This document summarizes the evolution of vertebrates from their earliest ancestors to modern forms. It describes the key traits that unite each major group, from non-vertebrate chordates like tunicates and lancelets, to the earliest jawless fish like hagfish and lampreys, to jawed fish groups like sharks and bony fish. It outlines the major transitions from marine to freshwater habitats and the evolutionary innovations in skeletal and sensory systems that occurred in the main vertebrate lineages over 500 million years.
Introduction
Ostracoderms (shell-skinned) are of several groups of extinct, primitive, jawless fishes that were covered in an armour of bony plates.
They appeared in the Cambrian, about 510 million years ago, and became extinct towards the end of the Devonian, about 377 million years ago. They were quite abundant during the upper Silurian and Devonian periods. Most of fossils of Ostracodermi were preserved in the bottom sediments of freshwater streams.
However, the opinion is sharply divided as to whether their habitat was freshwater or marine.
The first fossil fishes that were discovered were ostracoderms.
The Swiss anatomist Louis Agassiz received some fossils of bony armored fish from Scotland in the 1830s.
The ostracoderms resembled the present day cyclostomes (lampreys and hagfishes) in many respects and together with them constitute a special group of jawless vertebrates, the Agnatha.
Characteristics: They use gills exclusively for respiration but not for feeding . Earlier chordates with gills used them for both respiration and feeding. Ostracoderms had separate pharyngeal gill pouches along the side of the head, which were permanently open with no protective operculum. mostly small to medium-sized fishes, protected by a heavy, bony dermal (derived from skin) armor. bottom-dwellers; filter-feeders or grazers. no paired fins, but many with stabilizing paired flaps on either side of head.
(1) Ostracoderms were the first vertebrates.
(2) They were popularly called armoured fishes.
(4) They lived in freshwater.
(5) They were bottom dwellers.
(6) Their body was fish-like and did not exceed 30 cm in size.
(7) Paired fins were absent.
(8) Median and caudal fins were present.
(9) The caudal fin was of heterocercal type.
(10) The head and thorax were covered by heavy armour of bones. It protected ostracoderms from the giant scorpion like arthropods, eurypterids.
(11) Bony skull was well developed.
(12) Mouth was mostly present on the ventral side.
(13) They were having large number of gill slits.
(14) The nervous system had 10 pairs of cranial nerves.
(15) The head had a pair of lateral eyes, and a median pineal eye.
(16) They were filter feeders, feeding like a vacuum cleaner.
(17) The endoskeleton was either bony or cartilaginous.
Evolution is a developmental process from simple to complex form of life. Evolution of elephant started 60mya, from size of a pig. It spread all over world especially Africa and Asia. Today only two species Loxodonta and Elephas exist.
Introduction
Ostracoderms (shell-skinned) are of several groups of extinct, primitive, jawless fishes that were covered in an armour of bony plates.
They appeared in the Cambrian, about 510 million years ago, and became extinct towards the end of the Devonian, about 377 million years ago. They were quite abundant during the upper Silurian and Devonian periods. Most of fossils of Ostracodermi were preserved in the bottom sediments of freshwater streams.
However, the opinion is sharply divided as to whether their habitat was freshwater or marine.
The first fossil fishes that were discovered were ostracoderms.
The Swiss anatomist Louis Agassiz received some fossils of bony armored fish from Scotland in the 1830s.
The ostracoderms resembled the present day cyclostomes (lampreys and hagfishes) in many respects and together with them constitute a special group of jawless vertebrates, the Agnatha.
Characteristics: They use gills exclusively for respiration but not for feeding . Earlier chordates with gills used them for both respiration and feeding. Ostracoderms had separate pharyngeal gill pouches along the side of the head, which were permanently open with no protective operculum. mostly small to medium-sized fishes, protected by a heavy, bony dermal (derived from skin) armor. bottom-dwellers; filter-feeders or grazers. no paired fins, but many with stabilizing paired flaps on either side of head.
(1) Ostracoderms were the first vertebrates.
(2) They were popularly called armoured fishes.
(4) They lived in freshwater.
(5) They were bottom dwellers.
(6) Their body was fish-like and did not exceed 30 cm in size.
(7) Paired fins were absent.
(8) Median and caudal fins were present.
