This is an introductory presentation about zoology. It gives you insight into what's in this field and how to tackle it.
The lecture can be accessed
https://youtu.be/qhXqXaTlMPk
2. Life
Figure 1.1
A few of the many dimensions of
zoological research.
A, Observing moray eels in Maui,
Hawaii. B, Working
with tranquilized polar bears. C,
Banding mallard ducks.
D, Observing Daphnia pulex (150)
microscopically.
E, Separating growth stages of
crab larvae at a
marine laboratory.
3. What is life?
• Mythologies of nearly every human culture attempt to solve the
mysteries of animal life and its origin.
• The most outstanding general features in life’s history include
chemical uniqueness; complexity and hierarchical organization;
reproduction (heredity and variation); possession of a genetic
program; metabolism; development; environmental interaction;
and movement.
4. 1. Chemical uniqueness.
• Living systems demonstrate a unique and complex molecular
organization.
• Living systems assemble large molecules, known as macromolecules,
that are far more complex than the small molecules of nonliving matter.
• These macromolecules are composed of the same kinds of atoms and
chemical bonds that occur in nonliving matter and they obey all
fundamental laws of chemistry;
• it is only the complex organizational structure of these macromolecules
that makes them unique.
• We recognize four major categories of biological macromolecules:
nucleic acids, proteins, carbohydrates, and lipids .
• These categories differ in the structures of their component parts, the
kinds of chemical bonds that link their subunits together, and their
functions in living systems.
6. 2. Complexity and hierarchical organization.
• Living systems demonstrate a unique and complex hierarchical
organization.
• Nonliving matter is organized at least into atoms and molecules
and often has a higher degree of organization as well. However,
atoms and molecules are combined into patterns in the living
world that do not exist in the nonliving world. In living systems, we
fi nd a hierarchy of levels that includes, in ascending order of
complexity, macromolecules, cells, organisms, populations, and
species
8. 3. Reproduction.
• Living systems can reproduce themselves.
• Life does not arise spontaneously but comes only from prior life,
through reproduction.
• Although life certainly originated from nonliving matter at least
once this origin featured enormously long periods of time and
conditions very different from the current biosphere.
• At each level of the biological hierarchy, living forms reproduce to
generate others like themselves
• Genes are replicated to produce new genes. Cells divide to
produce
• new cells. Organisms reproduce, sexually or asexually, to produce
new organisms
10. 4. Possession of a genetic program.
• A genetic program provides fidelity of inheritance . Structures of the
protein molecules needed for organismal development and functioning
are encoded in nucleic acids (see Chapter 5).
• For animals and most other organisms, genetic information is contained
in DNA. DNA is a very long, linear chain of subunits called nucleotides,
each of which contains a sugar phosphate (deoxyribose phosphate) and
one of four nitrogenous bases (adenine, cytosine, guanine, or thymine,
abbreviated A, C, G, and T, respectively).
• The sequence of nucleotide bases contains a code for the order of
amino acids in the protein specifi ed by the DNA molecule.
• The correspondence between the sequence of bases in DNA and the
sequence of amino acids in a protein is called the genetic code.
12. 5. Metabolism.
• Living organisms maintain themselves by acq
• uiring nutrients from their environments ( Figure 1.7 ). The
• nutrients are used to obtain chemical energy and molecular
• components for building and maintaining the living system
• (see Chapter 4). We call these essential chemical processes
• metabolism. They include digestion, acquisition of energy
• (respiration), and synthesis of molecules and structures.
• Metabolism is often viewed as an interaction of destructive
• (catabolic) and constructive (anabolic) reactions.
14. 6. Development.
• All organisms pass through a characteristic life cycle.
Development describes the characteristic changes that an
organism undergoes from its origin (usually the fertilizationof an
egg by sperm) to its fi nal adult form
• Development usually features changes in size and shape, and
differentiation of structures within an organism.
• Even the simplest one-celled organisms grow in size and replicate
their component parts until they divide into two or more cells.
Multicellular organisms undergo more dramatic changes during
their lives. Different developmental
16. 7. Environmental interaction.
• All animals interact with their environments. The study of
organismal interaction with an environment is called ecology. Of
special interest are the factors that infl uence geographic
distribution and
• abundance of animals (see Chapters 37 and 38). The science
• of ecology reveals how an organism perceives environmental
• stimuli and responds in appropriate ways by
• adjusting its metabolism and physiology ( Figure 1.9 ). All
• organisms respond to environmental stimuli, a property
• called irritability.
18. 8. Movement.
