biogeography notes
TRANSCRIPT
Biology 241 – Biogeography: Life through time and space
Consider time and space: past, present and future
Course outline is same as Term Paper outline
Selected References:
Barry-cox and moore, biogeography
Cain, foundations of plant geography
Darlington, Zoogeography
Daubernmire, Plant geography
Pielou Biogeography
Polunin Introduction to plant ecology and geography
Udvardy Dynamic zoogeography
Watts Principles of biogeography
Wulff Historical Plant Geography
Assigned journals
Biogeography - the study of species distribution now existing and fossil and
on the basis of past and present areas, the elucidation of the origin and
history of biota which in turn gives us a key to an understanding of earth’s
history (Wolff 1933)
ELUCIDATION OF ORIGIN AND HISTORY – PAST, PRESENT,
ORGANISMS
Environment attendant to existence of species
None of the 4.5 M living species is ubiquitous [Ubiquitous: found
everywhere]; their range of distribution is limited (ten-fold of this includes
fossil organisms – 45M have lived on earth)
Speciation vs. extinction?
Nearly cosmopolitan: Dandelion (Taraxacum officinale L.) or Perigrine
falcon (Falco peregrinus)
No more than 100 sq meters in distribution (narrow endemic - relict)
Examples:
Isoetes philippinensis Merryl & Perry
(Philippine quillwort or rogiro) found
in a spring cove in the upper
headwater in Agos River in Balo-i,
Bulut Island, Lanao Del Sur (Agos
River feeds water to Ma. Cristina
Falls) Lowland vascular plant (other
species found in the upper slopes of
the Andes)
Tuatara: Sphenodon punctatus found only in New Zealand
Abucay – Philippine cockatoo (Cacatua haematurophygia) treated
as pest in the cornfield in samar, endemic to the Philippines…
how long to declare when it is extinct.
Biology + Geography is like a “shotgun marriage” – biology as a
distinct discipline is rich in information, almost all geographer are
biologist or taxonomist from the beginning, you’ll never undertand the
biology of an organism very well without knowing its geographic
distribution….
Objectives of the course:
1. To account for patterns of distribution that exist (find out about
distribution patterns: contracting vs. expanding)
Benguet pine – Pinus kesiya (synonymn is Pinus insularis Endlecker –
endemic to the country) but when it was discovered that P insularis was just
a synonymn of P kesiya, it became outlying in distribution from continental
SEA.
“To do science is to search for repetitive patterns, not simply to accumulate
facts. And to the science of biogeography, it is to search for patterns of
animal and plant life that can be put on a map” (Robert MacArthur 1972,
Geographical Ecology – Patterns in the Distribution of Species)
2. To explain the origin and history of world biota on the basis of their past
and present distributions
Ex. Gingko biloba, like the coelacanth, is a living fossil. Gymnosperm, found
in a monastery in Northern China. Widespread in the past (300M years old)
Example of reducing distribution pattern.
3. To know the different factors that determine the distribution of life on
earth
Mosses – Class Musci
Liverworts – Class Hepaticae Bryology
Hornworts – Class Anthocerotae
Jack rabbit – dessert dwelling animal ( Hare), how it will survive?
Jackrabbits are mostly nocturnal. They live in open habitat and run to
escape predators rather than hiding in the woods like the rabbit does. The
jackrabbit's large eyes are placed back on the head so he can see in front,
behind and overhead at the same time. Their keen sense of hearing helps
them be aware of their surroundings and potential danger and they rely
on their speed to escape from predators.
The jackrabbit's large ears also help the hare keep cool. The blood
vessels in the ears expand to allow the blood to cool before re-entering
the body. The jackrabbit can also decrease the blood flow through its ears
in the winter to stay warmer. Jackrabbits do not dig burrows. Instead,
they spend the hottest part of the day resting in a bed scratched out at
the base of a shrub or in a clump of tall grass where the shade will protect
it from the heat. In the winter, a jackrabbit builds its nest under thick
foliage that protects it from harsh winds. The black-tailed jackrabbit is an
herbivore. In the summer they eat mostly green plants and flowers that
are high in water content, so they do not require much water. They will
also eat sagebrush and cacti. In the winter, they don't hibernate, and
mainly eat shrubs. Jackrabbits are constantly eating and consume large
quantities of food relative to their size. Fifteen jackrabbits eat as much
food as a large grazing cow in one day. In agricultural areas the jackrabbit
may become a pest to farmers by eating their crops.
4. To show what in the present distribution of biota may be explained by the
present climate or environmental conditions and what the consequence of
these hallmark conditions are (De Candolle 1855)
Climate change – we are facing a hypsithermal condition (increasing
temperature - global warming)
Glacier – fossil ice with high isotopic oxygen content: lowers temperature in
the temperate regions
Find out for the last four ice glaciation?
American European
Stratigraphy
Wisconsin? - ?
Illinoian? - ?
Kansan? - ?
Nebraskan? - ?
Tropical rain forest – lowers temperature in tropical areas
Geography students quickly become aware of the problems of defining their
subject. Whereas the scope and subject matter of some branches of the
discipline can be relatively easily stated this is not the case with
biogeography
Geography has been defined as
Study of areal distributions; spatial patterns; locational analysis; man-land
relationships and the environmental relationships of man.
