Download Biology 5865 – Conservation Biology

Lecture 2
Biology 5865 –
Conservation Biology
What is Biological Diversity?
•
•
Chapter 2 – spend additional time on this chapter if
you have not had “ecology”
Generally – know the meaning and use of terms in
bold – also throughout the book
“Biodiversity contains the accumulated
wisdom of nature and the key to its future. If
you ever wanted to destroy a society, you
would burn its libraries and kill its
intellectuals. You would destroy its
knowledge. Nature’s knowledge is contained
in the DNA within living cells. The variety of
genetic information is the driving engine of
evolution, the immune system of life, the
source of adaptability.”
(From Meadows 1990 - Biodiversity: the key to
saving life on earth. Land Stewardship Letter 45)
from an Indian newspaper - Hyderabad
January 7, 2009
Box 2.1 Naming and Classifying Species
Figure 2.14 Keystone species determine the ability of large numbers of other
species to persist within a biological community
What is biological diversity?
(from Groom et al. (2006)
• “The sum total of all living things – the
immense richness and variation of the
living world.”
• “Few people are aware of the full spectrum
of biodiversity, because our own
experience focuses on interactions with
people and those species that interact
directly with people”
• Ignorance is bliss (my comment)
What is Biological Diversity or Biodiversity?
“The variety and variability among living organisms and the
ecological complexes in which they occur.” (US Office of
Technology Assessment, 1987)
Primack (2010) subdivides into three levels:
1.
2.
3.
Species diversity – All the species on Earth, from singlecelled bacteria and protists to the multicellular kingdoms
(plants, fungi, and animals),
Genetic diversity - The genetic variation within species,
both among geographically separate populations and
among individuals within single populations, and
Ecosystem diversity - The different biological
communities and their associations with the chemical and
physical environment (“the ecosystem”).
What is Biological Diversity continued..
• Most „modern‟ definitions, however, would include basic
biological and ecological processes that have led to the
previous 3 – “the ecological processes that link with one
another and with soil, air, and water” (Hunter 1996)
• Another viewpoint (Noss 1990)
– Structural diversity - genetic structure,
physiognomy, landscape patterns
– Functional diversity – ecological and evolutionary
processes (e.g., photosynthesis, biogeochemical
cycling, predation, parasitism, life history, etc.)
– Compositional diversity – genes, species,
ecosystems
David Montgomery – Professor of Earth and Space
Sciences, University of Washington
What is biological diversity – continued?
Noss (in Groom et al. 2006) –
• “Biodiversity and how to save it is the subject
matter of conservation biology”
• “It (biodiversity) is complex and it is always
changing”
• “How on earth can a conservation biologist or
land manager deal with this mess?”
The Species Game
• Estimated 26,000
species vanishing each
year
• About 18,000 species
described each year
• In 2007
Science 330: 745, 5 Nov „10
– 75 % were invertebrates
– 11 % were vascular plants
– 7 % vertebrates
Biodiversity – the Heart of Conservation
Biology
•
•
•
•
•
•
What is species diversity?
What is genetic diversity?
What is ecosystem diversity?
Where is this diversity?
Why is this diversity there?
Is high or low diversity good or bad?
What is a species?
• Species are groups of actually or
potentially interbreeding natural
populations, which are reproductively
isolated from other such groups (Mayr
1942 from Hunter 1996, p. 32)
What is a species - 2
Species are generally defined in one of two ways (Primack
2002, 2006, 2010):
1. A group of individuals that are morphologically,
physiologically, or biochemically distinct from other
groups in some important characteristic is the
morphological definition of species – (most commonly
used by taxonomists) – genetic methods are
increasingly being used to distinguish species,
2. A group of individuals that can potentially breed among
themselves in the wild and that do not breed with
individuals of other groups is the biological definition of
species.
What is a species? - 3
• The ambiguity of the “species category” –
stems from the fact that the biological
world is a continuum of organization, from
atoms and molecules, through cells, organ
systems, and individuals, to populations
and species, to communities, ecosystems,
and landscapes. Cut-off points that
separate categories within this continuum
are often fuzzy (Meffe and Carroll 1994).
Complications of the species
concept – it is not necessarily clear
• A single species may have many varieties –
– Dogs – all derived from the gray wolf,
– Cabbage, cauliflower, brussels sprouts, and broccoli all derived
from Brassica oleracea
• Is the Mallard duck a separate species from the Black
Duck or from the Mexican duck?
• What is a subspecies in light of geographic variation?
• It is estimated that 70 % of angiosperms owe their
origins to hybridization (Grant 1981, Whitham et al. 1991
from Hunter 1996, pg. 33).
Two major ways of viewing species
(adapted from Meffe and Carroll (1994)
• Typological - views species as categorical entities, distinct
and somewhat clearly differentiated. Originated from the
Greek philosopher, Plato, who maintained that all physical
objects in our world represent an eternal and changeless
ideal or “perfect type” - variations about that ideal are merely
unfortunate imperfections of the material world.
• Populational or evolutionary - focuses directly on the
variation within species. This view recognizes that a
category such as the species is a group of individuals that
collectively express genetic, morphological, physiological,
and behavioral variation. This variation is not unimportant
and annoying, but is in fact the basis for evolutionary
change and adaptation.
“For the typologist, the type is
real and the variation an illusion,
while for the populationist the
type (average) is an abstraction
and only the variation is real. No
two ways of looking at nature
could be more different” (from
Mayr 1959).
Current View of Species
• Virtually all contemporary biologists accept the
population view of species, but genetic analysis
is the “best” way to define a species
• Population view of species emphasizes the need
to preserve the genetic variation of species, but
how much can be preserved? This is a hot
topic and a difficult one to deal with in
conservation biology (e.g., protection of
subspecies, protection of species populations
throughout their range, etc.)
• It is obvious by now that the nature and
definition of species is an area fraught with
difficulty, and one which has the potential
to bog us down and obstruct our progress
toward more pressing questions in
conservation (Meffe and Carroll 1992)
• Conservation biologists need to be aware
of the debate over species definitions, but
they cannot allow themselves to be
paralyzed by it (Rojas 1992 in Hunter
1996, p. 34)
Summary of species concept
• Biologists need to understand the Biological
Species Concept and its shortcomings
• Yet, the public will best understand “species”
protection, especially charismatic megafauna
like mammals and birds
– e.g., mountain lion, gray wolf, spotted owl, elephants
and other flagship species
• Preservation of genetic diversity, ecosystems,
habitats, etc. must be done on large “ecosystem”
and “landscape” scales along with corridors of
interconnecting areas to allow appropriate gene
flow among populations
Beetles not Beatles
• When asked by a group
of theologians what he
learned about God from
having spent a lifetime
studying His creations,
J.B.S. Haldane (a 19th
century biologist) replied
(in Hunter 1996, p. 34) • “ He seems to have
inordinate fondness for
beetles.”