Difference between revisions of "Zoology" - New World Encyclopedia

From New World Encyclopedia
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==History of zoology==
 
==History of zoology==
  
Humans have been fascinated by the animal kingdom throughout history. In early [[Europe]], they gathered up and treasured stories of strange animals from distant lands or deep seas, such as are recorded in the ''Physiologus'', in the works of Albertus Magnus (''On Animals''), and others. These accounts were often [[apocryphal]] and creatures were often described as "legendary." This period was succeeded by the age of collectors and travelers, when many of the stories were actually demonstrated as true when the living or preserved specimens were brought to Europe.
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 +
 
 +
===Zoology in ancient times===
 +
 
 +
:From the very beginning people must have had knowledge about plants and animals that made them capable in hunting and agriculture. For example, they had to know how to avoid poisonous plants and how to treat animals. Biology hence predates the written history of humans.
 +
 
 +
Ancient [[Orient]]al people knew about the pollination of [[date palm]] from a very early point of time. In [[Mesopotamia ]] they knew that pollen could be used in fertilizing plants. A business contract of the [[Hammurabi]] period (c. 1800 B.C.E.) mentions flowers of the date palm as an article of commerce.
 +
 
 +
In [[India]] texts described some aspects of bird life. In [[Egypt]] the mathamorphosis of insects and frogs was described. Egyptians and babylonians also knew of anatomy and physiology in various forms. In [[Mesopotamia]], animals were sometimes kept in what can be described as the first zoological gardens.
 +
 
 +
However, superstitious thoughts often blended with real knowledge. In [[Babylon]] and [[Assyria]] organs of animals were used in prediction, and in Egypt medicine included a large amount of mysticism.
 +
[[Image:Aristotle.jpg|thumb|left|[[Aristotle]] (sculpture)]]
 +
In the Graeco-Roman world scholars became more interested in rationalist methods. [[Aristotle]] is one of the most prolific natural philosophers of [[Classical antiquity|Antiquity]]. He made countless observations of nature, especially the [[habit]]s and [[Abstraction|attributes]] of [[plant]]s and [[animal]]s in the world around him, which he devoted considerable attention to [[categorization|categorizing]].
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In ancient Rome, [[Pliny the Elder]] is known for his knowledge of plants and nature. Later, Claudius [[Galen]] became a pioneer in medicine and anatomy.
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 +
 
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Humans have been fascinated by the animal kingdom throughout history. Greek scientist and philosopher[[Aristotle]], during the 300's B.C.E. described many animals and their behaviors. In early [[Europe]], there were stories of strange animals from distant lands or deep seas, such as are recorded in the ''Physiologus'', in the works of Albertus Magnus (''On Animals''), and others. These accounts were often [[apocryphal]] and creatures were often described as "legendary." This period was succeeded by the age of collectors and travelers, when many of the stories were actually demonstrated as true when the living or preserved specimens were brought to Europe.
  
 
===The rise of the naturalist===
 
===The rise of the naturalist===
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Scientists who studied the structure of the human body were able to compare human anatomical structures with those of other animals.  Comparative anatomy came into existence as a branch of inquiry apart from zoology, and it was only in the latter part of the 19th century that the limitation of the word zoology to a knowledge of animals that expressly excludes the consideration of their internal structure was rejected by scientists.  
 
Scientists who studied the structure of the human body were able to compare human anatomical structures with those of other animals.  Comparative anatomy came into existence as a branch of inquiry apart from zoology, and it was only in the latter part of the 19th century that the limitation of the word zoology to a knowledge of animals that expressly excludes the consideration of their internal structure was rejected by scientists.  
  
===16th century developments===
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During the Renaissance (roughly from mid-1300's C.E. to early 1600's C.E.), naturalists described and classified many animals., and artists such as Michelangelo and leonardo da Vinci contributed accurate drawings of animals. (Renaissance) Interestingly, as many visual artists were interested in the bodies of animals and humans, they studied the physiology in detail. Such comparisons as that between a horse leg and a human leg were made. [[Otto Brunfels]], [[Hieronymus Bosch]] and [[Leonhard Fuchs]] were three men who wrote books about wild plants; they have been referred to as the German fathers of botany. Books about animals were also made, such as those by [[Conrad Gesner]], illustrated by, among others, [[Albrecht Dürer]]. Inaccurate knowledge, often a gross one, was still in effect, and in many cases old legends of the Greeks were preserved.
 +
 
  
 
Scientific zoology advanced in the 16th century with the awakening of the new spirit of observation and exploration; however, for a long time it ran a separate course uninfluenced by the progress of the [[medicine|medical]] studies of anatomy and physiology. The active search for knowledge by means of observation and experiment found its natural home in the universities. Owing to the connection of medicine with these seats of learning, it was natural that the study of the structure and functions of the human body and of the animals nearest to humans should take root there; the spirit of inquiry which now for the first time became general showed itself in the anatomical schools of the [[Italy|Italian]] universities of the 16th century, and spread fifty years later to the University of Oxford.
 