(9) The caudal fin was of heterocercal type.
(10) The head and thorax were covered by heavy armour of bones. It protected ostracoderms from the giant scorpion like arthropods, eurypterids.
(11) Bony skull was well developed.
(12) Mouth was mostly present on the ventral side.
(13) They were having large number of gill slits.
(14) The nervous system had 10 pairs of cranial nerves.
(15) The head had a pair of lateral eyes, and a median pineal eye.
(16) They were filter feeders, feeding like a vacuum cleaner.
(17) The endoskeleton was either bony or cartilaginous.
Evolution is a developmental process from simple to complex form of life. Evolution of elephant started 60mya, from size of a pig. It spread all over world especially Africa and Asia. Today only two species Loxodonta and Elephas exist.
A vertebrate is an animal with a spinal cord surrounded by cartilage or bone. The word comes from vertebrae, the bones that make up the spine. Animals that are not vertebrates are called invertebrates. Vertebrates include birds, fish, amphibians, reptiles, and mammals
Phylum Mollusca, Class Cephalopoda, Locomotion, Digestion,Reproduction, Devel...Dr. Muhammad Moosa
In this presentation, Phylum Mollusca Is described. After watching this you will learn Evolutionary Perspective of Mollusca and Relationships to Other Animals, Molluscan Characteristics, Class Gastropoda, Torsion, Shell Coiling, Locomotion, Feeding and Digestion, Other Maintenance Functions, Reproduction and Development, Gastropod Diversity, Class Bivalvia, Shell and Associated Structures Gas Exchange, Filter Feeding, and Digestion, Other Maintenance Functions Reproduction and Development, Bivalve Diversity, Class Cephalopoda, Shell, Locomotion, Feeding and Digestion, Other Maintenance Functions, Learning, Reproduction and Development, Class Polyplacophora, Class Scaphopoda, Class Monoplacophora, Class Solenogastres, Class Caudofoveata, Further Phylogenetic Considerations. It is part of BS Zoology Course, Animal diversity.
The integumentary system comprises the skin and its appendages. Skin + derivatives= Integument.
It aims to protect the body from various kinds of damage, such as loss of water or damages from outside.
The integumentary system in chordates includes hair, scales, feathers, hooves, and nails.
It may serve to water proof, and protect the deeper tissues.
Excrete wastes, and regulate body temperature.
It is the attachment site for sensory receptors to detect pain, sensation, pressure, and temperature.
A vertebrate is an animal with a spinal cord surrounded by cartilage or bone. The word comes from vertebrae, the bones that make up the spine. Animals that are not vertebrates are called invertebrates. Vertebrates include birds, fish, amphibians, reptiles, and mammals
Phylum Mollusca, Class Cephalopoda, Locomotion, Digestion,Reproduction, Devel...Dr. Muhammad Moosa
In this presentation, Phylum Mollusca Is described. After watching this you will learn Evolutionary Perspective of Mollusca and Relationships to Other Animals, Molluscan Characteristics, Class Gastropoda, Torsion, Shell Coiling, Locomotion, Feeding and Digestion, Other Maintenance Functions, Reproduction and Development, Gastropod Diversity, Class Bivalvia, Shell and Associated Structures Gas Exchange, Filter Feeding, and Digestion, Other Maintenance Functions Reproduction and Development, Bivalve Diversity, Class Cephalopoda, Shell, Locomotion, Feeding and Digestion, Other Maintenance Functions, Learning, Reproduction and Development, Class Polyplacophora, Class Scaphopoda, Class Monoplacophora, Class Solenogastres, Class Caudofoveata, Further Phylogenetic Considerations. It is part of BS Zoology Course, Animal diversity.
The integumentary system comprises the skin and its appendages. Skin + derivatives= Integument.
It aims to protect the body from various kinds of damage, such as loss of water or damages from outside.
The integumentary system in chordates includes hair, scales, feathers, hooves, and nails.
It may serve to water proof, and protect the deeper tissues.
Excrete wastes, and regulate body temperature.
It is the attachment site for sensory receptors to detect pain, sensation, pressure, and temperature.
This is the introductory immunology lecture that I created and presented as part of the Introductory Biology 10.010 course for Singapore University of Technology and Design. This presentation was for a 90 minute lecture for freshman non-major students.
