1. Chapter 7 Animal Classification, Phylogeny, and Organization
Opener Chapter 7
Chapter 7
Animal Classification, Phylogeny, and Organization

2. Problem with common names
Crawdads, crayfish, or crawfish?
English sparrow, barn sparrow, or a house sparrow?
Problem with common names
Vary from region to region
Common names often does not specify particular species

3. Binomial system of Nomenclature brings order to a chaotic world of common names
Universal
Clearly indicates the level of classification
No two kinds of animals have the same binomial name
Every animal has one correct name International Code of Zoological Nomenclature

4. Homo sapien or H. sapien Genus begins with a Capital letter
Entire name italicized or underlined
Homo sapien or H. sapien

5. Kingdom of Life
1969 R. Whittaker- five kingdom classification
System of classification that distinguished b/w kingdoms according to
cellular organization
mode of nutrition

6. Monera- bacteria and cyanobacteria are prokaryotic

7. Protista- single or colonies of eukaryotic cells (Ameoba, Paramecium)

8. Plantae- eukaryotic, multicellular, and photosynthtic
Plantae- eukaryotic, multicellular, and photosynthtic. Have cell wall, and usually nonmotile

9. Fungi-eukaryotic and multicellular. Have cell wall and nonmotile
Fungi-eukaryotic and multicellular. Have cell wall and nonmotile. Mode of nutrition distiguishes fungi from plant- fungi digest extracellularly and absorb the breakdown products

10. Animalia- eukaryotic and multicellular, usually feed by ingesting other organisms, cell lack cell walls, and usually motile

11. Figure 7.2 (a)

12. Challenge of the five class system
Ribosomal RNA excellent for studying evolution
rRNA changes very slow (evolutionary conservation)
Closely related organisms have similar rRNAs
Comparison of rRNA of different organisms concludes
All life shares a common ancestor
Three major evolutionary lineage (domains) and supersedes the kingdom as the broadest taxonomic grouping

13. The three domains
Arhaea- prokaryotic microbes live in extreme environments, inhabit anaerobic environments
Reflect the conditions of early life
Archaea the most primitive life form
Archaea give rise to two other domains
Eubacteria- true bacteria and are prokaryotic microorganisms
Eukarya- include all eukaryotic organisms, diverged more recently thus more closely related to archae (protists, fungi, plants and animals)

14. Figure 7.2 (b)

15. Text devoted to animals
Except for Chapter 8 Animal like protists (Amoeba and Paramecium)
The inclusion of protozoa is part of a tradition
Once considered a phylum (Protozoa) in the animal kingdom

16. Pattern of Organization
Symmetry
Asymmetry
Radial symmetry
Bilateral symmetry

17. Figure 7.7 Asymmetry red encrusting sponge

18. Radial symmetry tube coral pulp
Figure 7.8
Radial symmetry tube coral pulp

19. Part 2

20. Bilateral animals
Bilateral symmetry = important evolutionary advancement
Important for active, directed movement
Anterior, posterior ends
One side of body kept up (dorsal) vs. down (ventral)
Cephalization and bilateral symmetry evolved together

21. Directed movement evolved with anterior sense organs cephalization
specialization of sense organs in head end of animals

22. Bilateral Symmetry Divided along sagittal plane into two mirror images
sagittal= divides bilateral organisms into right and left halves

23. Anterior= head end
Posterior= tail end
Dorsal= back side
Ventral= belly side

24. Symmetry, fig. 7.9
Median= sagittal

25. Other Patterns of Organization may reflect evolutionary trends
Unicellular (cytoplasmic)- organisms consist of single cells or cellular aggregates,
provide functions of locomotion, food acquisition, digestion, water and ion regulation, sensory perception and reproduction in a single cell.
Cellular aggregates consist of loose association, cells that exhibit little interdependence, cooperation, or coordination of function
Some cells may be specialized for reproduction, nutritive or structural function