Scientific zoology advanced in the 16th century with the awakening of the new spirit of observation and exploration; however, for a long time it ran a separate course uninfluenced by the progress of the [[medicine|medical]] studies of anatomy and physiology. The active search for knowledge by means of observation and experiment found its natural home in the universities. Owing to the connection of medicine with these seats of learning, it was natural that the study of the structure and functions of the human body and of the animals nearest to humans should take root there; the spirit of inquiry which now for the first time became general showed itself in the anatomical schools of the [[Italy|Italian]] universities of the 16th century, and spread fifty years later to the University of Oxford.
 +
 +
This time (Medieval) is often called the dark age of biology. However, some people who dealt with medical issues, was showing their interest in plants and animals as well. In the Arab world, science about nature was kept. Many of the greek works was translated and the knowledge of Aristotle was used. Of the Arab biologists, al-Jahiz, who died about 868, is particularly noteworthy. He wrote ''Kitab al Hayawan'' (''Book of animals''). In the 1200's the german scholar named [[Albertus Magnus]] (He was by the way the teacher of [[Thomas Aquinas]]) wrote ''De vegetabilibus'', seven books, and ''De animalibus'', 26 books. He was particularly interested in plant propagation and reproduction and discussed in some detail the sexuality of plants and animals.
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===17th and 18th century developments===
 
===17th and 18th century developments===
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Later, the Academy of Sciences of [[Paris]] was established by [[Louis XIV of France|Louis XIV]]. The influence of these great academies of the 17th century on the progress of zoology was precisely to effect that bringing together of the museum curators and the physicians or anatomists, which was needed for further development. While collectors and systematisers gained prominence in the latter part of the 18th century, notably in [[Carolus Linnaeus|Linnaeus]], a new type of scientist appeared in such men as John Hunter and other anatomists, who, not satisfied with the superficial observations of the popular zoologists, set themselves to work to examine anatomically the whole animal kingdom, and to classify its members by aid of the results of such study.  
 
Later, the Academy of Sciences of [[Paris]] was established by [[Louis XIV of France|Louis XIV]]. The influence of these great academies of the 17th century on the progress of zoology was precisely to effect that bringing together of the museum curators and the physicians or anatomists, which was needed for further development. While collectors and systematisers gained prominence in the latter part of the 18th century, notably in [[Carolus Linnaeus|Linnaeus]], a new type of scientist appeared in such men as John Hunter and other anatomists, who, not satisfied with the superficial observations of the popular zoologists, set themselves to work to examine anatomically the whole animal kingdom, and to classify its members by aid of the results of such study.  
 +
 +
 +
[[Carolus Linnaeus]] develoed a classificaiton for animals based on shared characteristics. His new system greatly standardized the rules for grouping of animals (and plants).
 +
  
 
Under the influence of the strict inquiry process advanced by the Royal Society, accurate observations and demonstrations of a host of new wonders accumulated, among which were numerous contributions to the anatomy of animals, and none perhaps more noteworthy than the observations, made by the aid of [[microscope]]s constructed by [[Anton van Leeuwenhoek|Leeuwenhoek]], the [[Netherlands|Dutch]] naturalist (1683).
 
Under the influence of the strict inquiry process advanced by the Royal Society, accurate observations and demonstrations of a host of new wonders accumulated, among which were numerous contributions to the anatomy of animals, and none perhaps more noteworthy than the observations, made by the aid of [[microscope]]s constructed by [[Anton van Leeuwenhoek|Leeuwenhoek]], the [[Netherlands|Dutch]] naturalist (1683).
 +
 +
In the middle and late 1600's, the pioneering use of the microscope led to insights on physiology, such as observations on book by marcello Malphighi, and minute organisms, such as Robert hooke who published ''Micrographia'' in 1665, based on his observations using a compound microscope. Hooke describe the compartments of cork tissue as "cells." [[Anton van leeuwenhoek]], who makde more than 400 microscopes himself, was the first person to view single-celled microbes.
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 +
As technology moved forward, so did the science. The predecessors of the microscope were constructed in the following time. [[Antony van Leeuwenhoek]] (1632-1723) investigated blood this way. On this point of time, people also learned to know [[sperm cells]], although strange thoughts about their functions often was spread. Systematizing and classifying dominated biology throughout much of the 17th and 18th centuries, the most famous person here is [[Carl von Linné]] (1707-1778). He it was inventing the [[taxonomy]] system with [[Binomial nomenclature|scientific names]] in latin. The long-held idea that living organisms could originate from nonliving matter (spontaneous generation) began to crumble. It was finally disproved by [[Louis Pasteur]].
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===19th century developments===
 
