The Biology of Amphibians @ Agnes Scott College Mark Mandica - PowerPoint PPT Presentation

The Biology of Amphibians @ Agnes Scott College Mark Mandica Executive Director The Amphibian Foundation mark@amphibianfoundation.org 678 379 TOAD (8623) Phyllomedusidae: Agalychnis moreletii

1.2 : Introduction of Amphibians Centrolenidae: Hyalinobatrachium valeroi

Evolution of Amphibians Tetrapodomorpha † *Gerobatrachus † Gymnophiona (Reptiles, Mammals) Actinopterygian Triadobatrachus † (stem-tetrapods) Lepospondyls † (’frogomander’) (Ray-fin Fishes) Coelacanth, Caudata Eocaecilia † Karaurus † Amniota Lungfish Anura (including Apoda Urodela Prosalirus †) Salientia Batrachia Lissamphibia *Gerobatrachus may be the sister taxon to Batrachia Temnospondyls † Tetrapods Osteichthyes Sarcopterygian (Bony Fishes) (Lobe-fin Fishes) A m p h i b i a n R e i g n Devonian Carboniferus Permian Triassic Jurassic Cretaceous Time Period (420 MYA) (350 MYA) (300 MYA) (250 MYA) (200 MYA) (150-65 MYA) Present Day Millions of Years Ago resembles Plate Tectonics Gondwana + Laurussia Pangea Pangea Pangea begins to break Pangea breaks present day T h e B i o l o g y o f A m p h i b i a n s amphibbio.amphibianfoundation.org

Plate Tectonics Evolution of Amphibians † † a Gymnophiona h ) s p n s † u l a r a h i o ) s s † g m c u m ) ) , d ’ y s h a r m s h o o e r e t r l † Caudata c e n d p y t d h a d a † a t a a n p s o M a b r c r a n a o i p i s t F t t o o a h m l a a e o , i u n r n l s s p c b i e r t i e r e o t fi fi t - n s e u o c o m G e m l g - g i o a a d A y C T t * o n e p p c r a a A r a u t e o i R s e f K r L L ’ E T ( ( R ( ( Anura (including Apoda Urodela Prosalirus †) Salientia Batrachia Lissamphibia *Gerobatrachus may be the sister taxon to Batrachia Temnospondyls † Tetrapods Osteichthyes Sarcopterygian (Bony Fishes) (Lobe-fin Fishes) A m p h i b i a n R e i g n Devonian Carboniferus Permian Triassic Jurassic Cretaceous Time Period (350 MYA) (420 MYA) (300 MYA) (250 MYA) (200 MYA) (150-65 MYA) Present Day Millions of Years Ago resembles Plate Tectonics Gondwana + Laurussia Pangea Pangea Pangea begins to break Pangea breaks present day T h e B i o l o g y o f A m p h i b i a n s amphibbio.amphibianfoundation.org

Evolution of Amphibians Tetrapodomorpha † *Gerobatrachus † Gymnophiona (Reptiles, Mammals) Actinopterygian Triadobatrachus † (stem-tetrapods) Lepospondyls † (’frogomander’) (Ray-fin Fishes) Coelacanth, Caudata Eocaecilia † Karaurus † Amniota Lungfish Anura (including Apoda Urodela Prosalirus †) Salientia Batrachia Lissamphibia *Gerobatrachus may be the sister taxon to Batrachia Temnospondyls † Tetrapods Osteichthyes Sarcopterygian (Bony Fishes) (Lobe-fin Fishes) A m p h i b i a n R e i g n Devonian Carboniferus Permian Triassic Jurassic Cretaceous Time Period (420 MYA) (350 MYA) (300 MYA) (250 MYA) (200 MYA) (150-65 MYA) Present Day Millions of Years Ago resembles Plate Tectonics Gondwana + Laurussia Pangea Pangea Pangea begins to break Pangea breaks present day T h e B i o l o g y o f A m p h i b i a n s amphibbio.amphibianfoundation.org

Phylogenetic tree (or cladogram) clade = monophyletic A group of organisms which includes the most recent common ancestor of all of its members and all of the descendants of that most recent common ancestor paraphyletic A group of organisms which includes the most recent common ancestor of all of its members, but not all of the descendants of that most recent common ancestor polyphyletic X A group of organisms which does not include the most recent common ancestor of those organisms; the ancestor does not possess the character shared by members of the group. node The point at which the branch of a phylogenetic tree (or cladogram) intersects or terminates. phylogeny -- The evolutionary relationships among organisms; the patterns of lineage branching produced by the true evolutionary history of the organisms being considered.

