bio final

The rotifers

(Rotifera, commonly called wheel animals) make up a phylum of microscopic and near-microscopic pseudocoelomate animals. Some rotifers are free swimming and truly planktonic, others move by inch-worming along a substrate, and some are sessile, living inside tubes or gelatinous holdfasts that are attached to a substrate. About 25 species are colonial (e.g., Sinantherina semibullata), either sessile or planktonic. Rotifers are an important part of the freshwater zooplankton, being a major food source and with many species also contributing to the decomposition of soil organic matter. - Wiki

Metanephridia (plural)

(meta = "after") is a type of excretory gland found in many types of invertebrates such as annelids, arthropods and molluscs. (In molluscs it is known as the Bojanus organ.) A metanephridium typically consists of a ciliated funnel opening into the body cavity or coelom connected to a duct which may be variously glandularized, folded or expanded (vesiculate) and which typically opens to the organism's exterior. These ciliated tubules pump water carrying surplus ions, metabolic waste, toxins from food, and useless hormones out of the organism by directing them down funnel-shaped bodies called nephrostomes. This waste is passed out of the organism at the nephridiopore. The primary urine produced by filtration of blood (or a similar functioning fluid) is modified into secondary urine through selective reabsorption by the cells lining the metanephridium The metanephridia filter and excrete wastes in certain inverts.

Cubozoans

(mostly found in Australia)often have highly toxic cnidocytes •For example, the sting of the sea wasp off the coast of northern Australia can lead to respiratory failure, cardiac arrest, and death within minutes. You are headed to Medical, Dental, Veterinary, Graduate School, etc. As I have stated many times, I am always on the lookout for references to pathology, pharmacology and toxicology to aid in your future studies.

phyla- cladogram

*** Important - This figure shows 15 of the 36 animal phyla. Please know the characters and the clades backwards and forwards as we progress through our discussions of the animals.

Note the Embryological Development Steps (most animals).......

**** Note the steps are alphabetical*** 1). Blastulation 2). Gastrulation 3). Neurulation **** - The only tricky part is that "the blastopore" forms during gastrulation ****

The Bryozoa

, also known as Polyzoa or Ectoprocta,[5] are a phylum of aquatic invertebrate animals. Typically about 0.5 millimetres (0.020 in) long, they are filter feeders that sieve food particles out of the water using a retractable lophophore, a "crown" of tentacles lined with cilia. Most marine species live in tropical waters, but a few occur in oceanic trenches, and others are found in polar waters. One class lives only in a variety of freshwater environments, and a few members of a mostly marine class prefer brackish water. Over 4,000 living species are known. One genus is solitary and the rest colonial. - Taylor, P.D.; Berning, B.; Wilson, M.A. (2013). "Reinterpretation of the Cambrian 'bryozoan' Pywackia as an octocoral". Journal of Paleontology 87 (6): 984-990. doi:10.1666/13-029.

Frogs

- Frogs (anurans) lack tails and have powerful hind legs for locomotion on land Frogs with leathery skin are called "toads"

Newly born neurons in the brain of an adult mouse

- Green = A New Neuron - Red = DNA

The vertebrate nervous system

- In humans, there are 31 pairs of spinal nerves and 12 pairs of cranial nerves.

remember

- Please remember that we have seen the term "zygote" in many other groups of life

Ventricles, gray matter, and white matter

- Replete with CSF

NOTE

- Seahorse males do something highly unusual in the animal kingdom; the males "get pregnant" (female deposits the eggs in his pouch) and he "delivers" their offspring. Scientists don't have a clear reason (not maladaptive - stays in the gene pool) "why" or how seahorses evolved this way, but they theorize this is one of the ways seahorses try to help the species survive. Neither parent gets involved in the progeny -rearing, though. When the male delivers the babies, they are on their own!

IMPORTANT

- The mantle cavity of a bivalve contains gills that are used for feeding as well as gas exchange -Most species are sedentary, but some have limited motility

A Ghost Crab

- a decapod

Know these terms

- metazoan = multicellular - umetazoans= has tissues

primitive "heart"

- structures are starting to appear as the animals evolve more complex anatomy and physiology. - NOTE - the folded nature of the book lungs maximizes CO2 and O2 exchange between the air and the hemolymph.