Austin Journal of Clinical Immunology is an open access, peer reviewed, scholarly journal dedicated to publish articles in all areas of immunology, asthma and allergy. The aim of the journal is to develop a knowledge sharing platform and an interactive network for immunologists, researchers, physicians, and other health professionals for exchange of scientific information in the areas of immunology.
Austin Journal of Clinical Immunology accepts original research articles, review articles, case reports, clinical images and rapid communication on all the aspects of immunology and immunotechnology.
Austin Journal of Clinical Immunology strongly supports the scientific upgradation and fortification in related scientific research community by enhancing access to peer reviewed scientific literary works. Austin Publishing Group also brings universally peer reviewed journals under one roof thereby promoting knowledge sharing, mutual promotion of multidisciplinary science.
Phylum Mollusca-my report..
sorry for some overlapping of texts... i was not able to edit it..it is actually because of the animations that i put it..... i just uploaded it directly :)
Fish are the gill-bearing aquatic craniate animals that lack limbs with digits. They form a sister group to the tunicates, together forming the olfactores. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups.
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...Scintica Instrumentation
Intravital microscopy (IVM) is a powerful tool utilized to study cellular behavior over time and space in vivo. Much of our understanding of cell biology has been accomplished using various in vitro and ex vivo methods; however, these studies do not necessarily reflect the natural dynamics of biological processes. Unlike traditional cell culture or fixed tissue imaging, IVM allows for the ultra-fast high-resolution imaging of cellular processes over time and space and were studied in its natural environment. Real-time visualization of biological processes in the context of an intact organism helps maintain physiological relevance and provide insights into the progression of disease, response to treatments or developmental processes.
In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
2. Who are the living vertebrates?
•Jawless fish: hagfish and lamprey
•Fish with jaws & cartilage skeletons: sharks and rays
•Fish with jaws & bony skeletons: all other fish (tuna, flounder, bass, etc.)
3. •Amphibians: frogs and salamanders: cold- blooded, lay eggs in water
•Reptiles: turtles, snakes and lizards: cold- blooded, lay eggs on land
•Birds: warm-blooded, feathers, lay eggs
•Mammals: warm-blooded, hair, eggs & live birth, nurse young.
4. What traits unite vertebrates?
•Spinal cord: A hollow nerve tube that runs on top or through backbone
•Heads: Brains and sense organs at the front end.
•Tails: Nerves, back support and muscles that extend past our butts.
5. What traits unite vertebrates?
•Hearts: A closed circulatory system with a muscular pump to move fluid.
•"Gill" Slits: Openings in pharnyx connecting throat to exterior.
•Segmented muscle on body wall: V-shaped muscles masses.
7. Non-Chordate Next of Kin
•Echinoderms: e.g., starfish, crinoids, sea cucumbers
•Range: Cambrian - Recent
•Habitat: Exclusively marine
8. •Unique characters: 5-fold symmetry in adults, water-vascular system, a uniquely constructed calcite skeleton
•Shared novelties: Embryonic traits (Radial pattern of embryonic cleavage, Deuterostome, Mesoderm formed by pouching); Skin-based nerve network; Bilateral, cilia-covered larvae.
9. •Hemichordates: Acorn Worms
•Range: Cambrian - Recent
•Habitat: Exclusively marine
•Unique characters: Acorn worms are large(up to 2 m), burrowing worm-like filter-feeders with a long muscular proboscis and a fleshy collar.
•Shared novelties: Adults are bilaterally symmetric; Closed circulatory system; Paired openings in the throat.
10. Chordate Next of Kin
•Urochordates: Tunicates or sea squirts
•Range: No fossil record
•Habitat: Exclusively marine
•Unique characters: Tunicates are small, box- like filter-feeding animals that live either alone or in colonies cemented to the sea floor.
11. •Shared novelties: Notochord; Hollow nerve cord along back; Tail; Endostyle (a group of ciliated cells with alternating mucus cells; used to entangle food) an organ used for filter feeding.
12. •Cephalochordates: Branchiostoma
•Range: Cambrian (Pikaia from the Burgess Shale) - Recent
•Habitat: Exclusively marine
•Unique characters: Branchiostoma, also known as the lancelet, is a small, free-living fish-like animal that lives among sand grains and filter feeds.
