l Chordata subphyla Urochordata Cephalochordata Vertebrata Patterns in

l. Chordata subphyla: Urochordata Cephalochordata Vertebrata

Patterns in evolution: Innovation, radiation, competitive contraction

5. Major Phyla Deuterostomes: l. Chordata Vertebrata “Jawless fishes” Lampreys and Hagfish Lamprey larvae look very much like cephalochordates

5. Major Phyla Deuterostomes: I. Chordata Vertebrata “Jawless fishes” Evolve in late Cambrian, radiate in the Ordovician

5. Major Phyla Deuterostomes: l. Chordata Vertebrata Gnathostomes – Jawed Vertebrates Move from detritivores to predators

5. Major Phyla Deuterostomes: l. Chordata Vertebrata Gnathostomes – Jawed Vertebrates The Devonian was the “Age of Fishes” – a radiation of the first jawed vertebrates, dominated first by the Placoderms and then by Cartilaginous and bony fishes Arthrodires Placoderms Antiarchs Chondrichthyes (Sharks, rays) Acanthodians Teleosts Ray-finned Fishes Bony Fish Lobe-finned Fishes

5. Major Phyla Deuterostomes: l. Chordata Vertebrata Gnathostomes – Jawed Vertebrates The Devonian was the “Age of Fishes” – a radiation of the first jawed vertebrates, dominated first by the Placoderms and then by cartilaginous and bony fishes

5. Major Phyla Deuterostomes: l. Chordata Vertebrata Gnathostomes – Jawed Vertebrates Bony fishes dominate today: lighter skeleton and swim bladder Ray-finned Fishes Lobe-finned Fishes

5. Major Phyla Deuterostomes: l. Chordata Vertebrata Gnathostomes – Jawed Vertebrates Bony Fishes (Osteichthyes) comprise 40% of living vertebrate species

5. Major Phyla Deuterostomes: l. Chordata Vertebrata Gnathostomes - Tetrapods 350 mya Devonian 417 mya

Radiation of the “stem tetrapods” !!! Carboniferous Coastal swamps! Old friends a fish

5. Major Phyla Deuterostomes: l. Chordata Vertebrata Gnathostomes - Tetrapods Caecilians Salamanders Frogs

Radiation of the “stem tetrapods” !!! Carboniferous Coastal swamps! Old friends a fish

5. Major Phyla Deuterostomes: l. Chordata Vertebrata Gnathostomes Tetrapods - Amniotes The Permian Formation of Pangaea dries the landscape; amniotes dominate like the gymnosperms.

5. Major Phyla Deuterostomes: l. Chordata Vertebrata Gnathostomes Tetrapods - Amniotes The amniotic egg was a big advance Resist desiccation - amnion protects the embryo - yolk sac provides nourishment - allantoic sac holds waste produced by embryo Provision embryo allows for colonization of dry habitats

5. Major Phyla Deuterostomes: l. Chordata Vertebrata Gnathostomes Tetrapods - Amniotes SYNAPSID Amniote ancestor ANAPSID (turtles? ) Hylonomus Casineria DIAPSID

5. Major Phyla Deuterostomes: l. Chordata Vertebrata Gnathostomes Tetrapods - Amniotes Dimetrodon – a Pelycosaur The Permian Pelycosaurs The synapsids radiate and dominate Dicynodonts Gorgonopsids Therapsids Cynodonts A cynodont Mammals

5. Major Phyla Deuterostomes: l. Chordata Vertebrata Gnathostomes Tetrapods - Amniotes Mammals - excellent transitional sequences from cynodont ‘reptiles’ - first fossils with all mammalian features (jaw, ear, dentition, fur) date to ~200 mya - Morganucodontids

Radiations of Mammals They diversify during the Mesozoic, but the modern groups radiate and dominate in the Cenozoic

5. Major Phyla Deuterostomes: l. Chordata Vertebrata Gnathostomes Tetrapods - Amniotes Mammals - Monotremes: lay eggs, “sweat” milk

