{
  "annotation_id": "de8f63b4-ec7b-4795-94b0-a6385589b559",
  "date_created": "2026-03-02T18:00:29.222000Z",
  "date_modified": "2026-03-02T18:00:29.222000Z",
  "file_hash": "92f1eeec190157643c705e575cd1b0a3a0a7fa335a5d2718f6d83c21b55cff65",
  "private": false,
  "record": {
    "abstract": "For taxonomic levels higher than species, the abundance distributions of\nnumber of subtaxa per taxon tend to approximate power laws, but often show\nstrong deviationns from such a law. Previously, these deviations were\nattributed to finite-time effects in a continuous time branching process at the\ngeneric level. Instead, we describe here a simple discrete branching process\nwhich generates the observed distributions and find that the distribution\u0027s\ndeviation from power-law form is not caused by disequilibration, but rather\nthat it is time-independent and determined by the evolutionary properties of\nthe taxa of interest. Our model predicts-with no free parameters-the\nrank-frequency distribution of number of families in fossil marine animal\norders obtained from the fossil record. We find that near power-law\ndistributions are statistically almost inevitable for taxa higher than species.\nThe branching model also sheds light on species abundance patterns, as well as\non links between evolutionary processes, self-organized criticality and\nfractals.",
    "arxiv_id": "physics/0002001",
    "authors": [
      "Johan Chu",
      "Chris Adami"
    ],
    "categories": [
      "physics.bio-ph",
      "nlin.AO",
      "physics.data-an",
      "q-bio.PE"
    ],
    "doi": "10.1073/pnas.96.26.15017",
    "journal_ref": "Proc. Nat. Acad. Sci. 96 (1999) 15017",
    "title": "A Simple Explanation for Taxon Abundance Patterns",
    "url": "https://arxiv.org/abs/physics/0002001"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "a0e053a0-2b9e-4e25-8ee4-764021ca6411",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}