Neurotransmitters

-A single neurotransmitter may bind specifically to more than a dozen different receptors. Receptor activation and postsynaptic response cease when neurotransmitters are cleared from the synaptic cleft -Know This - Neurotransmitters in the synapse are removed by: simple diffusion, inactivation by enzymes, or "recapture" (reuptake) into the presynaptic neuron. The recapturing is accomplished by PRE-synaptic, neurotransmitter reuptake proteins. -GOOD Question - What happens to the amount of neurotransmitter IN the synapse if a drug BLOCKED the neurotransmitter reuptake proteins on the presynaptic side???

Conduction of Action Potentials

-AP = Wave of depolarization (Na+ into the cell) along a cell membrane. -At the site where the action potential is generated (usually the axonal hillock) an electrical "current" depolarizes the neighboring region of the axon membrane -Action potentials travel in only one direction: toward the synaptic terminals -Inactivated Na+ channels behind the zone of depolarization prevent the action potential from traveling backwards

Acetylcholine

-Acetylcholine is a common neurotransmitter in vertebrates and invertebrates -It is involved in muscle stimulation, memory formation, and learning -Vertebrates have two major classes of acetylcholine receptor, one that is ligand gated and one that is metabotropic

nodes of Ranvier

-Action potentials are formed only at nodes of Ranvier, gaps in the myelin sheath where voltage-gated Na+ channels are found -Action potentials in myelinated axons jump between the nodes of Ranvier in a process called saltatory conduction

Lifestyle and Ecology of Amphibians

-Amphibian means "both ways of life," referring to the metamorphosis of an aquatic larva into a terrestrial adult -Tadpoles are herbivores that lack legs, but legs, lungs, external eardrums, and adaptations for carnivory may all arise during metamorphosis -Most amphibians have moist skin that complements the lungs in gas exchange. This is called trans-cutaneous gas exchange.

Generation of Action Potentials: A Closer Look

-An action potential can be considered as a series of stages -At resting membrane potential: 1.Most voltage-gated sodium (Na+) and potassium (K+) channels are closed 2.What I really want you to know here is that the Action Potential starts at THRESHOLD!!!

The Basics of the Action Potential (AP):

-An action potential must first be setup by resting membrane potential (inside of the cell has a negative charge relative to the outside). -An action potential is a wave of depolarization (inside of cell becomes more positive - Na+ diffuses in) along a membrane. -It is an "All of None" physiological response and it is the same EVERY time - once the AP starts it cannot be stopped under normal circumstances. -There are ONLY more or fewer action potentials - NO "larger" or "smaller" APs!!

Nervous systems consist of circuits of neurons and supporting cells

-By the time of the Cambrian explosion more than 500 million years ago, specialized systems of neurons had appeared that enables animals to sense their environments and respond rapidly -Remember - Cephalization allowed for the increased complexity and development of anterior nerve bundles that eventually would become brains. Moreover, the ossification of the head allowed for protection of the brain.

Caecilians

-Caecilians (apoda) are legless, nearly blind, and resemble earthworms -The absence of legs is a secondary adaptation

refractory period

-During the refractory period after an action potential, a second action potential cannot be initiated -The refractory period is a result of a temporary inactivation of the Na+ channels

Half a Billion Years of Backbones...

-Early in the Cambrian period, about 530 million years ago, an astonishing variety of invertebrate animals inhabited Earth's oceans -One type of animal gave rise to vertebrates, one of the most successful groups of animals -The animals called vertebrates get their name from vertebrae, the series of bones that make up the backbone

-Postsynaptic potentials fall into two categories

-Excitatory postsynaptic potentials (EPSPs) are depolarizations that bring the membrane potential toward threshold -Inhibitory postsynaptic potentials (IPSPs) are hyperpolarizations that move the membrane potential farther from threshold

Glia - Remember, one question on the final exam over glial cells and their function!!

-Glial cells, or glia have numerous functions to nourish, support, and regulate neurons -Embryonic radial glia form tracks along which newly formed neurons migrate -Astrocytes induce cells lining capillaries in the CNS to form tight junctions, resulting in a blood-brain barrier and restricting the entry of most substances into the brain

-The brain and spinal cord contain:

-Gray matter, which consists of neuron cell bodies, dendrites, and unmyelinated axons -White matter, which consists of bundles of myelinated axons

Put this in your memory for the rest of your life....depolarization is Na+ into the cell; repolarization is K+ out. An action potential is a neuron is: Sodium in...Potassium out. The membrane depolarizes then it repolarizes.

