Part A: Classification and Evolutionary Relationships Vertebrate Classification:

1. Taxonomy - categorizing organisms into groups (taxa) 1.Organisms are grouped together based on similarities and differences amongst their: a.Physical traits - structure (anatomy) and function (physiology) b.Biochemical composition - DNA (genes) and proteins 2.The taxa (groups) used to categorize organisms from general characteristics to more specific are: Kingdom Phylum Class Order Family Genus Species 3.An organism’s scientific name includes its Genus and Species names.

This illustration shows the classification of the grizzly bear from kingdom to species. Note: as the groups go from more general to more specific, the number of organisms in each group decreases. Figure 15-5, Miller-Levine, Biology 2. Kingdom and 3. Phylum Vertebrates belong to Kingdom Animalia: multicellular, eukaryotic (cells with organelles), consumers. Vertebrates belong to Phylum Chordata: have nerve chord. There are 5 groups of Vertebrates we will study, including Mammalia (shown here)

Taxonomy and the Evolution of Vertebrates This phylogenetic tree shows one hypothesis of the evolutionary relationships among vertebrates & approximately when important traits appeared. Each organism’s taxonomic classification reflects these relationships. Note important evolutionary advancemnets (circled). Figure 36-2, Miller-Levine, Biology

Part B: Comparing Form & Function Among Vertebrate Classes Amphibians Birds Reptiles Fish Mammals

1. Body Temperature Control (Metabolism) 1. Fish, Amphibians, Reptiles 2. Move less and move slower Endotherms (“warm”-blooded): Produce heat metabolically 1. Birds, Mammals 2. Move more, move faster 3. More need for insulation (feathers, fur) Ectotherms (“cold” blooded): Get heat from environment 3. Less need for insulation Important Evolutionary Advancement: Endothermy (in Birds and Mammals): Allowed for survival in a greater variety of environments.

2. Movement (Muscles, Skeleton) Side to side movement. Fish, Amphibians, Reptiles Up and down movement. Birds, Mammals Limbs: Stick out sideways. Fish, Amphibians Point more directly down - hold more weight. Reptiles Point straight down. Birds, Mammals Vertebral column: Important Evolutionary Advancement: Strong skeleton and 4 limbs (first evolved in Amphibians) allowed for better movement on land.

3. Feeding and Digestion Important Evolutionary Advancement: Jaws (first evolved in Fishes). Allowed for greater food variety and size. Digestive system and other structures adapted to feeding habit of organism. Mammalian skulls

4. Respiration Anomaly: High complexity, air sacs Fish: Gills (in most cases) Low efficiency High efficiency Important Evolutionary Advancement: Lungs (first evolved in Fishes, further developed in other vertebrates): Led to movement on to land.

5. Internal Transport (Circulation) Fish and Amphibians Replies, Birds, Mammals 2 chambers 3 chambers4 heart chambers Heart Circulation Important Evolutionary Advancements: Double-Loop circulation and additional heart chambers allow for more efficient circulation of oxygen-rich blood.

6. Excretion Some anomalies! Fish Amphibs. Birds Mammals Reptiles Important Evolutionary Advancements: Urea and uric acid are less toxic to the body and can be held internally on land. Pure ammonia waste requires organisms to stay in water to “flush”.

7. Response (Nervous System) Brains Important Evolutionary Advancements: Folds and size of cerebrum allows for increased intelligence.

8. Reproduction Fish, Amphibian--> Reptiles, Birds --> Mammals External fertilizationInternal Fertilization Ovoparous --> Ovoviviparous --> Viviparous (Eggs) (developed eggs with amnion) (amnion, live birth) Lots of anomalies: some fish give live birth, some mammals have eggs, etc. Fish, Amphibians Reptiles, Birds Mammals Male and female organs (penis, vagina) Important Evolutionary Advancement: Amniotic Eggs (first evolved in Reptiles): Eggs with yolk allowed for permanent movement on to land. Internal fertilization allowed for reproduction on land.

8. Reproduction (Development) Early embryonic development (all vertebrates very similar) Later embryonic development (more complex organisms gain complexity)