Rolston, CNV, Chapter 2:
Diversity and Complexity Values
- TYPES OF DIVERSITY
- Other than biological diversity: earth's marvelous geological variety
- Is it appropriate for environmentalists to focus on preserving earth's
- Biodiversity no one thing: includes diversity of genes, species, ecosystems,
- Alpha (biodiversity): # of species (a very limited measure of biodiversity)
- Limits of this measure include:
- Habitat with 2000 caribou versus one with 125,000 caribou
- In each case, one species, but more diversity as more
- More species in Denver Zoo than in all of Colorado
- But the inter-connections lost, no ecosystems, few individuals
- Three species of dolphin versus a dolphin and a shark species
- Which has more diversity?
- Phyla/order different (Calls this "hierarchical diversity")
- Genetic diversity greater?
- Even though dolphin are more complex/more evolutionary
achievement/of higher value, might say the two constitute
more diversity and then three
- Beta diversity: Habitat/community diversity; how much
ecosystems/species vary in a region
- A 50 square mile area of alpine mountain down to sea versus 50 square
miles of grasslands (Arctic refuge versus prairie)
- Deserts, grasslands, montane forests, arctic tundra all next to
- Mountain to sea versus rainforest patch
- Rainforest has more species, but mountain to sea greater
- Costa Rica (size of West Virginia) has more different species than all
the continental U.S.; Panama has as many plant species as all of
- That these countries have far greater alpha diversity does not
mean they have greater beta diversity
- Gamma diversity: Diversity on regional/global scales (presence of
- Difference endemic and indigenous/native
- Endeminc = found no where else
- Indigenous/native = nonexotic, not from someplace else
- That a species found in an ecosystem is endemic, doesn't add to local
diversity very much (by one species only), but it adds to
- E.g. lose one species each in two different ecosystems, but one is an
endemic, much greater loss of biodiversity if lose endemic
- Remote islands could have low diversity (alpha, beta), but high
endemism; they add much to global diversity
- Introduced exotics: enhances species count, but lowers
- E.g., Adding dandelions to wilderness were none were
- An ecosystem with more trophic levels is more complex
- 10 producers and 10 grazers
- 10 producers, 8 grazers, 2 carnivores
- Monkeys are more complex than plants
- True plants can photosynthesize and monkeys can't
- But monkeys can give differential alarm calls and plants can't
- Have perceptual and neural complexity that is not involved in
- Language use more complex process than photosynthesis?
- Greater complexity, often (not invariably) correlates with more
sophistication, increased capacities, advancement, increased value
- Sometimes simpler is better
- Complexity doesn't necessarily correlate with survival value
- So then why would natural selection head toward
complexity as it only selects for survival value in given
- Greater/higher ecological achievement: Humans are at apex of
complexity, more complex than any other species and of greater
- Our brains, our cultures, and so on.
- VALUE OF DIVERSITY, COMPLEXITY, RARITY
- Rolston claims diversity (complexity, rarity?) is generally valuable, but not a value "ipso facto"
("by the fact itself" or "by the very nature of the case")
- Sometimes diversity is not a value: (See p. 39)
- There is pointless diversity:
- Unusual birthmark on student adds diversity to the College
- Deformed freaks of nature: two headed calves
- Superfluous diversity: not a benefit to have one more shampoo (if no
- Admit prince w/slave to university because it enhances diversity?
- No, because justice is more important than this diversity
- This shows that adding diversity is not always a good thing overall;
But this is compatible with the view that diversity itself always
enhances value, though it can come with disvalues that overwhelm its
- Thus, the claim that biodiversity is not ipso facto a value could
- One: Adding biodiversity is not necessarily an all things
considered value enhancer (because it might come with value
subtracting features), though the biodiversity itself does always
- Two: Adding biodiversity needn't add value, because some
biodiversity in itself is not valuable (freaks of nature? geep?)
- Is only wild biodiversity valuable?
- Genetic engineering enhances biodiversity, but not value?
- Flower gardens, farm fields, fruit trees, domesticated breeds of
animals don't ad biodiversity value to the world?
- Can't really separate products of natural history (5 million species, etc) from
processes (natural selection, evolution, speciation) & both are valuable (p.
- Worries about the genetic fallacy and the naturalistic fallacy
- "We do really have to know how we came to have some tings if we
are to value them appropriately"
- But: Evil processes can bring about good products, even when the
products are necessarily tied (in terms of identity) with the processes
that made them
- E.g., Child of rape; Holocaust and the state of Israel
- Nature has a heading toward value & order (complexity?); rejects the
nothing but chance idea
- Difference between human caused and natural extinction:
- Unlike nonanthropogenic extinction, human-caused extinction shuts
down life processes/speciation
- Rolston's principle for resolving conflicts nature/culture: "Principle of non-loss of goods"
- P. 62: "Gaining goods for people is very important, not the only
thing, but perhaps the main thing in any value decision"
- P. 66: "Are the human goods purchased by sacrificing biodiversity
basic to human needs...or rather simply peripheral, mere desires?"
- Perhaps we can sacrifice woods for housing for poor (but see below), ought not to sacrifice
endangered species for another mall
- Rolston: Trading in nature for culture made sense until about the 18th
century, but gone beyond where this type of trade optimizes values
- Biodiversity as a commons (heritage of all humanity), not private property
- But patenting newly developed organisms is permissible, when 3rd world countries ought not to be allowed to own the biodiversity on their lands
- Why? What is his answer to Vandana Shiva's worries?