26. Diploblastic Organization
Cells are organized into tissues in most animal phyla
Body parts are organized into layers derived from two embryonic tissue layers.
Ectoderm- Gr. ektos, outside + derm, skin gives rise to the epidermis the outer layer of the body wall
Endoderm- Gr. Endo, within, gives rise to the gastrodermis that lines the gut

27. Mesoglea- between the ecto and endo and may or may not contain cells
Derived from ecto and/or endo
Cells form middle layer (mesenchyme)
Layers are functionally inderdependent, yet cooperate showing tissue level organization i.e. feeding movements of Hydra or swimming movements of a jellyfish

28. Figure 7.10

29. The Triploblastic (treis, three +blaste, sprout)
Animals described in chapters 10-22
Tissues derived from three embryological layers
Ectoderm- outer layer
Endoderm- lines the gut
Mesoderm- meso, middle, Third layer between Ecto and Endo
Give rise to supportive cells

30. Figure 7.11

31. Most have an organ system level of organization
Usually bilaterally symmetrical or evolved from bilateral ancestors
Organized into several groups based on the presence or absence of body cavity and for those that posses one, the kind of body cavity present.
Body cavity- fluid filled space in which the internal organs can be suspended and separated from the body wall

32. Body cavities are advantageous
Provide more room for organ development
Provide more surface area for diffusion of gases, nutrients, and waste into and out of organs
Provide area for storage
Often act as hydrostatic skeletons (supportive yet flexible)
Provide a vehicle for eliminating wastes and reproductive products from the body
Facilitate increase in body size

33. What does acoelomate mean?
No coelom

34. Acoelomate a, without+ kilos, hollow
Mesoderm relatively solid mass
No cavity formed between ecto and endo
These cells within mesoderm often called parenchymal cells
Parenchymal cells not speciallized for a particular fnc.

35. What’s a coelom? coelom= true body cavity Fluid-filled
lined by mesoderm-derived epithelium
Earthworm

36. Acoelomates lack a true body cavity
Solid body
no cavity b/w the digestive tract and outer body wall

37. Do these questions now…
Think about aceolomate bilateral animals:
To what domain do they belong
“ ” kingdom ” ” ”
What phyla include these organisms
What is bilateral symmetry, and why was it an important evolutionary advantage
movie

38. Acoelomate Bilateral Animals
Consist of phyla:
Phylum Platyhelminthes
Phylum Nemertea
Others…

39. Architectural patterns of animals
Architectural patterns of animals. These basic body plans have been variously modivied during evolutoinary descent to fit aimals to a great variety of habitats. Ectoderm is shown in gray, mesoderm in red, and endoderm in yellow

40. Acoelomate Bilateral Animals
Simplest organisms to have bilateral symmetry
Triploblastic
Lack a coelom
Organ-system level of organization
Cephalization
Elongated, without appendages
Reproductive and osmoregulatory systems

41. Acoelomate Bilateral Animals
Simplest organisms to have bilateral symmetry
Triploblastic
Lack a coelom
Organ-system level of organization
Cephalization
Elongated, without appendages
Reproductive and osmoregulatory systems

42. Triploblastic Pseudocoelomate pseudes, false
Body cavity not entirely lined by mesoderm
No muscle or connective tissue associated with gut
No mesodermal

43. The Triploblastic Coelomate Pattern
Coelom is a body cavity completely surrounded by mesoderm
Peritoneum- mesodermal sheet that lines the inner body wall and serosa (outer covering of visceral organs)
Having mesodermally derived tissue (muscle, connective tissue) enhances the function of all internal body systems.

44. Figure 7.12

45. Fig 7.3 Evolutionary groups
Figure 7.3
Groups traced to separate ancestors
All descendants of a single ancestor
Includes some but not all of a members of a lineage
Fig 7.3 Evolutionary groups

46. Figure 7.4
Fig 7.4 Vertebrate Phylogenetic tree depicts the degree of divergence from a common ancestor

47. Symplesiomorphies- common characters in a group
Figure 7.5
Fig 7.5 Interpreting Cladograms
Five taxa (1-5) and characteristics (A-H)
Symplesiomorphies- common characters in a group

48. Figure 7.6

49. EOC Figure