A4.2 Conservation of biodiversity Flashcards
A4.2.1—Biodiversity as the variety of life in all its forms, levels and combinations
Include ecosystem diversity, species diversity and genetic diversity.
A4.2.2—Comparisons between current number of species on Earth and past levels of biodiversity
Millions of species have been discovered, named and described but there are many more species to be
discovered. Evidence from fossils suggests that there are currently more species alive on Earth today than
at any time in the past.
NOS: Classification is an example of pattern recognition but the same observations can be classified in
different ways. For example, “splitters” recognize more species than “lumpers” in a taxonomic group.
A4.2.3—Causes of anthropogenic species extinction
This should be a study of the causes of the current sixth mass extinction, rather than of non-anthropogenic
causes of previous mass extinctions. To give a range of causes, carry out three or more brief case studies of species extinction: North Island
giant moas (Dinornis novaezealandiae) as an example of the loss of terrestrial megafauna, Caribbean monk
seals (Neomonachus tropicalis) as an example of the loss of a marine species, and one other species that
has gone extinct from an area that is familiar to students
A4.2.4—Causes of ecosystem loss
Students should study only causes that are directly or indirectly anthropogenic. Include two case studies
of ecosystem loss. One should be the loss of mixed dipterocarp forest in Southeast Asia, and the other
should, if possible, be of a lost ecosystem from an area that is familiar to students.
A4.2.5—Evidence for a biodiversity crisis
Evidence can be drawn from Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem
Services reports and other sources. Results from reliable surveys of biodiversity in a wide range of habitats
around the world are required. Students should understand that surveys need to be repeated to provide
evidence of change in species richness and evenness. Note that there are opportunities for contributions
from both expert scientists and citizen scientists.
NOS: To be verifiable, evidence usually has to come from a published source, which has been peerreviewed and allows methodology to be checked. Data recorded by citizens rather than scientists brings
not only benefits but also unique methodological concerns.
A4.2.6—Causes of the current biodiversity crisis
Include human population growth as an overarching cause, together with these specific causes: hunting
and other forms of over-exploitation; urbanization; deforestation and clearance of land for agriculture with
consequent loss of natural habitat; pollution and spread of pests, diseases and invasive alien species due
to global transport.
A4.2.7—Need for several approaches to conservation of biodiversity
No single approach by itself is sufficient, and different species require different measures. Include in situ
conservation of species in natural habitats, management of nature reserves, rewilding and reclamation of
degraded ecosystems, ex situ conservation in zoos and botanic gardens and storage of germ plasm in
seed or tissue banks.
A4.2.8—Selection of evolutionarily distinct and globally endangered species for conservation prioritization
in the EDGE of Existence programme
Students should understand the rationale behind focusing conservation efforts on evolutionarily distinct
and globally endangered species (EDGE).
NOS: Issues such as which species should be prioritized for conservation efforts have complex ethical,
environmental, political, social, cultural and economic implications and therefore need to be debated.