5. Major Phyla Deuterostomes: l. Chordata Vertebrata Gnathostomes Tetrapods - Amniotes Mammals - Marsupials: live birth to embryo – attaches to nipple to complete development. Mother does not need to abandon the nest/young to feed. Pygmy possum – Australia (opossums in Western Hemisphere)

5. Major Phyla Deuterostomes: l. Chordata Vertebrata Gnathostomes Tetrapods - Amniotes Mammals - Monotremes: egg laying, “sweat” milk - Placentals: Longer internal development allows for precocial behavior (independence on birth); placental allows for direct, energyefficient transfer of nutrients between blood systems of mother and offspring. Each energy transformation is less than 100% efficient Milk production in mammary glands FOOD for OFFSPRING DIGESTION Nutrients in bloodstream of mother Placenta - Marsupials: live birth to embryo – attaches to nipple to complete development. Mother does not need to abandon the nest/young to feed. FOOD Nutrients in bloodstream of offspring

5. Major Phyla Deuterostomes: l. Chordata Vertebrata Gnathostomes Tetrapods - Amniotes - Archosaurs Crocodilians Pterosaurs Ornithiscians Dinosaurs Saurischians Sauropods Theropods Carnosaurs Birds

Feathers: - ornamentation - endothermy (insulation) - lift (flight)

5. Major Phyla Deuterostomes: l. Chordata Vertebrata Gnathostomes Tetrapods - Amniotes Birds: (derived traits) No teeth Feathers and endothermy flight feathers keeled breastbone Clavicles united into wishbone Pneumatic skeleton (houses air sacs from respiratory system) Unidirectional respiration

IV. The Domain Eukarya E. Fungi F. Animals G. Human Evolution 1. Overview: Linnaean Classification Hominidae Pongidae Hylobatidae Apes = primates (grasping hands, binocular vision) with no tails

IV. The Domain Eukarya E. Fungi F. Animals G. Human Evolution 1. Overview: Phylogenetic Classification 1 -4% difference Hylobatidae Hominidae

IV. The Domain Eukarya E. Fungi F. Animals G. Human Evolution 1. Overview: How can the small genetic difference account for the dramatic differences that occur between these species?

IV. The Domain Eukarya E. Fungi F. Animals G. Human Evolution 1. Overview: 2. Patterns: a. Morphological and Behavioral Homo sapiens Chimps, Gorillas Larger Head/body ratio smaller Smaller jaw/head ratio larger Shorter limb/body ratio longer Less hair more hair Better learning poorer learning

IV. The Domain Eukarya E. Fungi F. Animals G. Human Evolution 1. Overview: 2. Patterns: a. Morphological and Behavioral Differences correlate with developmental differences Juvenile Primate Adult Primate Larger Head/body ratio smaller Smaller jaw/head ratio larger Shorter limb/body ratio longer Less hair more hair Better learning poorer learning

IV. The Domain Eukarya E. Fungi F. Animals G. Human Evolution 1. Overview: 2. Patterns: a. Morphological and Behavioral Big head, short limbs Small head, long limbs

IV. The Domain Eukarya E. Fungi F. Animals G. Human Evolution 1. Overview: 2. Patterns: a. Morphological and Behavioral b. Genetic Developmental genes can have profound effects on the final morphology of the organism. Human Chimp Primate Developmental Trajectory

IV. The Domain Eukarya E. Fungi F. Animals G. Human Evolution 1. Overview: 2. Patterns: a. Morphological and Behavioral b. Genetic What are some of these genetic differences? The HAR 1 RNA molecule. - not a coding RNA; probably regulatory - nearby genes associated with transcriptional regulation and neurodevelopment are upregulated in humans. - only 2 changes in sequence between chicks and chimps; 18 between chimps and humans. “HAR” stands for “human accelerated region” – changing more rapidly than drift can explain. why? Selection. -Changes result in a profound change in RNA structure and, presumably, binding efficiency. Beniaminov A, Westhof E, and Krol A. 2008. Distinctive structures between chimpanzee and human in a brain noncoding RNA 14: 1270 -1275. Beniaminov A et al. RNA 2008; 14: 1270 -1275