-If a depolarization shifts the membrane potential sufficiently, it results in a massive change in membrane voltage called an action potential -Action potentials have a constant magnitude, are all-or-none, and transmit signals over long distances -They arise because some ion channels are voltage-gated, opening or closing when the membrane potential passes a certain level

Formation of the Resting Membrane Potential:

-In a mammalian neuron at resting potential, the concentration of K+ is highest inside the cell, while the concentration of Na+ is highest outside the cell -Sodium-potassium pumps (pumps 3 Na+ out; 2 K+ into the cell) use the energy of ATP to maintain these K+ and Na+ gradients across the plasma membrane -These concentration gradients represent chemical potential energy -IMPORTANT - The RMP of a cell comes from the (1), Na+/K+ ATPase pump and (2), the slow-leak K+ channel.

ganglia

-Interpreting signals in the nervous system involves sorting a complex set of paths and connections -Processing of information takes place in simple clusters of neurons called ganglia or a more complex organization of neurons called a brain -NOTE - A ganglion (ganglia = plural) is often times referred to as a group of cell somas (body of thee neuron) outside the central nervous system (CNS).

Summation of Postsynaptic Potentials

-Most neurons have many synapses on their dendrites and cell body -A single EPSP is usually too small to trigger an action potential in a postsynaptic neuron

Molluscs

-Phylum Mollusca includes snails and slugs, oysters and clams, and octopuses and squids -Most molluscs are marine, though some inhabit fresh water and some snails and slugs are terrestrial -Molluscs are soft-bodied animals, but most are protected by a hard shell

The scolex contains suckers and hooks for attaching to the host. Why????

-Proglottids are units that contain sex organs and form a ribbon behind the scolex -Fertilized eggs, produced by sexual reproduction, leave the host's body in fecal matter

Glial Cell Types

-Radial glial cells and astrocytes can both act as stem cells -Researchers are trying to find a way to use neural stem cells to replace brain tissue that has ceased to function normally -Ependymal Cells = make cerebrospinal fluid (CSF). -Astrocytes - Form blood-brain barrier; scavenge ions and neurotransmitter; hold nerves in place, etc.

Organization of the Vertebrate Nervous System

-The CNS develops from the hollow nerve cord -The cavity of the nerve cord gives rise to the narrow central canal of the spinal cord and the ventricles of the brain -The canal and ventricles fill with cerebrospinal fluid (CSF), which supplies the CNS with nutrients and hormones and carries away wastes

The Peripheral Nervous System

-The PNS transmits information to and from the CNS and regulates movement and the internal environment -In the PNS, afferent neurons transmit information to the CNS and efferent neurons transmit information away from the CNS

Lines of Communication

-The cone snail kills prey with venom that disables neurons -Neurons are nerve cells that transfer information within the body -Neurons use two types of signals to communicate: electrical signals (long-distance) and chemical signals (short-distance)

Command and Control Center

-The human brain contains about 100 billion neurons (100 TRILLION synapses), organized into circuits more complex than the most powerful supercomputers -Powerful imaging techniques allow researchers to monitor multiple areas of the brain while the subject performs various tasks. A recent advance uses expression of combinations of colored proteins in brain cells, a technique called "brainbow". -Please Read This - Human brain uses 20% of ALL oxygen intake; 20-25% of ALL glucose consumed; 45 meters of nerves JUST in the skin! To wit - the night before exams..... Starch and sleep!

What is physiology??? The movement of ions that causes proteins to change configuration. Form = Function

-The opening of ion channels in the plasma membrane converts chemical potential to electrical potential -A neuron at resting potential contains many open K+ "leak" channels and fewer open Na+ "leak" channels; K+ diffuses out of the cell (part of RMP) -The resulting buildup of negative charge within the neuron (inside the neuron) is the major source of membrane potential

A chemical synapse

-The presynaptic neuron synthesizes and packages the neurotransmitter in synaptic vesicles located in the synaptic terminal -The action potential causes the release of the neurotransmitter -The neurotransmitter diffuses across the synaptic cleft and is received by the postsynaptic cell

The PNS has two efferent (motor) components: the somatic motor system and the autonomic nervous system:

