Chapter 33 & 34: Invertebrates and Vertebrates
Chapter 33 & 34: Invertebrates and Vertebrates BYS 120
Popular in Organismal Biology
Popular in Biological Sciences
This 12 page Class Notes was uploaded by Amelia Notetaker on Tuesday December 1, 2015. The Class Notes belongs to BYS 120 at University of Alabama - Huntsville taught by Dr. Luciano Matzkin in Fall 2015. Since its upload, it has received 92 views. For similar materials see Organismal Biology in Biological Sciences at University of Alabama - Huntsville.
Reviews for Chapter 33 & 34: Invertebrates and Vertebrates
Report this Material
What is Karma?
Karma is the currency of StudySoup.
Date Created: 12/01/15
Chapter 33 and 34 Lecture Notes Echinodermata o Slow-moving or sessile marine animals o Thin epidermis covers an endoskeleton of hard calcarious parts o Water vascular system Network of hydrolic canals branching into tube feet that function in locomotion and feeding o Males and females are separate o Broadcast sponers o Most adults have radial-like symmetry with multiples of five Larvae have bilateral symmetry o Asterodia Sea stars have multiple arms radiating from central disk Under surface of each arm there are tubs that help moves Fed on bivalves by prying them open with tubed feet Can regenerate lost arms o Ophiuroidea Brittle stars have a distinct disk and long flexible arms for movement Suspension feeders, predators, or scavengers o Echinoidea Sea urchins and sand dollars No arms but 5 rows of tub feet Spines used for locomotion and protection Feed on seaweed using jaw-like structure o Crinoidea Sea lilies that live attached by stalk Feather stars can swim using long flexible arms o Holothuroidea Sea cucumbers lack spines Reduced exoskeleton 5 rows of tube feet some are modified as feeding tentacles Chordata o Oldest known fossil 530 MYA o All vertebrates and 2 groups of invertebrates are here o 4 key characteristics Notochord Dorsal, hallow nerve cord Pharyngal silts or clefts Muscular, post-anal tail o Some species don't have all at once Notochord o Longitudinal, flexible rod between digestive tube and nerve cord o Provide skeletal support throughout most of length of chordate Dorsal, hallow nerve cord o Embryo development from a plate of ectoderm that rolls into a tube dorsal to the notochord o Development into central nervous system: brain and spinal cord o Development of nerve cord: Pharyngeal slits or clefts o Grooves of pharynx o Develop into slits open to the outside of the body o Functions Suspension feeding Gas exchange Development into parts of ear, head and neck Muscular post-anal tail o Posterior to anus o Reduced in embryonic stage in some o Tail has skeletal elements and muscles o Can be propelling force in marine life Which is not one key characteristic traits of chordates o Four walking legs or 2 walking legs and 2 arms Cephalochordata o Include lancelets Filter feeders o Most basal of all chordates Urochordata o Most closely related to other chordates than lancelets o Resemble chordates during larval stage o As adult, drains water through incurrent syphon, filtering food particles o When attacked, shoots water through excurrent syphone Sea squirts Craniates o Skull, brain, eyes and other sensory organs o Origin of a head enabled chordates to coordinate more complex movement and feeding behavior o Have a neural crest Cells near dorsal margin of closing neural tube of embryo Give rise to a variety of structures (bones and cartilage in skull) o In aquatic craniates, pharyngeal clefts evolved into gill slits o Higher metabolism and more muscles o Have a heart with at lest 2 chambers, red blood cells, and kidneys o Around 530 MYA we see origin of skulls Myxini (hagfish) o Basal group of craniates o Skull (Cartilage) axil rod of cartilage derived from brain, eyes, ears, and tooth formations o Marine bottom dwelling and scavengers Vertebrates o Derived characters Vertebrae enclosing spine Elaborate skulls Fin rays in aquatic forms o Evolution Conodonts were the 1st vertebrates with mineralized skeletal elements in mouth and pharynx Teeth Other armored, jawless vertebrates had defensive plates of bone on their skin Mineralization appears in mouth parts of vertebrates Vertebrates' endoskeleton became fully mineralized much later Lampreys (Petromyzontida) o Oldest linage of vertebrates o Cartilaginous segments surrounding notochord and