Vertebrate Basics

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