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    Last modified 09/27/08


        Copyright © by Nila Gaede 2008
A mass extinction results
when the ecological
pyramid overturns
Adapted for the Internet from:

Why God Doesn't Exist

    1.0   The definition of the term mass extinction

    The traditional sense of the term ‘mass extinction’ is that a great percentage of species and entire families
    of animals disappear in a geologically swift period of time.

    “ [A mass extinction] occurs when there is a sharp decrease in the number
       of species in a relatively short period of time… a sharp drop in the rate of
       speciation” [1]

    Paleontologists infer mass extinctions from the bones they find in different layers of rock. Roughly, the
    thickness of a layer is a measure of the length of a period and contains certain types of bones. If the
    paleontologists come across a layer for which they cannot find certain types of animals that were quite
    prevalent in the previous layer, the conclusion is that these animals disappeared at the boundary.

    I prefer to define a mass extinction as one in which an entire food chain or several of them disappear.
    Thus, by definition, the cause of a mass extinction has to do with economics. The carrying capacity for a
    specific food chain crashes and the species that were members go down with it. This mechanism
    explains ‘a sharp drop in the rate of speciation’ (Fig. 1). Meanwhile, a new generation of plants and animals
    are unaffected by what happens around them, which tends to explain why mass extinctions are selective.
    If a local, background extinction has to do with aging, a global mass extinction has to do with a wide-
    ranging economic collapse.

    2.0   Wild economics: It’s a jungle out there!

    If we define economics as the management of resources, the first thing we must come to terms with is that
    all species, whether plant or animal, whether intentionally or unwittingly, practice some form of
    economics. All plants and animals make use of resources in one way or another. Here are some examples:

    •        Spatial resources: A gofer may dig a hole in the ground to build his burrow
    whereas a beaver collects wood to construct his shelter and a bird collects
    twigs to build its nest. Ants also make holes in the ground and a colony of
    termites constructs a mound. A crab may sleep under a rock.

    •         Reproduction: A stronger rat may crowd out weaker rats from sexual
    intercourse. A lion may challenge the reigning monarch, inherit the harem,
    and kill the princes.

    •        Food: If primary production (e.g., pasture, phytoplankton) goes scarce in a
    region, the herbivores which are dependent on these resources (e.g., cattle,
    zebras, zooplankton, fish) are now compelled to make involuntary choices.
    The scarcity of prey, in turn, compels predators to vie for the remnants.

    Again, whether these choices are conscious or result from instinct (whatever that is) is immaterial. The
    point is that scarce resources lead to peculiar behaviors such as migration, infighting, and starvation.
    Prodded by necessity, every member of a species scrambles to carve a niche for himself.

    The most important economic resource managed by animals is food. Without food, nothing else matters.
    And here we have no difficulty understanding Mother Nature’s fundamental law: all animals are ultimately
    dependent on plants. Without plants there would not be a world of animals. Therefore, in her infinite
    wisdom, Mother Nature made plants easy to ‘catch.’ Had it been in reverse and plants ran like cheetahs
    while animals were stuck to the ground like roots, the animals of such a strange world would not have
    had much of a chance. To compensate for this lack of mobility, Mother Nature blessed the plants with
    numbers. Hopefully, there are more grasses than cows, for what would become of the poor cattle if the
    reverse were true? Unfortunately, sometimes the reverse is true and cattle do in fact outnumber the
    grasses. We refer to these rare incidents either as scarcity, if we’re talking about a single species, or as
    the ‘loss of biological diversity,’ if we are dealing with an entire food chain. In these instances, the
    ecological pyramid overturns and we have a situation where the many chase the few (Fig. 2). We refer to
    these predictable events as mass extinctions. An important part of this process is the aging of species,
    specifically of species of plants.

Fig. 2   Speciation: Four snapshots in time

Fig. 2   Inversion of the Ecological Pyramid

The many chasing the few
    1.     A class of plants       overwhelmingly dominates the landscape. A food chain        consisting
    of top predator, large, medium, and small animals carve out niches in this habitat. Meanwhile,
    a new class of plants        develop which have a long-term, strategic advantage over the
    reigning species. They too discover tiny species of animals         carving niches into this new
    habitat.
    2.     The invading species of plants begin their expansion fueled by adaptive advantages. The
    number of animal species relying on them increases, but they remain small in size. The old
    guards are still formidable. The number of species of the old regime decreases as the habitat
    shrinks, yet the populations of each species expand at the expense of others. Competition
    fuels Cope’s Law.  
    3.   The expansion of the new species of plants and animals crowds out the old guards. The old
    species tied to a shrinking habitat must compete for a smaller piece of the pie. These older
    species disappear through attrition (background extinctions) and are not replaced with new
    ones from the same grand lineage. The newcomers are not yet enormous in size, but they
    are significant in numbers.
    4.   The new species of plants now dominate the landscape. Most of the old classes of plants
    have disappeared and the remaining ones are not important anymore. The species of
    animals that relied on them are about to become extinct, specifically those that developed to
    the largest sizes. Meanwhile, the new species of tiny animals are ready to take over as soon
    as the large species of animals of the old guard are gone. The newcomers will grow in size
    and become the new masters. What decides which of them will grow big is the environment,
    specifically the climate. Thus, the role of climate is not as most paleontologists believe: to kill
    species. The role of climate is to determine who will be the next ruler.
You think that
humans are the
only ones that get
pissed about
lousy economics?