4 Flashcards
What is the ultimate threat to biodiversity?
The extinction of species and/or habitats.
Which species are most susceptible to extinction?
Endemic species, due to their limited distribution and specialized habitat needs.
What does the acronym HIPPO stand for?
Habitat destruction, Invasive species, Pollution, human Population growth, and Overexploitation.
What is the difference between background extinction and mass extinction?
Background extinction occurs at a natural low rate, while mass extinction involves rapid loss of large numbers of species due to drastic environmental changes.
What is the current global extinction trend?
Human activities have accelerated extinction rates 100–1000 times above background levels, contributing to what is now called the 6th mass extinction
What is ecological extinction?
When so few individuals of a species remain that they no longer play a functional role in the ecosystem
How does island biogeography relate to extinction risk?
Smaller and more isolated islands support fewer species and have higher extinction rates due to limited habitat and population sizes
What are the three types of biological extinction?
Local (extirpation), ecological, and global (biological) extinction
What equation is used to predict species loss from habitat loss?
S = cA^z, where S is the number of species, A is area, and c and z are constants
Why are island species particularly vulnerable to extinction?
They have small, isolated populations, limited ranges, and are often endemic.
What traits make a species more vulnerable to extinction?
Large size, poor dispersal, specialized niche, low genetic variability, and need for stable or isolated environments.
What are neoendemics and paleoendemics?
Neoendemics are recently evolved species with restricted ranges; paleoendemics are ancient species with no close living relatives.
What are deterministic and stochastic extinction factors?
Deterministic are systematic (e.g. habitat loss); stochastic are random (e.g. weather, disease).
How does population size affect extinction risk?
Smaller populations face higher risk due to inbreeding, genetic drift, and inability to recover from environmental stochasticity.
Why is genetic diversity within species important to conserve?
It supports resilience, adaptability, and ecosystem function—its loss can be as severe as species-level extinction.
