conserving genetic resources for agriculture: economic ..._bioec… · beyond seeds collections...

Conserving Genetic Resources for Agriculture:

Economic Implications of Emerging Science

Douglas GollinOxford University

XX Annual BIOECON ConferenceKing's College, Cambridge

13 September 2018

D. Gollin (2018) Conserving Genetic Resources BIOECON Conference 1 / 46

Introduction and Background


Introduction

Conservation of genetic resources is a major global undertaking.

Massive collections of material are maintained by internationalorganizations and governments.

I CGIAR and Global Crop Trust

I National programs (e.g., USDA, Vavilov Institute, UK Millennium SeedBank)

Expenditures are large (e.g., Crop Trust seeks an endowment of $850million).


Botanic gardens and seed banks

A long history of collection and conservation.

Begins with botanic gardens and the �eld of economic botany.

I Colonial e�orts to collect and control genetic resources withcommercial uses.

I Observe how di�erent crops perform outside their native habitat.

I But also a commitment to conservation for science; e.g., Vavilov.

More recent history includes seed banks for crop breeding andconservation.

Increasing concerns over the potential �loss� of genetic resources.


International Rice Gene Bank

124,000 accessions of rice; two species of cultivated rice and 23 wildspecies.D. Gollin (2018) Conserving Genetic Resources BIOECON Conference 5 / 46

Svalbard Global Seed Vault

Capacity for 2.5 billion seeds (4.5 million varieties of crops).


Millennium Seed Bank at Kew

39,100 species and 2.25 billion seeds in storage from 189 countries(June 2018).


More than seed banks

In situ conservation(e.g., of rare breeds)

Tissue culture Cryo-preservation


Beyond seeds

Collections extend well beyond crop seeds.

USDA animal genetic resources collections:

I not just dominant livestock species: also honey bees, shrimp, oysters,sea slugs

I semen, embryos, ovaries, testis, and blood.

I cryo-preserved and stored in liquid nitrogen (-196C)

And beyond:I clonally propagated fruit treesI microbial culture collectionsI algae, fungi


How do you collect sperm from oysters?

�Just a lot of scraping and washing of the squishy insides� (T. Tiersch,pers. comm.)


Costly activities

Gene banks are expensive.

Costs vary depending on life form.

Main costs include:I Collection, cleaning, and catalogingI Capital costs for gene banksI Energy costs for refrigerationI Sta� costs for managing collectionsI Regeneration and multiplication of materials (primarily for seeds)I Costs associated with use: distribution and documentation

Global budget for gene banks?? Perhaps in the hundreds of millions ofdollars?


Complex legal framework

Ownership and control of genetic resources is now a complex issue.

Convention on Biodiversity came into e�ect in 1993

I calls for �fair and equitable bene�t sharing�

I seeks to ensure conservation of genetic resources (also ecosystems andspecies)

In principle creates a framework for compensation based oncommercial use of genetic diversity.

For crops, implemented through International Treaty on Plant GeneticResources for Agriculture

I spells out in greater detail the principles and practices of bene�tsharing.


Economic questions

Scarce funding; potentially unlimited needs for conservation

Big questions:

I What to collect?

I How to conserve?

I How to manage?

I How to �nance?

Important questions with relatively little theoretical or empiricalevidence.


Literature Review


Theory of genetic resources conservation

A good literature on the economics of genetic resources; especially onthe bene�ts of diversity; e.g.,Dasgupta (2000); Brock and Xepapadeas (2003); Kassar and Lasserre

(2004); Di Falco and Chavas (2008); Perrings et al. (2009); Pascual et al.

(2010).

Thoughtful analysis of the uses of genetic resources for R&D and thedivergence between private incentives and social values; e.g.,Goeschl and Swanson (2002, 2003); Sarr et al. (2008).

Useful discussions of property rights regimes for genetic resources;e.g., Swanson and Goeschl (2000).

