RAS question
Environmental DNA (eDNA) is used in conservation for:
Correct answer: (D) Detecting species presence from water or soil samples without seeing them.
Environmental DNA is used in conservation to detect the presence of species from water, soil, or sediment samples without directly observing the organisms.
Explanation
Environmental DNA, or eDNA, is genetic material that organisms leave behind in their surroundings, such as water, soil, or sediment. This DNA may come from traces such as skin, faeces, or mucus. NOAA Ocean Exploration describes the method as collecting environmental samples, filtering water so DNA left by animals is captured, and then analysing that genetic material to identify species in an environment without scientists having to see them. That is why eDNA is useful in conservation: it can reveal rare, elusive, cryptic, endangered, invasive, migratory, or targeted species that may be missed by direct observation alone.
Why the other options are wrong
- (A) Genetic modification changes an organism's genes, whereas eDNA only analyses genetic material already shed into the environment to detect species presence.
- (B) Creating new species is outside the role of eDNA, which identifies species from environmental traces rather than producing organisms.
- (C) Cloning extinct species would require reproductive biotechnology, while eDNA is used for detection and biodiversity monitoring from samples such as water, soil, or sediment.
Concept
This tests the biodiversity-monitoring tools portion of Environment and Ecology. It recurs in RAS because conservation questions often ask whether a technology is meant for detection, monitoring, restoration, or direct genetic intervention.