How does genetic diversity impact the extinction vortex in wildlife?5 answersGenetic diversity plays a crucial role in influencing the extinction vortex in wildlife populations. Studies on various species, including wild felids and mountain lions, have shown that reduced genetic diversity in small populations increases the risk of extinction due to inbreeding depression and genetic drift. The interaction between genetic and demographic factors significantly elevates the probability of extinction in isolated populations. While ecological processes dominate the risk of extinction in small populations, genetic effects become more pronounced as populations decrease in size. Maintaining genetic diversity through strategies like increasing landscape connectivity and preserving natural mutations is crucial for the long-term survival and adaptability of species facing anthropogenic threats and environmental changes.
What is the most common translocation in humans?5 answersThe most common translocation in humans is the t(11;22) translocation, which is a recurrent non-Robertsonian constitutional translocation. This translocation has been reported in over 160 unrelated families and is associated with the derivative 22 syndrome, leading to clinical features such as mental retardation, craniofacial abnormalities, and congenital heart defects. The breakpoints for the t(11;22) translocation have been mapped to specific Alu repeats on chromosomes 11 and 22, indicating an Alu-Alu recombination mechanism. Additionally, studies have shown that the t(11;22) translocation is subject to an unprecedented degree of selection, with minimal variation in the genomic sequence of breakpoints among unrelated individuals. This recurrent translocation highlights the significance of understanding the genetic mechanisms underlying structural chromosomal abnormalities in human populations.
How is genetic diversity of wildlife being threatened?5 answersThe genetic diversity of wildlife is being threatened by various factors such as habitat loss, climate change, inbreeding, and human-induced habitat fragmentation. Anthropogenic activities like translocations without considering genetic impacts, habitat destruction, and declining population sizes contribute to genetic diversity loss. For instance, the decline in populations and geographic ranges of species has led to reductions in genetic diversity, surpassing genetic preservation targets. Inbreeding due to declining population sizes can result in malformations and diseases, further compromising genetic health. Additionally, human-induced habitat fragmentation can lead to genetic differentiation between populations, affecting overall genetic diversity. Understanding and addressing these threats are crucial for the conservation and sustainable management of wildlife populations.
Why is important genetic diversity?5 answersGenetic diversity is important for several reasons. Firstly, it is crucial for the long-term sustainability of crop production systems. Increased genetic diversity in crops leads to resilience against unpredictable stresses, minimal risk of crop failure, and increased production. This diversity can be achieved through approaches such as evolutionary plant breeding and cultivar mixture. Secondly, genetic diversity is essential for the conservation and maintenance of plant and animal species. It helps in population monitoring, analysis, and conservation planning. Genetic diversity can be assessed at both phenotypic and genotypic levels using various tools such as biochemical markers and DNA-based molecular markers. Lastly, genetic diversity in plant genetic resources is vital for sustainable food security. It contributes to the development of new crop varieties with desirable traits and enables precise characterization and conservation of rare and endangered species. Biotechnological tools, such as next-generation sequencing and molecular markers, aid in maintaining diversity and developing new crop varieties.
What is the relationship between genetic diversity and the distribution of species?3 answersGenetic diversity in species is influenced by their distribution. The general center-periphery theory suggests that populations at the margins of a species' distribution have lower genetic diversity and greater genetic differentiation compared to populations in central areas. However, the relationship between genetic diversity and distribution is not always straightforward. Some studies have found a positive relationship between genetic diversity and environmental marginality, while others have found no consistent relationship. Additionally, the genetic diversity-area relationship (GAR) has been compared to the species-area relationship (SAR), with the hypothesis that maintaining genetic diversity is similar to maintaining species diversity. GAR trajectories can behave mathematically as SAR ones, with genetic diversity increasing with range size up to a certain level and then reaching an asymptote. Factors such as elevation gradient and habitat fragmentation can also influence genetic diversity in species.
How do older elephants adapt to translocation?4 answersOlder elephants adapt to translocation by playing an important role as repositories of information gained through experience. They provide necessary knowledge to optimize social and environmental skills and competence. However, translocation can disrupt elephants' social networks, leading to social disruption and reduced learning opportunities. Translocated elephants may experience stress, as indicated by changes in vocalizations and physiological measures. Evaluating translocation outcomes is important, and alternative measures such as comparing behavior and physiology to local residents can be employed. Translocated elephants showed convergence in behavioral time budgets with the local population over time. They also utilized habitat similar to their source site more than the local population. Careful consideration of timing, release location, and individuals targeted is recommended for future elephant translocations.