But little guidance in this literature for speci�cs of exactly what toconserve or how to conserve it.


The Weitzman principle

Weitzman (1992) articulates a set of key principles that come closest:

Conserving diversity implies conserving things that are unlike oneanother.

I Advocates maximizing (by some metric) the genetic distance betweenthings that are conserved.

I Measure distance based on cladistics; i.e., genealogical distance.

I Intuition is clear: prioritize genetic distance over closely related species.

A useful principle; reinforces the notion that redundancy should beavoided (spelled out in a di�erent context by Simpson et al. (1996)).


Weitzman logic

All else equal, maximize genetic distance based on heredity: �[D]e�nethe distance between any two species as the time ago when theydiverged from a common ancestor.�

But Weitzman acknowledges that other factors may come into play;e.g., in his example, the likelihood that something rare may be lost.


Weitzman logic, graphic exposition

///D. Gollin (2018) Conserving Genetic Resources BIOECON Conference 18 / 46

Is the Weitzman principle relevant?

What is the question for which this is the right answer?

I Arguably the right criteria for a �Noah's ark� space capsule to Mars.

I Consistent with producing a representative sample of diversity, by somemeasure.

But genealogical distance is a very odd criterion.

Some things that are quite closely related may be di�erent inimportant ways.

I chimps and humans

I potatoes and deadly nightshade

Not necessarily the correct criteria for the real world of gene banks.

Genetic distance should be just one of many criteria that we consider.


Other criteria for consideration

How should we weight other criteria:

I Bene�ts to humans?I Extent of current threats to survival.I Costs of collection and conservation.I Availability of expertise and institutional support.

Millennium Seed Bank:

I Prioritize collection of plants that are rare, local, and unrelated toother plants.

I Focus on countries where collection costs are low; collect exhaustivelyin certain locations.


Time and change

What is the time dimension for our conservation?

Do we collect only what exists at a moment in time?

Do we take repeated snapshots over time (�backup� strategy)?

Collection and conservation themselves can lead to selection:

I e.g., challenges of regeneration and genetic drift in seed banks


What is the unit of analysis?

Where is genetic diversity located, and where is it most valuable?

Standard approach assumes that conservation of diversity involvesindividual genotypes.

But at what level?

I Across species?I Within species (e.g., varieties, breeds)?I Individual variation

Should we instead focus on diversity at the level of landscapes orecosystems?

I e.g., a rice paddy or a rainforestI Can individual species or varieties exist outside these ecosystems?


Conservation of Genetic Resources for Agriculture


Conservation of crop genetic resources

In many ways, the simplest case for conservation.

Current practices re�ect a di�erent criterion for conservation:immediate utility.

I Conserve crop varieties (and perhaps wild relatives).I Intended uses in breeding and varietal development.I Based on a model from the middle of the last century.

Even more true with gene banks that draw heavily on materialcontributed from current commercial uses.

Logic: when collection and conservation are costly, focus on materialthat is directly useful.


Potential concerns with this view

Prioritizes present knowledge and utility over potential future uses.

Technology is rapidly changing...

I Even now, little direct use of materials from crop and animal genebanks.

I Greater use in genomics and gene discovery.

I Future may bring greater utility of materials that are less closely related.

How do we prioritize?


Weitzman principle and within-species diversity

Within-species diversity is a low priority for the Weitzman principle.

The principle can be applied to diversity at this scale as well.

But genealogical distance measures no longer apply.

I Which rice varieties to collect?I Spatial diversity?I Diversity of phenotypic characteristics?


New �ndings on diversity

Emerging question from science:

I Where is diversity located?

I How much diversity do we expect to �nd in two randomly chosenvarieties of wheat?

I Are the wheat varieties more or less genetically di�erent than a varietyof wheat and a variety of oats?

Emerging answer:

I Diversity and genetic distance are not always where you expect!


Evidence from livestock

Prior to widespread use of genetic analysis, livestock scientists thought50% of genetic variation was among breeds and 50% within breeds(Blackburn, pers. comm.).