-The somatic motor system carries signals to skeletal muscles and is voluntary -The autonomic nervous system regulates smooth and cardiac muscles and is generally involuntary

Evolutionary Adaptations of Axon Structure

-The speed of an action potential increases with the axon's diameter -In vertebrates, some axons are insulated by a myelin sheath, which causes an action potential's speed to increase -Myelin sheaths are made by glia— oligodendrocytes (glial cell) in the CNS and Schwann cells (glial cell) in the PNS

The autonomic nervous system has sympathetic and parasympathetic divisions

-The sympathetic division regulates arousal and energy generation ("fight-or-flight" response) -The parasympathetic division has antagonistic effects on target organs and promotes calming and a return to "rest and digest" functions -NOTE - I will expect you to know sympathetic from parasympathetic effects.

neurotransmitters

-The synaptic terminal of one axon passes information across the synapse in the form of chemical messengers called neurotransmitters -A synapse is a junction between an axon and another cell -NOTE - Neurotransmitters are the signaling molecule from one neuron to: another neuron, muscle or gland.

Ion pumps and ion channels establish the resting potential of a neuron

-VERY Important - Every cell has a voltage (difference in electrical charge) across its plasma membrane called a resting membrane potential -VERY IMPORTANT - The resting membrane potential is the membrane potential of a neuron not sending signals. Must have RMP before an action potential can be generated. -Changes in membrane potential act as signals, transmitting and processing information

Parthenogenesis

-is a natural form of asexual reproduction in which growth and development of embryos occur without fertilization. In animals, parthenogenesis means development of an embryo from an unfertilized egg cell. In plants parthenogenesis is a component process of apomixis. Parthenogenesis occurs naturally in some plants, some invertebrate animal species -certain invertebrates nematodes, eratnids, insects, all the way into vertebrates fish and amphibians. birds are reptiles, warm blooded.

Embryonic Development Sequence -

1- blastulation, then 2- gastrulation then 3-neurulation.

Most inclusive to least inclusive

1. Primates 2. Anthropoids 3. Apes 4. Hominids/Hominins 5. Homo (genus name) 6. sapiens (species name) - Important slide!!

Transition to Land.....

1.2 BYA - Primitive cyanobacteria, fungi and primitive "protists" 500-470 MYA - small plants and fungi 440-410 MYA - First animals 385 MYA - Tall plants 375 MYA - Tiktaalik (first vertebrate tetrapod) 350 MYA - First amniotes 310 MYA - First Reptiles

Transition to Land/Earliest Fossil Evidence:

1.2 BYA - Primitive cyanobacteria, fungi and primitive "protists" 500-470 MYA - small plants and fungi 440-410 MYA - First animals 385 MYA - Tall plants 375 MYA - Tiktaalik (first vertebrate tetrapod) 350 MYA - First amniotes 310 MYA - First Reptiles 200-140 MYA - First mammals 60 MYA - Ancestral primates 2.0-1.4 MYA - First members of the genus Homo

-When an action potential is generated: (Remember - the action potential starts at the membrane's threshold value; -50 millivolts for the average neuron).

2.Voltage-gated Na+ channels open first and Na+ flows into the cell 3.During the rising phase, the threshold is crossed, and the membrane potential increases 4.During the falling phase, voltage-gated Na+ channels become inactivated; voltage-gated K+ channels open, and K+ flows out of the cell

Amniotes - reptiles, birds, mammals

A fenestra (fenestration; plural fenestrae or fenestrations) is any small opening or pore, commonly used as a term in the biological sciences.[1] It is Latin for the word "window", and is used in various fields to describe a pore in an anatomical structure.

Homeobox (genes):

A homeobox is a DNA sequence (part of a gene),180 base pairs long, found within genes that are involved in the regulation of patterns of (embryological) anatomical development.

Schwann cells and the myelin sheath

A myelinated neuron/nerve has a HIGHER action potential conductance velocity!!

