{
  "abstract": "A pygmy shrew (Suncus etruscus, ≈2 g) sustains a resting heart rate near 1,000 beats min -1 and dies within two years; an African elephant (≈4,000 kg) beats at 28 beats min -1 and lives seven decades.Their chronological lifespans differ by a factor of 35, yet each accumulates close to 10 9 cardiac cycles before death-a near-constancy first noted by Rubner (1908) and quantified by Lindstedt and Calder (1981) [2], but never subjected to multi-clade statistical testing, phylogenetic correction, or explicit falsifiability criteria with a large modern dataset.We address this gap with a curated 230-species vertebrate dataset spanning non-primate placentals (n = 43), primates (n = 18), marsupials and monotremes (n = 19), duty-cycle-corrected bats (n = 31), dive-corrected cetaceans (n = 12), birds (n = 78), and Arrhenius-corrected ectotherms (n = 26), and subject the log-invariant ℓ = log 10 (N ⋆ )-where N ⋆ = fH L × 525,960 cardiac cycles-to four independent tests.OLS regression on non-primate placentals yields slope β ˆ = -0.903± 0.056 (R 2 = 0.863; BCa bootstrap 95 % CI [-1.017, -0.782]; p = 0.093 against H 0 : β = -1), consistent with exact inverse scaling.Phylogenetically independent contrasts on 112 endotherms tighten this to β ˆ = -0.99 ± 0.04 (R 2 = 0.94; p = 0.84), confirming the relation is not a phylogenetic artefact.One-way ANOVA across six endotherm clades yields F = 81.2(p < 0.001), decisively rejecting the West-Brown-Enquist kinematic null, which predicts zero inter-clade dispersion in ℓ.Arrhenius temperature correction (Ea = 0.65 eV) reduces the raw ectotherm-endotherm gap from 0.90 dex to 0.22 dex, bringing cold-blooded vertebrates into close alignment with the mammalian baseline.The non-primate placental baseline is ℓ ¯ = 8.994 ± 0.159 dex (N ⋆ ≈ 9.87 × 10 8 ), with significant structured clade offsets: +0.382 dex for primates (×2.41), +0.534 dex for birds (×3.42), +0.547 dex for duty-corrected bats (×3.52), and -0.192 dex for dive-corrected cetaceans (×0.64).Taken together, the data support a revised picture in which the lifetime heartbeat count is not a universal constant but a clade-structured invariant anchored to a common mammalian baseline and subject to quantifiable ecological and physiological departures; five explicit numerical falsification criteria with pre-registered thresholds are stated, and the full 230-species dataset is provided as Supplementary Data 1.",
  "abstract_shown": true,
  "affiliations": [
    "West Los Angeles College , Science Division 9000 Overland Ave , Culver City , CA 90230 , USA"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 1,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Mesfin Asfaw Taye",
      "orcid": "0000-0003-0119-7725"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/4da2dn3wysekv.bib",
  "cited_by": 6,
  "doi": "10.29322/ijsrp.16.05.2026.p17306",
  "fulltext_url": null,
  "id": "4da2dn3wysekv",
  "issns": [
    "2250-3153"
  ],
  "landing_url": "https://doi.org/10.29322/ijsrp.16.05.2026.p17306",
  "language": "en",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "2303|Physiological and biochemical adaptations"
    ]
  ],
  "openalex": "W7167270189",
  "pdf_url": "https://www.ijsrp.org/research-paper-0526/ijsrp-p17306.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-05-24",
  "publisher": "International Journal of Scientific and Research Publications",
  "ris": "https://research.draconitic.com/paper/4da2dn3wysekv.ris",
  "sources": [
    {
      "first_seen": "2026-11-07T13:21:03Z",
      "native_id": "W7167270189",
      "source": "openalex",
      "url": "https://doi.org/10.29322/ijsrp.16.05.2026.p17306"
    }
  ],
  "subjects": [
    {
      "field": "biology",
      "origin": "openalex:2303|Physiological and biochemical adaptations",
      "subfield": "ecology"
    }
  ],
  "title": "The Lifetime Cardiac-Cycle Invariant in Endothermic Vertebrates : A 230-Species Comparative Dataset, Statistical Validation, and Explicit Falsifiability Criteria",
  "title_text": "The Lifetime Cardiac-Cycle Invariant in Endothermic Vertebrates : A 230-Species Comparative Dataset, Statistical Validation, and Explicit Falsifiability Criteria",
  "type": "peer-reviewed",
  "updated_at": "2026-11-08T13:20:55Z",
  "url": "https://research.draconitic.com/paper/4da2dn3wysekv",
  "venue": "International Journal of Scientific and Research Publications",
  "versions": []
}