Characteristics of species

• What is a common ancestor?


  The species that two or more descendants have diverged from
• What are the shared characteristics that define mammals, primates, hominoids, and hominins?


  • Mammals: fur or hair, milk-producing mammary glands, specific teeth structure, single lower jaw bone, three middle ear bones, diaphragm, warm-blooded, vertebrates.
  • Primates: opposable thumbs, flat nails, binocular vision, large brains, long gestational period.
  • Hominoids: absence of tail, larger brains, distinctive molar teeth, long upper limbs, wider chest, arm rotation capability.
  • Hominins: bipedal locomotion, specific skeletal adaptations.
• What are the key features of mammals?


  Mammals have fur or hair, milk-producing mammary glands, and specific teeth structures.
• What are the types of teeth found in mammals?

  Incisors, canines, premolars, and molars
• How do mammals maintain their body temperature?


  Mammals are warm-blooded, allowing them to regulate their body temperature.
• What is a defining feature of primates?


  Opposable thumbs
• Why do primates have large brains relative to their body size?


  Large brains allow for complex behaviors and social interactions.
• What distinguishes hominoids from other primates?


  Hominoids lack a prehensile tail.
• What are the features of hominoids that support their complex brain function?


  Hominoids have larger and more complex brains that allow for problem-solving and communication.
• What is a key feature of hominins?


  Bipedal locomotion
• What structures are vital for bipedalism in hominins?


  • Position of the foramen magnum
  • Arrangement of femur and tibia
  • Leg length
  • Shape of the pelvis
  • S-shaped spine
• How does the position of the foramen magnum relate to bipedalism?


  If the foramen magnum is towards the center, the organism walks upright.
• What is the carrying angle in relation to bipedalism?


  The carrying angle is formed between the femur and tibia when it is vertical.
• How does leg length assist with bipedalism?


  Longer legs assist with bipedalism.
• What shape is the pelvis in hominins, and why is it important?


  The pelvis is more bowl-shaped, which supports bipedal locomotion.
• How does the S-shaped spine contribute to bipedalism?


  The S-shaped spine provides flexibility, which is important for walking upright.