Phylogenetic tree (or cladogram) derived Refers to a character or feature found within a sister group single lineage of a larger group; it is not shared 2 with all organisms in the larger group. Derived The two clades resulting from the characters are used to infer evolutionary splitting of a single lineage 
 relationships, as derived characters evolved ‘E’ (node 2) is the ‘sister group’ to node 1 after primitive characters (eg: node 2) 1 apomorphy pleisiomorphy A novel derived evolutionary trait that is A primitive character state for the unique to a particular species taxa under consideration. synapomorphy A character which is derived, and because it basal is shared by the taxa under consideration, is The earliest diverging group used to infer common ancestry within a clade (eg: node 1) systematics -- Field of biology that deals with the diversity of life. Systematics is usually divided into the two areas of phylogenetics and taxonomy.

Evolution of Amphibians Tetrapodomorpha † *Gerobatrachus † Gymnophiona (Reptiles, Mammals) Actinopterygian Triadobatrachus † (stem-tetrapods) Lepospondyls † (’frogomander’) (Ray-fin Fishes) Coelacanth, Caudata Eocaecilia † Karaurus † Amniota Lungfish Anura (including Apoda Urodela Prosalirus †) Salientia Batrachia Lissamphibia *Gerobatrachus may be the sister taxon to Batrachia Temnospondyls † Tetrapods Osteichthyes Sarcopterygian (Bony Fishes) (Lobe-fin Fishes) A m p h i b i a n R e i g n Devonian Carboniferus Permian Triassic Jurassic Cretaceous Time Period (420 MYA) (350 MYA) (300 MYA) (250 MYA) (200 MYA) (150-65 MYA) Present Day Millions of Years Ago resembles Plate Tectonics Gondwana + Laurussia Pangea Pangea Pangea begins to break Pangea breaks present day T h e B i o l o g y o f A m p h i b i a n s amphibbio.amphibianfoundation.org

Actinopterygii : Ray-finned Fishes Oncorhynchus clarkii lewisi

Evolution of Amphibians Tetrapodomorpha † *Gerobatrachus † Gymnophiona (Reptiles, Mammals) Actinopterygian Triadobatrachus † (stem-tetrapods) Lepospondyls † (’frogomander’) (Ray-fin Fishes) Coelacanth, Caudata Eocaecilia † Karaurus † Amniota Lungfish Anura (including Apoda Urodela Prosalirus †) Salientia Batrachia Lissamphibia *Gerobatrachus may be the sister taxon to Batrachia Temnospondyls † Tetrapods Osteichthyes Sarcopterygian (Bony Fishes) (Lobe-fin Fishes) A m p h i b i a n R e i g n Devonian Carboniferus Permian Triassic Jurassic Cretaceous Time Period (420 MYA) (350 MYA) (300 MYA) (250 MYA) (200 MYA) (150-65 MYA) Present Day Millions of Years Ago resembles Plate Tectonics Gondwana + Laurussia Pangea Pangea Pangea begins to break Pangea breaks present day T h e B i o l o g y o f A m p h i b i a n s amphibbio.amphibianfoundation.org

Sarcopterygii : Lobe-finned Fishes Bichir Coelacanth Lungfish

Sarcopterygii : Eusthenopteron † Tetrapodomorph fish Late Devonian period, about 385 million years ago

Sarcopterygii : Panderichthys † Tetrapodomorph fish Late Devonian period, about 380 million years ago

Sarcopterygii : Tiktaalik † Tetrapodomorph fish Late Devonian period, about 375 million years ago

Preparations for Terrestrial Life Why would Devonian vertebrates want to leave the water?

Preparations for Terrestrial Life Pre-adaptations What types of changes would need to occur to support life on land?

Preparations for Terrestrial Life Pre-adaptations Respiration Gills ————> Lungs

Preparations for Terrestrial Life Pre-adaptations Gravitational Support Bending of wrists and ankles Well developed ribs Weight bearing bones

Preparations for Terrestrial Life Pre-adaptations Sensory Perception Smells, sights and sounds are transmitted differently in air and water

Preparations for Terrestrial Life Pre-adaptations Larval Development A free-swimming aquatic larval stage metamorphoses into a terrestrial adult

Preparations for Terrestrial Life Pre-adaptations Neck Mobility Cervical vertebrae provide flexion for locating prey and predators

Preparations for Terrestrial Life Pre-adaptations Hindlimb Locomotion Development of sacrum and sacral vertebrae

Preparations for Terrestrial Life Pre-adaptations Feeding Changes in feeding mechanism from suction feeding to biting