Name: saving small populations with genetic diversity
Uploaded: 2019-08-01T08:31:57.000Z
Duration: 2 min 4 s
Channel: JoVE

K12 Standards

north-carolina-k-12-science-standard-course-of-study

North Carolina K-12 Science Standard Course of Study

9-12

Biology

ecosystems-interactions-energy-and-dynamics

Ecosystems- Interactions, Energy, and Dynamics

LS.Bio.5.2

Conservation of Small Populations

- [Narrateur] La priorité de la biologie de la conservationest la préservation de la diversité biologique. 
Pour atteindre cet objectif,les scientifiques doivent identifier les populationsmenacées d'extinction. 
Les petites populations, telles que les panthèresde Floride, sont particulièrement exposées,car elles possèdent une faible diversité génétique,ce qui les empêche de résister aux maladiesou de s'adapter aux changements de leur environnement. 
Ces chats parcouraient autrefois la Floride jusqu'àla Louisiane le long de la côte du golfe. 
En raison de l'aménagement des terres, leur habitata été réduit à une petite zone dans le sud de la Floride. 
En 1973, il ne restait plus que 25 panthères. 
Une population aussi réduite a entraîné une consanguinité,ce qui a provoqué la queue entortillée, des malformationscardiaques et d'autres anomalies génétiquesréduisant leur capacité de reproduction. 
Une fois parvenue à un nombre extrêmement réduit,la population peut vivre ce que l'on appelle unvortex d'extinction, une chaîne d'événements circulairesqui se renforcent mutuellement pour réduire encore la taillede la population et provoquer sa disparition. 
Cela fonctionne de cette façon. 
Une petite population est sujette à la consanguinitéou à l'accouplement avec des parents proches. 
En conséquence, il y aura moins de diversité génétiquedans la population. 
Une diversité génétique plus faible entraîne une diminutiondes taux de survie et de reproduction dans la populationau fil du temps,ce qui diminue encore la taillede la population jusqu'au point de son extinction. 
Un moyen de prévenir un vortex d'extinctionconsiste à importer des individus d'autres populations. 
Par exemple, des biologistes de la conservationont introduit des panthères du Texasdans la population de la Floride afin d'accroître sa tailleet sa diversité génétique. 
Aujourd'hui, il y a environ 125 panthères de la Floridegrâce à ces efforts de conservation. 
Bien que la population ait augmenté,la conservation est toujours nécessaire. 
Les colliers GPS sont utilisés pour suivre chaque panthère,ce qui permet aux défenseurs de l'environnementde surveiller la santé de la population.

Robinson JA et. al. « Signatures génomiques de consanguinité extensive chez les loups de l’Isle Royale, une population au seuil de l’extinction. » Science Advances 5, no. 5 (29 mai 2019) :eaau0757. [<a href="https://doi.org/10.1126/sciadv.aau0757">Source</a>]

conservation des petites populations

Les petites tailles de population mettent une espèce en danger extrême d’extinction en raison d’un manque de variation, et d’une diminution conséquente de l’adaptabilité. Cela affaiblit les chances de survie sous des pressions telles que le changement climatique, la concurrence d’autres espèces ou de nouvelles maladies. Les grandes populations sont plus susceptibles de survivre à des pressions comme celles-ci car ces populations sont plus susceptibles d’abriter des individus ayant des variantes génétiques qui s’adaptent sous de nouvelles contraintes. Les petites populations sont beaucoup moins susceptibles d’avoir de telles variations.
 
 Les techniques génomiques modernes peuvent identifier l’homozygositie dans les gènes délétères qui est causée par la consanguinité. Cela se produit lorsque des organismes étroitement apparentés produisent une descendance ; celle-ci a plus de chances de recevoir deux allèles délétères identiques. Par exemple, les loups du parc national de l’Isle Royale ont connu une réduction extrême de la population causée par l’émergence d’une maladie, ce qui a entraîné une augmentation de la consanguinité. La population de loups a continué de diminuer, ne contenant à un moment donné que deux loups.
 
 Le séquençage de l'ensemble du génome a permis aux chercheurs d'identifier la lignée des loups restants sur l'île Royale, ce qui a révélé des accouplements entre frères et sœurs et entre parents et descendants dans la petite population, sur la base des modèles d'hérédité chromosomique. L’analyse des séquences génétiques a montré des polymorphismes délétères d’un seul nucléotide (SNP) dans les gènes fonctionnels qui réduisent l’aptitude de ces loups. Ces mutations expliquent les caractéristiques physiques que l’on peut voir chez les loups de l’île Royale, comme les malformations dans leurs colonnes vertébrales et leurs cages thoraciques.
 