• Living systems and their parts show precise and controlled movements
arising from within the system. The
• energy that living systems extract from their environments permits them
to initiate controlled movements. Such movements at the cellular level
are essential for reproduction, growth, and many responses to stimuli in
all living forms and for development in multicellular ones.
• Autonomousmovement reaches great diversity in animals, and much of
this book comprises descriptions of animal movement and the many
adaptations that animals have evolved for locomotion.
• On a larger scale, entire populations or species may disperse from one
geographic location to another one over time through their powers of
movement.
19. the origin of life.
• According to the big-bang model, the universe originated from a
primeval fireball and has been expanding andcooling since its inception
10 to 20 billion years ago.
• The sun and planets formed approximately 4.6 billion years ago
• from a spherical cloud of cosmic dust and gases. The cloud collapsed
• under the infl uence of its own gravity into a rotating disc.
• As material in the central part of the disc condensed to form the
• sun, gravitational energy was released as radiation. The pressure
• of this outwardly directed radiation prevented a collapse of the
• nebula into the sun. The material left behind cooled and eventually
• produced the planets, including earth
21. Spontaneous Generation of Life?
• From ancient times, people commonly thought that life arose
repeatedly by spontaneous generation from nonliving material in
addition to parental reproduction.
• For example, frogs appeared to arise from damp earth, mice from
putrefi ed matter, insects from dew, and maggots from decaying
meat. Warmth, moisture, sunlight, and even starlight often were
mentioned as factors that encouraged spontaneous generation of
living organisms.
22. • Among the efforts to synthesize organisms in the laboratory is a
recipe for making mice, given by the Belgian plant nutritionist
Jean Baptiste van Helmont (1648). “If you press a piece of
underwear soiled with sweat together with some wheat in an open
jar, after about 21 days the odor changes and the ferment . . .
Changes the wheat into mice.
• But what is more remarkable is that the mice which came out of
the wheat and underwear were not small mice, not even miniature
adults or aborted mice, but adult mice emerge!”
23. Biogenesis
• In 1861, the great French scientist Louis Pasteur convinced
scientists that living organisms cannot arise spontaneously from
nonliving matter.
• In his famous experiments, Pasteur introduced fermentable
material into a fl ask with a long S-shaped neck that was open to
air.
• The flask and its contents were then boiled for a long time to kill
any microorganisms that might be present.
• Afterward the fl ask was cooled and left undisturbed. No
fermentation occurred because all organisms that entered the
open end were deposited in the neck and did not reach the
fermentable material.
24. • When the neck of the fl ask was removed, microorganisms in the air
promptly entered the fermentable material and proliferated. Pasteur
concluded that life could not originate in the absence of previously
existing organisms and their reproductive elements, such as eggs and
spores.
• Announcing his results to the French Academy, Pasteur proclaimed,
“Never will the doctrine of spontaneous generation arise from this mortal
blow.”
• All living organisms share a common ancestor, most likely apopulation of
colonial microorganisms that lived almost 4 billion years ago. This
common ancestor was itself the product of a long period of prebiotic
assembly of nonliving matter, including organic molecules and water, to
form self-replicating units.
• All living organisms retain a fundamental chemical composition inherited
from their ancient common ancestor.
25. • In the 1920s, Russian biochemist Alexander I. Oparin and British
biologist J. B. S. Haldane independently proposed that life
originated on earth after an inconceivably long period of
“abiogenic molecular evolution.”
• Rather than arguing that the first living organisms miraculously
originated all at once, anotion that formerly discouraged scientifi
c inquiry, Oparin and Haldane argued that the simplest form of life
arose gradually by the progressive assembly of small molecules
into more complex organic molecules.
• Molecules capable of self-replication eventually would be
produced, ultimately leading to assembly of living
microorganisms.
26. ZOOLOGY AS A PART OF BIOLOGY
• Animals form a distinct branch on the evolutionary tree of life. It is a
large and old branch that originated in the Precambrian seas over 600
million years ago.
• Animals form part of an even larger limb known as eukaryotes,
organisms whose cells contain membrane- enclosed nuclei. This
larger limb includes plants, fungi and numerous unicellular forms.
Perhaps the most distinctive characteristic of the animals as a group
is their means of nutrition, which consists of eating other organisms.
• Evolution has elaborated this basic way of life through diverse
systems for capturing and processing a wide array of food items and
for locomotion.
27. Zoology
Zoology (Gr. zoon, animal, logos, to study) the scientific study of animal
life, builds on centuries of human observations of the animal world.