Derived Characters of Humans

A number of characters distinguish humans from other apes •Upright posture and bipedal locomotion •Larger brains capable of language, symbolic thought, artistic expression, the manufacture and use of complex tools - evolution of the prefrontal cortex of the brain is extremely important! •Reduced jawbones and jaw muscles •Shorter digestive tract

There are two variations on the body plan: the sessile polyp and motile medusa:

A polyp adheres to the substrate by the aboral (opposite or away from mouth) end of its body A medusa has a bell-shaped body with its mouth on the underside Medusae do not attach to the substrate but move freely

Gastropods

About three-quarters of all living species of molluscs are gastropods Most are marine Some are freshwater species Snails and slugs are terrestrial

Acoelomate

Acoelomates - lack body cavity •Mesoderm is filled with tissue Platyhelminthes (flatworms)

Ray-Finned Fishes

Actinopterygii, the ray-finned fishes, include nearly all the familiar aquatic osteichthyans Ray-finned fishes originated during the Silurian period (444 to 416 million years ago) The fins, supported mainly by long, flexible rays, are modified for maneuvering, defense, and other functions

Derived Characters of Chordates

All chordates share a set of derived characters Some species have some of these traits only during embryonic development Five key characters of chordates: •Notochord •Dorsal, hollow nerve cord •Pharyngeal slits or clefts •Muscular, post-anal tail •Endostyle

Functions of Amniotic Membranes

Allantois - becomes umbilical vessels in higher vertebrates. Chorion - becomes fetal contribution to placenta in higher vertebrates. Amnion - secretes amniotic fluid ("shock absorber"). Yolk Sac - nutrition source; first site of RBC biosynthesis in most vertebrates

Derived Characters of Amniotes

Amniotes are named for the major derived character of the clade, the amniotic egg, which contains membranes that protect the embryo NOTE - The extraembryonic membranes are the amnion, chorion, yolk sac, and allantois NOTE = Allows for gas exchange, nutrient storage and prevents desiccation!!

Amoebocytes.......

Amoebocytes are able to distribute engulfed particles to different cells; able to secrete silica and calcium carbonate and are totipotent!! Totipotent (cell) - A totipotent cell is an undifferentiated cell that is capable of becoming other types of cells. Ergo, sponges can adapt quickly to environmental pressures. Important - Sponges can also produce anticancer and antibiotic compounds (Ex.: Cibriostatin)!!!

Conduction of an action potential

An action potential is a wave of depolarization along a membrane

Features Used to Classify Animals

Animals are classified according to certain morphological and developmental characteristics •Symmetry •Number of tissue layers •Origin of mouth and anus •Body plan and cavities

Animal Characterization Based on Features of Embryological Development

Animals are divided into two major groups: •Parazoa ('beside' animals) •No true tissues or symmetry •Sponges (Phylum Porifera) •Eumetazoa ('true' animals) (has tissues) •Remaining animals with distinct tissues & symmetry

Annelids

Annelids are coelomates with bodies composed of a series of fused rings The phylum Annelida was traditionally (NOTE the "was") divided into three clades: •Polychaeta (polychaetes) •Oligochaeta (oligochaetes) Hirundinea (leeches)

Arachnids

Arachnids have six pairs of appendages: the chelicerae, the pedipalps, and four pairs of walking legs Gas exchange in spiders occurs in respiratory organs called book lungs - stacked plate like structures. Many spiders produce silk, a liquid protein, from specialized abdominal glands

Animal Characterization Based on Body Symmetry

Arrangement of body parts along body axis •Asymmetrical •Lack of symmetry •Porifera (sponges)

Planarians and Asexual Reproduction

Asexually, flatworms procreate via fragmentation, fission, parthenogenesis and budding. Fragmentation, also called "cloning", occurs when a flatworm splits off a part of its body, allowing the separated portion to regenerate into a new worm. With budding, a flatworm grows an extension from its body. Fission (It is BACK!!)- In this mode of planarian reproduction, the planarian simply constricts its body until it actually separates into two parts, one the anterior and the other the posterior ends. Each of the parts then regenerates the missing portion through binary fission and thus two complete individuals arise. Binary fission is common in many types of simple organisms like bacteria.

Australopiths

Australopiths are a paraphyletic assemblage of hominins living between 4 and 2 million years ago Some species, such as Australopithecus afarensis walked fully erect

Derived Characters of Humans (Important)!!

Bipedalism--->opposable thumbs---->widening of the hips---->brains became larger. Needed to be bipedal to see over the tall grass. We also learned how to cook!! Cooking made nutrition more readily absorbable which helped the brain develop in size. In the last 2 million years the human brain has TRIPLED in size!!!! Homo habilis to Homo sapiens We have (evolved into) the prefrontal cortex!!

