Zoology

Zoolo

gy

The Study of Animals

“Specializations” in Zoology

• Anatomy

• Cytology

• Ecology

• Embryology

• Genetics

• Histology

• Molecular Biology

• Parasitology

• Physiology• Systematics

• Entomology

• Herpetology

• Ichthyology

• Mammalogy

• Ornithology

• Protozoology

*We will be doing more work in the computer lab to find what some of these specializations are all

about.

Classification of OrganismsCh.7-Where we will Begin

• Systematics:– The study of the kinds

and diversity of organisms and of the evolutionary relationships among them. (AKA: Taxonomy)

• Nomenclature:– The assignment of a

distinctive name to each species.

Aristotle

• 384 BC – 322 BC

• Wrote History of Animals

• Classified using hierarchy, "Ladder of Life"

• Ordered according to complexity of structure and function so that higher organisms showed greater vitality and ability to move.

Carolus Linnaeus

• 1707-1778• Carl Linnaeus, also known

as Karl von Linné or Carolus Linnaeus

• Father of Taxonomy• His system for naming,

ranking, and classifying organisms is still in wide use today (with many changes).

A Taxonomic Hierarchy

• Taxon: Any grouping of animals that shares a particular set of characteristics.

• Von Linne recognized five taxonomic categories, today we recognize Seven…

• Can you name any of the 7???

Taxonomic Categories(Broad Specific)

KingdomPhylum

ClassOrder

Family Genus Species

Can you give an example of an animal classification from broad to specific?

Common Names

NomenclatureAssignment of a distinctive name to each species.

• Binomial Nomenclature (2 names)– Von Linne simplified naming:– One Latin name to indicate the genus, and one

"shorthand" name for species

Two names make up the binomial ("two names") species name.

International Code ofZoological Nomenclature

• The binomial system of nomenclature is universal and clearly indicates the level of classification.

• No two kinds of animals have the same binomial name.

• Genus begins with a capital letter, species begins with a lowercase letter, and the entire scientific name is italicized or underlined because it is Latin or Latinized.

• Ex. Canis familiaris or Canis familiaris

What is a Kingdom?– Kingdoms are a part of

classification that distinguishes organisms according to cellular organization and mode of nutrition.

– There are currently 6 kingdoms recognized:ArchaebacteriaEubacteriaProtistaPlantaeFungiAnimalia

Kingdom Protista – eukaryotic, unicellular or colonies of cells, some photosynthetic, some non-photosynthetic•We will spend a brief time looking at Kingdom Protista-a refresher from Biology•Will include because protists are “animal like”

Kingdom Animalia – eukaryotic, multicellular, ingestion, no cell walls

•All of our time will be spent here! (Hence the course name: Zoology-study of animals )

Animal Systematics

(Goal of animal systematics: to arrange animals into groups that reflect evolutionary

relationships)• 1. Molecular approach – using DNA or RNA• 2. Evolutionary relationships – see page 100

– Monophyletic Group – one ancestral species– Polyphyletic Group – can be traced to separate

ancestors (insufficient knowledge)

• 3. Cladistics - see page 101 & 103– developing cladograms and phylogenetic trees

• The easiest patterns in organisms is in their body plan

• Symmetry describes how parts of an animal are arranged around a point or an axis

Patterns of Organization

Radial Symmetry

• Any plane passing through the oral- aboral axis divides the animal into mirror images (can be modified by arrangement of some structures in pairs, or other combinations around the central axis).

Bilateral Symmetry

• Arrangement of body parts such that a single plane passing between the upper and lower surfaces and through the longitudinal axis divides the animal into right and left mirror images

• Characteristic of active, crawling, swimming animals.

• Cephalization: head• Ex. Crayfish

Examples of Bilateral Symmetry:

Asymmetry• Arrangement without

a central axis or point.

• Ex. Amoeba

Examples of symmetry:

Terms of Direction

• See Page 105, Table 7.3

Example:I found this picture online. I did the research and added labels and label lines.

Anterior Posterior

Dorsal fin

Caudal fin

Ventral or pelvic fin

Pectoral fin

Ventral surface

Dorsal surface

Eye

Mouth

Anal fin

Gill cover

Please label with the following terms of directions

• Anterior• Posterior• Ventral• Dorsal• Lateral line• Oral• Caudal• Cranial/Cephalic

Anterior Posterior

Dorsal

Ventral

Lateral Line

Oral

CaudalCranial/Cephalic

Who Can Label this Guy?

