Topic 8.7 - Disruptions to Ecosystems 𖦹⋆｡°✩ Flashcards
what is evolution characterized by
change in the genetic makeup of a population over time
what is an adaptation
a genetic variation favoured by natural selection, manifested as a trait that provides an advantage to an organism in a particular environment
how do adaptations arise
through random mutations that are not directed by specific environmental pressures
what will happen to the allele frequency if that adaptation is selected for
will increase in frequency if environment continues to select for this trait (increase in biodiversity, populations evolve, speciation can occur)
what can result in uncontrolled population growth and ecological changes
the availability of resources
what is an invasive species
one that is not native to a specific area and harms the community it is introduced to
what new niches do invasive species exploit
༻ niche is free of predators/ competitors
༻ outcompete other organisms for resources
༻ population increases unchecked
what is an example of an invasive species
domestic cats (feral cats specifically) are unsocialized and invasive in North America
when were cats brought to the US
in the 17th century by European settlement
what impact do cats have on the surrounding environment
༻ kill billions of small animals and birds each year - contribute to major reductions and even extinction of many small animal species
༻ outcompete other small predators
how can habitats change overtime
because of human activity
how does human impact affect change
human impact accelerates change at local and global levels
what are some examples of human impact
༻ urbanization
༻ deforestation
༻ erosion
༻ extinction
༻ pollution
༻ climate change
what is the impact of disease on new species and what can accelerate the spread of disease
the introduction of new disease can devastate new species. human migration and overpopulation can accelerate the spread of disease
what affect do geological and meteorological events have on an ecosystem
can affect habitat change and ecosystem distribution
༻ large habitat/chemical disruptions
༻ can accelerate evolution
༻ can cause extinction