Birds

Birds are archosaurs, but almost every feature of their reptilian anatomy has undergone modification in their adaptation to flight (however - not all birds can fly) Remember - Birds are reptiles.

Bivalves

Bivalves are aquatic and include many species of clams, oysters, mussels, and scallops They have a shell divided into two halves drawn together by adductor muscles. Remember, muscles relax when they run out of energy. An eventuality the sea stars have exploited - more on that later in the lecture. Some bivalves have eyes and sensory tentacles along the edge of their mantle

Evolutionary significance of a coelom

Body cavities, compartmentalization, and connective tissue to hold organs in place.

(B) - Ophiuroidea: Brittle Stars

Brittle stars have a distinct central disk and long, flexible arms, which they use for movement Some species are suspension feeders, while others are predators or scavengers Can use tube feet to attach to substrates

Cambrian 'Explosion' of Animal Life

Cambrian period - 542-488 mya •One of the most rapid periods in animal evolution à new phyla •Cambrian 'explosion' •Most of today's phyla originated •Echinoderms, mollusks, worms, arthropods, chordates

Cephalopods

Cephalopods are carnivores with beak-like jaws surrounded by tentacles of their modified foot They are able to immobilize prey with a poison present in their saliva Most octopuses creep along the sea floor in search of prey

Chelicerates

Chelicerates, clade Chelicerata, are named for clawlike feeding appendages called chelicerae. Chelicerae - modified first pair of appendages (usually mouth parts or fangs). They have an anterior cephalothorax and a posterior abdomen The earliest chelicerates were eurypterids (water scorpions) Most marine chelicerates (including eurypterids) are extinct, but some species survive today, including horseshoe crabs

Chitons

Chitons are oval-shaped marine animals encased in an armor of eight dorsal plates They use their foot like a suction cup to grip rock, and their radula to scrape algae off the rock surface NOTE - chiton is NOT the same as chitin!!

Muscular, Post-Anal Tail

Chordates have a tail posterior to the anus In many species, the tail is greatly reduced during embryonic development The tail contains skeletal elements and muscles It provides propelling force in many aquatic species. NOTE - Try to think of all of the uses that chordates could (and do) use a tail for.

Cnidarians

Cnidarians are carnivores that use tentacles to capture prey The tentacles are armed with cnidocytes (this is where Cnidarians get there name - an autapomorphic trait), unique cells that function in defense and capture of prey Nematocysts are specialized organelles within cnidocytes that eject a stinging thread

coelomate

Coelomates ("eucoelomates") •Arises completely within mesoderm - •Body cavity & internal organs lined with mesoderm •Tissue holds organs in place, allowing motion •Most other animals

Post-Cambrian Evolution and Mass Extinctions

Cretaceous-Paleogene (Tertiary) boundary (~66 mya) •Dust from large meteorite impact near Yucatan plus volcanic activity à severe climate change •Plants, most herbivores and carnivores died, opening niches •Allowed radiation of mammals, birds and flowering plants

Crustaceans

Crustaceans live in marine and freshwater environments Many crustaceans have highly specialized appendages Small crustaceans exchange gases through the cuticle; larger crustaceans have gills

Important Slide:

Derived Characters of Birds Many characters of birds are adaptations that facilitate flight referred The major adaptation is wings (convergent evolution) with keratin feathers Other adaptations include lack of a urinary bladder, females with only one ovary, small gonads, and loss of teeth ALSO....large pectoral muscles (for flight.)

•Radial Symmetry

Diploblastic - 2 embryonic tissues (endoderm and ectoderm) •Cnidarians and Ctenophores

Post-Cambrian Evolution and Mass Extinctions

Dramatic global and regional climate change (changes in moisture and temperature) can also lead to mass extinctions •Major losses of diversity •Permian-Triassic boundary - greatest extinction event •Likely due to extensive climate change from impact event(s) and/or volcanic activity

Animal Reproduction and Development

Early development after zygote forms •Cleavage (series of mitotic cell divisions) •After three divisions à 8-cell stage •Cells continue to divide and/or rearrange... •Blastula •Migration of cells à 6 to 32-cell hollow 'ball' •Blastocoel is internal cavity

Earthworms - Former Oligochaete

Earthworms eat through soil, extracting nutrients as the soil moves through the alimentary canal Earthworms are hermaphrodites but cross-fertilize Some reproduce asexually by fragmentation followed by regeneration - engage in sexual reproduction as well.

