61: Sequence of evolutionary innovations in vertebrate classes Flashcards
What genetic event contributed significantly to vertebrate success?
Two rounds of genome duplication.
What are examples of jawless fishes in Class Agnatha?
Hagfish and Lampreys.
What type of skeleton do jawless fishes have?
Cartilaginous skeleton.
How many pairs of gill pockets do jawless fishes have?
Seven or more pairs.
Why are some jawless fishes known as “slime fish”?
Due to the production of a thick, sticky slime as a defense mechanism.
What evolutionary transition did jawless fishes contribute to?
The transition from filter-feeding to predation.
What are key developments in vertebrate evolution attributed to jawless fishes?
Development of a complex head, early backbone, heart with distinct chambers, and a primitive kidney.
What evolutionary step is significant for Class Chondrichthyes (Cartilaginous Fishes)?
Development of jaws from modifications of cartilages in the first pharyngeal arch.
What key feature did Class Chondrichthyes introduce?
Introduction of predation.
What capabilities did the development of Class Chondrichthyes contribute to vertebrate evolution?
Development of bone production capabilities.
What are the skeletal features of Class Osteichthyes (Bony Fishes)?
Primarily bone.
What are the subdivisions of Class Osteichthyes?
Ray-finned fishes and Lobe-finned fishes.
What universal feature do all bony fishes share?
Universal bony endoskeleton.
What significant evolution occurred in lobe-finned fishes?
Evolution of lungs leading to pulmonary circulation.
What major transition did some lobe-finned fishes undergo?
Transition to land.
Into what did lobe fins evolve for terrestrial movement?
Limbs.
What group do four-legged amphibians belong to?
Tetrapoda.
Describe the reproductive adaptation of Class Amphibia.
Eggs laid in water with indirect development through an aquatic larval stage.
What limb evolution did amphibians contribute to vertebrate evolution?
Paired fins evolved into pentadactyl limbs.
How did the skull attachment of amphibians contribute to their evolution?
The skull became semi-motile due to the presence of condyles, allowing greater flexibility.
What is significant about the auditory development in amphibians?
Evolution of the middle ear with one bone and an external eardrum.
What are the key respiratory adaptations in amphibians?
Transformation of posterior nostrils into choanae for nasal breathing and lungs becoming the primary respiratory organs.
What digestive and excretory enhancements did amphibians develop?
Development of salivary glands and a motile tongue, cornified skin with multicellular glands, and differentiated intestines.
How did the cardiovascular system of amphibians evolve?
The heart evolved into three chambers to support dual circulatory systems.
What is the evolutionary significance of amniotes?
Adapted to terrestrial life post-amphibians.
What are the key traits of amniotes?
Evolution of amniotic eggs, dry skin, advanced pulmonary respiration, and thermoregulation.
What is the function of the egg shell in amniotic eggs?
Provides protection and allows oxygen exchange.
What roles do the chorion and allantois play in amniotic eggs?
Facilitate gas exchange and waste management.
What is the evolutionary divergence of amniotic eggs?
Led to Sauropsida and Synapsida.
What reproductive adaptation is significant in amniotes?
Internal fertilization and amniotic eggs.
What physical and functional developments are seen in amniotes?
Elimination of the larval stage, fully motile head, elongated neck, dry skin, and enhanced pulmonary ventilation.
What neurological and renal adaptations occurred in amniotes?
Brain development prioritized over spinal cord and transition to compact kidneys.
What is the defining characteristic of mammals?
Presence of mammary glands which produce nutrient-rich milk.
From which group do mammals descend?
Synapsida.
What is the significance of endothermy in mammals?
Maintains constant body temperature, enabling activity across various climates.
What dental evolution is significant in mammals?
Development of heterodonty for precise occlusion and efficient feeding.
How does the integumentary system of mammals enhance their survival?
Hair-covered glandular skin.
What are the key reproductive innovations in mammals?
Mammary glands, expanded nasal conchae, and increased brain size and complexity.
How did the reproductive system of mammals evolve?
Viviparity and the evolution of the uterus and placenta in metatherians and eutherians to support embryonic development.
What is the correct order?
Agnatha, Chondrichthyes, Osteichthyes, Amphibians, Reptiles, Mammals, Birds