Molecular genetic studies now show consistently that 15-20% ofvariation is across breeds and 80-85% within breed.

Breeds are often not genetically very distinct; or distinctions re�ectrelatively super�cial traits.

Production gains from within-breed genetic improvement can be large.

I Holstein cattle: little genetic variation but huge and steady productivitygains.


Evidence from DNA �ngerprinting studies

Old presumptions:

I Farmers in developing countries often cultivate landraces.I Landraces are relatively uniform genetically.I Variation across farms and locations.I Conserving diversity means conserving landraces.

New evidence is emerging from �eld studies in developing countries.

Challenges these notions!


Field evidence

Interesting �ndings from MAPS study in Uganda, a data experimentcarried out by the World Bank LSMS-ISA team.

�Methodological Experiment on Measuring Maize Productivity, SoilFertility, and Variety�

Thanks to Talip Kilic for sharing slides on an early-stage paper; Ilukoret al. (2017).

Similar results in Kosmowski et al. (2018).

Studies compared farmer identi�cation of varieties with other modesof identi�cation, benchmarked by DNA �ngerprinting.


Key �ndings

Farmers are growing very mixed genetic material.

Farmer identi�cation is poor; unclear on whether material is traditionalor improved.

Farmer identi�cation does not map consistently into any identi�ablematerials.

Genetic diversity within plots is high!


Farmer-Reporting DNA Fingerprinting


Implications

Even in the �simple� case of crop genetic resources, collection andconservation raise challenges.

Old understandings of taxonomy and assumptions about diversity donot match new �ndings.

I �Varieties� and �landraces� are not necessarily biologically meaningfulconcepts.

I Species boundaries are not as clear as once thought.

I Genetics of agricultural systems are constantly changing throughfarmer selection and introduction of new materials.

Should we collect �rst and worry later about what we have collected?

I An economic question.


Questions for Research


What collections do we need?

What should we collect and conserve?

Where is diversity concentrated?

Are there many rare traits?

Are large collections necessary?


How valuable is information?

Gollin et al. (2000) argued that information about the materials in agene bank is of great value.

I Allows for more targeted searches and reduces both search costs andtime lags.

What information should we collect?I Herbaria collections yield unexpected insights into long-term

environmental change.I We don't always know what information will have value!

Is there value in genetic resources without information?I No: Analogous to a library with no catalog information.I Yes: Perhaps we can search through �piles� of genes for useful

combinations, without actually knowing much about the source.


How should we store?

In what form should materials be stored?

I Seeds / embryos / semen etc.

I Non-reproductive tissue

I Extracted DNA

I Dematerialized data.

Depends on costs and eventual uses (breeding vs genomics)


Conserve rare and valuable genes

Weitzman & Simpson/Sedjo:

I Avoid duplication.

I Recognize the potential for redundancy.

We want to conserve relatively rare genes.

We also want to conserve valuable genes.


How common are rare genes?

Quite a lot of data available on phenotypic variation for useful traits.

I Increasingly available in centralized data sources.

Increasingly, data available from sequencing on allelic frequency.

I How common are rare alleles?

I How likely are rare alleles to be valuable alleles?

I The value of large collections depends on having lots of valuable andrare alleles.


How close is the future?

What is the realistic ability of scientists to move useful genes acrosslife forms in productive ways?

I Di�ers from the technical capabilities of genetic modi�cation or geneediting.

Many traits are multigenic, and moving gene complexes remainschallenging.

Many genes are themselves not simple; expression of genes is notstraightforward.

Conserving dematerialized DNA will not be a useful strategy for sometime.

Technology is moving rapidly...

But the horizon also recedes!


Conclusions and Challenges


A call to research!

Lots of important economic questions to ask.

An area demanding new approaches and methods.

Also requires some �xed cost in learning the language of geneticistsand biologists.