•Shared novelties: Segmented muscles on upper body wall.
13. Craniates: the most primitive "vertebrates"
•Hagfish: the most primitive known "vertebrate“
•Range: Carboniferous-Recent
•Habitat: Exclusively marine
14. •Unique characters: Scavengers and carnivores that actively feed by rasping at prey with a bony tongue. They tie themselves into a knot to lever a chunk out of prey. They can coat themselves with mucous for defence. They contain no vertebrae and no bone.
15. •Shared novelties: A head (cartilage brain case; partial cranium); Sense organs on the head (weak eyes); A true heart; True gills for efficient oxygen retrieval from water; Cartilage gill supports to hold up these flimsy sheets.
16. •Heterostracans: the first truly abundant fishes
•Range: Cambrian - Devonian
•Habitat: Originate in marine waters, later invade fresh water
•Unique characters: Jawless, armored body with scales on the tail. The tail was the main source of propulsion. Bottom feeding hunters and detritus feeders. Still no vertebrae.
17. •Shared novelties: Improved sense organs (better balance & vision, lateral line system for motion detection and probably electroreception (used to hunt); Bone on the outer skull but not on the braincase.
18. Why Bones of Calcium Phosphate?
•Less soluble than calcite, not as subject to dissolution by metabolic acids.
•Store of an important nutrient, phosphate.
•May serve as insulation for electroreceptors.
•Protection.
19. The first true vertebrates
•Lamprey: another extant jawless "fish"
•Range: Carboniferous - Recent
•Habitat: Originate in marine waters, later invade fresh water.
20. •Unique characters: The adult is a parasitic bloodsucker. It is jawless, but its mouth has many hooks for latching onto prey, then they use the tongue to bore through the side of the prey. No bone on the body - an evolutionary reversal.
•Shared novelties: Vertebrae surrounding notochord (made of cartilage); Dorsal and anal fins; Endostyle turns into thyroid.
21. •Osteostracan: another group of extinct armored jawless fish
•Range: Silurian - Devonian
•Habitat: Some marine, mostly fresh water
22. •Unique characters: Similar to heterostracans, with a bony head shield, scales on the tail, propulsion from the tail, well developed sense organs, and elaborate plumbing for gill system. They were active swimmers. Many were bottom feeders.
•Shared novelties: Paired pectoral fins (source of forelimbs); Braincase covered in bone.
23. The first vertebrates with jaws
•Placoderms: the most primitive jawed fish
•Range: Silurian - Carboniferous
•Habitat: Marine and fresh water
24. •Unique characters: Heavy armour on head and front of the trunk, scales on the tail, no teeth, just plates of bone for shearing food, heavy fish (probably slow swimmers).
•Shared novelties: Jaws; Paired pelvic fins (source of hind limbs); Paired nasal openings.
25. •Acanthodians: earliest known jawed fishes
•Range: Silurian - Permian
•Habitat: Initially marine, later invade fresh water.
26. •Unique characters: Their fins were supported by erectable spines. Some filter fed, others had teeth. Highly manueverable swimmers propelled by their tails.
•Shared novelties: Teeth; Advanced jaw joint.
28. •Unique characters: No bone except in their scales (an evolutionary reversal). Fin and tail structures suggest an active, highly efficient swimming for a predatory life style. Sharks give birth to live young. This requires internal fertilization of eggs. They link up when breeding by using claspers.
•Shared novelties: Regular pattern of tooth replacement.
29. Vertebrates with skeletons made entirely of bone
•Osteichthyes: Bony fish - fish with bony skeletons.
•Range: Silurian - Recent
•Habitat: Marine and fresh water.
•Shared novelties: Skeleton completely composed of bone, including skull, vertebral column, fins, and ribs; Swim bladder for buoyancy control.
30. Two major groups within the bony fish
•Ray-finned fish
•Range: Silurian - Recent
•Habitat: Marine and fresh water
•Shared Novelty uniting bony fish: Fins made of bony spines connected by poorly muscled webs.
32. •Unique Characters: Torpedo shaped body with heavy scales, unusual bone with many pores, perhaps for electroreceptive cells.
•Shared novelties: Paired pectoral and pelvic fins that are fleshy and muscular; Peculiar convoluted dentin and enamel.