Evolution and Diversity of Multicellular Organisms

These flashcards cover key concepts from the lecture notes on the evolution and diversity of multicellular organisms, focusing on chordate features, evolutionary transitions, and evidence of evolution.

What is a key topic discussed in phylogenetics and animal diversity?

The lines of evidence used to document great evolutionary transitions such as the origin of tetrapods.

What are the four key traits that all chordates share?

Notochord, Dorsal hollow nerve chord, Pharyngeal slits, Post-anal tail.

What are two evolutionary changes in Phylum Chordata?

Evolution of a backbone and evolution of jaws.

What is the function of the notochord in vertebrates?

It provides support and eventually becomes the vertebrae.

What do pharyngeal slits become in terrestrial vertebrates?

They develop into jaw and inner ear bones.

Why might tetrapods have moved onto land?

Land offered abundant food resources and escape from aquatic predators.

What is the significance of Tiktaalik in evolutionary studies?

It provides fossil evidence confirming the transition from water to land for vertebrates.

What challenges do animals face when transitioning to land?

Adaptation to gravity, desiccation, gas exchange, and sensory equipment.

How do homologous structures provide evidence for evolution?

They reveal shared ancestral origins and demonstrate modifications of common anatomical features.

What evidence do fossils provide regarding evolution?

They document anatomical changes, reveal behavioral patterns, indicate dietary habits, and offer insights into growth and development.

What does the discovery of the 'Sonic Hedgehog' gene demonstrate?

Evolutionary innovations can build upon preexisting developmental mechanisms.

What features distinguish gnathostomes from early invertebrate chordates?

Jaws, a more developed skeleton, and the presence of teeth.