An agent-based computational model of the evolution of reproductive isolation in populations of digital plants

The process of speciation is a fascinating area of research in the biological sciences. Development of mathematical and computational models are an important part of developing speciation theory. The Pseudophyte Evolutionary Algorithm PEA is a individual-based population model developed to test hypotheses concerning process of speciation. The individuals pseudophytes are digital plants. Biologically, they are haploid annuals, each producing pollen and ovules. Pseudophytes are implemented as binary strings representing loci which encoded six traits. Loci were divided into two chromosomes each with three traits. The loci are mapped to a phenotype which determines the behavior of the pseudophyte. The PEA examines the evolution of pre-mating (accepting or rejecting pollen) and postzygotic (offspring inviability) reproductive isolation. Experiments were performed to study the effect of habitat fragmentation, number of loci, method of computing the energy need of a pseudophytes, ovule production, and linkage on the rate at which reproductive isolation evolves. Speciation occurred under low levels of habitat fragmentation, but not high. The effect of moderate habitat fragmentation resulted in faster and more complete reproductive isolation when simulations began with specialist, but speciation did not occur when the initial populations consisted of generalists. Increasing the number of loci tended to delay speciation and result in less between and more within habitat postzygotic isolation. Energy need computation that imposed greater requirements resulted in fewer instances of speciation and less reproductive isolation when it did occur. Linkage experiments revealed complex interaction between the traits.*;*This dissertation is a compound document (contains both a paper copy and a CD as part of the dissertation). The CD requires the following system requirements: Adobe Acrobat; WinZip

Piscataquis Community High School (ME)

With permission from the school principal, students in grades 9–12 at Piscataquis Community High School were given a link to an anonymous, electronic survey in February 2019. Participation was voluntary. Piscataquis Community High School had 120 students during 2018–2019, 120 of which took the survey for a participation rate of 100%. Every question was optional, so the number of responses varies by question. Fact sheets for all schools and each county are available online at: https://digitalcommons.library.umaine.edu/rural_youth_futures

Marshfield High School (OR)

With permission from the school principal, students in grades 8–12 in Marshfield High School were given a link to an anonymous, electronic survey in April 2019. Participation was voluntary. Marshfield High School had 1,000 students during 2018-2019, 400 of which took the survey for a participation rate of 40%. Every question was optional, so the number of responses varies by question. Fact sheets for all schools and each county are available online at: https://digitalcommons.library.umaine.edu/rural_youth_futures

Piscataquis & N. Somerset Counties (ME)

With permission from school principals, students at 5 schools in Piscataquis and N. Somerset Counties in Maine were given a link to an anonymous, electronic survey between February and May, 2019. Participation was voluntary. The schools had a combined 666 students enrolled during 2018–2019, 578 of which took the survey for a participation rate of 87%. Every question was optional, so the number of responses varies by question. Fact sheets for all schools and each county are available online at: https://digitalcommons.library.umaine.edu/rural_youth_futures

Winter Lakes High School (OR)

With permission from the school principal, students in grades 7–12 at Winter Lakes High School were given a link to an anonymous, electronic survey in March 2019. Participation was voluntary. Winter Lakes High School had 300 students during 2018–2019, 68 of which took the survey for a participation rate of 23%. Every question was optional, so the number of responses varies by question. Fact sheets for all schools and each county are available online at: https://digitalcommons.library.umaine.edu/rural_youth_futures

Powers Jr./Sr. High School (OR)

With permission from the school principal, students in grades 7–12 at Powers Jr./Sr. High School were given a link to an anonymous, electronic survey in February 2019. Participation was voluntary. Powers Jr./Sr. High School had 50 students during 2018–2019, 27 of which took the survey for a participation rate of 54%. Every question was optional, so the number of responses varies by question. Fact sheets for all schools and each county are available online at: https://digitalcommons.library.umaine.edu/rural_youth_futures

Coquille Jr./Sr. High School (OR)

With permission from the school principal, students in grades 7–12 at Coquille Jr./Sr. High School were given a link to an anonymous, electronic survey in February 2019. Participation was voluntary. Coquille Jr./Sr. High School had 350 students during 2018–2019, 311 of which took the survey for a participation rate of 89%. Every question was optional, so the number of responses varies by question. Fact sheets for all schools and each county are available online at: https://digitalcommons.library.umaine.edu/rural_youth_futures

North Bend High School (OR)

With permission from the school principal, students in grades 7–12 at North Bend High School were given a link to an anonymous, electronic survey in May 2019. Participation was voluntary. North Bend High School had 772 students during 2018–2019, 260 of which took the survey for a participation rate of 34%. Every question was optional, so the number of responses varies by question. Fact sheets for all schools and each county are available online at: https://digitalcommons.library.umaine.edu/rural_youth_futures

Sedomocha Middle School (ME)

With permission from the school principal, students in grades 6–8 in SeDoMoCha Middle School were given a link to an anonymous, electronic survey in February 2019. Participation was voluntary. SeDoMoCha Middle School had 242 students during 2018-2019, 199 of which took the survey for a participation rate of 82%. Every question was optional, so the number of responses varies by question; middle schoolers had fewer questions to answer. Fact sheets for all schools and each county are available online at: https://digitalcommons.library.umaine.edu/rural_youth_futures

Forest Hills Consolidated School (ME)

With permission from the school principal, students in grades 6–12 at Forest Hills Consolidated School were given a link to an anonymous, electronic survey in May 2019. Participation was voluntary. Forest Hills Consolidated School had 68 students in these grades during 2018-2019, 62 of which took the survey for a participation rate of 91%. Every question was optional, so the number of responses varies by question. Fact sheets for all schools and each county are available online at: https://digitalcommons.library.umaine.edu/rural_youth_futures