Introduction to Evolution and Development

A set of vocabulary flashcards covering key concepts from the lecture notes on evolution and animal diversity.

Evo-Devo

A field combining evolutionary biology and developmental biology, established roughly 15-20 years ago, investigating mechanisms of evolution focusing on the speed and nature of evolutionary changes and how diverse species morphologies arise from shared ancestry.

Approximately how long ago was the field of Evo-Devo established?

Roughly 15-20 years ago.

Parazoa

Animals that lack true tissues, such as sponges. They do not possess a gut and absorb nutrition through specialized cells.

What is a characteristic example of a Parazoan?

Sponges.

Eumetazoa

Animals that possess true tissues; they are further classified based on layers of tissues (diploblastic vs. triploblastic).

How are Eumetazoa further classified based on tissue layers?

They are classified as diploblastic or triploblastic.

Diploblastic

Animals with two tissue layers (e.g., cnidarians).

Triploblastic

Animals with three tissue layers, encompassing more complex body separations and functions.

Cnidarians

A group of Eumetazoa with radial symmetry, including jellyfish, corals, and hydras, characterized by nematocysts (stinging cells) and a closed gastrovascular cavity.

What are nematocysts?

Stinging cells characteristic of Cnidarians.

Mesoglia

An inert, body-filling material found in some animals (like cnidarians) that aids structural integrity without needing metabolic support.

Ctenophores

Known as comb jellies, distinct from cnidarians, featuring directed movement via cilia and a one-way gut for digestion.

What distinguishes the digestive system of Ctenophores from Cnidarians?

Ctenophores have a one-way gut, while Cnidarians have a closed gastrovascular cavity.

Bilaterians

Animals broken down into Protostomes and Deuterostomes based on embryonic development (blastopore fate, becoming mouth vs. anus respectively).

What embryonic development feature distinguishes Protostomes from Deuterostomes?

The fate of the blastopore during embryonic development (mouth vs. anus).

Protostomes

A major group of bilaterians where the blastopore develops into the mouth. Includes Lophotrochozoa and Ecdysozoa.

Deuterostomes

A major group of bilaterians where the blastopore develops into the anus. Includes vertebrates, chordates, acorn worms, and sea stars.

Lophophore

A tentacle-lined organ used for filter feeding, characteristic of some Lophotrochozoans like Phoronida, Bryozoa, Brachiopoda.

Trochophore

A larval form featuring specialized cilia for locomotion, found in some Lophotrochozoans like Annelida and Mollusca.

Ecdysozoa

A group of protostomes characterized by molting a cuticle (ecdysis). Includes Nematoda and Arthropoda.

What is ecdysis?

The process of molting a cuticle, characteristic of Ecdysozoa.

Arthropods

The most diverse group of animals, characterized by hard exoskeletons, segmented bodies, and jointed appendages. Examples include insects, spiders, crustaceans.

Amniotes

A group including reptiles, birds, and mammals, characterized by amniotic eggs that can have up to four membranes, allowing for terrestrial life independence from water.

What significant advantage does the amniotic egg provide for Amniotes?

Independence from water for reproduction and terrestrial life.

Endothermy

The evolution of internal heat production for maintaining stable internal temperatures, advantageous yet resource-intensive.

What is a main disadvantage of endothermy?

It is resource-intensive.

Matrotrophy

Direct nourishment of the embryo, resulting in fewer, larger offspring that are more developed at birth.