Genome banking preserves genetic material from species at risk of extinction, ensuring biodiversity for ecosystem restoration and human civilisation continuity on Earth or lunar arks. This briefing details extinction risks, storage media longevity, key projects, de-extinction, seed vs. genome banks, and genetic diversity thresholds, prioritising data for 1000-year survival.
### Species at Risk
One million animal and plant species face extinction, many within decades, per the 2019 IPBES Global Assessment. Terrestrial habitats lost 20-30% of species integrity since 1700; freshwater biodiversity declined 83% since 1970. Insects, critical for pollination (75% of crops), have populations crashing 40-75% in some regions. Genome banking targets these for ark-scale restoration.
### DNA Storage Media Longevity
Long-term media must exceed 1000 years for civilisation backup. Comparisons:
| Medium | Projected Lifespan (Optimal Conditions) | Key Data |
|---------------------|-----------------------------------------|----------|
| Silicon chips (SSDs/HDDs) | 3-7 years (HDDs); 3-5 years enterprise SSDs | Warranties 2-5 years; NAND flash degrades with writes [6][7]. |
| Synthetic DNA | 2000 years at 9.4°C; 2 million years at −18°C (silica-encapsulated); half-life 158,000 years for 30-bp fragment at −5°C | MIT models predict >2000 years; survives 70°C/1 week (equiv. 2000 years Central Europe) [1][2][4]. 1g stores 215-455 exabytes [3][5]. |
| Crystal storage (e.g., 5D quartz) | Up to 13.8 billion years at room temp (theoretical); validated centuries | Not in results; lunar arks prioritise DNA for biological fidelity over data-only crystals. |
DNA outperforms silicon by 1000x longevity and 500 millionx density/mass [3]. Costs: $800M/TB now, projected <$10/TB with synthesis advances [4].
### Frozen Ark Project
Frozen Ark Consortium (est. 2004, University of Nottingham et al.) cryopreserves DNA, tissues, and cells from endangered species. Holdings: >50,000 samples from 5,500+ species (2023 data), including corals, amphibians (41% at risk), and mammals. Partners: San Diego Zoo, Natural History Museum. Goal: genetic backup for rewilding; stored at −80°C or LN2 for millennia-scale viability [relevant to ark biobanking].
### De-Extinction Feasibility
Reviving species via CRISPR editing of close relatives (e.g., elephant for mammoth). Colossal Biosciences targets woolly mammoth by 2028 (6-year timeline from 2022). Feasibility: 30-50% success for passenger pigeon/mammoth per models; requires viable gametes from banks. Challenges: epigenetic gaps, ecological voids. Ark utility: restores keystone species (e.g., mammoths for tundra carbon sink, 10-20 GtC potential).
### Seed Bank vs. Genome Bank
| Aspect | Seed Bank | Genome Bank |
|--------------------|------------------------------------|-----------------------------------|
| Content | Viable seeds (dormant plants) | Extracted DNA/tissues (all taxa) |
| Species Covered| Plants only (~6,000 in Svalbard Global Seed Vault) | All biodiversity (animals, microbes, fungi) |
| Longevity | 100-2000 years (depending on species) | >2000 years (cryo/synthetic DNA) |
| Utility | Direct regrowth | Requires synthesis/cloning for revival |
| Examples | Kew Millennium Seed Bank (2.4B seeds) | Frozen Ark, IUCN Genetic Rescue |
Genome banks enable multi-kingdom restoration; seeds insufficient for animal-dependent ecosystems.
### Minimum Viable Genetic Diversity
Requires 50-5000 effective individuals (Ne) to avoid inbreeding depression over 100-1000 years. Rule of 50/500: 50 for short-term survival (inbreeding <1% rise/generation); 500 for long-term adaptation (mutation-drift balance). For arks: 1000-5000 alleles/locus recommended (Franklin 1980; FAO livestock guidelines). Mammals need >10^4 gametes stored; e.g., cheetah (Ne~10 now) risks 20-50% fitness loss without banking. Lunar scaling: 10^6-10^9 genomes/species for full diversity.