It is one of the broadest fields in all of science.
It is estimated that 4 to 10 million species of animals living today.
(Over 1 million animal species have been described.)
Many more, about 90%, existed in the past and have become extinct
28. Zoology
for example, more than 28,000 described species of bony fishes and more
than 400,000 described (and many more undescribed) species of beetles.
Zoologists usually specialize in one or more of the subdisciplines of
zoology.
They may study particular functional, structural, or ecological aspects of
one or more animal groups, or they may choose to specialize in a
particular group of animals
31. Ichthyology
Ichthyology, is the study of fishes, and ichthyologists
work to understand the structure, function, ecology, and
evolution of fishes.
These studies have uncovered an amazing diversity of
fishes.
One large family of bony fish, Cichlidae, contains 2,000
to 3,000 species.
Tilapia species that grace our dinner plates and a host
fish that hobbyists maintain in freshwater aquaria.
(a) This dogtooth cichlid,(Cynotilapia afra) is
native to Lake Malawi in Africa. The female
of the species broods developing eggs in
her mouth to protect themfrom predators.
(b) The fontosa
Image courtesy@Zoology by Miller and Harley
32. Ichthyology
Ichthyologists have described a wide variety of feeding
habits in cichlids.
These fish include algae scrapers like Eretmodus that
nip algae with chisel-like teeth; insect pickers like
Tanganicodus; and scale eaters like Perissodus.
All cichlids have two pairs of jaws.
The mouth jaws are used for scraping or nipping food,
and the throat jaws are used for crushing or macerating
food before it is swallowed.
(a) This dogtooth cichlid,(Cynotilapia afra) is
native to Lake Malawi in Africa. The female
of the species broods developing eggs in
her mouth to protect themfrom predators.
(b) The fontosa
Image courtesy@Zoology by Miller and Harley
33. Cichlids
Many cichlids mouth brood their young.
A female takes eggs into her mouth after the eggs are
spawned.
She then inhales sperm released by the male, and
fertilization and development take place within the
female’s mouth!
Even after the eggs hatch, young are taken back into the
mouth of the female if danger threatens.
Hundreds of variations in color pattern, body form, and
behavior in this family of fishes illustrate the remarkable
diversity present in one relatively small branch of the
animal kingdom.
Zoologists are working around the world to understand
and preserve this enormous diversity.
(a) This dogtooth cichlid,(Cynotilapia afra) (b) The
fontosa (c) A Scale-Eating Cichlid. Scale-eaters
(Perissodus microlepis)
Image courtesy@Zoology by Miller and Harley
35. Animal Classification
and Evolutionary Relationships
• Like all organisms, animals are named and classified into a hierarchy of
relatedness. Although Carl von Linne (1707–1778) is primarily
remembered for collecting and classifying plants, his system of naming—
binomial nomenclature—has also been adopted for animals.
• A two-part name describes each kind of organism. The first part is the
genus name, and the second part is the species epithet. Each kind of
organism (a species)—for example, the cichlid scale-eater Perissodus
microlepis—is recognized throughout the world by its twopart species
name
36. • . Verbal or written reference to a species refers to an organism
identified by this two-part name.
• The species epithet is generally not used without the
accompanying genus name or its abbreviation (see chapter 7).
• Above the genus level, organisms are grouped into families,
orders, classes, phyla, kingdoms, and domains, based on a
hierarchy of relatedness (figure 1.4).
• Organisms in the same species are more closely related than
organisms in the same genus, and organisms in the same genus
are more closely related than organisms in the same family, and
so on.
37. • When zoologists classify animals into taxonomic groupings they
are making hypotheses about the extent to which groups of
animals share DNA, even when they study variations in traits like
jaw structure, color patterns, and behavior, because these kinds
of traits ultimately are based on the genetic material.
• Evolutionary theory has affected zoology like no other single
theory. It has impressed scientists with the fundamental unity of
all of life.
• As the cichlids of Africa illustrate, evolutionary concepts hold the
key to understanding why animals look and act in their unique
ways,
• live in their particular geographical regions and habitats, and
share characteristics with other related animals.
39. 1.2 ZOOLOGY: AN ECOLOGICAL
PERSPECTIVE
• Just as important to zoology as an evolutionary perspective is an
ecological perspective. Ecology (Gr. okios, house + logos, to study) is
the study of the relationships between organisms and their environment
(see chapter 6).
• Throughout our history, humans have depended on animals, and that
dependence too often has led to exploitation.