Biogeography implies linkage between biology and geography
Studies distribution of biological materials over earth’s surface and factors
responsible for the observed spatial patterns
Falcatifolium (gruezoi de laubenfels) – Coniferales and Taxales,
Type locality: Mt. Falcon, also found in samar, sibuyan island.
i.e., Persia: biome is desert; distribution pattern is regular; there is
no competition; root system is fibrous
Distribution pattern: looking for dispersal patterns
Variation in distribution of plants, animals and soil provides spatial
patterns for study as fundamental as variation in rock type
(geology), land forms (geomorphology) or atmospheric processes
(meteorology). We seek not to describe these patterns but also to
explain them: “Where?” Must be followed by “Why?”
o i.e.: Cocos nucifera L. (Palmae/ Arecaceae) – would you
believe that coconut has two types?
Types: Assignment! Why the distribution of Palms are
confined in the tropics
Mt. Banahaw – mossy forest, every 1000 masl reduced
temperature to -6 degree Celsius..
We are studying what biologists have always regarded as
biogeography but what the geographer has tended to call Plant or
Animal Geography. But if the study is at the more local level (large
scale) and centres on the individual species or the way species form
recognizable assemblages which interact with their effective
immediate environment, then the study becomes Plant or Animal
Ecology
Biogeography usually places as much emphasis on the distributional
aspects as on environmental relationships; tends to stress role of man in
patterns and processes or importance for man of the findings in terms of
past, present or future in land relationships. Over the years it is this type
of study which increasingly has become relevant.
Distinctions are not clear, and draws info obtained from many
sources (botany, zoology, meteorology, geomorphology, geology,
archaeology & sociology)
i.e : manatee and sea cow – closely related taxa that have diff.
distribution ranges.
Both [biogeography and geography] aim at explanation through synthesis
of these data. Biogeography as a subfield of geography, noting various
definitions and possible research themes (Hill), while the contribution of:
the biologist to the subject is apparent, the geographical or spatial
elements should not be underated.
Assignment:
Molecular Clock – ?
(Coconut) → Manila - Acapulco Galleon Trade – ?
Bicol region, tabaco albay. San Miguel Island – origin of the kadang
kadang, disease of coconut
Darwin: “that grand subject, that almost keystone of the laws of
creation, Geographical Distribution” in a letter to Dalton Hooker in
1845.
17th Century Philosopher Francis Bacon: we cannot command nature
unless we obey her. Only recently have we come to appreciate the
vital importance of this dictum. With the industrial and scientific
revolutions of the 18th, 19th and 20th centuries, there grew up a
feeling that man was becoming somehow independent of nature
and would eventually be able to control many aspects of his
environment. In the last few decades we have become painfully
aware that our relationship with the other parts of nature is now
becoming not less but more important.
TERM PAPER
Abstract
Taxonomy
Ecology & Botany
Distribution
Example: Hypothesis on the Geographical Centre of Origin and Diversity of
Rafflesia
Acknowledgement
Literature cited
Biogeographical discourse is important!
“We cannot command Nature unless we obey her. Only recently have we
come to appreciate the vital importance of this dictum” (Francis Bacon,
17th century) – fundamental principle for biogeography
Principle of uniformitarianism: physical and chemical laws of the
universe remain constant; in the context of our current experiences, these
are processes that occurred in the past, still occurring and will occur in
the future
Resources are not unlimited and if we continue to destroy, pollute or
overexploit our physical environment then we severely threaten out own
existence as a species. We are now the dominant species over most of
the globe, either by virtue of our actual presence or as a consequence of
our activities. The emphasis of biogeography on the role of man in
ecological studies makes it a subject of increasing relevance our future
well being of our population.
Paradox in biogeography: biogeography is a respectable branch of science
but little paradoxical as there are very few scientists that can be called
biogeographers because those who are involved in it are not geographers
but taxonomists, such as:
PJ Darlington – entomologist at the Museum of Comparative
Zoology, Harvard
Eric Hulten – deals with arctic flora, i.e. Flora of Alaska and Yukon,
flora of Aleutian Islands; 1937 : phytogeographical work on history
and origin of Arctic Flora
Biogeography makes use of info derived from systematics in the solution
of evolutionary problems and others
There is really a need to study the organisms as information cannot be
derived from anybody or any reference
Information is a joint venture between the collectors and the taxonomists
who systematically collect, analyze and evaluate them
A systematic unit is required and should be defined then actual
distribution of this unit can be made or drawn (level in the hierarchy)
Species within the genus should have a common ancestor
Interaction between genetic make-up and environment: Identical twins
subjected to different environments
Many plants and animals can exist outside of their localities of
environment: hence distribution is not solely dependent on interaction
between genetic make-up and environment
Caragana arborescens – shrub member of leguminosae: not native
to north America (Alberta) but native of Siberia
Pinus sylvestris – European scotch pine, is not indigenous or native
to north America, introduced in Alberta, Canada for timber
Picea abies –Norway spruce, introduced in Alberta, Canada for
timber
Theobroma cacao – native to central and south America, now found
in nearly all tropical countries of the world
Rattus rattus norvegicus – introduced in almost all parts of the world
through trading ships