tree” with no value as timber into an important medicinal plant when it was discovered to contain taxol, a chemical that has proven very effective in the treatment of ovarian cancer and breast cancer (Miller et al. 2008). Another example comes from the mountains of Ecuador where a rare shrub, Diplostephium rhododendroides, is the source of chemicals with great promise in the treatment of hepatitis C and diabetes (Ibrahim et al. 2013). Surveys for medically important plants have long been expedited by consulting with local people about their use of local plants (although less often sharing the commercial benefits of doing so); indeed there is a whole journal, the Journal of Ethnopharmacology, devoted to the topic, along with various journals that cover ethnobotany.
Medicines derived from microorganisms include penicillin, tetracycline, and most other antibiotics, as well as a variety of vaccines, hormones, and antibodies (Cragg and Newman 2013). Better understanding of the role of the microbiome that occupies the bodies of larger organisms is likely to have profound implications for the practice of medicine, for people, domestic species, and those wild species that demand our attention (Qin et al. 2010; Huttenhower et al. 2012; Redford et al. 2012). An intriguing study from Finland found that young people living in diverse settings (as measured by the diversity of plant species and different types of land use) were less likely to suffer from allergies and this was tied to the diversity and abundance of beneficial bacteria found on their skins (Hanski et al. 2012).
Although animals are the source of some medicines – for example, chemicals used to prevent blood clots have been isolated from the saliva of two blood‐sucking animals, leeches and vampire bats – they are generally more widely used in medical science as biological systems to be investigated for insights. The role of mice, rats, and primates as surrogates for people in medical research is well known, but animals’ contribution to medical science goes far beyond this. For example, research on the metabolism of black bears during their winter dormancy may provide significant insights for medical researchers concerned with kidney function (Stenvinkel et al. 2013). The interplay between wild and domestic animals and humans with respect to emerging diseases such as avian influenza (bird flu), SARS (severe acute respiratory syndrome), and of course COVID 19, which rocked the world in 2020, is another field where medical and conservation sciences intersect and new medicines may be forthcoming.
The role of different species in medicine is of particular interest to conservation biologists because it so clearly highlights the need to maintain biodiversity. From a biochemical perspective every species is unique and thus potentially could be the source of a major scientific breakthrough. If we lose a species, we may have lost an invaluable opportunity. Who knows what modern pharmacologists could do for society if they had access to silphion (the extinct source of birth control mentioned previously) and its active compounds? The scope for screening organisms for their biochemical properties remains enormous, and it promises to be an endless task because of continuous advances in medical technology and the ever‐expanding discovery of new species.
Clothing, Shelter, Tools, and Trinkets
Plastics, metals, glass, and concrete may constitute the bulk of materials people use today, but more traditional materials such as wood, cotton, thatch, sisal, wool, silk, leather, fur, and others remain very important to us. In industrialized nations natural materials often command a premium price because people prefer to walk on hardwood floors rather than linoleum and to sit on leather upholstery rather than plastic. In places that are far from industrial centers, or where a subsistence economy prevails over a cash economy, many people still rely mainly on natural materials (Fig. 3.7).
Figure 3.7 Natural building materials remain very important, especially in rural areas where they can be obtained locally, such as these houses in India with roofs made of thatch from local grasses.
(Roop_Dey/Shutterstock)
A conservation biology perspective on the use of organisms for materials parallels our earlier discussion about using organisms for food – wild relatives of domestic populations, wild species that might be domesticated, and direct use of wild species. One issue stands out: the overexploitation of wild populations for materials seems particularly unacceptable when they are used to produce nonessential items, especially status symbols for wealthy people such as luxurious fur coats, ivory knickknacks, elephant feet for trash baskets, snakeskin boots, rhino‐horn dagger handles, or Brazilian rosewood guitars.
Fuel
One of the single biggest uses we make of other living creatures, measured in gigatons, is burning them as biomass fuel. Trees provide most of this material, with over two of the seven billion people on Earth relying on wood for cooking and heating (FAO; see www.fao.org/forestry/energy); peat and agricultural residues are another significant portion. Of course, all forms of life are full of carbon and will burn given sufficient heat and oxygen. Closely related to fuel are various oils and waxes used for lubricants, chemical feedstocks, and other specialized uses. Some of these substances are unique to certain species. For example, sperm whale oil has special properties as a lubricant, properties so valuable that sperm whale populations have been grossly overexploited. Fortunately, scientists have discovered that a plant, the jojoba, which can easily be cultivated, produces an oil with qualities very similar to sperm whale oil, enabling sperm whales to slowly recover.
Recreation
A person's requirements for food, clothing, shelter, tools, and fuel are fundamental, but we also have emotional needs that drive our search for well‐being. Virtually all of us find pleasure in interacting with other people, and most of us also seek enjoyment from our interactions with other living creatures. Enjoying another species does not necessarily require economic activity, but, in practice, our attraction to other species involves large sums of money (Fig. 3.8). Keeping pets and growing ornamental plants are the basis for enormous businesses. Dogs, cats, and roses may be a large part of this trade, but thousands of species from ants to zinnias are involved, and most of them are not domesticated.
Figure 3.8 People enjoy the diversity of nature in many ways. Some seek particular species; some just wish to enjoy a beautiful, peaceful environment; for some, nature inspires indoor hobbies.
(Matee Nusermn/Shutterstock, paseven/Shutterstock, wavebreakmedia/Shutterstock, Daniel Wilhelm Nilsson/Shutterstock, top to bottom, left to right)
The selling of encounters with wild plants and animals is part of a substantial enterprise known as nature tourism or ecotourism (Wearing and Schweinsberg 2018), a growing component of mass tourism, the largest industry on Earth. People pay to travel long distances for the privilege of seeing redwoods, coral reefs, whales, lions, and many other species. Most ecotourists carry expensive cameras and binoculars; some of them carry guns or fishing rods. Overall, hunters and anglers pay the highest sums to pursue their recreation, sometimes thousands of dollars per person per day. Closer to home, backyard interactions with wild creatures are the basis for large sales: sales of wild bird food, bird feeders, birdhouses, and birdbaths tally over $5 billion per year
