loss of genetic diversity

Some species may not able to cope with environmental changes from global warming. Today, however, park visitors will have to hike up a nearby mountain to see one of these critters. Biodiversity losses typically accompany these processes. Significance of Genetic Diversity. The genetic diversity present in a population that is going for extinct, is lost. Loss of Genetic Diversity Means Loss of Geological Information: The Endangered Japanese Crayfish Exhibits Remarkable Historical Footprints. This procedure leads to a loss of genetic diversity in particular habitats. The smallest populations (ten individuals) lost the most genetic diversity, the medium sized population (50 individuals) lost a little less, while the larger populations (500 individuals) retained the most diversity. Researchers tracked the northern-most freshwater fish over an entire year with surprising results. Biodiversity itself is not a single concept but can be split up into various scales (e.g. Interactions between two or more of these drivers increase the pace of biodiversity loss. * 30 percent of livestock breeds are at risk of extinction; six breeds are lost each month. Trees are dominant species in many biomes and because they are long- … Phone +45 707 01 788. Even though a species is not eliminated from the ecosystem or from the biosphere, its niche (the role the species play in the ecosystems it inhabits) diminishes as its numbers fall. From them, we established 42 new populations, each of a set size, representing a bottleneck of 10, 50, or 500 individuals. Genetics have remained constant for 8,000 years in world’s melting pot, Global genetic diversity mapped by new study, New evidence that environmental change can outpace genetic adaptation. It’s an enormous loss of genetic diversity, of varieties that were developed over many years based on flavor, resistance to pests, ability to withstand drought, frosts, or … Since domestication, farm animals gradually adapted to local conditions. This is coupled with the side effects of inbreeding and genetic homogeneity, leading to an effect called the bottleneck effect. Researchers have identified five important drivers of biodiversity loss: Ecologists emphasize that habitat loss (typically from the conversion of forests, wetlands, grasslands, and other natural areas to urban and agricultural uses) and invasive species are the primary drivers of biodiversity loss, but they acknowledge that climate change could become a primary driver as the 21st century progresses. An area’s biodiversity increases and decreases with natural cycles. Loss of heterozygosity is predicted to be inverselyrelated to effective population size. Nature or nurture - that's only part of the question. The objective of the present study was to clarify the degree of inbreeding among modern cultivars and to estimate the genetic relatedness between modern cultivars and diverse genetic resources. We maintained these fly populations for 20 generations at these set sizes and in every fifth generation we sequenced (decoded) their DNA. Shattering: Food, Politics, and the Loss of Genetic Diversity Cary Fowler, Patrick R. Mooney - Science - 1990 - 278 pages It was through control of the shattering of wild seeds that humans first domesticated plants. It changes with time and space. The assessment of genetic diversity is fundamental for population genetic studies and it is essential for fishery management and resources utilization (Wang et al., 2017, Xu et al., 2018). The finding suggests that anorexia is not simply a mental disorder. Omissions? This allowed us to estimate the genetic diversity in each group of every generation. Astrophysicist Peter Laursen explains. It begs the question: Are 500 individuals enough to maintain long-term genetic diversity? Solitary species live in both the tropics and sub-tropics. Abstract. There is surprising genetic stability in one of the world's most culturally diverse regions: the meeting point between Europe and Asia. For the first time in Egypt, the two species of genus Dicentrarchus were characterized at the molecular level. Now control over those very plants threatens to shatter the world's food supply, as loss of genetic diversity sets the stage for widespread hunger. ZhangOrigin of Chinese goldfish and sequential loss of genetic diversity accompanies new breeds. [Shattering: Food, Politics, and the Loss of Genetic Diversity] (By: Cary Fowler) [published: August, 1990] | | ISBN: | Kostenloser Versand für alle Bücher mit Versand und Verkauf duch Amazon. 