arching partly over nerve cord Gnathostomes o Sharks and their relatives, ray finned fish, lobe finned fish, amphibians, reptiles (birds), and mammals o Jaws that might've evolved from skeletal supports of pharyngeal slits o Enlarged forebrain associated with enhanced vision and smell o In aquatic forms, the lateral lim is sensitive to vibration o Earliest (450 MYA) fossil records are an extinct linage of armored vertebrates called placoderms o 3 lineages Chondrichthyes o Skeleton mostly cartilage o Largest most diverse group o Sharks Steam-lined body and are swift swimmers Suspension feeders, but most are carnivorous Acute senses includes sight, smell, and can detect electrical fields from nearby animals Eggs are fertilized internally but embryos can develop different ways Uviparous Eggs hatch outside Ovoviviparous Embryo development in uterus and is nourished in egg yolk Viviparous Within the uterus nourished with yolk sac placenta from mother's blood Development genes in chordate evolution o Changes in developmental genes were fundamental in diversification in morphological evolution observed in chordates o The same hox genes organize vertebrate's brain are expressed in lancelet's simple nerve cord tip o Hox genes duplication around craniates's beginning 2 sets of evergy hox genes o Duplication of (DIX) distal-less homeobox at vertebrates and higher Limb development o Genome duplication (including Hox) in gnathostomes and higher (400 MYA) o Genome duplication again in actinptergii (8 sets) 200 MYA Common genes in chordate evolution o Genome sequence suggest Genes associated with heart and thyroid are common to all chordates Genes associated with transmission of nerve impulses are unique to vertebrates Osteichthyans o Have lungs or modified lungs o Vast majority of vertebrates o Nearly all have bony endoskeleton o Bony fish and tetrapods Fish o Most breathe by drawing water over gills protected by opericulum o Control buoyancy with air sac known as swim bladder Modified lung o Lateral line system o Oviparous, some have internal fertilization and live birth Actinopterygii o Ray-finned fish, all aquatic o During siturian period (444-416 MYA) o Locomotion and defense (fins) Lobed fins (Sacropterygii) o Rod shaped bones o Originated around same time as actinopterygii Tetrapods o Limbs with digits o Characteristics include 4 limbs and feet with digits Neck which allow separate movement of head Fusion of pelvic girdle to backbone Absence of gills (except some aquatic species) Ears for detecting airborne sound o Fossil from 375 MYA o Tiktaalik, "fishapod" shows both fish and tetrapod characteristics Fins, gills, lungs, and scales Ribs breathe air and support body A neck Fins with bone pattern of a tetrapod Could prop itself up on fins Appeared around 365 MYA Amphibia o Urodela Salamanders o Anura Frogs and toads o Apoda Caecilians (legless salamanders) o Undergo metamorphosis from an aquatic larva into a terrestrial adult o Moat have moist skin that complements the lungs in gas exchange o External fertilization in most Eggs require moist environment o Some (male or female) care for eggs on back, mouth or stomach Amniotes o Includes reptiles, birds, and mammals o Clade is amniotic eggs Contains 4 extraembyronic membranes Amnion, chorion, yolk sac, and allantoes Most eggs of reptiles and some mammals have shells o Eggs adapted, has a relatively premeable skin and ability to use rib cage to ventilate lungs o Living amphibians and amniotes split 350 MYA o Early amniotes lived in dry conditions compared to mammals Reptiles o Scales create waterproof barrier o Most lay shelled eggs on land o Ectothermic: absorb external heat as main source of body heat Only in most, not all o Birds Endothermic: capable of keeping body heat through metabolism Oldest fossil in carboniferous period (359-299 MYA) Parareptiles were 1st group Large herbivores Adapted for flight Wings with keratin feathers Lack of urinary bladder Females have 1 ovary Small gonads Loss of teeth Flight enhances hunting and scavenging and escape from predators and migration Requires a lot of energy as well as acute vision an fine muscle control Evolved from male theropods Carnivorous dinosaurs Feathers have evolved or insulation, camouflage, and courtship display Helped with left when jumping, gaining traction when running up hills, and gliding from tree to tree