Phil 2.25.19

7:00 – 2:30 ASRC TL

2:30 – 4:30 PhD

  • Fix directory code of LMN so that it remembers the input and output directories – done
  • Add time bucketing capabilities. Do this by taking the complete conversation and splitting the results into N sublists. Take the beginning and ending time from each list and then use those to set the timestamp start and stop for each player’s posts.
  • Thinking about a time-series LMN tool that can chart the relative occurrence of the sorted terms over time. I think this could be done with tkinter. I would need to create and executable as described here, though the easiest answer seems to be pyinstaller.
  • Here are two papers that show the advantages of herding over nomadic behavior:
    • Phagotrophy by a flagellate selects for colonial prey: A possible origin of multicellularity
      • Predation was a powerful selective force promoting increased morphological complexity in a unicellular prey held in constant environmental conditions. The green alga, Chlorella vulgaris, is a well-studied eukaryote, which has retained its normal unicellular form in cultures in our laboratories for thousands of generations. For the experiments reported here, steady-state unicellular C. vulgaris continuous cultures were inoculated with the predator Ochromonas vallescia, a phagotrophic flagellated protist (‘flagellate’). Within less than 100 generations of the prey, a multicellular Chlorella growth form became dominant in the culture (subsequently repeated in other cultures). The prey Chlorella first formed globose clusters of tens to hundreds of cells. After about 10–20 generations in the presence of the phagotroph, eight-celled colonies predominated. These colonies retained the eight-celled form indefinitely in continuous culture and when plated onto agar. These self-replicating, stable colonies were virtually immune to predation by the flagellate, but small enough that each Chlorella cell was exposed directly to the nutrient medium.
    • De novo origins of multicellularity in response to predation
      • The transition from unicellular to multicellular life was one of a few major events in the history of life that created new opportunities for more complex biological systems to evolve. Predation is hypothesized as one selective pressure that may have driven the evolution of multicellularity. Here we show that de novo origins of simple multicellularity can evolve in response to predation. We subjected outcrossed populations of the unicellular green alga Chlamydomonas reinhardtii to selection by the filter-feeding predator Paramecium tetraurelia. Two of five experimental populations evolved multicellular structures not observed in unselected control populations within ~750 asexual generations. Considerable variation exists in the evolved multicellular life cycles, with both cell number and propagule size varying among isolates. Survival assays show that evolved multicellular traits provide effective protection against predation. These results support the hypothesis that selection imposed by predators may have played a role in some origins of multicellularity. SpontaniousClustering\

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