Vertebrate Basics

Timeline

• Earth is 4.6 billion years old

• Oldest evidence of life: 3.5 - 4 billion years ago

• First vertebrates: 600 MYA

• First land animals: 400 MYA

• First dinosaurs: 200 MYA

• First mammals and birds: 150 MYA

• Dinosaurs extinct: 65 MYA

• First hominid: 4 MYA

• Homo sapiens: 500,000 YA

Classification Basics

• 5 Kingdoms—Monera, Fungi, Protista, Plant and Animal

• All vertebrates: Kingdom = Animalia

• Phylum = Chordata

• Subphylum = Vertebrata

  • all creatures we learn are in this subphylum

Cladogram

• shows evolutionary relationships via lines

• smaller V= more closely related

• extinct = branch ends before others

Common Vertebrate Characteristics

• Vertebrae - “backbone”

• Cranium/braincase

• Cartilage or bone or both

• Most have paired appendages and limb girdles

• Pharyngeal clefts present in embryos

Diversity of Vertebrates

• Little and big creatures

• Wide variety of habitats

• Adaptations

• Niches

Adaptations

• Persists in population through natural selection

• Survival and reproductive success » fitness

• Vestigial structures are different

  • “useless” leftover structures from evolution

Temperature regulation in vertebrates

• Poikilothermy = variable body temperature

• Homeothermy = relatively constant body temperature

• Ectothermy = body heat acquired from the environment

• Endotherm = body heat derived from metabolism

Types of locomotion in vertebrates

• Terrestrial

  • quadrupedal

  • bipedal

• Aerial

  • gliding

  • flying

• Saltatorial—jumping

• Arboreal—move through trees