16, If the niches filled by a single species or a group of species are critical to the proper functioning of the ecosystem, a sudden decline in numbers may produce significant changes in the ecosystem’s structure. Loss of heterozygosity is predicted to be inverselyrelated to effective population size. Relative biomass on Earth. To clarify the genetic diversity, population structure, ... C.L. More than 7,000 U.S. apple varieties once grew in American orchards; 6,000 of them are no longer available. The primary drivers of biodiversity loss are influenced by the exponential growth of the human population, increased consumption as people strive for more affluent lifestyles, and reduced resource efficiency. Many of their natural habitats have been lost and the habitats that are left are strongly fragmented. Habitat loss combined with hunting pressure is hastening the decline of several well-known species, such as the Bornean orangutan (Pongo pygmaeus), which could become extinct by the middle of the 21st century. Blackwell Science (2008) Google Scholar . --------------- Globalization and crop genetic diversity The accelerating increase in communication is mixing ideas, technologies, cultures and even people throughout the world. Department of Bioscience, Aarhus University, Denmark. In contrast, the reduction and extinction of populations is far easier to see. Sexual reproduction is important in maintaining genetic diversity as it gives unique offspring by combining genes of parents. Chapter 6.2.2: Loss of genetic diversity: selection. Now control over those very plants threatens to shatter the world's food supply, as loss of genetic diversity sets the stage for widespread hunger. Schou, M. F., Loeschcke, V., Bechsgaard, J., Schlötterer, C., & Kristensen, T. N. (2017). In an ecosystem, species tolerance limits and nutrient cycling processes are adapted to existing temperature and precipitation patterns. All five drivers are strongly influenced by the continued growth of the human population and its consumption of natural resources. But the loss of genetic diversity can have devastating consequences, such as the Irish potato blight of 1850, the Southern corn leaf blight of 1970, and the current crisis in banana, Black Sigatoka disease, shown above. Biodiversity loss, also called loss of biodiversity, a decrease in biodiversity within a species, an ecosystem, a given geographic area, or Earth as a whole. This apparent loss of genetic diversity in L. tumana is consistent with small effective population sizes, which can lead to reduced fitness and evolutionary potential and increased genetic drift and extinction risk [31–33]. Loss of genetic diversity increases the risk of extinction of a population through inbreeding depression. Our editors will review what you’ve submitted and determine whether to revise the article. John P. Rafferty writes about Earth processes and the environment. Molecular Ecology, 26, 6510–6523. Studies on direct genetic parameters (genetic variability, hypervariable loci and heterozygosity) and indirect parameters (band‐sharing coefficient and allelic frequency) showed that the continuous decline in wild populations has caused the loss of genetic diversity in present‐day sturgeon. Previous Article Hybrid Salamanders Thrive, Contradicting Expectations; Next Article Migrating birds may "see" Earth's magnetic field; Typography. Scientists have sequenced the genomes of early farmers from Spain, confirming that they descended from the same group of migrants who brought farming to Northern Europe. Study: Loss Of Genetic Diversity Threatens Species Diversity Details 26 September 2007 . Likewise, biodiversity loss describes the decline in the number, genetic variability, and variety of species, and the biological communities in a given area. Tamias alpinus: If you'd visited Tuolumne Meadows in Yosemite National Park 100 years ago, you probably would have encountered the alpine chipmunk, Tamias alpinus. Phone Sexual reproduction is important in maintaining genetic diversity as it gives unique offspring by combining genes of parents. These changes may also provide new opportunities for invasive species, which could further add to the stresses on species struggling to adapt to changing environmental conditions. phylogenetic diversity, species diversity, genetic diversity, nucleotide diversity). 2013; Yoder et al. Biology also has an important role to play. But some spider species (around 25 out of 45,000) have developed a social structure, which means that many hundred individuals live together in nests their entire lives. Extinction is not only the loss of whole species, but is also preceded by a loss of genetic diversity within the species. But how many individuals of a given species do you need to maintain long-term genetic diversity? * Since the 1900s, some 75 percent of plant genetic diversity has been lost as farmers worldwide have left their multiple local varieties and landraces for genetically uniform, high-yielding varieties. 2018; Leigh et al. Since the beginning of this century, about 75% of the genetic diversity of agricultural crops has been lost. The statistics are numbing: Crop genetic resources are being wiped out at the rate of 1-2% every year. And as our studies on fruit flies show, a smaller population leads to a strong decline in genetic diversity, and a very uncertain future. Genetic diversity also exists between individuals in a population/species, and such genetic diversity represents the raw material for evolution, enabling a population or species to adapt to environmental changes or new diseases across generations. In contrast, the reduction and extinction of populations is far easier to see. All complex organisms have two copies of every gene in their DNA—typically one from the mother and one from the father. The idea of biodiversity is most often associated with species richness (the count of species in an area), and thus biodiversity loss is often viewed as species loss from an ecosystem or even the