===19th century developments===
  
 
It was not until the 19th century that the microscope, applied by Leeuwenhoek, Malpighi, [[Robert Hooke|Hooke]], and Swammerdam to the study of animal structure, was greatly improved as an instrument. The perfecting of the microscope led to a greater comprehension of the  doctrine of [[cell (biology)|cell structure]] and the establishment of the facts that(1) all organisms are either single corpuscles ("cells") of living material (microscopic "animalcules," etc.) or are built up of an immense number of such units; (2)that all organisms begin their individual existence as a single unit or corpuscle of living substance, which multiplies by binary fission, the products growing in size and multiplying similarly by binary fission; and (3) that the processes of life should be studied via an understanding of the chemical and physical changes which go on in each individual corpuscle or unit of living material or [[protoplasm]].
 
It was not until the 19th century that the microscope, applied by Leeuwenhoek, Malpighi, [[Robert Hooke|Hooke]], and Swammerdam to the study of animal structure, was greatly improved as an instrument. The perfecting of the microscope led to a greater comprehension of the  doctrine of [[cell (biology)|cell structure]] and the establishment of the facts that(1) all organisms are either single corpuscles ("cells") of living material (microscopic "animalcules," etc.) or are built up of an immense number of such units; (2)that all organisms begin their individual existence as a single unit or corpuscle of living substance, which multiplies by binary fission, the products growing in size and multiplying similarly by binary fission; and (3) that the processes of life should be studied via an understanding of the chemical and physical changes which go on in each individual corpuscle or unit of living material or [[protoplasm]].
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:
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In the [[19th century]] the area of [[genetics]] developed, when the [[Austria]]n [[monk]] [[Gregor Mendel]] formulated his [[laws of inheritance]] published in [[1866]]. However, his work was not recognized for a few decades afterward. The other important scientist that influenced this field was the British scientist [[Charles Darwin]], who was encouraged to publish his thoughts in the field by the independent work of [[Alfred Russel Wallace]].
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Darwin's famous work ''[[On the Origin of Species]]'' ([[1859]]) describes [[natural selection]], the primary mechanism for [[evolution]]. Implications of evolution on fields outside of pure science have led to both [[Social effect of evolutionary theory|opposition and support]] from different parts of society.
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[[Image:Charles Darwin.jpg|left|thumb|[[Charles Darwin]], [[1854]]]]
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By [[1953]] [[James Watson]] and [[Francis Crick]] clarified the basic structure of [[DNA]], the [[genetic material]] for expressing [[life]] in all of its forms{{fn|3}}.
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Meanwhile, other sciences were impacting zoology. The [[astronomy|astronomical]] theories of development of the [[solar system]] from a [[gas]]eous condition to its present form, put forward by [[Immanuel Kant|Kant]] and by [[Pierre-Simon Laplace|Laplace]], had impressed minds with the conception of a general movement of spontaneous progress or development in all nature. The science of [[geology]] came into existence, and the whole panorama of successive stages of the [[Earth]]s history, each with its distinct population of unknown [[animal]]s and [[plant]]s, unlike those of the present day and simpler in proportion as they recede into the past, was revealed by [[Georges Cuvier]], [[Louis Agassiz]], and others. The history of the crust of the earth was explained by [[Charles Lyell]] as due to a process of slow development, in not from any cataclysmic agencies or mysterious forces differing from those operating in the present day. Thus ,he carried on the narrative of orderly development from the point at which it was left by Kant and Laplace—explaining by reference to the ascertained laws of [[physics]] and [[chemistry]] the configuration of the Earth, its [[mountain]]s and [[sea]]s, its [[igneous rock|igneous]] and its [[stratified rock]]s, just as the [[astronomer]]s had explained by those same laws the evolution of the [[Sun]] and [[planet]]s from diffused [[gas]]eous matter of high temperature. The suggestion that living things must also be included in this great development became apparent.
 
