mod 6 manus Flashcards
(15 cards)
Discuss the impact of bushfires on genetic diversity in Australian ecosystems
Bushfires can create genetic bottlenecks by drastically reducing population sizes, particularly in species with limited mobility. This leads to decreased genetic diversity and potential inbreeding depression. However, fires can also promote diversity by creating habitat mosaics, facilitating gene flow between previously isolated populations, and triggering germination in fire-adapted plant species with dormant seed banks.
Explain how introduced species in Australia can drive genetic change in native species
Introduced species drive genetic change in native Australian species through: selective pressure favoring individuals with resistance to new predators/competitors; hybridization (e.g., dingoes and domestic dogs); altered pollination patterns disrupting plant reproduction; and creating new niches that favor certain genotypes. These changes can lead to rapid evolution but may also threaten genetic integrity of native species.
Evaluate the effectiveness of captive breeding programs for endangered Australian species
Captive breeding programs for species like the orange-bellied parrot and corroboree frog preserve genetic diversity through careful mate selection and studbooks. Successes include preventing extinction and reintroducing individuals to the wild. Challenges include genetic adaptation to captivity, limited genetic diversity in founder populations, and difficulty maintaining wild behaviors necessary for survival upon release.
Describe how environmental factors in Australia can act as mutagens
Environmental factors acting as mutagens in Australia include: high UV radiation due to ozone depletion, causing DNA damage and contributing to high skin cancer rates; naturally occurring radioactive soils in some regions; bushfire smoke containing mutagenic compounds; and agricultural chemicals. These factors can induce mutations in wildlife, plants, and human populations, potentially affecting biodiversity and health.
Analyze the genetic consequences of habitat fragmentation in Australian ecosystems
Habitat fragmentation in Australian ecosystems leads to isolated populations with reduced gene flow, increasing genetic drift and inbreeding. This reduces genetic diversity and adaptive potential, particularly affecting species with limited dispersal abilities like the mountain pygmy possum. Edge effects create selection pressures favoring certain genotypes, while small fragments may not support minimum viable populations, accelerating genetic decline.
Discuss the role of genetic technologies in addressing agricultural challenges specific to Australia
Genetic technologies address Australian agricultural challenges through: developing drought and heat-tolerant crop varieties suited to variable climate; breeding livestock with parasite resistance and heat tolerance; creating salt-tolerant varieties for salinized farmland; and engineering disease resistance for unique Australian pathogens. These applications help maintain food security while reducing environmental impacts of farming in Australia’s challenging conditions.
Explain how transposable elements contribute to adaptation in Australian native species
Transposable elements (jumping genes) create genetic variation in Australian native species by inserting into new genome locations, potentially altering gene expression or function. This variation provides raw material for adaptation to Australia’s extreme conditions. For example, transposon activity increases during stress, potentially accelerating adaptation to drought, fire, or temperature extremes in species like eucalypts and marsupials.
Evaluate the potential impacts of gene drives for controlling invasive species in Australia
Gene drives could control invasive species like cane toads and rabbits by spreading genes that reduce fertility or survival. Benefits include targeted control without chemicals and reaching inaccessible areas. Risks include unintended spread to native populations, ecosystem disruption if successful, evolution of resistance, and ethical concerns. Australia’s island status makes containment more feasible but increases stakes if things go wrong.
Describe how chromosomal mutations have contributed to speciation in Australian fauna
Chromosomal mutations have driven speciation in Australian fauna through mechanisms like polyploidy in frogs, chromosomal inversions in Drosophila, and Robertsonian fusions in marsupials. These mutations can establish reproductive barriers when heterozygotes have reduced fertility. Australia’s geographic isolation and diverse habitats have allowed these chromosomal variants to establish distinct populations that eventually became separate species.
Analyze the ethical considerations surrounding genetic modification of organisms in the Australian context
Ethical considerations in Australia include: cultural perspectives of Indigenous peoples regarding manipulation of native species; potential impacts on unique ecosystems and biodiversity; questions of ownership and patenting of genetic resources; consumer rights to information and choice; and balancing precautionary principles with innovation needs. Australia’s regulatory framework attempts to address these through the Office of the Gene Technology Regulator and public consultation processes.
Discuss the significance of the dingo genome and its implications for conservation
The dingo genome reveals its distinct evolutionary history from domestic dogs, supporting its status as a unique wild canid deserving conservation. Genetic studies show hybridization with domestic dogs threatens dingo genetic integrity, with pure populations primarily remaining on Fraser Island and remote areas. This information guides conservation strategies, including maintaining genetic purity in protected populations and recognizing the dingo’s ecological role as apex predator.
Explain how genetic drift has shaped isolated populations on Australian islands
Genetic drift has strongly influenced island populations like Tasmanian devils (reduced genetic diversity), Kangaroo Island kangaroos (distinct subspecies), and Lord Howe Island species (unique characteristics). Small founder populations, limited gene flow, and bottleneck events have accelerated genetic differentiation. These isolated populations demonstrate how random changes in allele frequencies can lead to significant divergence from mainland relatives, creating unique conservation challenges.
Evaluate the use of DNA barcoding in cataloging and conserving Australian biodiversity
DNA barcoding helps catalog Australia’s vast biodiversity by identifying species using standardized genetic markers. It’s particularly valuable for cryptic species, incomplete specimens, and invertebrate groups where taxonomic expertise is limited. The technique supports conservation by identifying illegal wildlife trade, monitoring invasive species, and discovering previously unknown diversity. The Australian Barcode of Life Network contributes to this global initiative.
Describe how genetic rescue is being implemented to save threatened Australian species
Genetic rescue introduces new genetic material to inbred populations, increasing fitness through heterosis. In Australia, it’s been applied to mountain pygmy possums (translocating males between isolated populations), bridled nailtail wallabies (introducing captive-bred individuals), and eastern barred bandicoots (mixing island and mainland genetics). The approach balances introducing genetic diversity while preserving local adaptations and avoiding outbreeding depression.
Discuss the role of citizen science in genetic research and conservation in Australia
Citizen science contributes to genetic research through programs like FrogID (collecting audio samples for species identification), Koala Count (gathering DNA from scats), and Reef Blitz (collecting specimens for genetic analysis). These initiatives expand data collection capacity, engage the public in conservation, and monitor genetic changes in populations over time. They’re particularly valuable for tracking responses to climate change and habitat fragmentation across Australia’s vast landscape.
