Connecting Global Priorities Biodiversity and Human Health

SHUTTERSTOCK
9. Biodiversity and
biomedical discovery
1. Introduction
The diversity of life on earth has been an engine
of biomedical discovery and sustained human
health for millennia, contributing to countless
medical advances. Ironically, in many instances,
the very organisms that have given humanity
vital insights into human diseases, or are the
sources of human medications, are endangered
with extinction because of human actions. While
other sources explore these subjects in detail
(see Chivian and Bernstein 2008), this chapter
briefly explores the substantial contribution of
biodiversity to biomedical discovery, and discusses
key health challenges posed by accelerating rates
of biodiversity loss.
2. Why biodiversity matters to
medical discovery
Many of the diseases that afflicted or killed most
people a century ago are today largely curable
or preventable. How did this happen? Applying
scientific methods to medical research certainly
contributed to this development, as did the
engagement of many researchers and medical
professionals. However, no amount of scientific
rigour, researchers, or any other factor could
suffice on its own to reduce the human suffering
realized in the twentieth century, as many of these
developments depended, wholly or in part, on
biological diversity (Chivian and Bernstein 2008).
Antibiotics rank among the most significant
breakthroughs that have considerably improved
human health in the twentieth century. Death from
pneumonia was so prevalent in the early twentieth
century, for instance, that Sir William Osler
described it is as the “captain of the men of death”
(see, for example, Barry 2005). With the arrival
of penicillin and its descendants, rates of death
from pneumonia plummeted (see, for example,
Podolsky 2006). The penicillins as well as nine of
the thirteen other major classes of antibiotics in
use derive from microorganisms. Between 1981
and 2010, 75% (78 of 104) of the antibacterials
newly approved by the United States (US) Food
and Drug Administration can be traced back to
natural product origins (Newman and Cragg
2012). Percentages of antivirals and antiparasitics
derived from natural products approved during
that same period are similar or higher. The overand
misuse of antibiotics has cultivated a slew of
highly resistant bacterial strains, which in some
instances cannot be effectively treated with any
currently available antibiotic (Levy and Marshall
2004; Davies and Davies 2010). A race to find
new antibiotics to overcome so-called superbugs
ensued (e.g. Spellberg et al. 2008). As of February
2014, at least 45 new antibiotics that carry the
potential to treat serious bacterial infections are in
164 Connecting Global Priorities: Biodiversity and Human Health