Meanwhile, other sciences were impacting zoology. The [[astronomy|astronomical]] theories of development of the [[solar system]] from a [[gas]]eous condition to its present form, put forward by [[Immanuel Kant|Kant]] and by [[Pierre-Simon Laplace|Laplace]], had impressed minds with the conception of a general movement of spontaneous progress or development in all nature. The science of [[geology]] came into existence, and the whole panorama of successive stages of the [[Earth]]s history, each with its distinct population of unknown [[animal]]s and [[plant]]s, unlike those of the present day and simpler in proportion as they recede into the past, was revealed by [[Georges Cuvier]], [[Louis Agassiz]], and others. The history of the crust of the earth was explained by [[Charles Lyell]] as due to a process of slow development, in not from any cataclysmic agencies or mysterious forces differing from those operating in the present day. Thus ,he carried on the narrative of orderly development from the point at which it was left by Kant and Laplace—explaining by reference to the ascertained laws of [[physics]] and [[chemistry]] the configuration of the Earth, its [[mountain]]s and [[sea]]s, its [[igneous rock|igneous]] and its [[stratified rock]]s, just as the [[astronomer]]s had explained by those same laws the evolution of the [[Sun]] and [[planet]]s from diffused [[gas]]eous matter of high temperature. The suggestion that living things must also be included in this great development became apparent.
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===20th Century===
 
===20th Century===
 
[[Gregor Mendel]]'s experiments hybridizing certain cultivated varieties of plants were published in 1865, but failed to attract notice until thirty-five years later in the early 20th century, sixteen years after his death. Mendel's object was to gain a better understanding of the principles of [[heredity]]. Mendel made his chief experiments with cultivated varieties of the self-fertilizing edible [[pea]]. The merging of Darwinian theories with an understanding of heredity led to the "modern evolutionary synthesis" or [[neo-Darwinism]], which would be integral to 20th century zoology.
 
[[Gregor Mendel]]'s experiments hybridizing certain cultivated varieties of plants were published in 1865, but failed to attract notice until thirty-five years later in the early 20th century, sixteen years after his death. Mendel's object was to gain a better understanding of the principles of [[heredity]]. Mendel made his chief experiments with cultivated varieties of the self-fertilizing edible [[pea]]. The merging of Darwinian theories with an understanding of heredity led to the "modern evolutionary synthesis" or [[neo-Darwinism]], which would be integral to 20th century zoology.
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Exciting breakthroughs in genetics and molecular biology occured in the 20th century, including the recognition of DNA as the means to pass on hereditary traits, understandin of the immune system and nervous system, and the development of the field of animal ecology.
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:
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After the success of the discovery of the structure of DNA, Crick turned to the problem of [[consciousness]]; in the meantime, the studies of [[developmental biology]] came to the fore as ''[[unsolved problems in biology|unsolved problems]]''. [[Cloning|Clone]]s of both [[plant]]s and [[animal]]s were attempted, with some success, but with attendant [[ethics|ethical questions]]. In particular, [[stem cells|totipotent stem cell]]s have come to be recognized as a fundamental object of study for the understanding of developmental biology, and for medical therapies.
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The beginnings of animal ecology can be traced to R. Hesse of German and Charles Elton of England in the early 20th century (Smith 1996). In the United States, charles Adams and Victor Shelford were pioneering animal ecologists, with Adams publishing the first textbook on animal ecology, and Shelford emphasizing plant-animal interactions.  
 
The beginnings of animal ecology can be traced to R. Hesse of German and Charles Elton of England in the early 20th century (Smith 1996). In the United States, charles Adams and Victor Shelford were pioneering animal ecologists, with Adams publishing the first textbook on animal ecology, and Shelford emphasizing plant-animal interactions.  
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{{credit3|Zoology|34813866|History_of_zoology_(before_Darwin)|35113885|History_of_zoology,_post-Darwin|33838006}}
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{{credit4|Zoology|34813866|History_of_zoology_(before_Darwin)|35113885|History_of_zoology,_post-Darwin|33838006|History_of_biology|33320394}}
  
 
[[Category:Life sciences]]
 
[[Category:Life sciences]]

Revision as of 18:54, 20 January 2006

Note: This is only a very rough draft, with notes that may be useful in developing the article. Please do not edit this article until the actual article is complete — i.e., when this notice is removed. You may add comments on what you would like to see included. Rick Swarts 00:05, 28 Sep 2005 (UTC)


Zoology is the scientific study of animals. A branch of biology, zoology includes the study of structure and physiology of animals (from the molecular level to the whole organism), the development and life cycle of individual animals, classification studies, animal behavior, population and distribution studies, and the interactions between animals and their biotic (living) and abiotic (nonliving) environments.