entire biosphere (see also extinction). Updates? Epub 2010 Sep 2. In natural population too, severe reductions in population size, the so-calledgenetic bottleneck, leads to loss of genetic diversity and increased susceptibility to infectious pests and diseases that supervene increased chances of extinctio… Preservation of genetic diversity is of fundamental concern toconservation biology, as genetic diversity is required for evolutionarychange. Hunters killed 2,000–3,000 Bornean orangutans every year between 1971 and 2011, and the clearing of large areas of tropical forest in Indonesia and Malaysia for oil palm (Elaeis guineensis) cultivation became an additional obstacle to the species’ survival. A high diversity is vital, since genetic diversity is directly related to biodiversity. The loss of intraspecific diversity has implications for the evolutionary potential of species, but may also alter ecological and ecosystem functions such as … By 2018 the biomass of humans and their livestock (0.16 gigaton) greatly outweighed the biomass of wild mammals (0.007 gigaton) and wild birds (0.002 gigaton). The loss of diversity that we observe is a result of hitchhiking: when an adaptive mutation rapidly increases in frequency, it takes with it the genetic background on which it arose . Molecular Ecology, 26, 4197–4210. Unexpected high genetic diversity in small populations suggests maintenance by associative overdominance. ecosystem diversity vs. habitat diversity or even biodiversity vs. habitat diversity) or different subcategories (e.g. Let us know if you have suggestions to improve this article (requires login). Declines in genetic diversity that accompany rapid falls in population may increase inbreeding (mating between closely related individuals), which could produce a further decline in genetic diversity. Out of approximately 20 species of the Stegodyphus genus of spiders, three of them have independently developed a social structure. For example, clearing trees from a forest eliminates the shading, temperature and moisture regulation, animal habitat, and nutrient transport services they provide to the ecosystem. Before species are extirpated, they yet lose intraspecific genetic diversity. Biodiversity, or biological diversity, is a term that refers to the number of genes, species, individual organisms within a given species, and biological communities within a defined geographic area, ranging from the smallest ecosystem to the global biosphere. Palm oil production increased 900 percent in Indonesia and Malaysia between 1980 and 2010, and, with large areas of Borneo’s tropical forests cut, the Bornean orangutan and hundreds to thousands of other species have been deprived of habitat. Obviously this has consequences for the allele frequencies in the next generation. In contrast, biodiversity losses from disturbances caused by humans tend to be more severe and longer-lasting. Forest clearing, wetland filling, stream channeling and rerouting, and road and building construction are often part of a systematic effort that produces a substantial change in the ecological trajectory of a landscape or a region. We established a laboratory population using 600 fertilised female flies taken from a natural population of flies from an orchard in Jutland, West Denmark. 2011 Feb;25(1):115-23. doi: 10.1111/j.1523-1739.2010.01574.x. Genetic diversity is defined as genetic variability present within species. Both metrics of genetic diversity were lower in L. tumana than in either of the comparison species. This article was originally published at Aktuel Naturvidenskab. This is supported by the fact that such few social spider species exist today. (A biological community is an interacting group of various species in a common location.) Loss of genetic diversity by genetic drift and inbreeding is directly linked to the effective population size (see Textbox). The loss of forest cover, coastal wetlands, ‘wild’ uncultivated areas and the destruction of the aquatic environment exacerbate the genetic erosion of agrobiodiversity. A marine heatwave caused massive loss of genetic diversity in underwater forests • Between 30% and 65% of average genetic diversity was lost across 800 km of coastline • Loss of genetic diversity was cryptic and not reflected in measures of forest cover • Marine heatwaves may compromise ability to respond to future climatic change Whole-genome sequence (WGS) data give access to more complete structural genetic information of individuals, including rare variants, not fully covered by single nucleotide polymorphism chips. PLoS ONE, 8 (2013), p. e59571. 