03 · Why a discipline of its own
Biological data
is not just data.
A sales figure doesn't change once it's recorded. A blood sample does. Biological data is a snapshot of something alive, and living things change, vary, err, evolve and belong to someone. That is why this data needs care that no other data field has to provide all at once.
01 · uncertainty
Every measurement carries uncertainty
Sequencers don't read DNA, they estimate it. Every sequenced base comes with an error probability on the Phred scale: Q20 means 1 error in 100 and Q30 means 1 in 1,000. Mass spectrometers, sensors and automated microscopes work the same way. Biological data without its confidence is only half the data.
Q30 → 99.9% accuracy per base
02 · time
The clock keeps running after collection
Once removed from the organism, the material stays alive for a while: cells consume nutrients, RNA degrades and proteins change. A sample processed 2 hours after collection is no longer the one it was 10 minutes after. The collection time, the processing time and the interval between them are all part of the data.
collected 08:14 · processed 10:41 · Δ 2h27 ⚠
03 · moment
Time of day and stage of life matter
Circadian rhythm, fasting, season, developmental stage and reproductive cycle all change the results. The same individual gives different numbers at different moments. Without that context, a comparison may be measuring nothing but coincidence.
cortisol: high in the morning, low at night
04 · interference
Observing changes what is observed
Capturing an animal raises its stress, a biopsy triggers inflammation, and freezing and thawing break cells. The act of collecting changes the biology itself, so how it was done must be recorded as a condition of the data.
temperature · preservative · freeze–thaw cycles
05 · variability
No two living beings are the same
There is variation between individuals, between cells in the same tissue and between repeats of an experiment. You must tell biological replicates from technical ones, and real effects from batch effects. An average without its variation does not describe life.
biological replicate ≠ technical replicate
06 · unrepeatable
Samples run out and moments don't return
Tissue is finite and perishable. Patients recover, crops are harvested, species can vanish. Often there is no second measurement, and the data is the only record left of that organism at that moment.
unique, unrepeatable material
07 · reference
Knowledge itself gets new versions
Reference genomes are updated (GRCh37 → GRCh38), species get new names and genes are renamed. Even Excel has forced changes: genes such as SEPT1 and MARCH1 kept turning into dates and were renamed SEPTIN1 and MARCHF1. All biological data must state which version of knowledge it was interpreted against.
SEPT1 → 1-Sep → SEPTIN1
08 · privacy
Biological data belongs to someone
A genome identifies a person and reveals information about their whole family, and perfect anonymization doesn't exist. Brazil's LGPD and Europe's GDPR classify genetic data as sensitive personal data. Consent, purpose and access rules are part of the data, not paperwork beside it.
LGPD art. 5 II · GDPR art. 9
09 · sovereignty
Biodiversity is heritage
In Brazil, access to genetic heritage and associated traditional knowledge is regulated by Law 13,123/2015 and must be registered in SisGen. Worldwide, it is governed by the Nagoya Protocol. Where a sample comes from has legal consequences and determines how benefits are shared.
Law 13,123/2015 · SisGen · Nagoya
10 · scale
From molecule to ecosystem
Biological data spans scales (molecules, cells, organs, individuals, populations, biomes) and formats (sequences, images, time series, occurrence records). Integrating all of it takes shared ontologies and identifiers, not just tables.
genome · image · sensor · occurrence
11 · provenance
A complete chain of custody
Data travels from organism → sample → aliquot → library → run → file → analysis. Any step can introduce error or contamination. Without end-to-end traceability, results cannot be reproduced.
who · when · where · how
12 · longevity
Value that lasts for centuries
Herbarium specimens collected more than 100 years ago now reveal the effects of climate change and preserve ancient DNA. Well-documented biological data can answer questions nobody has asked yet, as long as it is findable, accessible, interoperable and reusable (FAIR).
FAIR principles
The Biodadic proposal
All biological data should carry its own story.
In Biodadic, a measured value never travels alone. It always carries its uncertainty, its time, its context, its origin and its permissions, from the first record to the last reuse.
ValueUncertaintyTimeContextProvenancePermissions
{
"value": "ATGGCGTACCTGA…",
"uncertainty": "Q32 · 99.94% per base",
"collected": "2026-11-12T08:14-03:00",
"processed": "2026-11-12T10:41-03:00",
"interval": "2h27min", // ⚠ over 2h
"condition": "4 °C · EDTA · 0 thaws",
"organism": "Homo sapiens · NCBITaxon:9606",
"reference": "GRCh38.p14",
"provenance": "sample BD-0192 → lib L07 → run R2311",
"permission": "consent 2026-118 · sensitive data"
}
Ordinary data describes things. Biological data describes something that was alive, and a moment later had already changed.