The term zoology is most commonly pronounced with the first syllable as "zō," rhyming with "row." Another popular, but less common pronunciation is with the first syllable rhyming with "zoo," as in "two." (Zoo is short for "zoological garden".) The term comes from the Greek "ζώον" or zoon ("animal") and "λόγος" or logos ("word," or "speech," with a literal meaning of "that which refers to." )

Humans are classified as animals, as species Homo sapiens; however, humans are unique, and define themselves in not just biological or zoological terms, but also in psychological, moral, spiritual, and social terms. Thus, the study of humans goes well beyond the discipline of zoology.

Branches of zoology

As the science that studies one of the major classifications of living and once-living organisms, zoology, like botany (the study of plants), is a very diverse field. The study of animals includes numerous sub-disciplines, including the following:

  1. The structure and physiology of animals is studied under such fields as anatomy, embryology, pathology, animal nutriology, and physiology;
  2. The common genetic and developmental mechanisms of animals (and plants) is studied in molecular biology, molecular genetics, cellular biology, biochemistry, and developmental biology;
  3. The ecology and interactions of animals is covered under behavioral ecology, physiological ecology, insect ecology, biodiversity, conservation, parasitology, marine biology, and other fields, including ecology in general;
  4. The evolution and history of animals is considered in evolutionary studies and paleontology;
  5. The distribution of animals is studied in zoogeography;
  6. Animal behavior is considered in ethology, animal behavior, and reproductive biology;
  7. The classification, naming, and describing of animals is part of systematics and taxonomy.

In addition, the various taxonomically oriented-disciplines, such as mammalogy, primatology, herpetology, ornithology, icthyology, and so forth, study aspects that are specific to those groups.

Zoology is such a diverse discipline that there is not any professional society that covers all branches of zoology in a dominant manner. Rather, one finds societies according to the various taxons, such as birds, mammals, fish, snakes, wildlife, and so forth.

Zoology serves a a common and useful undergraduate major for many medical students because it provides a valuable foundation for understanding human physiology, anatomy, genetics, embryology, and pathology.

Systems of classification

Main articles: Taxonomy and Animal

As the science of describing, naming, and classifying living and extinct organisms, taxonomy is integral to the discipline of zoology. The study of animals requires that zoologists are clear on the name, description, and classification of their subjects. In order to standardize such matters, the International Code of Zoological Nomenclature (ICZN) was created. The ICZN is a set of rules in zoology to provide the maximum universality and continuity in classifying animals according to taxonomic judgment.

Animals are one of the major groups of organisms, and are classifed as the Kingdom Animalia, or Metazoa. Within this kingdom, a major division is between invertebrates and vertebrates. Invertebrates share the common lack of a trait: a vertebral column, or backbone. About 97 percent of all animal species are invertebrates. Vertebrates are animals with a backbone. With invertebrates, there are more than a dozen phyla, including Porifera (sponges), Cnidaria or Coelenterata (jellyfish, corals), Ctenophora (comb jellies), Mollusca (clams, snails, cotopuses, etc.), and Arthropoda (arthropods). Vertebrates, which are a subphylum of the phylum Chordata, include such familiar animals as fish, amphibians, reptiles, birds, and mammals. (For a more comprehensive discussion, see the article on animals.)

Morphography includes the systematic exploration and tabulation of the facts involved in the recognition of all the recent and extinct kinds of animals and their distribution in space and time. The museum-makers of olden times and their modern representatives the curators and describers of zoological collections, the early explorers and the modern naturalists and writers on zoogeography, and (3) the collectors of fossils and present-day palaeontologists are the chief varieties of zoological workers coming under this heading. Gradually, since the time of John Hunter and Georges Cuvier, anatomical study has associated itself with the more superficial morphography until today no one considers a study of animal form of much value if it does not include internal structure, histology and embryology in its scope.

General scheme of animal categorization, from the Cyclopaedia, 1728.

History of zoology

Zoology in ancient times

From the very beginning people must have had knowledge about plants and animals that made them capable in hunting and agriculture. For example, they had to know how to avoid poisonous plants and how to treat animals. Biology hence predates the written history of humans.

Ancient Oriental people knew about the pollination of date palm from a very early point of time. In Mesopotamia they knew that pollen could be used in fertilizing plants. A business contract of the Hammurabi period (c. 1800 B.C.E.) mentions flowers of the date palm as an article of commerce.