 Les gardes du parc font venir des loups de l’extérieur du parc pour établir une diversité génétique saine sur l’île Royale. Compte tenu d’une population plus saine et plus importante, les loups devraient être en mesure de prospérer sur l’île Royale. Les gardes suivent également les loups de l’île avec des colliers GPS pour déterminer si leurs méthodes de conservation sont efficaces.

Conservation des petites populations

La petite taille des populations expose une espèce à un risque extrême d’extinction en raison d’un manque de variation et d’une diminution conséquente de la capacité d’adaptation. Cela affaiblit ...

Education

Enseignement

JoVE Core

Biologie

Ecology

Écologie

Biodiversity and Conservation

Biodiversité et conservation

KEY TERMS AND CONCEPTS

TERMES ET CONCEPTS CLÉS

saving small populations with genetic diversity

Small populations can be hard to save because they often lose genetic diversity. When variation is low, a species has fewer traits that may help it adapt to climate change, competition from other species, or new diseases. That makes extinction more likely.

Large populations usually have a better chance of surviving new stresses. They are more likely to include individuals with genetic variants that are helpful in changing conditions. Small populations are much less likely to contain this kind of variation.

Genomic tools can reveal another problem in small populations: inbreeding. Inbreeding happens when closely related organisms produce offspring. The offspring then have a higher chance of inheriting two identical harmful alleles, which can make deleterious genes homozygous.

The wolves on Isle Royale National Park show how this can happen. A disease outbreak caused a sharp population drop, and increased inbreeding followed. The wolf population kept declining, and at one point only two wolves remained. Whole-genome sequencing helped researchers trace the remaining wolves' lineages and showed sibling-sibling and parent-offspring matings from chromosomal inheritance patterns.

Gene sequence analysis also found deleterious single-nucleotide polymorphisms, or SNPs, in functional genes. These mutations lower the wolves' fitness and help explain visible problems such as spinal and rib cage malformations. To improve the population, park rangers are bringing in wolves from outside the park to restore healthy genetic diversity. Rangers also use GPS collars to track the wolves and see whether the conservation plan is working.

Saving Small Populations with Genetic Diversity

saving-small-populations-with-genetic-diversity

what is weather?

How Sunlight Shapes Daily Weather

Weather is the current state of the atmosphere at a specific time and place. It is temporary and changes from one location to another. Weather is shaped by the interaction of the sun, atmosphere, hydrosphere, and geosphere. Solar radiation reaches Earth and interacts with water and land. These surfaces release that energy as thermal radiation, or heat, which warms the air above them. Some of that heat escapes back into space, but some is trapped by atmospheric gases. This heat retention is...

global climate change

Ancient Clues to Climate Change

Ancient climate clues help scientists track global climate change. Paleoclimatology is the study of climate conditions in Earth’s past and the causes and effects behind them. By comparing recent climate patterns with older records, researchers can find strong evidence for human-caused warming. Earth’s climate has changed many times over its 4.5 billion year history. In the last 650,000 years, there have been seven cycles of glacial advance and retreat. The most recent ice age ended more than...

what is biodiversity?

Biodiversity Across Genes, Species, and Ecosystems

Biodiversity is the variety of living things at the genetic, species, and ecosystem levels. It includes not only how many kinds of organisms exist, but also how they are related and how they interact with the world around them. Species diversity spans the full evolutionary tree. It includes single-celled prokaryotes such as bacteria and archaea, as well as the eukaryotic kingdoms: plants, animals, fungi, and protists. About 1.75 million species have been identified so far, and scientists...

threats to biodiversity

How Humans Change Biodiversity

Human activity is changing biodiversity and pushing Earth toward a sixth extinction event. Earlier mass extinctions ended many species, and then new species spread into the changed environment. Today, the Holocene epoch is seeing a mass extinction linked to human actions, and it is often called the Anthropocene. Human numbers and human biomass show how large this impact has become. In 2019, the human population reached 7.7 billion and is projected to rise to 10 billion by 2060. By biomass,...

conservation of declining populations

Saving Species Through Population Recovery

Conservation of declining populations focuses on detecting a population drop, finding its cause, and stopping further loss. The goal is to prevent extinction by using scientific methods to identify the agents behind the decline. Once the cause is known, conservation teams can remove, oppose, or neutralize it. A common step is to test possible causes with a small trial group. If the cause is confirmed, the remaining animals may be moved to an unaffected area. When the population is too small or...

biodiversity and human values

Biodiversity in Food, Tools, and Medicine

Biodiversity supports human life through food, tools, medicine, and many other needs. Changes in the variety of species can also change the environment. Those environmental shifts can alter weather patterns and affect human civilizations. People have depended on biodiversity for agriculture since early human history. Agriculture began when ancestral humans found species that were good sources of food. At least 11,000 years ago, people started selecting plant and animal species to raise on...

what is conservation biology?

