MétaCan
Menu
← Back to cohort
Record W3000078314 · doi:10.1073/pnas.1921256117

Life-history models reconstruct mammalian evolution

2020· letter· en· W3000078314 on OpenAlexafffund
John M. Fryxell

Bibliographic record

VenueProceedings of the National Academy of Sciences · 2020
Typeletter
Languageen
FieldEnvironmental Science
TopicPhysiological and biochemical adaptations
Canadian institutionsUniversity of Guelph
FundersCanada First Research Excellence FundNatural Sciences and Engineering Research Council of CanadaGovernment of Canada
KeywordsBiologyPopulationForagingEvolutionary biologyEcologyConstruct (python library)TaxonOddsSimple (philosophy)Mathematical economicsStatisticsMathematicsDemographyComputer scienceSociology

Abstract

fetched live from OpenAlex

While ecologists sometimes bemoan the complexities of the discipline, several of the overarching patterns of nature can be boiled down to surprisingly simple terms. One of the most intriguing of these is Damuth’s law (1) that population density is scaled with body mass raised to the power of −3/4 irrespective of taxa or time. Because metabolic demand is allometrically scaled in identical fashion, a local population of 5-kg hares requires essentially the same energy to sustain itself as a herd of 50-kg deer. This implies that different species of organisms are energetically equivalent and hence interchangeable in a very basic sense. On the other hand, reconstructions of mammalian lineages consistently demonstrate gradual replacement of small species with larger versions over evolutionary time. This pattern, known as Cope’s rule (2), suggests that fundamental selective advantages accrue with increase in body size, seemingly at odds with Damuth’s law. If large animals are no more energetically efficient than their smaller brethren, why would one expect any directional trajectory over evolutionary time? This paradox is neatly explained by Bhat et al.’s paper (3) in PNAS. Linking a body of metabolic theory championed by J. H. Brown et al. (4) with fractal-based conjectures (5, 6) about the degree of patchiness in food supply experienced by animals of different size, Bhat et al. (3) use energetic cost−benefit analysis to construct a minimalist model of mammalian life-history constraints. Because the process of gathering food items is inherently stochastic, whereas metabolic costs of foraging are continuous, the energy state of each individual gradually drifts upward or downward over time, much like wind-borne grains of pollen (2). This diffusive process occasionally results in a lucky individual acquiring sufficient energy to facilitate a reproductive event, at which point the energy balance is reset to a new lower level, much … [↵][1]1Email: jfryxell{at}uoguelph.ca. [1]: #xref-corresp-1-1

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame machine prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.

metaresearch head score (Codex)0.001
metaresearch head score (Gemma)0.004
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Simulation or modeling · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: none
Teacher disagreement score0.004
Threshold uncertainty score0.010

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0010.004
Meta-epidemiology (narrow)0.0010.000
Meta-epidemiology (broad)0.0000.001
Bibliometrics0.0010.000
Science and technology studies0.0010.001
Scholarly communication0.0010.002
Open science0.0020.001
Research integrity0.0010.001
Insufficient payload (model declined to judge)0.0030.001

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.072
GPT teacher head0.245
Teacher spread0.172 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designSimulation or modeling
Domainnot available
GenreEmpirical

How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".

Quick stats

Citations0
Published2020
Admission routes2
Has abstractyes

Explore more

Same venueProceedings of the National Academy of Sciences→Same topicPhysiological and biochemical adaptations→French-language works237,207→