In India texts described some aspects of bird life. In Egypt the mathamorphosis of insects and frogs was described. Egyptians and babylonians also knew of anatomy and physiology in various forms. In Mesopotamia, animals were sometimes kept in what can be described as the first zoological gardens.

However, superstitious thoughts often blended with real knowledge. In Babylon and Assyria organs of animals were used in prediction, and in Egypt medicine included a large amount of mysticism.

Aristotle (sculpture)

In the Graeco-Roman world scholars became more interested in rationalist methods. Aristotle is one of the most prolific natural philosophers of Antiquity. He made countless observations of nature, especially the habits and attributes of plants and animals in the world around him, which he devoted considerable attention to categorizing.

In ancient Rome, Pliny the Elder is known for his knowledge of plants and nature. Later, Claudius Galen became a pioneer in medicine and anatomy.


Humans have been fascinated by the animal kingdom throughout history. Greek scientist and philosopherAristotle, during the 300's B.C.E. described many animals and their behaviors. In early Europe, there were stories of strange animals from distant lands or deep seas, such as are recorded in the Physiologus, in the works of Albertus Magnus (On Animals), and others. These accounts were often apocryphal and creatures were often described as "legendary." This period was succeeded by the age of collectors and travelers, when many of the stories were actually demonstrated as true when the living or preserved specimens were brought to Europe.

The rise of the naturalist

Verification by collecting of things, instead of the accumulation of anecdotes, then became more common, and scholars developed a new faculty of careful observation. The early collectors of natural curiosities were the founders of zoology, and to this day naturalists, museum curators, and systematists, play an important part in the progress of zoology. Indeed, the historical importance of this aspect of zoology was previously so great that the name zoology had until the beginning of the 20th century been associated entirely with it, to the exclusion of the study of minute anatomical structure (anatomy) and function (physiology).

Anatomy and the study of animal mechanism, animal physics, and animal chemistry were initially excluded from the usual definition of the word by the fact that zoologists had museums, unlike botanists who possessed living specimens. Early zoologists were deprived of the means of anatomical and physiological study, which was later supplied by the method of preserving animal bodies in alcohol when the demands of medicine for a knowledge of the structure of the human animal brought into existence a separate and special study of human anatomy and physiology.

Scientists who studied the structure of the human body were able to compare human anatomical structures with those of other animals. Comparative anatomy came into existence as a branch of inquiry apart from zoology, and it was only in the latter part of the 19th century that the limitation of the word zoology to a knowledge of animals that expressly excludes the consideration of their internal structure was rejected by scientists.

During the Renaissance (roughly from mid-1300's C.E. to early 1600's C.E.), naturalists described and classified many animals., and artists such as Michelangelo and leonardo da Vinci contributed accurate drawings of animals. (Renaissance) Interestingly, as many visual artists were interested in the bodies of animals and humans, they studied the physiology in detail. Such comparisons as that between a horse leg and a human leg were made. Otto Brunfels, Hieronymus Bosch and Leonhard Fuchs were three men who wrote books about wild plants; they have been referred to as the German fathers of botany. Books about animals were also made, such as those by Conrad Gesner, illustrated by, among others, Albrecht Dürer. Inaccurate knowledge, often a gross one, was still in effect, and in many cases old legends of the Greeks were preserved.


Scientific zoology advanced in the 16th century with the awakening of the new spirit of observation and exploration; however, for a long time it ran a separate course uninfluenced by the progress of the medical studies of anatomy and physiology. The active search for knowledge by means of observation and experiment found its natural home in the universities. Owing to the connection of medicine with these seats of learning, it was natural that the study of the structure and functions of the human body and of the animals nearest to humans should take root there; the spirit of inquiry which now for the first time became general showed itself in the anatomical schools of the Italian universities of the 16th century, and spread fifty years later to the University of Oxford.

This time (Medieval) is often called the dark age of biology. However, some people who dealt with medical issues, was showing their interest in plants and animals as well. In the Arab world, science about nature was kept. Many of the greek works was translated and the knowledge of Aristotle was used. Of the Arab biologists, al-Jahiz, who died about 868, is particularly noteworthy. He wrote Kitab al Hayawan (Book of animals). In the 1200's the german scholar named Albertus Magnus (He was by the way the teacher of Thomas Aquinas) wrote De vegetabilibus, seven books, and De animalibus, 26 books. He was particularly interested in plant propagation and reproduction and discussed in some detail the sexuality of plants and animals.


