New York 41.127 -73.731 Temperate Loam Eastern Deciduous Forest April-September 4°C/-5°C 28°C/19°C 5 cm 10 cm mizuna) and artificially selected lines (e.g. Fast Plants) of B. rapa, and populations have become feral or naturalized. This species was chosen due to its demonstrated ability to rapidly evolve in response to artificial (Williams & Hill 1986, Agren & Schemske 1994) and natural (Franks et al. 2007) selection. Franks et al. (2007) documented the evolution of earlier flowering time in populations of B. rapa following a five-year drought in southern California. The derived pheno- types were able to flower at a smaller size, demonstrating a flexible relationship between size and flowering (Franks & Weis 2008). This study examines evolution directly following coloni- zation in an experimentally introduced population of Bras- sica rapa. In May 2011, seeds from a population in Southern California were introduced to ten replicated plots in Armonk, New York. These sites are separated by 4500 km from their locality of origin and differ from this in many characteristics, including climate, soil type and species composition (table 1). We thus expect that the introduced population would ex- marianna strona calactiva anacon The intenduoad monula

Biology 2e

2nd Edition

ISBN:9781947172517

Author:Matthew Douglas, Jung Choi, Mary Ann Clark

Publisher:Matthew Douglas, Jung Choi, Mary Ann Clark

Chapter47: Conservation Biology And Biodiversity

Section: Chapter Questions

Problem 1VCQ: Figure 47.6 Scientists measured the relative abundance ot fern spores above and below the K-Pg...

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