Need to move past the general theories and to grapple with speci�cpolicy problems.

Need to work with existing institutions to help them answerfundamental questions for management.

Good news: rich sources of data...


Conclusion

Conservation of genetic resources is an important frontier foreconomics.

Public expenditures are large.

A pressing need to re-evaluate strategies that may (or may not) be outof date.

Looming concerns:I property rights issues and international conventions that make

conservation challenging.I low priority for genetic resources from most governments and

institutionsI immensity of challenges

Loss of diversity has the potential to cause crises; ecosystemvulnerability; food system impacts.

Research can play an important role.


References


References I

Brock, W. A., Xepapadeas, A., 2003. Valuing biodiversity from an economic perspective: auni�ed economic, ecological, and genetic approach. American Economic Review 93 (5),1597�1614.

Dasgupta, P., 2000. Valuing biodiversity. Unpublished Working paper. Available fromhttp://www. econ. cam. ac. uk/faculty/dasgupta/index. htm.

Di Falco, S., Chavas, J.-P., 2008. Rainfall shocks, resilience, and the e�ects of crop biodiversityon agroecosystem productivity. Land Economics 84 (1), 83�96.

Goeschl, T., Swanson, T., 2002. The social value of biodiversity for r&d. Environmental andResource Economics 22 (4), 477�504.

Goeschl, T., Swanson, T., 2003. Pests, plagues, and patents. Journal of the European EconomicAssociation 1 (2-3), 561�575.

Gollin, D., Smale, M., Skovmand, B., 2000. Searching an ex situ collection of wheat geneticresources. American Journal of Agricultural Economics 82 (4), 812�827.

Ilukor, J., Kilic, T., Stevenson, J., Gourlay, S., Kosmowski, F., Kilian, A., Sserumaga, J., Asea,G., 2017. Blowing in the wind: The quest for accurate crop variety identi�cation in �eldresearch, with an application to maize in uganda. In: CGIAR SPIA Conference on the Impactof Agricultural Research: Rigorous Evidence for Policy, Nairobi, Kenya.

Kassar, I., Lasserre, P., 2004. Species preservation and biodiversity value: a real optionsapproach. Journal of Environmental Economics and Management 48 (2), 857�879.


References II

Kosmowski, F., Aragaw, A., Kilian, A., Ambel, A., Ilukor, J., Yigezu, B., Stevenson, J., 2018.Varietal identi�cation in household surveys: results from three household-based methodsagainst the benchmark of dna �ngerprinting in southern ethiopia. Experimental Agriculture,1�15.

Pascual, U., Muradian, R., Brander, L., Gómez-Baggethun, E., Martín-López, B., Verma, M.,Armsworth, P., Christie, M., Cornelissen, H., Eppink, F., et al., 2010. The economics ofvaluing ecosystem services and biodiversity.

Perrings, C., Baumgärtner, S., Brock, W. A., Chopra, K., Conte, M., Costello, C., Duraiappah,A., Kinzig, A. P., Pascual, U., Polasky, S., et al., 2009. The economics of biodiversity andecosystem services. Naeem, S., Bunker, DE, Hector, A., Loreau, M. and Perrings, C.,Biodiversity, ecosystem functioning, and human wellbeing: an ecological and economicperspective. Oxford University Press, Oxford, 230�247.

Sarr, M., Goeschl, T., Swanson, T., 2008. The value of conserving genetic resources for r&d: Asurvey. Ecological Economics 67 (2), 184�193.

Simpson, R. D., Sedjo, R. A., Reid, J. W., 1996. Valuing biodiversity for use in pharmaceuticalresearch. Journal of Political Economy 104 (1), 163�185.

Swanson, T., Goeschl, T., 2000. Property rights issues involving plant genetic resources:implications of ownership for economic e�ciency. Ecological Economics 32 (1), 75�92.


conserving genetic resources for agriculture: economic ..._bioec… · beyond seeds collections...

Documents