Most fishes breathe by drawing water over gills protected by an operculum (a covering)

Fishes control their buoyancy with an air sac known as a swim bladder Fishes have a lateral line system (think black bass) Most species are oviparous, but some have internal fertilization and birthing

Most fishes breathe by drawing water over gills protected by an operculum (a covering)

Fishes control their buoyancy with an air sac known as a swim bladder Fishes have a lateral line system (think black bass) Most species are oviparous, but some have internal fertilization and birthing

note

Flight is one key to the great success of insects (Remember....wings are analogous traits; convergent evolution) An animal that can fly can escape predators, find food, and disperse to new habitats much faster than organisms that can only crawl NOTE - Insect wings are an extension of the cuticle

Jawless Fish

Hagfish -slime -scavengers Lampreys -Rows of teeth -Some bore teeth into fish; some are filter-feeders

Hagfishes

Hagfishes (Myxini) are jawless "vertebrates" that have a cartilaginous skull, reduced vertebrae, and a flexible rod of cartilage derived from the notochord They have a small brain, eyes, ears, and tooth-like formations Hagfishes are marine; most are bottom-dwelling scavengers SLIME as a defense (food procurement)!!

Insects

Hexapoda is an enormous clade including insects and their relatives. Extensive biodiversity found within the insects. Insects live in almost every terrestrial habitat and in fresh water (some are marine). The internal anatomy of an insect includes several complex organ systems NOTE - Animal organ systems are becoming more and more complex.

Bipedalism

Hominins began to walk long distances on two legs about 1.9 million years ago Bipedal walking was energy efficient in the arid environments inhabited by hominins at the time Important - Bipedalism also allowed the pelvic bones to widen anatomically. This allowed for newborns to be born with a larger cranium/larger brain.

Mammals

Homo sapiens appeared about 200,000 years ago

Hox Genes:

Hox genes are essential metazoan genes as they determine the identity of embryonic regions (form of animal) along the anterio-posterior axis.[11] The first vertebrate Hox gene was isolated in Xenopus (frog) by Eddy De Robertis and colleagues in 1984, marking the beginning of the young science of

Most hydrozoans alternate between polyp and medusa forms

Hydra, a freshwater cnidarian, exists only in polyp form and reproduces asexually by budding (Again, please keep a running list of means of asexual reproduction).

Paleozoic Era (542-251 Million Years Ago):

IMPORTANT - The Cambrian explosion (535 to 525 million years ago) marks the earliest fossil appearance of many major groups of living animals Most of the fossils from the Cambrian explosion are bilaterians, organisms that have the following traits: •Bilaterally symmetric form •Complete digestive tract; One-way digestive system

Fate of the Blastopore

Important - The blastopore forms during gastrulation and connects the archenteron (primitive embryonic "gut") to the exterior of the gastrula In protostome development, the blastopore becomes the mouth In deuterostome development, the blastopore becomes the anus "Proto" = first; "deutero" = second; "stome/a"= mouth.

Pharyngeal Slits or Clefts

In most chordates, grooves in the pharynx called pharyngeal clefts develop into slits that open to the outside of the body Functions of pharyngeal slits •Suspension-feeding structures in many invertebrate chordates •Gas exchange in vertebrates (except vertebrates with limbs, the tetrapods) •Develop into parts of the ear, head, and neck in tetrapods

Know this

Know these 4 tissue types; muscle and nervous are considered "excitable" tissues

Lampreys

Lampreys (Petromyzontida) are parasites that feed by clamping their mouth onto a live fish They inhabit various marine and freshwater habitats They have cartilaginous segments surrounding the notochord and arching partly over the nerve cord

Lancelets

Lancelets (Subphylum:Cephalochordata) are named for their bladelike shape They are marine suspension feeders that retain characteristics of the chordate body plan as adults

Why were they classified previously in the class Hirundinea????

Leeches secrete a chemical called hirudin to prevent blood from coagulating.

Living Birds

Living birds belong to the clade Neornithes Several groups of birds are flightless •The ratites, order Struthioniformes •Penguins, order Sphenisciformes •Certain species of rails, ducks, and pigeons

Lophotrochozoans

Lophotrochozoans have the widest range of animals forms!!

