The Origin and Evolution of Vertebrates

These flashcards cover key vocabulary and definitions related to the origin and evolution of vertebrates, focusing on their anatomical features, evolutionary milestones, and classification.

Notochord

A flexible rod providing skeletal support in chordates.

Dorsal Hollow Nerve Cord

A bundle of nervous tissue that runs along the back of chordates, developing into the brain and spinal cord.

Pharyngeal Arches

Openings or grooves along the pharynx that may evolve into structures in aquatic and terrestrial vertebrates.

Post-Anal Tail

An extension of the body beyond the anus, used for propulsion or balance.

Endostyle

A groove in the pharynx that secretes mucus to trap food; modified in most chordates into a thyroid gland.

Gnathostomes

Vertebrates with jaws, allowing for more active predation.

Tetrapods

Gnathostomes that have limbs, adapted for life on land.

Amniotes

Tetrapods that have a terrestrially adapted egg, allowing for reproduction away from water.

Mineralized Skeleton

A hard skeleton structure that provides protection and support; crucial for vertebrate evolution.

Cambrian Explosion

An event during the Paleozoic era marked by a rapid diversification of animal phyla.

Hox Genes

Regulatory genes that control the body plan development of animals.

Lophotrochozoa

A clade within Bilateria that includes animals with a lophophore or trochophore larval stage.

Deuterostomia

A clade of animals characterized by developing the anus before the mouth.

Endothermy

The ability to regulate one’s own body temperature, seen in mammals and birds.

Ediacaran Biota

The earliest known macroscopic animals found in the Neoproterozoic Era.

Chordata

The phylum that includes all vertebrates and some invertebrates with a notochord.

Neural Crest

A collection of cells unique to vertebrates, contributing to various tissues and structures.

Amniotic Egg

An egg with specialized membranes that allow for development on land.

Mammals

Amniotes that possess hair and produce milk.

Marsupials

A group of mammals characterized by a unique reproductive strategy involving pouches.

Eutherians

Placental mammals with complex reproductive biology and long gestation periods.

Mineral Homeostasis

The process of maintaining stable levels of minerals like calcium and phosphate.

Phylogeny

The evolutionary history and relationships among species.

Fossil Record

A historical archive of preserved organisms, providing insights into evolution.

Tetrapod Evolution

The transition of some fish ancestors to land-dwelling animals.

Jawless Fish

Early vertebrates lacking jaws, classified as Agnatha.

Evolutionary Arms Race

The dynamic interplay of predator and prey adaptations over time.

Invertebrates

Animals lacking a backbone; some are closely related to chordates.

Diversity of Life

The variety of living organisms within different ecosystems.

Embryonic Development

The process of growth and formation of mature organisms from a fertilized egg.

Hox Gene Duplication

A process that has led to increased complexity in vertebrate body plans.