One of the key sticking points that non-believers like to
bring up when criticizing Fortean Zoology is that of “Breeding Population” This is the number of animals which can
interbreed freely. It also would, by
definition, allow evolutionary change. In other words, this is the number of
males and females of a species that is sufficient to reproduce at a rate that
would keep the species from extinction.
Within the calculation of Breeding Population is something
called Minimum viable population (MVP). This is the lowest number of the population
of a species that can survive in the wild. In biology, ecology, and
conservation biology, MVP is the smallest possible size at which a biological
population can exist without facing extinction from natural disasters or
demographic, environmental, or genetic order or plan. This is usually estimated as the population
necessary to ensure between 90 and 95 percent probability of survival between
100 to 1,000 years.
A variety of assumptions are required for future forecasting
and this causes some debate on the accuracy of any MVP estimate. Proponents of using this number believe that
absolute accuracy is not necessary, but rather a tool for approximating for the
sake of conservation. In the case of
Cryptozoology, an approximation would necessarily be questionable given that
such species have yet to even be proven to exist in small numbers.
This Population uncertainty comes from four sources; Demographic
stochasticity, Environmental stochasticity, Natural catastrophes, and Genetic
stochasticity. Demographic stochasticity
is the variability in population growth rates that comes from random
differences among individuals (of a breeding species) within a season. This
variability will occur even if all individuals have the same expected ability
to survive and reproduce and the rate doesn’t change from one generation to the
next. It is generally important only in
populations that are already fairly small.
Certainly in the case of most cryptids, the population will be small. In Crypto terms, Demographic Stochasticity
would be the variation of the numbers of offspring in a lake monster, for
instance, from year to year, and the
morbidity rate of the same period There
really is no way that this number can be accurately calculated for any
population given that the number of offspring, while usually within a certain
range, is not constant. In larger
populations, this variability would not be as important.
Environmental Stochasticity is the unpredictable fluctuation
in environmental conditions. When we say
that a winter was “unusually warm” or “there is a lot less rain this year” we
are highlighting a normally occurring environmental fluctuation. Environment also includes the physical,
chemical and biological conditions, such as temperature, food availability and
the presence of predators. Generally, this fluctuation is used to represent a
longer term than just a few years. In
the form of an evolutionary time scale, environmental stochasticity affects the
overall life history of a species. Environments do change, so these predictions
can be unpredictable. Additionally,
major environmental changes can occur over long periods of time within the
evolutionary age and would affect any predicted “final outcome” of the
estimate. For Cryptozoology, this would
be a real factor for water “monsters” especially. The creation and changes in the lakes, rivers
and even oceans would be difficult to predict.
Along those same lines, natural disasters can factor into
the uncertainty of population models.
Ice ages, meteor strikes, earthquakes and tsunamis, and volcanic
eruptions would certainly affect biological populations. Even small disasters, tornadoes for instance,
can potentially wipe out enough of a population to bring it below the MVP. While in modern times, there is a better
model for predicting such disasters, it is by no means certain.
Another problem in calculating MVP for small populations is
Genetic Stochasticity. Genetic
stochasticity refers to changes in the genetic composition of a population
unrelated to things like selection, inbreeding, or migration. In small
populations, or those with communal inbreeding, this reduced amount of
diversity in genetic materials retained within populations would increase the
chance that recessive genes become the norm.
With disease often tied so closely to genetics, this lack of diversity
could be catastrophic. The loss of
diversity would limit a species’ ability to adapt to future environmental
changes or even reduce the capacity to reproduce at all.
Applying all this relative uncertainty to the populations of
cryptids can be problematic at best.
What would the MVP of a lake monster be?
Without knowing the biological makeup of such creatures, there is no way
to tell the genetics or the evolution.
We don’t know what they eat, so environment can only partially be
supposed. Without knowing the breeding
cycles—or even the breeding methods-of such creatures, these shaky estimates
become shakier still.
Arm yourself with this knowledge the next time a skeptic
decides to come at you with a value for how many of a species are needed to
sustain them. They couldn’t possibly
know. Until even one is documented, such
suppositions are completely baseless.
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