Vertebrates Overview

These flashcards cover essential concepts from the lecture on vertebrates, highlighting their key characteristics, evolutionary significance, and distinctions among groups.

What are the defining characteristics of chordates?

Chordates have a notochord, a dorsal hollow nerve cord, bilateral symmetry, and segmented bodies.

What is the role of the notochord in chordates?

The notochord provides skeletal support and is present throughout most of the length of a chordate.

What are the four key characters shared by all chordates?

Notochord, dorsal hollow nerve cord, pharyngeal slits, and a muscular post-anal tail.

What evolutionary significance do pharyngeal slits have in vertebrates?

Pharyngeal slits function in gas exchange in vertebrates and develop into parts of the ear, head, and neck in tetrapods.

What characterizes vertebrates compared to other chordates?

Vertebrates have a backbone and a more complex skeletal and nervous system.

What are gnathostomes?

Gnathostomes are vertebrates that have jaws.

Define tetrapods.

Tetrapods are gnathostomes that have limbs, allowing them to move onto land.

What is the amniotic egg and why is it important?

The amniotic egg allows for reproduction on land, reducing dependence on water.

What are derived characters of mammals?

Mammals have mammary glands, hair, endothermy, a large brain-to-body-size ratio, and differentiated teeth.

How do marsupials differ from eutherians?

Marsupials give birth to underdeveloped young that continue developing in a pouch, while eutherians develop fully in the uterus and are born more developed.

What adaptations do birds have for flight?

Birds have wings with feathers, a lightweight skeleton, and a high metabolic rate.

What significant features make humans distinct among mammals?

Humans have a large brain, bipedal locomotion, reduced jawbones, and a capacity for complex language and tool use.

What evidence is there for early hominins walking upright?

Fossils such as the Laetoli footprints indicate bipedal locomotion in early hominins.

What common ancestor do humans share with chimpanzees?

Humans and chimpanzees share a common ancestor that lived approximately 5-7 million years ago.

What was the fate of Neanderthals in relation to modern humans?

Neanderthals coexisted with early humans and interbred, with genetic evidence showing gene flow between the two species.

How are primates characterized?

Primates have mobile limbs, grasping hands and feet, flat nails, and complex brains.

What is the significance of Tiktaalik in tetrapod evolution?

Tiktaalik shows transitional features between fish and tetrapods, illustrating the evolution of limbs from fins.