17th and 18th century developments

In the 17th century, adherents of the new philosophy of investigation of nature by means of observation and experiment, banded themselves into academies or societies for mutual support and dialogue. The first founded of surviving European academies, the Academia Naturae Curiosorum (1651) especially confined itself to the description and illustration of the structure of plants and animals; eleven years later (1662), the Royal Society of London was incorporated by royal charter, having existed without a name or fixed organization for seventeen years previously (from 1645).

Later, the Academy of Sciences of Paris was established by Louis XIV. The influence of these great academies of the 17th century on the progress of zoology was precisely to effect that bringing together of the museum curators and the physicians or anatomists, which was needed for further development. While collectors and systematisers gained prominence in the latter part of the 18th century, notably in Linnaeus, a new type of scientist appeared in such men as John Hunter and other anatomists, who, not satisfied with the superficial observations of the popular zoologists, set themselves to work to examine anatomically the whole animal kingdom, and to classify its members by aid of the results of such study.


Carolus Linnaeus develoed a classificaiton for animals based on shared characteristics. His new system greatly standardized the rules for grouping of animals (and plants).


Under the influence of the strict inquiry process advanced by the Royal Society, accurate observations and demonstrations of a host of new wonders accumulated, among which were numerous contributions to the anatomy of animals, and none perhaps more noteworthy than the observations, made by the aid of microscopes constructed by Leeuwenhoek, the Dutch naturalist (1683).

In the middle and late 1600's, the pioneering use of the microscope led to insights on physiology, such as observations on book by marcello Malphighi, and minute organisms, such as Robert hooke who published Micrographia in 1665, based on his observations using a compound microscope. Hooke describe the compartments of cork tissue as "cells." Anton van leeuwenhoek, who makde more than 400 microscopes himself, was the first person to view single-celled microbes.

As technology moved forward, so did the science. The predecessors of the microscope were constructed in the following time. Antony van Leeuwenhoek (1632-1723) investigated blood this way. On this point of time, people also learned to know sperm cells, although strange thoughts about their functions often was spread. Systematizing and classifying dominated biology throughout much of the 17th and 18th centuries, the most famous person here is Carl von Linné (1707-1778). He it was inventing the taxonomy system with scientific names in latin. The long-held idea that living organisms could originate from nonliving matter (spontaneous generation) began to crumble. It was finally disproved by Louis Pasteur.


19th century developments

It was not until the 19th century that the microscope, applied by Leeuwenhoek, Malpighi, Hooke, and Swammerdam to the study of animal structure, was greatly improved as an instrument. The perfecting of the microscope led to a greater comprehension of the doctrine of cell structure and the establishment of the facts that(1) all organisms are either single corpuscles ("cells") of living material (microscopic "animalcules," etc.) or are built up of an immense number of such units; (2)that all organisms begin their individual existence as a single unit or corpuscle of living substance, which multiplies by binary fission, the products growing in size and multiplying similarly by binary fission; and (3) that the processes of life should be studied via an understanding of the chemical and physical changes which go on in each individual corpuscle or unit of living material or protoplasm.

In the 19th century the area of genetics developed, when the Austrian monk Gregor Mendel formulated his laws of inheritance published in 1866. However, his work was not recognized for a few decades afterward. The other important scientist that influenced this field was the British scientist Charles Darwin, who was encouraged to publish his thoughts in the field by the independent work of Alfred Russel Wallace.

Darwin's famous work On the Origin of Species (1859) describes natural selection, the primary mechanism for evolution. Implications of evolution on fields outside of pure science have led to both opposition and support from different parts of society.

By 1953 James Watson and Francis Crick clarified the basic structure of DNA, the genetic material for expressing life in all of its forms3.


Meanwhile, other sciences were impacting zoology. The astronomical theories of development of the solar system from a gaseous condition to its present form, put forward by Kant and by Laplace, had impressed minds with the conception of a general movement of spontaneous progress or development in all nature. The science of geology came into existence, and the whole panorama of successive stages of the Earths history, each with its distinct population of unknown animals and plants, unlike those of the present day and simpler in proportion as they recede into the past, was revealed by Georges Cuvier, Louis Agassiz, and others. The history of the crust of the earth was explained by Charles Lyell as due to a process of slow development, in not from any cataclysmic agencies or mysterious forces differing from those operating in the present day. Thus ,he carried on the narrative of orderly development from the point at which it was left by Kant and Laplace—explaining by reference to the ascertained laws of physics and chemistry the configuration of the Earth, its mountains and seas, its igneous and its stratified rocks, just as the astronomers had explained by those same laws the evolution of the Sun and planets from diffused gaseous matter of high temperature. The suggestion that living things must also be included in this great development became apparent.