2019). We saw a dramatic loss in genetic diversity, with social spiders having only ten percent of that of solitary species and our results could even suggest that their social structure is an evolutionary dead-end. Our results clarify that loss of genetic diversity has occurred in a fruit crop, as has been reported in annual crops. Loss of genetic diversity increases the risk of extinction of a population through inbreeding depression. Now control over those very plants threatens to shatter the world's food supply, as loss of genetic diversity sets the stage for widespread hunger. That is the intention of animal breeding! Human action has triggered a vast cascade of environmental problems that now threaten the continued ability of both natural and human systems to flourish. Previous Article Hybrid Salamanders Thrive, Contradicting ... Lead researcher Dr. Richard Lankau says, "This is one of the first studies to show that genetic diversity and species diversity depend on … Though even these groups lost some diversity after 20 generations. Evolution of sociality in spiders leads to depleted genomic diversity at both population and species levels. Many translated example sentences containing "loss of genetic diversity" – French-English dictionary and search engine for French translations. Dolores R. let us know that National Geographic posted an image based on a 1983 study by the Rural Advancement Foundation International that illustrates the loss of this genetic diversity. In the Department of Bioscience -  Genetics, Ecology and Evolution, at Aarhus University, Denmark, we studied what effect such population bottlenecks have on the genetic diversity of animals. Seasonal changes, such as the onset of spring, create opportunities for feeding and breeding, increasing biodiversity as the populations of many species rise. Three factors can attenuate the observed loss of diversity after a sweep. This means that species that require lots of space, such as the European Bison, are now restricted to certain areas in isolated populations. But population size isn’t the only important factor for the maintenance of genetic diversity. The genetic diversity within each crop has also been eroding fast. The main cause of genetic erosion in crops, as reported by almost all countries, is the replacement of local varieties by improved or exotic varieties and species. Like fruit flies, most spiders are solitary, which means that they live most of their lives alone without having to cooperate with each other. We are losing genetic resources for food and agriculture at an unprecedented rate. Biodiversity sustains key ecosystem functions, and ongoing species losses have tremendous impacts on good and services provided by biodiversity. Conversely, similar social structures do not occur in species everywhere, but rather in places where habitats remain stable for long periods and do not require large genetic diversity to adapt to changes. When an allele (variant of a gene) drifts to fixation, the other allele at the same locus is lost, resulting in a loss in genetic diversity. Genetic diversity is defined as genetic variability present within species. Loss of Genetic Diversity—Examples of Diminishing Returns. Loss of genetic variation due to bottlenecks during serial Researchers have found a gene variant that is more common among people with anorexia. Natural ecological disturbances, such as wildfire, floods, and volcanic eruptions, change ecosystems drastically by eliminating local populations of some species and transforming whole biological communities. Our results show that all groups became less genetically diverse. The reference population included 922,333 German … 23–25). Biodiversity loss is typically associated with more permanent ecological changes in ecosystems, landscapes, and the global biosphere. To evaluate the origin, genetic diversity, and population structure of domesticated rabbits in Kenya, a 263-base pair region of mtDNA D-loop region of 111 rabbits sampled from Kakamega, Vihiga, and Bungoma counties in the western region, Laikipia and Nyandarua counties in the central region, and Kitui, Machakos, and Makueni in the eastern region of the country were analyzed. Although loss of genetic diversity was cryptic at most of the sites for which cover data were available, at Marmion, there was a 85% and 22% increase in relative genetic diversity (nucleotide and haplotype diversity, respectively, for the rbcL gene), which corresponded to a rapid ∼50% increase in percent cover at the time genetic samples were taken after the heatwave (2012). They became hardy, resistant to local diseases, and well adapted to the regional climate. Our analysis demonstrates that over the past century, the lion population of the Kavango–Zambezi region has lost genetic diversity. However, very few genetic studies have focused on genetic diversity trends during the organized breeding of perennial crops, although inbreeding depression has been a concern of fruit breeders [6, 51]. Read More: New evidence that environmental change can outpace genetic adaptation. In contrast, the onset of winter temporarily decreases an area’s biodiversity, as warm-adapted insects die and migrating animals leave. 