The Biodiversity Crisis, and Why It Matters

John Merck

The Crass Practicality: We need biodiversity

A Simple Analogy: Lemmings.

  • What are they?
  • The common metaphore: Groups of individuals rushing to their destruction.
  • The deeper biodiversity metaphore, based on Swedish lemming studies of the 1980s.

    Human agriculture and habitat diversity.

  • The effect of agriculture on world habitats also creates a dichotomy between a varied mosaic of different crops and varieties on a local scale - "patchy agricultural environments" and monoculture agriculture, based on the industrial scale cultivation of a single crop. Consider the US situation in the early 1990s (Union of Concerned Scientists Background Paper 2001):

  • Monocultures have some awesome advantages, especially in the near term:

    But it has its down-side:

    But all of this is minor compared to the long term threat: The day may come when the pests evolve faster than our ability to cope with them. There have been foreshadowings:

    Thus, the human situation mirrors that of the tundra lemmings, just on a longer time scale. Our agricultural monoculture is productive now, but we must constantly improve the allied technologies to forestall disaster. The worst-case scenario is a full-blown human boom and crash cycle (of which we are now in the boom). We have seen this before on smaller scales:

    Is there a more fail-safe approach? In hindsight, Ireland's mistake was to become dependant on a potato monoculture. You can hardly blame them. In near-term costs and benefits, it was the rational course. No one anticipated the sudden appearance of an alien plant pathogen. But by their fruits we shall know them.

    The more we limit the diversity of the biological resources (crops) on which we depend, the more we set ourselves up for lemming-like boom and crash cycles. The alternative is deliberately to hedge our bets by cultivating a much wider range of crops than we think we need. In some ways, America is moving in this direction with:

    It's a beginning. But where do these foods come from? Natural Biodiversity. There are conceivably many more useful food crops waiting to be domesticated. (Indeed, we already know of some that have been left alone because they are economically infeasible now but might become feasible in the future - oak trees.)

    This principle applies even more strongly to medicines. Humans have been mining the biodiversity for food for thousands of years. We are only beginning a new age of discovery of pharmaceuticals.

    National Council on Biodiversity and Human Health formed by pharmacological industry in 1998.

    How are we doing? - The general picture with mammal diversity from Pough et al., 1990.

  • According to a 2008 report by the International Union for the Conservation of Nature (IUCN), 25% of known mammals are at risk of extincton.
  • Current special crises in biodiversity reduction: -Amphibians. We've already seen the potential uses of some of the compounds in their skin. Canaries in mineshaft becaus eof unique physiology. and yet they are in serious decline:

  • According to the 2004 Global Amphibian Assessment, a vast and authoritative study , almost a third of the 5,743 known species are at risk of extinction; up to 122 have disappeared within the last 25 years.

  • The action plan emerging from this meeting lists six major reasons behind the decline:

    Working groups drawn from a wide range of scientific institutions and conservation organisations have established budgets for tackling each of these issues; the overall total comes to US$404m .

    The problems that comtemporary amphibians are facing are not new. A synopsis of major events in North America:

    The practical conclusion is obvious:

    But beyond practicality lie moral issues of environmental stewardship:

    But there is another dimension: Natural biodiversity holds out promises but also threats. Whenever humans have radically changed their behavior patterns or invaded habitats and regions in which they did not evolve, they have encountered a flavor of biodiversity for which they are not adapted:


  • What are disease organisms?

    - pathogenic organisms in humans

  • Origins in domestic animals

  • Evolutionary biology of symtoms - pathogen seeks optimum transmission strategy


  • Crowd diseases

  • As humans expand into new habitats, we encounter new disease vectors and take the process of transmission of diseases from animals to a new level. (E.g. Ebola, HIV, SARS)

  • As mass communications and travel becomes more prevalent, it becomes more difficult to isolate diseases. (E.G. HIV hung out in some small corner of central Africa for centuries before being released in late 20th century.)

  • Reasons for fear: We haven't seen the worst case scenario.