Protecting Biodiversity in Conservation Biology

Conservation biology is the science of protecting biodiversity and keeping ecosystems healthy. It looks at how living things, habitats, and human needs are connected. The goal is to preserve biodiversity so ecosystems can continue to function well. Healthy ecosystems provide people with important natural resources. These include food, medicines, and building materials. Ecosystems also deliver key services, such as cleaning air and water. Evidence shows that these services depend on...

what is climate?

Climate Patterns and Earth’s Energy Balance

Climate describes the usual weather conditions in a place over a long period of time. The idea is simple: climate is what you expect, while weather is what you get. Climate is shaped by geographic factors such as latitude, terrain, and how close an area is to bodies of water. Weather and climate are related, but they work on different time scales. Weather is the state of the atmosphere at a specific time and place. Climate is the average pattern of weather over much longer periods. Because of...

sustainable development

Protecting Oceans for Sustainable Development

Sustainable development depends on protecting oceans while meeting human needs. As the human population grows and uses more resources, people must stay aware of the planet’s natural limits. The goal is to improve life now without taking away the resources future generations will need. Long-term sustainability depends on understanding how human actions affect ecological systems. Oceans are a major part of this balance. They provide food for people, produce much of the atmosphere’s oxygen, and...

conservation of small populations

Small populations can be hard to save because they often lose genetic diversity. When variation is low, a species has fewer traits that may help it adapt to climate change, competition from other species, or new diseases. That makes extinction more likely. Large populations usually have a better chance of surviving new stresses. They are more likely to include individuals with genetic variants that are helpful in changing conditions. Small populations are much less likely to contain this kind...

habitat fragmentation

How Fragmented Habitats Affect Wildlife

Habitat fragmentation breaks one continuous habitat into smaller, separate patches. Human land conversion is a major cause of this change, and slower geological shifts in the physical environment can also fragment habitats. The process usually follows the same stages: perforation, dissection, fragmentation, shrinkage, and attrition. Perforation and dissection often begin during land development. Perforation happens when undeveloped land is cleared for something like a home, and dissection...

key terms and concepts

Learn how low genetic diversity, inbreeding, and genome sequencing affect small wolf populations on Isle Royale, and how conservation can help.

Saving Small Populations with Genetic Diversity | JoVE K12

JoVE Core series brings biology to life through over 300 concise and easy-to-understand animated video lessons that explain key concepts in biology, plus more than 150 scientist-in-action videos that show actual research experiments conducted in today’s laboratories.

biology

La collection JoVE Core Biologie donne vie à la biologie à travers plus de 300 leçons vidéos animées concises et faciles à comprendre qui expliquent les concept clés de la biologie, mais aussi plus de 150 vidéos de scientifiques à l'action effectuant des expériences de recherche dans des laboratoires modernes.

