Connecting Global Priorities Biodiversity and Human Health

development for use in the US. Most of these rely
upon a natural product predecessor (Pew Health
Initiatives 2014).
For as long as we know, humanity has relied upon
compounds from nature designed to treat what
ails us (see also the chapter on traditional medicine
in this volume). Otzi, the oldest known natural
mummy, who was found under a thawing glacier
in the Italian Alps, died more than 5000 years
ago and carried with him a pouch that contained
birch polypore fungus Piptoporus betulinus known
to reduce inflammation and kill bacteria (see,
for example, Bortenschlager and Oeggl 2000).
Reliance upon biodiversity for new drugs continues
to this day in most domains of medicine. More
than half of the 1355 newly approved drugs by the
US Food and Drug Administration between 1981
and 2010 had natural product origins (Newman
and Cragg 2012).
The success of drug development from natural
products manifests the common molecular
currency of life on earth. Species as diverse as
Conus geographus, Penicillium citrinum and Taxus
brevifolia – a meat-eating marine snail, rice
fungus and boreal conifer – produce molecules
that in humans relieve pain, reduce cholesterol,
and treat breast, ovarian, lung and other cancers,
respectively, because organisms, as diverse as they
are, communicate within themselves and other
creatures using common molecular currencies
(Chivian and Bernstein 2008). As discussed in
the chapter on traditional medicine, this often
increases the appeal for bioprospecting for
medicines.¹
While most of the medicinal potential of nature
has yet to be tapped, we may be losing potential
new cures with biodiversity loss. One of several
examples is the two species of gastric brooding
frogs indigenous to the rainforests of Queensland,
Australia. These species employ perhaps the most
unusual reproductive strategies in the animal
kingdom, using their stomachs as wombs for their
young (Chivian and Bernstein 2008; McNeely
2006). Having gone extinct in the 1980s, their
unique reproductive physiology was lost with
them, which could have alleviated the suffering
of tens of millions of worldwide who have peptic
ulcer disease and related disorders.
Plants have been the single greatest source of
natural product drugs to date, and although an
estimated 400 000 plant species populate the
earth, only a fraction of these have been studied
for their pharmacological potential (Hostettmann
et al. 1998). For example, one of the largest plant
specimen banks, the natural products repository
at the National Cancer Institute, contains ~60 000
specimens (Beutler et al. 2012). The same number
of species – 60 000 – are thought to be used for
medicinal purposes worldwide and perhaps as
many as 40% of these species are considered
threatened with extinction (Biodiversity Indicators
Partnership 2010; CBD 2014; see also the chapter
on traditional medicines in this volume).
Plant species as diverse as the Himalayan yew,
Taxus wallichiana (and other Taxus spp.) or African
cherry, Prunus africana, long used in traditional
medicines, have been threatened by factors such
as overharvesting and international trade, driven
by high consumer demand (Hamilton 2003). Both
are listed under the Convention of International
Trade in Endangered Species of Flora and Fauna
(CITES). The establishment and enforcement of
effective management and trade of wild-collected
species, both by governments and corporations,
remains a critical need in plant conservation (e.g.
Phelps et al. 2014).
Other realms of the living world, especially
the microbial and marine, are almost entirely
unstudied and hold vast potential for the
development of new drugs, given both their
diversity and the medicines already discovered
from them (Chivian and Bernstein 2008).
¹ For further discussion on marine bioprospecting see, for example, Hunt and Vincent (2006).
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