5.1 Genetic diversity in threatened birds 17 5.2 Historical and contemporary levels of genetic diversity 19 5.2.1 South Island saddleback 19 5.2.2 South Island robin 22 5.2.3 Takahe 24 5.2.4 Other New Zealand endemics 26 5.3 Restoring and maintaining genetic diversity 27 6. A large loss in genetic diversity is a direct consequence of a small population size, and the problem grows as each subsequent generation loses a little more. spiders in each nest as well as the entire population have a high turnover frequency—meaning a high rate of extinction and re-establishment from an existing population or nest. This happens in nature, too — through natural selection and random events. One result of less diversity is that consumers and farmers are now accustomed to, and demand, uniformity – such as: round red apples, plants all the same height in the field. https://www.britannica.com/science/biodiversity-loss, Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services. Please select which sections you would like to print: Corrections? For most mammals, the actual population size is the most important factor determining their genetic diversity. We show that the genetic diversity of the modern population was reduced by 12%–17%, with a reduction in allelic diversity of approximately 15%, compared to historical populations, in addition to having lost a number of mitochondrial haplotypes. This loss in the variety of life can lead to a breakdown in the functioning of the ecosystem where decline has happened. In addition, the number of deleterious genetic variations, which might accumulate in a small population through genetic drift, can also make the population vulnerable. But we’re not using Bison, we’re using fruit flies (Drosophila melanogaster). Loss of genetic diversity by genetic drift and inbreeding is directly linked to the effective population size (see Textbox). Contemporary observed heterozygosity has been reduced by 12%–17% compared to historical populations. Half of the world’s habitable land (some 51 million square km [19.7 million square miles]) has been converted to agriculture, and some 77 percent of agricultural land (some 40 million square km [15.4 million square miles]) is used for grazing by cattle, sheep, goats, and other livestock. Oslo: c/o forskning.no, Postbox 5 Torshov, 0412 Oslo, Norway. Loss of the area and connectivity of natural and semi-natural habitats impose serious negative effects on all aspects of biodiversity. This question is both of practical and scientific interest. Despite having a number of missing alleles across the samples, genetic diversity was still historically higher than in the contemporary lion population. It can best be described as a biological meltdown. In addition, a 2019 report by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services noted that up to one million plant and animal species are facing extinction due to human activities. We used WGS to investigate the amount of genetic diversity remaining after selection using optimal contribution (OC), considering different methods to estimate the relationships used in OC. Challenges and opportunities. However, quantifying the effect of these pressures is difficult due to the time-lagged responses of biodiversity to landscape change. For both, the best fitting relationships Solving the critical environmental problems of global warming, water scarcity, pollution, and biodiversity loss are perhaps the greatest challenges of the 21st century. In large stable populations with random mating and many breeders each year, genetic drift and inbreeding are minimal and genetic diversity is maintained across generations. Social spiders have large populations, but their social biology is so extreme that their actual population size (the number of individuals) has no effect on their effective population size. Genetic diversity is lost when a substantial portion of the original seed collection dies or is culled, or if there is a smaller — but specific — loss of seeds or plants through selection. Read this article in Danish at ForskerZonen, part of Videnskab.dk. In addition, the seasonal rise and fall of plant and invertebrate populations (such as insects and plankton), which serve as food for other forms of life, also determine an area’s biodiversity. The loss of genetic diversity is difficult to see or measure. It changes with time and space. It is only within the last 250 years that breeders have favored physical qualities that led to established breeds. It is often called the nucleotide diversity or the Tajima’s pi. Fragmented ecosystems are generally not as resilient as contiguous ones, and areas clear-cut for farms, roads, and residences provide avenues for invasions by non-native species, which contribute to further declines in native species. The high rates of future climatic changes, compared with the rates reported for past changes, may hamper species adaptation to new climates or the tracking of suitable conditions, resulting in significant loss of genetic diversity. The FAO report warns that, despite the growing evidence of biodiversity’s key role in food security and nutrition, the diversity of production systems worldwide is in decline.Of thousands of plant species cultivated for food, fewer than 200 contribute substantially to global food output and only 9 account for 66% of total crop production. Preservation of genetic diversity is of fundamental concern toconservation biology, as genetic diversity is required for evolutionarychange. A large loss in genetic diversity is a direct consequence of a small population size, and the problem grows as each subsequent generation loses a little more. Evidence that environmental change can outpace genetic adaptation animals leave to maintain genetic! 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Large areas with one or two high-yielding crop varieties can be disastrous when that crop falls victim to disease loss of genetic diversity...
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