• We depend on animals for food, medicines, and clothing. We also
depend on animals in other, more subtle ways. This dependence may
not be noticed until human activities upset the delicate ecological
balances that have evolved overhundreds of thousands of years.
40. • In the 1950s, the giant Nile perch (Lates niloticus) was introduced
into Lake Victoria in an attempt to increase the lake’s fishery
(figure 1.5).
• This voracious predator reduced the cichlid population from 80%
to less than 1% of the total fish biomass (total mass of all fish in
the lake). Predation by the Nile perch has also resulted in the
extinction of 65% of the cichlid species.
• Because many of the cichlids fed on algae, the algae in the lake
grew uncontrolled. When algae died and decayed, much of the
lake became depleted of its oxygen.
• The introduction of nonnative water hyacinth, which has
overgrown portions of the lake, has resulted in further habitat
loss.
41. • To make matters worse, when Nile perch are caught, their excessively
oily flesh must be dried.
• Fishermen cut local forests for the wood needed to smoke the fish.
• This practice has resulted in severe deforestationaround Lake Victoria.
The resulting runoff of soil into the lake has caused further
degradation.
• Decreased water quality not only presented problems for the survival of
individual cichlids, but also increased turbidity that interfered with
critical behavioral functions.
• Many of these species rely on their bright colors as visual cues during
mating. Mouth-brooding species rely on vision to pick up developing
eggs. The loss of Lake Victorian cichlids may be the largest extinction
event of vertebrate species in modern human history.
42. • There are some hopeful signs in this story. Although many Lake
Victorian species have been lost forever, some cichlids are recovering.
Heavy fishing pressure on the Nileperch has reduced its population
density. (It still comprises more than 50% of catch weight—down from
about 90% in the1980s.)
• This decline has promoted the recovery of some cichlids that feed on
small animals in the upper portions of open-water areas. (The Nile
perch is predominately a bottom-dwelling predator.)
• One cichlid (Haplochromis pyrrhocephalus) is faring better than most
other cichlid species. Over a 20-year period, scientists have observed
rapid evolution of increasedgill surface area and associated changes in
head morphology,which have allowed this species to survive the
loweredoxygen concentrations now present in Lake Victoria.
43. • The Lake Victoria example also illustrates how ecological decisions
made for economic reasons can have far-ranging economic and
ecological consequences. Nile perch are marketed to Nairobi, the
Middle East, and Europe to restaurants and fish markets.
• The hide is used in belts and purses, and the urinary bladder is used in
oriental soup stock and as filter material by European alcohol
producers. Catching, processing, and marketing such large fish to
diverse foreign markets have resulted in the fishing and processing
industries being taken from the hands of local fishermen and
processors.
• These functions are primarily the work of large-boat fishing fleets and
large fish processing corporations. Changes in the local economy to
agriculture have resulted in deforestation of the surrounding
landscapes, and untreated sewage and agricultural and industrial runoff
have further polluted Lake Victoria.
45. World Resources
and Endangered Animals
• There is grave concern for the ecology of the entire world, not just
Africa’s greatest lakes.
• The problems, however, are most acute in developing countries,
which are striving to attain the same wealth as industrialized
nations. Two problems, global overpopulation and the exploitation
of world resources, are the focus of our ecological concerns.
46. Population
• Global overpopulation is at the root of virtually all other environmental
problems. Human population growth is expected to continue in the
twenty-first century.
• Virtuallyall of this growth is in less developed countries, where 5.4 billion
out of a total of 7.3 billion humans now live. Sincea high proportion of
the population is of childbearing age,the growth rate will increase in the
twenty-first century.
• Bythe year 2050, the total population of India (1.65 billion) isexpected
to surpass that of China (1.31 billion) and thetotal world population will
reach 9.6 billion. The 2010 U.S. population was 160 million.
• In 2050, it is projected to increase to 401 million. Even though Africa
does not have the highesthuman population, its population is increasing
more rapidlythan other major regions of the world (table 1.3). As the
humanpopulation grows, the disparity between the wealthiest
andpoorest nations is likely to increase.
48. World Resources
• Human overpopulation is stressing world resources. Although new
technologies continue to increase food production, most food is produced in
industrialized countries that already have a high per-capita food consumption.
• Maximumoil production is expected to continue in this millennium.Continued
use of fossil fuels adds more carbondioxide to the atmosphere, contributing to
the greenhouseeffect and climate change.
• Deforestation of large areas of the world results from continued demand for
forest products,fuel, and agricultural land.
