The effect of outliers in biological synchronization phenomena

2019 Fiscal Year Final Research Report

• Project/Area Number: 19K21199
• Project/Area Number (Other): 18H06076 (2018)
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund (2019); Single-year Grants (2018)
• Review Section: 0703:Biology at organismal to population levels and anthropology, and related fields
• Research Institution: Hokkaido University (2019); The University of Tokyo (2018)
• Principal Investigator: Hayashi Tatsuya 北海道大学, 情報科学研究院, 博士研究員 (80824755)
• Project Period (FY): 2018-08-24 – 2020-03-31
• Keywords: 振動現象 / シオミズツボワムシ / 個体群動態 / 外れ値 / 数理モデル

Outline of Final Research Achievements

"Outliers" that exhibit exceptional behavior are universally observed in biological synchronization phenomena. However, such exceptions were excluded from the discussion, and the significance of their existence was not fully discussed. In this work, we constructed a mathematical model for the population dynamics of rotifers and investigated the effect of outliers when the population was disturbed. We constructed a discrete model that describes population dynamics including the nutritional status and the stress. Numerical results showed that the life span of the population is extended by the appearance of "outliers" that give up on their survival and lay eggs under the fasting condition.

Free Research Field

数理生物学

Academic Significance and Societal Importance of the Research Achievements

本研究では，シオミズツボワムシの個体群変動をテーマに外れ値が系に与える影響について調べた．結果として，絶食下において自身の生存をあきらめて産卵する”外れ値”個体が出現することによって，個体群の存命期間が延長されることが示された．仮に，大多数が絶食下で産卵を選択した場合，孵化率が低いため個体群の絶滅が早まるものと推測される．このように本研究では，自然界に出現する外れ値が個体群の維持に寄与する例を見出した．