Besides Symmetry, there are other levels of Organization in animals:

• Unicellular (Cytoplasmic) Level

• Diploblastic Organization

• Triploblastic Organization

Unicellular (cytoplasmic)

• A body where all the living functions are carried out within the confines of a single cell! (Not simple…think about it…..)

• These functions must include: locomotion, food acquisition, digestion, water and ion regulation, sensory perception, and reproduction.

• Examples: Protists

Diploblastic (two)

• Cells are arranged into tissues (simple tissues)

• Tissue-level organization– 1. Ectoderm: outer body layer (epidermis)– 2. Mesoglea: middle layer (may or may not

contain cells)– 3. Endoderm: inner body layer, the gut

(gastrodermis)

Diploblastic

Triploblastic (three)

• Animals with tissues derived from three embryological layers.

• Most have organ-system level of organization:– 1. Ectoderm: outer body layer (epidermis)– 2. Mesoderm: middle body layer

(supportive, contractile, and blood cells)– 3. Endoderm: inner body layer, the gut

(gastrodermis)

Triploblastic Body Plans

Acoelomate

Pseudocoelomate Coelomate

Advantages of Body Cavities:1. Provide more room for organ development

2. Provide more surface area for diffusion of gases, nutrients, and wastes into and out of organs

3. Provide an area for storage4. Often act as hydrostatic skeletons5. Provide a vehicle for eliminating

wastes/reproductive products from the body6. Facilitate increased body size

Acoelomate

• The mesoderm forms a solid mass of cells between the endoderm an ectoderm.

Pseudocoelomate

• Has a false body cavity not entirely lined by a mesoderm

Coelomate

• A true body cavity or coelom that is lined by mesoderm.

• A thin peritoneum lines the inner body wall and is continuous with the serosa (lining of internal organs).

Further Classification…..

• In this book, the bilaterally symmetrical animals are divided into two large groups:1. Protostomia

2. Deuterostomia

Based on the observation that embryological events may be similar because of shared ancestry

Developmental Embryology

• A. Protostomes: – Early cleavage of zygote– Fate of cells is determined early in embryonic

development– Many protosomes have top-shaped larva

(trochophore larva)

Trochophore larva - top-shaped larva

Animal Phyla that are Protostomes

• Phyla:– Platyhelminthes - flatworms– Nematoda - roundworms– Mollusca – head-foot plan (like snail, clam,

oyster, octopus, squid, nautilus)– Annelida – True coelom worms– Arthropoda – Jointed exoskeleton (insect,

spider, crab, shrimp, centipede)

Developmental Embryology

• Deuterostomes:– Radial cleavage results in cells directly over one

another– Fate of cells is determined later on in

development– Gut tract and coelom formation differs– Some produce a kidney-bean shaped larval

stage (dipleurula)– But, there is no single kind of larval stage! (as

there was with protosomes-trochophore)

Dipleurula - kidney-bean shaped larval

Animal Phyla that are Deuterostomes

• Phyla:– Echinodermata – sea stars, urchins, sea

cucumbers– Chordata – sea squirts, amphioxus,

hagfishes, lampreys, sharks, fishes, amphibians, reptiles, birds, mammals

If you discovered a new species….how would you classify it?

• A Dichotomous Key is a tool that allows the user to determine the identity of items in the natural world, such as trees, wildflowers, mammals, reptiles, rocks, and fish. Keys consist of a series of choices that lead the user to the correct name of a given item. "Dichotomous" means "divided into two parts". Therefore, dichotomous keys always give two choices in each step.

How can we tell these aliens apart?

We can classify the aliens by their characteristics.

Your Challenge

Your group will be given 16 aliens to classify.

Choose one general characteristic to categorize your aliens into two large groups. Ex: has ‘abc’ and does not have ‘abc’.

Groups do not have to have the same number of aliens in each.

Record your info on the chart provided.

Decide as a Group

• After you have completed your two groups, split each group into two new groups.

• Choose one characteristic to separate the first group.

• Choose one characteristic to separate the second group.

• You should have 4 groups when completed.

• Continue splitting each group until you can no longer split them into new categories anymore.

Oh NO! I forgot about these aliens! Where do they go?

Can you tell me where you would put them in your classification scheme? Start from the beginning of your

chart.