IV. The Domain Eukarya E. Fungi F. Animals G. Human Evolution 1. Overview: 2. Patterns: a. Morphological and Behavioral b. Genetic c. Fossils Chimpanzee Human Sahelanthropus tchadensis – discovered in Chad in 2001. Dates to 6 -7 mya. Only a skull. Is it on the human line? Is it bipedal? Probably not (foramen magnum). Primitive traits, as a common ancestor might have.

Ardipithecus ramidus: 4. 3 -4. 5 mya. Discovered in 1994 by Haile-Sailasse, Suwa, and White, with the most complete fossils were not described until 2009. Arboreal, but facultatively bipedal. Grasping toes.

IV. The Domain Eukarya E. Fungi F. Animals G. Human Evolution 1. Overview: 2. Patterns: a. Morphological and Behavioral b. Genetic c. Fossils Sahelanthropus tchadensis Chimpanzee nsis us afare c e h t i p alo Austr canus s afri u c e h t i op Austral Ardipithecus s abili h o m o H Homo erectus Human Homo sapiens

Australopithecus afarensis: 2. 8 -3. 9 mya. A femur discovered in 1973 by Donald Johansson suggested an upright gait, confirmed by his discovery in 1974 of the ‘Lucy” specimen. Also, the Laetoli prints (found by Mary Leakey) were probably made by A. afarensis, and in 2006, a juvenile A. afaresis was found.

Competitive contraction? Radiation of Bipedal Hominids Innovation: Bipedality

Paranthropus aethiopicus: 2. 5 -2. 7 mya, discovered by Alan Walker and Richard Leakey, the “black skull” is one of the most imposing hominid fossils there is! Aside from the high cheekbones and the sagittal crest, it has similar proportions to A. afarensis and is probably a direct descendant. It probably gave rise to the “robust” lineage of Paranthropus.

Paranthropus boisei: 1. 2 -2. 6 mya. Discovered by Mary Leakey in Olduvai Gorge in 1959, it was originally classified as Zinjanthropus and nicknamed “Zinj” or “nutcracker man” because of the large grinding molars.

Paranthropus robustus: 1. 2 -2. 0 mya. Discovered in South Africa in 1938 by Robert Broom.

Competitive contraction? Radiation of Bipedal Hominids Innovation: Bipedality

Homo habilis: 1. 4 -2. 3 mya, discovered by Louis and Mary Leakey, in association with stone tools. “Handy man”. Longer arms and smaller brain than other members of the genus.

Homo ergaster (H. erectus): 1. 3 -1. 8 mya, the most complete fossil hominid skeleton was discovered in 1984 by Alan Walker who called it “Turkana Boy”. Some consider this species intermediate to H. habilis and H. heidelbergensis/H. sapiens, leaving H. erectus as a distinct Asian offshoot of the main line to H. sapiens. However, most paleontologists suggest that H. ergaster is the African ancestor – even a chronospecies or population - of H. erectus, which is ancestral to more recent Homo species.

Homo erectus: 0. 2 -1. 8 mya; originating in Africa, but then leaving for Asia (Peking and Java Man). Discovered in Java by Eugene Dubois in 1891. Certainly one of the most successful hominid species in history; perhaps lasting as relictual species on islands in Indonesia as: Homo floresiensis: 94, 000 -13, 000 years, discovered by Mike Mormood on the island of Flores. Shoulder anatomy is reminiscent of H. erectus, but could be an allometeric function of the small size (3 ft).

Homo neaderthalensis: 30, 000 -150, 000; first discovered in 1829. Descended from H. heidelbergensis. Homo sapiens idaltu: 160, 000 – oldest Homo sapiens fossil – found in Africa in 2003… afar valley.

Competitive contraction? Radiation of Bipedal Hominids Innovation: Bipedality