નવા અશ્વ સાથીદાર ને ખરીદતી વખતે ધ્યાન માં લેવા જેવી બાબતો
Creators: name: ડૉ. રાહુલ ચૌહાણ', ડૉ. દેવાંગીની પંડયા*, ડૉ. હેમલતા પટેલ*
Publisher: name: The Science world a Monthly e magazine
Year: 2024

description: Fishes constitute the most diverse group of vertebrates, encompassing over 33,000 described species. They inhabit almost all significant aquatic ecosystems and perform a multitude of ecological functions (Helfman et al., 2009). However, fish populations are increasingly subjected to altered environmental conditions caused by human activities. Specifically, overexploitation, habitat destruction, pollution, and the introduction of non-native species have resulted in a global decline in marine and freshwater fish biodiversity (Leidy & Moyle, 1998; Pauly & Zeller 2016). Furthermore, fish populations are increasingly confronted with the consequences of global climate change. This includes ocean acidification, rising water temperatures, and anticipated regional alterations in salinity, dissolved oxygen levels, and circulation patterns within aquatic environments (Crozier & Hutchings, 2014; Levitus et al., 2012; O’Reilly et al., 2015; Pachauri et al., 2014). Consequently, differentiating between fish species capable of adapting to future environmental conditions and those requiring intervention is crucial for effective conservation and management. Genetic diversity emerges as a potential indicator for predicting a species' adaptive capacity. Genetic diversity quantifies the variation in gene and non-coding DNA sequences within a population (Hughes et al., 2008). Moreover, reduced genetic diversity can compromise population viability and increase the likelihood of extinction, particularly for populations exposed to challenging environmental conditions (Markert et al., 2010; Vandewoestijne et al., 2008; Reed & Frankham 2003). A comprehensive understanding of genetic diversity patterns across fish

species can facilitate predictions about their adaptive potential and vulnerability to extinction (Reed & Frankham, 2003; Stockwell et al., 2003).

Genetic Diversity and its importance

 

Genetic diversity is a quantitative measure of the variability in gene and non-coding DNA sequences within a population. A population's capacity for adaptation and evolution is often linked to both heterozygosity, the proportion of individuals with different alleles at a specific genetic locus, and the overall number of alleles present within the population (Allendorf, 1986; Frankham, Bradshaw, & Brook 2014).Genetic diversity arises from the mutation of genes and the recombination of homologous chromosomes during meiosis. Genetic drift and gene flow also contribute to this variation. Genetic diversity results in phenotypic variation among individuals, enhancing their ability to adapt to stress, diseases, and unfavourable environmental conditions. As a primary driver of evolution, genetic diversity is fundamental to natural selection and the survival of the fittest. Asexually reproducing organisms exhibit lower levels of genetic diversity. A reduction in genetic diversity can lower the population viability and increase the risk of extinction, particularly when populations encounter challenging environmental conditions. Understanding the patterns of genetic diversity among fish species could help in predicting which species are likely to adapt to future environmental changes and which are particularly vulnerable to extinction. Fish populations face growing threats from overexploitation, pollution, habitat destruction, and climate change. Genetic diversity is declining at a faster rate than species diversity, amidst escalating environmental threats.