Oldest fossil 150 MYA archaeopteryx o Diapsids Lepidosaurs Snakes Legless, evolved from lizards Carnivorous and some venomous lizards Archosaurs Crocodiles and dinosaurs Not a characteristic of all chordates? o 4 walking legs or 2 walking legs and 2 arms Mammalia o Have Mammary glands --> produce milk hair High metabolic rate --> due to endothermy Larger brain than any other vertebrate of equivalent size Differentiated teeth o Evolved from synapsids 287 MYA Had fenestra: hole behind eye socket to support muscles 2 bones that formally made up jaw joint were incorporated into mammalian middle ear Incus (quadrate) and Malleus (articular) o By early Cretaceous (about 140 MYA) 3 living lineages Monotremes Small group of egg laying mammals including platypus 5 species Marsupials Opossums, Kangaroos, and Koalas Embryo develop within placenta in uterus Early development leaves and goes into pouch and nurse and finish development there Convergent evolution has resulted in a diversity of marsupials that resemble eutherians Eutherian More complex placentas than marsupials Complete development in uterus and found to mone with placenta o Largest amount of diversification was after dinosaurs went extinct Primates o In addition to humans the mammalian order includes lemurs, monkeys, tansies, etc o Most have hands and feet adapted to grasping and flat nails o Large brain and short jaws o Forward looking eyes close together on face, providing depth perception o Complex social behavior and parental care o Fully opposable thumb (monkeys and apes) o 3 main groups Humans in anthropoids Anthropoid evolution o 1st monkeys evolved in old world (africa and asia) o New world (south america) appeared 35 MYA o New world and old world monkeys under went separate adaptations and radiations Ape evolution o Gibbons, orangutans, etc o Diverged from old world monkeys 20-25 MYA Human characteristics o Humans and chimps genomes are 99% identical o Upright posture and bipedal locomotion o Larger brains capable of language, symbolic thought, and artistic expression, the manufacture and use of complex tools o Reduced jaw bones and jaw muscles o Shorter digestive tract o Changes in regulatory genes can have large effects Hominin evolution o Closely related to humans than chimps o Fossils of about 20 species that are now extinct o Originated in africa 6-7 MYA o Early ones show evidence of small brains and increasing bipedalism o Australopiths are a paraphyletic assemblage of hominins 4-2 MYA Fully erect Australopiths o Robust: had sturdy skulls and poweful jaws o Gracile: more slender and light jaws Bipedalism o Began walking long distances on 2 legs 1.9 MYA Tools o Oldest evidence of tools, cut marks on animal bones 2.5 MYA Homo halibis o Earliest homo fossil 2.4-1.6 MYA o Stone tools have been found with these --> "handy man" Homo nalede o New fossil found in south africa o About 5 feet tall o Could be one of the earliest homos, but they're dating the fossil now Homo ergaster o First fully bipedal, large-brained o Existed between 1.9-1.5 MYA o Significant decrease in sexual dimorphism (size difference between sexes) compared to ancestors Homo erectus o Originated in africa 1.8 MYA o 1st hominin to leave africa Homo neanderthalensis o Neanderthals lived in europe and near east for 35,000 to 28,000 years ago o Think boned with larger brain, buried their dead and made hunting tools Homo sapiens o Appeared in africa by 195,000 years ago o All living humans are descended from these ancestors from africa o Oldest fossils outside africa was about 15,000 years ago and was in the middle east Arrive to the new world before 15,000 years ago Homo neanderthalensis and Homo sapiens o What happened to Neanderthals? o In 2010 neanderthal genome was sequenced o Hybridization between the 2 species occurred in Euroasia European descent have about 4% neanderthal genes Homo floresiensis o In 2004, 18,000 year old fossils were found in indonesia Small Homo sapiens population structure o Although there's variation across populations it is only a very small fraction of overall species - level variation Deviance of DNA differs between species not populations o The term "race" has no biological support in homo sapiens Classification of us o Sapiens --> homo --> homonidae --> primates --> mammalia --> chordata --> animalia (metozoa) --> eukarya o Not the end product of evolution