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ScienceWeek
SCIENCEWEEK
New Books & Miscellany in the Sciences
May 23, 2003
Vol. 7 - Number 21C
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ON BIOLOGICAL SPECIES
Charles Darwin's landmark book The Origin of Species, which
presented to scientists and the lay public alike overwhelming
evidence for the theory of natural selection, ironically never
explains where new species come from.
Species are names given to extremely similar organisms, whether
animals, plants, fungi, or microorganisms. Because we need to
identify poisons, predators, shelter materials, fuel, food, and
other necessities, we have long bestowed names on living and
once-living objects... Until the Renaissance, however, names of
live beings varied from place to place and were seldom precisely
defined. The confusion of local names and inconsistent
descriptions led the Swedish naturalist Carolus von Linne
(1709—1789) to bring rigor and international comprehensibility to
the descriptions. Since Linnaeus (his Latin name) imposed order
on some 10,000 species of live beings, scientists use a first
name (the genus -- the larger, more inclusive group) and a second
name (the species -- the smaller, less inclusive group) to refer
to either live or fossil organisms.
Most Linnaean names are Latin or Greek. By today's rules the
species and genus names are introduced into the scientific
literature with a "diagnosis", which is a brief description of
salient properties of the organism: its size, shape, and other
aspects of its body (its morphology); its habitat and way of
life; and what it has in common with other members of its genus.
The diagnosis appears in a published scientific paper that
describes the organism to science for the first time. The paper
also includes details beyond the diagnosis, called the
"description". To be a valid name not only must the names,
diagnosis, and description be published but a sample of the body
of the organism itself must be deposited in a natural history
museum, culture collection, herbarium, or other acknowledged
repository of biological specimens.
Fossils are dead remains, evidence of former life. The word comes
from "fosse" in French, something dug up from the ground. Fossil
species, like the enigmatic trilobite Pamdoxides paradoxis-simus,
also are given names and grouped on the basis of morphological
similarities and differences.
The word "species" comes from the Latin word "speculare", to see-
like spectacles or special. Everyone, knowingly or not, uses the
morphological concept of species -- dogs look like dogs, they are
dogs, they are all classified as Canus familiaris. The problems
come when we try to name coyotes (Canus latrans), wolves (Canus
lupus, gray wolf, or Canus rufus, red wolf), and other closely
related animals.
Zoologists, those who professionally study animals, have imposed
a distinct concept of species, which they call the "biological
species concept". Coyotes and dogs in nature do not mate to
produce fully fertile offspring. They are "reproductively
isolated". The zoological definition of species refers to
organisms that can hybridize -- that can mate and produce fertile
offspring. Thus organisms that interbreed (like people, or like
bulls and cows) belong to the same species. Botanists, who study
plants, also find this definition useful.
L. Margolis and D. Sagan: Acquiring Genomes: A Theory of the
Origins of Species. Basic Books 2002, p.3. More information at:
http://www.amazon.com/exec/obidos/ASIN/0465043917/scienceweek
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NEW BOOKS:
Brenda Maddox: Rosalind Franklin: The Dark Lady of DNA.
HarperCollins 2002, 380pp. Puts the double-helix story into a
rich and understandable human context. Franklin emerges as a
cultured scientist committed to excellence. More information at:
http://www.amazon.com/exec/obidos/ASIN/0060184078/scienceweek
H-O. Adami et al (eds.): Textbook of Cancer Epidemiology. Oxford
University Press 2002, 599pp. A concise and systematic account of
cancer epidemiology with coverage of key issues for the future.
More information at:
http://www.amazon.com/exec/obidos/ASIN/0195109694/scienceweek
G. Nossal and R. Coppel: Reshaping Life: Key Issues in Genetic
Engineering. 3rd Edition. Cambridge University Press 2002, 264pp.
Authoritative and lucid description of modern molecular biology
and genetics, offering a working knowledge of DNA science. More
information at:
http://www.amazon.com/exec/obidos/ASIN/0521524237/scienceweek
David A. Wharton: Life at the Limits: Organisms in Extreme
Environments. Cambridge University Press 2002, 320pp.
"Interesting discussion on what those organisms can tell us about
the origins of life and the possibilities of finding life on
other planets." -- Northeastern Naturalist. More information at:
http://www.amazon.com/exec/obidos/ASIN/0521782120/scienceweek
Richard J. Epstein: Human Molecular Biology: An Introduction to
the Molecular Basis of Health and Disease. Cambridge University
Press 2002, 656pp. Lavishly illustrated with two-color diagrams
and full-color clinical pictures. More information at:
http://www.amazon.com/exec/obidos/ASIN/052164481X/scienceweek
M. Alley: The Craft of Scientific Presentations: Critical Steps
to Succeed and Critical Errors to Avoid. Springer 2003, 264pp.
Scores of examples from contemporary and historical scientific
presentations to show clearly what makes an oral presentation
effective. More information at:
http://www.amazon.com/exec/obidos/ASIN/0387955550/scienceweek
G. Boerner: The Early Universe: Facts and Fiction. 4th Edition.
Springer 2003, 586pp. Written in a style accessible to advanced
undergraduates and graduate students. A classic text. More
information at:
http://www.amazon.com/exec/obidos/ASIN/3540441972/scienceweek
Gregg Herken: Brotherhood of the Bomb: The Tangled Lives and
Loyalties of Robert Oppenheimer, Ernest Lawrence, and Edward
Teller. Henry Holt 2002, 448pp. Tells the story through the lives
of three men who were central in creating the nuclear age -- the
result of 10 years of intensive research by the author. More
information at:
http://www.amazon.com/exec/obidos/ASIN/0805065881/scienceweek
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Copyright (c) 1997-2003 SCIENCEWEEK
All Rights Reserved
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