congress genetics
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www.congressgenetics.eu
1. Conservation
Genetics in biodiversity policy
2. Genetic resources
What is genetic diversity?
High and low diversity
3. For effective species survival
Practical applications and studies
Conservation genetics – a tool for species survival
Conservation
Genetics in biodiversity policy
Genetic diversity – politically important • Genetic diversity is recognised as a key component of biodiversity
• Biological diversity is comprised of genetic differences within species, the diversity of species and the variety of ecosystems (The Convention on Biological Diversity, CBD)
• Three levels of biodiversity:
• Genetic diversity: between individuals and populations
• Species diversity
• Ecosystem diversity
Genetics in legislation• Until recently, genetics has been inadequately represented in European
biodiversity policy
• The Habitats Directive, the corner stone of Europe’s nature conservation policy, does not directly refer to genetic differences within species• Article 1i defines the Favourable Conservation Status of species in
broad terms: • … it is maintaining itself on a long-term basis as a viable
component of its habitats, the natural range is not being reduced and there is a sufficiently large habitat to maintain its populations on a long-term basis
• In the USA, the Endangered Species Act defines species to include subspecies and distinct population segments
Why is genetics important for effective conservation of species?
• Can the challenges of the biodiversity strategies be met?• Can the conservation status of species be improved? • Can the viability of populations in their natural range in a long-term
basis be ensured?
Conservation genetics research indicates• Genetic diversity is important for both the short- and long-term
viability and future evolution of populations • Genetic diversity is a buffer against population crashes in
environmental changes
• The Habitats Directive stresses the necessity of research in order to implement meaningful species conservation measures
Laikre et al., 2009, Conservation Biology
Genetic diversity: an emerging aspect in biodiversity policy• The UN Strategic Plan for Biodiversity 2011–2020 requires strategies
for minimizing genetic erosion and safeguarding genetic diversity (Aichi Biodiversity Targets, Strategic Goal C)
• The EU biodiversity strategy to 2020 recognizes that the innovation potential of genetic diversity in ecosystem restoration is largely untapped
• Article 17 of the Habitats Directive requires Member States to report about the progress made with the implementation of the Habitats Directive – the present reporting period ends in 2012• Explanatory Notes & Guidelines for the period 2007-2012
recognizes that Favourable Reference Populations should be based on the ecology and genetics of the species
Laikre et al., 2009, Conservation Biology
Future prospects?Conservation genetics offers
• Highly applicable tools for measuring genetic diversity
• Information to evaluate the viability of populations in the changing conditions
• New methods for assessing favourable conservation status provided by the Habitats Directive
• Help striving towards the goals of the Convention on Biological Diversity (CBD), the Aichi Biodiversity Targets and the EU biodiversity strategy to 2020
Genetic resources
What is genetic diversity?
What is genetic diversity?
• The genome contains the genetic code of an individual• DNA in most species• An individual’s blueprint is encoded in genes. The gene information
is encoded by ‘building blocks’: A, C, G, T• The code of a gene varies slightly between individuals this is
genetic diversityLynx family in Heinburg, Germany.
Photos: Joachim S. Müller
Differences create diversity
• There are often small differences in the code of a gene, even between individuals of the same population
• These genetic differences contribute to individual differences in e.g. height, fur colour, temperature tolerance
• More differences = more genetic diversity in individuals, populations and species
Tawny owls (Strix aluco) with different plumage colour. Photo: Dick Forsman
Genetic diversity is everywhere
Genetic diversity exists• Between individuals• Between populations• Between species
Genetic resources
High and low diversity
High genetic diversity helps populations survive• Low genetic diversity can lead to inbreeding depression
• Genetically similar individuals have a higher risk of producing offspring that have hereditary diseases
Endangered species suffer from low genetic diversity• Human induced changes have led to smaller population sizes
• Habitat fragmentation caused by urbanisation, forestry, agriculture, fishing etc.
• Lower genetic diversity and higher risk of inbreeding
• 80 % of endangered species have lower genetic diversity
(Spielman et al. 2004, PNAS)
Clear-cut in southern Finland. Photo: Marjatta Sihvonen
Genetic diversity can reflect adaptation• Populations that have
adapted to their local environment are expected to have distinct genetic patterns
• Maintaining these differences can help to maintain the populations and halt genetic erosion
Otters. Photo: Cyril Blazy
Genes for the future• Climate change is forcing species to adapt to new conditions or move
away
• High genetic diversity means there are more genetic variants that might be suited to the new conditions
• Higher genetic diversity provides a population with more ‘tickets in the lottery’
Dryas octopetala in the Alps, Italy. Photos: Sarah Gregg and Fabio Marini
Creating biodiversity
Differences in genes (genetic variation)
Differences in an individual’s characteristics
Adaptation to changing conditions
Locally adapted populations
For effective species survival
Studies and applications
What can conservation genetics do to help preserve diversity? • Where do individuals come from and what population or species they
belong to?
