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ANIMAL CLASSIFICATION, PYLOGENY & ORGANIZATION

Roselyn Aperocho – NaranjoUSPF, College of Pharmacywww.roselynnaranjo.vze.com

http://www.roselynnaranjo.vze.com/

Animal Classification, Phylogeny and Organization

IntroductionA. Biologists have named and described more than 1.4 million species

B. More than .75 of these are animals C. Many zoologists group organisms by shared characteristics 1.these shared characteristics

are a consequence of shared evolutionary

processes 2. these groupings reflect order found in living systems 3. there are still 4 - 30 million undescribed species, lots of work left


IntroductionA. Biologists have named and described more than 1.4 million species

B. More than .75 of these are animals C. Many zoologists group organisms by shared characteristics

4. There are 36 different animal phyla, the highest taxon under the kingdom level 5. the most recently discovered

animal phylum was designated in 1995 by Kirstensenand Funch in Denmark - Cycliophora


Introduction

Cycliophora


Classification of Organisms 1. Language helps us to communicate, but

also to encode and classify concepts, objects and organisms

2. To name organisms just by species names does not help us much

3. A classification system reflects the order and relationships that arise from evolutionary processes

4. The study of the diversity among organisms, the evolutionary relationships among them is called systematics; taxonomy is the naming and classifying of organisms


Classification of Organisms 5. These studies result in description of new species and org of animals into groups (taxa) based on evolutionary relatedness

6. Nomenclature is the assigning of a distinctive name to each species


Taxonomic hierarchy

1.Karl von Linne - Carolus Linnaeus - 1707-1778 instituted binomial system we use today

2. grouped different species into broader categories based on shared characteristics

3. A grouping of animals that shares characteristics is called a taxon - kpcofgs.


Taxonomic hierarchy

a. housefly shares 1 pr wings w/ all true flies – same genus

taxon - kpcofgs

b. share other characteristics with bees, butterflies, beetles - all are insects

c. above spp. level, definitions of what forms taxon are not precise - lots of arguments

d. ideally, members of same taxon are more closely related genetically than w/others not in taxon


Nomenclature

1. binomial nomenclature adds precision to names of organisms

2. common names vary from city to city, country to country

3. common names often designate genera, not species

4. no other animal or organism has the same binomial nomenclature

5. genus is capitalized, species is lowercase; both are italicized or underlined, separately


D. Molecular approaches to systematics1. molecular bio has provided important info for taxonomy of plants and animals

2. relatedness of particular organisms is reflected in shared DNA sequences, as well as in protein products

3. genes and proteins from related animals are more similar than genes and proteins from distantly related animals

4. since mutation rate is constant, a relationship to frequency of cell division, taxonomists can

ascertain the length of time since divergence from a common ancestor


D. Molecular approaches to systematics

5. using mitochondria in eukaryotes involves relatively small quantities of DNA that change at a relatively constant rate

6. this is called a molecular clock

7. molecular clocks run at difft rates depending on if you are looking at DNA, RNA, protein, etc


E. Kingdoms of Life 1.1. WhittakerWhittaker - 1969 - described 5 kingdoms based on

cellular organization and mode of nutrition


E. Kingdoms of Life MONERA

Cell: •not enclosed in a distinct nuclear membrane

•Very small in size (about 1 micrometer)

•may be arranged in rows or in clusters )

•can survive unfavorable conditions such as extreme dryness or heat by producing an extra spore coat.

•can be round, rodshaped, or spiral-shaped •can be round, rodshaped, or spiral-shaped

Reproduction: reproduce through binary fission(asexual) or conjugation (sexual)



Respiration: •obligate aerobes, the prokaryotes must have oxygen to live

•obligate anaerobes, the organisms cannot survive in the presence of oxygen

• facultative anaerobes they can survive with or without oxygen.

extracellular (outside the cell) and nutrients are absorbed into the cell

Digestion:



Circulation: • accomplished through diffusion

•Autotrophs manufacture their own organic compounds

• Heterotrophs obtain their energy by feeding on other organic substances

Nutritional Diversity:

• Saprophytes, a special kind of heterotroph, obtain energy by feeding on decaying matter


E. Kingdoms of Life FUNGI

• are unicellular or filamentous.• their body is prepared by the mycelium that comprise the thread like hyphae. • Mycelium appears like the web of spider.• Walls of most of the hyphae are made up of chitin and cellulose.• Number of nuclei in the cells may be one, two or more.• they do not have chlorophyll and starch in their cells. • Glycogen is the reserve food.


E. Kingdoms of Life FUNGI


E. Kingdoms of Life PROTISTA

• Protista have simple unicellular, colonial and eukaryotic organization.• There are true nucleus and membrane bound other

cell organelles, cytoplasmic streaming and sap vacuoles.

• Locomotion is generally present.• It occurs with the help of flagella and pseudopodia.•

euglena



• Some protista are covered with cell wall while others do not posses it.

• It is diverse photosynthetic holozoic.• Photosynthetic nutrition occurs in unicellular algae euglena like organisms.• Organisms with mixotrophic nutrition are called as plant-animals.• Sexual reproduction is present but an embryo

stage is absent.