• This trend contributes to climate change by increasing atmospheric carbon
dioxide from burning forests and impairing the ability of the eart to return
carbon to organic matter through photosynthesis.
• Deforestation also causes severe regional water shortages and results in the
extinction of many plant and animal species, especially in tropical forests.
49. • Forest preservation would result in the identification of new
species of plants and animals that could be important human
resources: new foods, drugs, building materials, and predators of
pests (figure 1.6).
• Nature also has intrinsic value that is just as important as its
provision of resources for humans.
• Recognition of this intrinsic worth provides important aesthetic
and moral impetus for preservation.
51. Solutions
• An understanding of basic ecological principles can help prevent
ecological disasters like those we have described.
• Understanding how matter is cycled and recycled in nature, how
populations grow, and how organisms in our lakes and
52. WILDLIFE ALERT
An Overview of the Problems
• Extinction has been the fate of most plant and animal species. It is a natural
process that will continue. In recent years, however, the threat to the welfare of
wild plants and animals has increased dramatically—mostly as a result of habitat
destruction. Tropical rain forests are one of the most threatened areas on the
earth.
• It is estimated that rain forests once occupied 14% of the earth’s land surface.
Today this has been reduced to approximately 6%.
• Each year we lose about 150,000 km2 of rain forest. This is an area of the size of
England and Wales combined.
• This decrease in habitat has resulted in tens of thousands of extinctions.
Accurately estimating the number of extinctions is impossible in areas like rain
forests, where taxonomists have not even described most species. We are losing
species that we do not know exist, and we are losing resources that could lead to
new medicines, foods, and textiles.
• Other causes of extinction include climate change, pollution, and invasions from
foreign species. Habitats other than rainforests—grasslands, marshes, deserts, and
coral reefs—are also being seriously threatened.
53. • No one knows how many species living today are close to
extinction.
• As of 2014, the U.S. Fish and Wildlife Service lists 1,531 species in
the United States as endangered or threatened.
• The IUCN has assessed 71,000 species worldwide and of these
more than 20,000 species are listed as endangered or threatened.
• Recall that it is estimated that there are between 4 and 100
million species of animals living today.)
54. • An endangered species is in imminent danger of extinction
throughout its range (where it lives).
• A threatened species is likely to become endangered in the near
future.
• Clearly, much work is needed to improve these alarming statistics.
• In the chapters that follow, you will learn that saving species
requires more than preserving a few remnant individuals.
• It requires a large diversity of genes within species groups to
promote species survival in changing environments.
55. • This genetic diversity requires large populations of plants and
animals.
• Preservation of endangered species depends on a multifaceted
conservation plan that includes the following components:
• 1. A global system of national parks to protect large tracts of land
and wildlife corridors that allow movement between natural areas
• 2. Protected landscapes and multiple-use areas that allow
controlled private activity and also retain value as a wildlife
habitat
• 3. Zoos and botanical gardens to save species whose extinction is
imminent
56. • forests use energy is fundamental to preserving the environment.
• There are no easy solutions to our ecological problems.
• Unless we deal with the problem of human overpopulation,
• however, solving the other problems will be impossible.
• We must work as a world community to prevent the spread of
disease, famine, and other forms of suffering that
accompanyoverpopulation.
• Bold and imaginative steps toward improved social and
economic conditions and better resource management are
needed.
57. Government college University Hyderabad
Department of Zoology
Animal Diversity: Muhammad Moosa Abro
Small discussion group class
Week 1
Chapter 1
Zoology:An Evolutionary and Ecological Perspective
Book. Miller, A.S. and Harley, J.B. ; 10th Edition (International), Singapore : McGraw Hill.
Lecturer ppt 1
Question to be answered
1. Why is life difficult to define?
2. What are the basic chemical differences that distinguish living from nonliving systems?
3. Describe the hierarchical organization of life. How does this organization lead to the emergence of new properties at different levels of biological complexity?
4. What is the relationship between heredity and variation in reproducing biological systems?
5. How is zoology related to biology? What major biological concepts, in addition to evolution and ecology, are unifying principles shared between the two disciplines?
6. What are some current issues that involve both zoology and questions of ethics or public policy? What should be the role of zoologists in helping resolve these issues?
7. Many of the ecological problems facing our world concern events and practices that occur in less developed countries.
8. Many of these practices are the result of centuries of cultural evolution.
9. What approach should people and institutions of developed countries take in helping encourage ecologically minded resource use?
10. Why should people in all parts of the world be concerned with the extinction of cichlids in Lake Victoria?