• Do populations mix in nature?
• How to detect hybrid individuals?
• Are populations suffering from low genetic diversity?
• How to identify distinct populations and relevant conservation units?
• How to predict the genetic outcome of management or harvesting decisions?
• Are populations diverse enough for the future?
Where do individuals come from and what population or species they belong to?
X
Genetics for forensics – saving endangered tuna species• The genus Thunnus comprised of eight species known as tunas
• Several species widely traded including the Atlantic bluefin tuna (Thunnus thynnus)
• One of the most endangered trade fish in the world
• Traded as commercial commodities, the identification of endangered species is difficult
Viñas et al., 2009, PLoS One
Casestudy
DNA cannot be hidden in tuna salad• DNA-based methodologies provide very precise tools for identifying
marine species
• Using genetic markers, all eight tuna species can now be distinguished from any kind of processed tissue
• This new DNA tool can improve conservation efforts and trade control
Casestudy
Viñas et al., 2009, PLoS One
Do populations mix in nature?• If populations are genetically different, most likely they do not mix = no
gene flow
• Check whether populations are connected
Photo: Mick Melvin
Assessing past and recent connectivity• Bears in the Cantabrian mountains (Spain) are critically endangered (D)
in the IUCN Red List
• Formerly one large, but now two small, subpopulations separated by 30-50 kilometres
• Recent isolation of these subpopulations can be seen as differences in their genetic profiles
Perez et al, Ursus 2010 Perez et al., Conservation Genetics 2009
Casestudy
Photo: José Mª F. Díaz-Formentí
Genetic methods identified:• Natural reforestation of intervening habitat has resulted in recent
migration from the eastern to the western subpopulations
• Two cubs as a result of ‘between-population’ matings
• Gene flow, as would have occurred naturally in historical times, has been achieved!
Perez et al, Ursus 2010 Perez et al., Conservation Genetics 2009
Photo: Bob Jagendorf
Casestudy
Detecting hybrid individuals• Hybrids: Individuals that have genetic
characteristics of two species
• Lesser white-fronted goose (Anser erythropus) listed as vulnerable on the IUCN Red List
• Has suffered a rapid population reduction in key breeding populations in Russia, decline predicted to continue
• The Fennoscandian population has undergone a severe historical decline, and has not yet recovered
Lesser white-fronted goose that escaped from captivity in Espoo, Finland.
Photo: Matti Rekilä
Casestudy
Captive population unsuitable for the wild• Genetic signals of hybridisation with two other goose species in captive
population • Unsuitable for wild stock supplementation• Supplementation with other individuals from other wild populations
recommended instead
Ruokonen et al. 2007, Conservation Genetics
Casestudy
Are populations suffering from low genetic diversity? Conservation genetics can
Monitor genetic diversity• Compare past and present levels
Estimate population size• See whether population size is changing
Plan breeding programs to avoid inbreeding or species mixing
Genetic rescue• A population of Swedish adders
suffered from inbreeding depression• Stillborn offspring, low
genetic variability• Researchers released 20 males
from a nearby population → breeding success and population size increased
• Recovery corresponded to increase in genetic diversity
Madsen et al. 1999, Nature Adder in spring mood.
Photo: Marjatta Sihvonen
Casestudy
Gene banks within species
Identifying distinct populations• Genetically distinct populations can be valuable to protect • Conservation genetics can
• Find distinct genetic patterns• Identify priority populations for conservation• Plan units for conservation or management
Management unit 1
Managementunit 2
Discovering distinct genetic patterns• Teno river salmon in northern
Finland and Norway - one of the largest salmon populations in the world
• Previously considered as one management unit• Conservation genetics
researchers showed there were many distinct genetic units within the river
Vähä et al. 2007, Molecular EcologyVähä et al. 2008, Evolutionary Applications
Casestudy
What do the differences mean?• Changes in management
strategies are being made to recognise and protect the distinct population units within the river• When deciding catch limits
• Results suggest that individuals may be adapted to the specific conditions of each river section
• Ecological information also suggests this
Vähä et al. 2007, Molecular EcologyVähä et al. 2008, Evolutionary Applications
Teno salmon. Photo: Panu Orell
Casestudy
Prioritizing populations for conservation• Borderea pyrenaica is an
endemic plant of the Pyrenees• Classified as vulnerable in the
IUCN Red List• Only 12 populations in France
Segarra-Moragues, J. G. and Catala´n, P. 2010, Genetica
Borderea pyrenaica in the French PyreneesPhoto: Marc Leclercq
Casestudy
The problem of vulnerable species• The high relative abundance of
vulnerable species often precludes management of all populations and individuals
• Vulnerable species require a cost-effective management plan• In France, genetic
information was used to identify relevant conservation units in order to make a successful management plan for B. Pyrenaica
Segarra-Moragues, J. G. and Catala´n, P. 2010, Genetica
Casestudy
Relevant Conservation Units of B. Pyrenaica• With limited human and
economical resources, all 12 populations of B. Pyrenaica in France cannot be protected
• Genetic analyses support differentiation of the B. Pyrenaica populations into different management units
• Five populations would allow preservation of over 98 % of the genetic variation of B. Pyrenaica
• This approach could potentially be applied to other low-extinction risk category species
Segarra-Moragues, J. G. and Catala´n, P. 2010, Genetica
Casestudy
Predicting the genetic outcome of management or harvesting decisions?• Which individuals/ populations should be used for stocking?• Which individuals/ populations can be hunted?
