Authors

Tanya Strydom

Friends

Published

September 19, 2024

Why build paleo food webs?

  • Because its interesting?

  • Value in using hindcasting to aid in forecasting. e.g., the Toarcian ms shows how we can use these paleo communities to understand trophic-level responses to extinctions.

How do we do it?

  • There is an evolving body of work that focuses on developing tools specifically for the task of predicting food webs.

  • There are a handful that have been developed specifically in the context of paleo settings e.g., TODO but we can also talk about those that might have been developed/tested in contemporary settings but still have applicability in paleo ones.

  • Different underlying theory though

    • Focus here on the idea of different ‘currencies’ but also aggregations - energy vs compatibility.
  • Insert brief overview of the different methods as they pertain to approach (so the T4T triangle)

  • Challenges we face (even in contemporary settings)?

    • keep high level - I think the argument here should fall more in the data trade offs…

The cost of prediction

  • different models need different data and/or are making some very opinionated assumptions

  • this is going to link back to the goal of prediction as well (desire to discover or describe)

  • which means need to make a cost-benefit analysis

  • especially if we want to think about how this intersects with model performance/benchmarking

Understanding how networks are different

  • Not always representing the same things (i.e., different underlying philosophies). So, although they may all be representing food webs (and feeding links between species) they are ‘telling different stories’ - T4T work…

    • feasibility (e.g. PFIM) vs energy (e.g. ADBM)

      • fundamental vs realised niche analogy??
    • understanding what links are representing

  • Need to be careful when we are ‘presenting’/analysing these different food webs and we can’t really compare on contrast

  • e.g., Brimacombe et al. (2023) shows that the research group influences the ‘criteria’ that defines interactions/networks and so we can’t actually meaningfully integrate these networks into the same database and assume that they ‘fit’ together.

  • Petchy dilemma?

Challenges specific to paleo communities/networks

  • I think the goal here should be more a way of acknowledging some of the limitations we face and not a ‘this is a complete waste of time’ narrative

    • It’s a case of being aware of your blind spots and working with the acknowledgement that they are there.
  • Don’t actually have both the complete community (preservation bias) or location specific occurrence (to account for preservation bias often need to aggregate from different locations???)

  • We can’t truly validate any predictions (maybe some)

Dataset Overview

  • Species

  • Time/space

  • And probably some other paleo things that will be relevant…

Methods to use

  • PFIM (mechanistic compatibility)

  • ADBM (energy explicit)

  • Body size ratio (energy implicit)

  • Niche (topographical/generative)

Section Overview

  • introduce/discuss some of the food web reconstruction methods

  • construct networks for (ideally) a datasets across distinct time units using these (or some of) approaches

  • compare and contrast if they tell us a different story

References

Brimacombe, Chris, Korryn Bodner, Matthew Michalska-Smith, Timothée Poisot, and Marie-Josée Fortin. 2023. “Shortcomings of Reusing Species Interaction Networks Created by Different Sets of Researchers.” Edited by Pedro Jordano. PLOS Biology 21 (4): e3002068. https://doi.org/10.1371/journal.pbio.3002068.