Zoology and Darwin

Main article: Charles Darwin

In 1859, Charles Darwin, with his publication of The Origin of Species, placed the theory of organic evolution on a new footing, by his marshalling of evidence for evolution by descent with modification, and by presentation of a process by which it could occur, the theory of natural selection. Darwin's theories revolutionized the zoological and botanical sciences.

Darwin's work intersected with the breeding of animals and plants, their congenital variations, and the transmission and perpetuation of those variations. This branch of biological science may be called thremmatology—the science of breeding. Outside the scientific world, an immense mass of observation and experiment had grown up in relation to this subject. From the earliest times the shepherd, the farmer, the horticulturist, and the fancier had for practical purposes made themselves acquainted with a number of biological laws, and successfully applied them without exciting more than an occasional notice from the academic students of biology. Darwin made use of these observations and formulated their results to a large extent as the laws of variation and heredity. As the breeder selects a congenital variation which suits his requirements, and by breeding from the animals (or plants) exhibiting that variation obtains a new breed characterized by that variation, so Darwin proposed that in nature there a selection among the congenital variations of each generation of a species.

Natural selection depends on the fact that more young are born than will survive to reproduce, yielding a struggle for existence and a survival of the fittest. In the process, selection either maintains accurately the form of the species from generation to generation or leads to its modification in correspondence with changes in the surrounding circumstances that have relation to its fitness for success in the struggle for life. According to the theory of natural selection, structures either are present because they are selected as useful or because they are inherited from ancestors to whom they were useful, though no longer useful to the existing representatives of those ancestors.

Darwin's theory gave a new basis to the study of organic structure, and directed the classifications of the systematist toward construction of the genealogical tree or pedigree of plants and animals. Darwin's theory also countered a conception of life as an entity above and beyond the common properties of matter, leading to the movement toward the view that the marvelous and exceptional qualities of living matter are nothing more nor less than an exceptionally complicated development of those chemical and physical properties that we recognize in a gradually ascending scale of evolution in the carbon compounds, containing nitrogen as well as oxygen, sulphur and hydrogen as constituent atoms of their enormous molecules.


20th Century

Gregor Mendel's experiments hybridizing certain cultivated varieties of plants were published in 1865, but failed to attract notice until thirty-five years later in the early 20th century, sixteen years after his death. Mendel's object was to gain a better understanding of the principles of heredity. Mendel made his chief experiments with cultivated varieties of the self-fertilizing edible pea. The merging of Darwinian theories with an understanding of heredity led to the "modern evolutionary synthesis" or neo-Darwinism, which would be integral to 20th century zoology.

Exciting breakthroughs in genetics and molecular biology occured in the 20th century, including the recognition of DNA as the means to pass on hereditary traits, understandin of the immune system and nervous system, and the development of the field of animal ecology.

After the success of the discovery of the structure of DNA, Crick turned to the problem of consciousness; in the meantime, the studies of developmental biology came to the fore as unsolved problems. Clones of both plants and animals were attempted, with some success, but with attendant ethical questions. In particular, totipotent stem cells have come to be recognized as a fundamental object of study for the understanding of developmental biology, and for medical therapies.


The beginnings of animal ecology can be traced to R. Hesse of German and Charles Elton of England in the early 20th century (Smith 1996). In the United States, charles Adams and Victor Shelford were pioneering animal ecologists, with Adams publishing the first textbook on animal ecology, and Shelford emphasizing plant-animal interactions.

Although the formal study of animal ecology began in the 19th century, with George J. Romanes, in the 20th century it grew prominent, developing along four major lines: behaviorism (study of behavior mechanism), ethology (study of the function and evolution of behavior), behavioral ecology (investigation of how animals interact with their biotic and abiotic environment, with emphasis on the influence of natural selection), and sociobiology (a controversisial discipline, pioneered by E. O. Wilson, that applied the principles of evolutinoary biology to animal social behavior, and ultimately to humans) (Smith 1996).

In 1947, the Society of Systematic Zoology was formed, and in 1952, the Society published its journal Systematic Zoology (Hull 1988). G.G. Simpson published Principles of Animal Taxonomy in 1961, and Ernst Mayr published Principles of Systematic Zoology in 1969.

Notable zoologists


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