No stockingHunting OK
Golden eagles in the British Isles – one or two populations?• Golden eagle (Aquila
chrysaetos) • Once widely distributed in the
British Isles• Now extinct in Ireland, mainly
found in the highlands of Scotland
• Can the British population be used to reintroduce eagles in Ireland?
Bourke et al. 2010, Conservation Genetics
Golden eagle at the bird of prey centre in Hagley. Photo: Alex Hay
Casestudy
Past and present diversity compared by genetic methods• Genetic diversity of the modern British population was compared to
British and Irish museum specimens• Only slight evidence for a loss of genetic variation• The population persisted despite ancient bottleneck
• No evidence for population genetic structure• Therefore, all eagles belong to the same population
Bourke et al. 2010, Conservation Genetics
Casestudy
Safeguarding one population and habitat• The golden eagles of the British Isles should be considered a single
population unit – the extinct Irish population was not differentiated from the British one• Individuals from the British population are suitable for the Irish
reintroduction effort
• The main objective of conservation measures:• Increasing population sizes by safeguarding of individuals• Habitat management
Bourke et al. 2010, Conservation Genetics
Casestudy
Are populations diverse enough to survive in the future?
Seagrasses: genetic diversity and survival in the changing world?• Seagrasses are an ecologically successful group of marine angiosperms• Seagrasses provide habitat for fishes and invertebrates and play an
important role in nutrient cycling and sediment stabilization• i.e. help to maintain ecosystem services in a changing world
• Zostera marina is the key species of seagrass meadows worldwide
Reusch et al. 2005, PNAS, Procaccini et al. 2007, J. Exp. Mar. Biol. Ecol.
Seagrass medow in the Baltic Sea. Photo: Metsähallitus 2008
Casestudy
Promoting ecosystem resilience• In 2003, an extreme heat wave hit the south-western Baltic Sea
• Seagrass communities with higher genetic diversity recovered faster from the heat wave
• Genetic diversity promoted ecosystem resilience!
• The benthic fauna also preferred genetically diverse seagrass meadows• More genetic diversity in seagrass more individuals of bivalves,
snails and isopods
Reusch et al. 2005, PNAS, Procaccini et al. 2007, J. Exp.Mar. Biol. Ecol.
Casestudy
Biodiversity in genes – preparing for the future• Genetic diversity of key species can replace the role of species diversity
in a species-poor coastal ecosystem• High genetic diversity can provide a buffer against extreme climatic
events• Genetic diversity is important for maintaining both genetic and species
diversity in order to enhance ecosystem resilience
Reusch et al. 2005, PNAS, Procaccini et al. 2007, J. Exp.Mar. Biol. Ecol.
Casestudy
Practical considerations• DNA for genetic analysis is easy to obtain
• Single hair, feather, scale or leaf• Costs:
• 10 to 50 € per individual• 500 to 25 000 € per study• The overall price depends on methods and numbers of
populations • Genetic work can be outsourced• Choosing the right tools is important
• Contact conservation geneticists when planning the project• Advice available about samples and analyses needed to answer
the questions you are interested in
More information: www.congressgenetics.eu
More information: www.congressgenetics.eu
Copyright issues
• The photographs in this presentation are used under creative commons license or permission by the photographer and should not be used for other purposes.
• More information:
• Joachim S. Müller
• Dick Forsman
• Cyril Blazy
• Sarah Gregg
• Fabio Marini
• Mick Melvin
• José Mª F. Díaz-Formentí
• Bob Jagendorf
• Marc Leclercq
• Alex Hay
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