E. Kingdoms of Life PLANTAE

• Plants are living organisms which cannot move and prepares their food themselves by the process of photosynthesis

• Plant kingdom includes trees, shrebs, herbs, grasses, ferns, bushes etc.,. Some of the nourishment that is needed to our body is provided by plants.

• Plant Kngdom was originally proposed by Linnaeus



BryophytesPteridophytesGymnospermsAngiosperms

Monocotyledons Dicotyledons



Bryophytes

These are the simple land plants without leaves and roots. They have hair like structures called Rhizoids to hold the surface. They need water for fertilization. Embryo forms after fertilization. Eg. Moses. We can find Bryophytes growing on rocks, soil and on trees.



Pteridophytes

In these plant body contains stem, roots and leaves. Vascular system is present. Fertilized egg becomes embryo.



Gymnosperms

Stem is erect and have branches. Reproduction is sexual. Leaves are photosynthetic. Gametophytes are very reduced in their size. These are the first seeded plants. The literal meaning of Gymnosperms is Naked Seed.



Gymnosperms



Angiosperms

Monocotyledons Have only one cotyledon in the seed. Eg., wheat, maize and paddy.

Dicotyledons Have two cotyledons in the seed. Eg., Ground nut, Bean Pea.


E. Kingdoms of Life ANIMALIA

Characteristics:

1. Animals are heterotrophic, meaning they depend on other organisms for food. Unlike plants and other photosynthetic organisms, animals do not contain chlorophyll that is essential in food production.

2. All animals are multicellular. Their cells are highly specialized to perform specific functions, such as digestion, movement, reproduction, and excretion.


E. Kingdoms of Life ANIMALIA

Characteristics:

3. Animal cells are eukaryotic, meaning they have a well-defined nucleus. They also have membrane-bound organelles.

4. Many animals are motile. They move from place to place in search of food, mate, a better place to live, and to avoid danger.

5. Most animals exhibit sexual reproduction. Each individual grows from a fertilized egg and passes through various distinct stages of embryonic development.


E. Kingdoms of Life 2.2. Ribosomal RNARibosomal RNA is pretty constant, doesn’t

change much- exhibits evolutionary conservation can’t mess too much w/ protein making mechanism

3. biologists compare ribosomal RNA of different RNA of different organismsorganisms to find how sequences are different.

4. look at all possible arrangement arrangement and figure out which arrangement best explains data

5. Studies of ribosomal RNA indicates that there are 3 main evolutionary lineages3 main evolutionary lineages - domains


E. Kingdoms of Life

6. domains (Bacteria, Archaea, EukaryaBacteria, Archaea, Eukarya) are broadest taxonomic grouping

a. archaea - all anaerobic, from hostile environmentsb. Archaeans gave rise to bacteria - true bacteria = eubacteria, prokaryoticc. eubacteria diverged first from archaea, then eukarya diverged. So all eukaryotes are more closely related to archaea than eubacteria


F. Animal SYstematics

1. goal is to arrange animals into groups that reflect evolutionary relationships

2. groups should include ancestral species and all descendants - monophyletic group

1. molecular traits - e.g. DNA sequence2. anatomical features - e.g. bones in forelimbs3. monophyletic group - includes ancestor and all descendants4. paraphyletic group - includes some but not all members of a lineage


F. Animal SYstematics

1. goal is to arrange animals into groups that reflect evolutionary relationships

2. groups should include ancestral species and all descendants - monophyletic group

5. polyphyletic group - members that can be traced to a different lineage6. 3 different schools have developed due to disagreements on whether data may be used to describe distant evolutionary relationships, and methods of investigation


F. Animal SYstematics distant evolutionary relationships/ methods of investigation

a. evolutionary systematics - "traditional approach"

1. basic assumption - organisms more closely related to an ancestor will

resemble the ancestor more than they resemble distantly related organisms

2. homology vs. analogy a) analogies often develop in response

to similar selective pressures - convergent evolution

3. work often portrayed in phylogenetic trees



b. numerical taxonomy - believed criteria for traditional systematics had become too arbitrary and vague

1. objectivity - mathematical models, computer aided techniques to group samples of

organisms according to overall similarity2. do not attempt to distinguish homology and

analogy - data will overshadow and correct3. limit discussions of ancestry to closely related

taxa4. least popular of all the schools



c. phylogenetic systematics - also called cladistics

1. goal is to generate hypotheses of ancestry among monophyletic groups

2. they argue that their methods are more objective than traditional approach

3. use analogy and homology, but are most interested in homologies of recent origin

4. character shared by all members of a group is called symplesiomorphy




5. to decide what character is ancestral to a group of organisms, they pick a related group called the outgroup

a. characters that have arisen since common ancestry with the outgroup are called synapomorphies or derived characters

6. cladogram is a family tree depicting a hypothesis of regarding monophyletic lineages




7. cladogram, traditional groupings on top; see bird/reptile relationships

a. generations of taxonomists have assigned class level status to birdsb. reptiles have also had class statusc. birds more closely related to alligators and crocs than other

reptiles;d. grouping should reflect thise. trad. maintain correctness, bc feathers are important traits

to distinguish them, cladistics maintains that value judgments have no place here

f. this is part of science, and what drives investigation

VIDEO PRESENTATION

Biological Classification: Kingdoms

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