Earth and Environmental Science

Earth's Systems

ESS.EES.4.4

Pennsylvania State Academic Standards

Life Science

interdependent-relationships-in-ecosystems

Interdependent Relationships in Ecosystems

3.1.9-12.N

3.1.9-12.V

Louisiana Student Standards for Science

High School

Life Sciences

Ecosystems: Interactions, Energy And Dynamics

HS-LS2-1

HS-LS2-7

Environmental Science

Environmental Awareness And Protection

HS-EVS2-2

HS-EVS2-1

ohios-learning-standards-and-model-curriculum

Ohio’s Learning Standards and Model Curriculum

Diversity And Interdependence Of Life

Ecosystems

Loss of diversity

Tennessee Academic Standards

Biological Change: Unity and Diversity

BIO1.LS4.3

Virginia  Standards of Learning

HIgh School

BIO.8

BIO.8.d

LS.9

LS.9.a

Minnesota Academic Standards in Science

Earth and Space Science

3.2.2 9E.3.2.2.1

4.2.2 9L.4.1.1.3

Arizona Science Standards

HS+E.E1

HS+E.E1U3.11

new-jersey-student-learning-standards-for-science

New Jersey Student Learning Standards for Science

Ecosystems: Interactions, Energy, and Dynamics

HS-LS2-2

Biological Evolution: Unity and Diversity

HS-LS4-6

Earth and Human Activity

HS-ESS3-3

engineering-technology-and-applications-of-science

Engineering, Technology and Applications of Science

Engineering Design

HS-ETS1-3

HS+B.L2

HS+B.L2U1.1

Alabama Course of Study Science

Ecosystems: Interactions Energy and Dynamics

9-12.B.2.9.a

9-12.EVS.4.10

Next Generation Science Standards

heredity-inheritance-and-variation-of-traits

Heredity: Inheritance and Variation of Traits

HS-ESS3-4

Florida Department of Education

SC.912.L.17

SC.912.L.17.8

SC.912.L.17.17

Texas Essential Knowledge and Skills

BIO.13

BIO.13.D

Georgia Standards of Excellence

Botany

SBO3.

All Standards

south-carolina-college-and-career-ready-science-standards

South Carolina College and Career Ready Science Standards

B-LS2-2.

B-LS2-7.

B-LS4-6.

Earth and Space Science (ESS)

E-ESS3-2.

E-ESS3-4.

new-york-state-science-learning-standards

New York State Science Learning Standards

HS-LS2-7.

Natural Selection and Evolution

HS-LS4-5.

Earth and Space Sciences

Human Sustainability

HS-ESS3-3.

HS-ESS3-4.

SEV4.

SEV4.d

Entomology

SEN1.

SEN1.d

SEC1.

SEC1.c

SB5.e

myJoVE Corporation

What are Biogeochemical Cycles?

The most common elements in organic molecules, carbon, hydrogen, oxygen, nitrogen, sulfur, and phosphorus, are only available in the ecosystem in limited ...

The Water Cycle

The Earth&rsquo;s hydrosphere includes all of the areas where the storage and movement of water occurs. Since water is the basis of all living processes, ...

The Carbon Cycle

Carbon is the basis of all organic matter on Earth, and is recycled through the ecosystem in two primary processes: one in which carbon is exchanged among ...

The Nitrogen Cycle

Nitrogen atoms, present in all proteins and DNA, are recycled between abiotic and biotic components of the ecosystem. However, the primary form of ...

The Phosphorus Cycle

Unlike carbon, water, and nitrogen, phosphorus is not present in the atmosphere as a gas. Instead, most phosphorus in the ecosystem exists as compounds, ...

The Sulfur Cycle

Sulfur, an important element in the chemical makeup of proteins, is recycled through the atmosphere and aquatic and terrestrial environments. Found in the ...

Use models to illustrate how processes in organisms contribute to the flow of energy and the cycling of matter within an ecosystem.

LS.Bio.4.1

What are Populations and Communities?

Populations are groups of individuals of the same species that inhabit a shared environment. Communities include multiple co-existing, interacting ...

Distribution and Dispersion

Ecology is the study of how organisms interact with their environment and with one another. An important aspect of ecology is understanding where species ...

Life Histories

Constrained by limited energy and resources, organisms must compromise between offspring quantity and parental investment. This trade-off is represented ...

Energy Budgets and Reproductive Strategies

Organisms must balance energy intake with the energy required for growth, maintenance, and reproduction. These trade-offs result in a variety of ...

Population Growth

Population size is dynamic, increasing with birth rates and immigration, and decreasing with death rates and emigration. In ideal conditions with ...

Use models to explain the relationship between the flow of energy and cycling of matter among organisms in an ecosystem.

LS.Bio.4.2

Ecological Niches

All organisms have a position within an ecosystem. The complete set of living and nonliving factors&#x2014;including food resources, climate, and ...

Ecological Succession

Ecological succession is influenced by the processes of facilitation, inhibition, and toleration. Facilitation occurs when early successional species ...

Keystone Species

Measures of species biodiversity, such as richness (i.e., the number of species present) and evenness (i.e., their relative abundance), describe an ...

Symbiosis

Symbiotic relationships are long-term, close interactions between individuals of different species that affect the distribution and abundance of those ...

Use mathematics and computational thinking to explain how interactions between organisms (predator/prey, competition) affect carrying capacity and maintain stability in an ecosystem.

LS.Bio.5.1

Analyze the relationships between matter and energy within ecosystems.

Saving Small Populations with Genetic Diversity

Description

Transcript

Tags

More videos by Standards