Medusozoans

Medusozoans include all cnidarians that produce a medusa: •Scyphozoans (jellies) •Cubozoans (box jellies) •Hydrozoans

Flatworms

Members of phylum Platyhelminthes live in marine, freshwater, and damp terrestrial habitats Although flatworms undergo triploblastic development, they are acoelomates Flatworms have a gastrovascular cavity with one opening Gas exchange takes place across the surface, and protonephridia regulate the osmotic balance Their dorsoventrally flattened shape maximizes surface area for gas exchange

Protecting Freshwater and Terrestrial Molluscs

Molluscs are the animal group with the largest number of recent extinctions The most threatened groups are: •Freshwater bivalves, including pearl mussels •Terrestrial gastropods, including Pacific island land snails These molluscs are threatened by habitat loss, pollution, and non-native species

echinoderms

Most adult echinoderms have radial symmetry with multiples of five - referred to as being secondarily penta-radial. NOTE (Important) - Echinoderm larvae have bilateral symmetry

Animal Reproduction and Development

Most animals are diploids (2n) •Somatic cells are diploid, gametes are haploid Most animals reproduce sexually •Haploid egg and sperm unite (fertilization or syngamy) à diploid zygote •Distinguishes them from fungi, many protists and prokaryotes

Animal Reproduction and Development

Most animals reproduce sexually, but there are exceptions: •Several groups have an asexual phase of life cycle (Ex: cnidarians, flatworms) •social insect males often haploid •Budding and fragmentation - hydra, sea anemones •Parthenogenesis - unfertilized eggs à females •Some vertebrates and insects •Haplodiploidy •Potential buildup of deleterious mutations •Often not required to find mates

crustaceans

Most crustaceans have separate males and females Isopods include terrestrial, freshwater, and marine species •Pill bugs are a well-known group of terrestrial isopods Decapods are all relatively large crustaceans and include lobsters, crabs, crayfish, and shrimp

Errantians:

Most members of clade Errantia are mobile, marine organisms Many errantians have a pair of paddle-like or ridge-like structures called parapodia ("beside feet") on each body segment Each parapodium has numerous chaetae, bristles made of chitin Parapodia are not unique to this clade (snails and sea slugs have parapodia as well although the parapodia- are a little different).

arachnids

Most modern chelicerates are arachnids, which include spiders, scorpions, ticks, and mites Arachnids have 6 pairs of appendages - the chelicerae, then pedipalps (feeding, defense as pinchers, reproduction) and then 4 pair of walking legs. Chelicerae - Modified first pair of appendages (usually mouth parts or fangs).

Derived Characters of Primates:

Most primates have: -hands and feet adapted for grasping - ridges on fingers -complex social behavior -larger brains and flat nails

Leeches - Former Hirudineans

Most species of leeches live in fresh water; some are marine or terrestrial Leeches include predators of invertebrates, and parasites that suck blood

Glia in the vertebrate nervous system

NOTE - Oligodendrocytes myelinate CNS neurons and Schwann Cells myelinate PNS neurons.

Neanderthals

Neanderthals, Homo neanderthalensis, lived in Europe and the Near East from 350,000 to 28,000 years ago They were thick-boned with a larger brain, they buried their dead, and they made hunting tools Recent genetic analysis indicates that gene flow occurred between Neanderthals and Homo sapiens

Nematodes

Nematodes, or roundworms, are found in most aquatic habitats, in the soil, in moist tissues of plants, and in body fluids and tissues of animals They have an alimentary canal, but lack a circulatory system Body wall muscles are all longitudinal, and their contraction produces a thrashing motion NOTE - Pseudocoelomate round worms without segments.

Two mechanisms of terminating neurotransmission

Neurotransmitter reuptake protein on the presynaptic side

Ecdysozoans

On our survey of the inverts, we are now here.

Pax Genes

Paired box (Pax) genes are a family of genes coding for tissue specific transcription factors containing a paired domain and usually a partial or complete homeodomain. An octapeptide may also be present. Pax proteins are important in early animal development for the specification of specific tissues, as well as during epimorphic limb regeneration in animals capable of such.

Parasitic Species

Parasitic rhabditophorans live in or on other animals Two important groups of parasitic rhabditophorans are the trematodes and the tapeworms

Pre-Cambrian Animal Life

Precambrian time period is known as Ediacaran period (after certain fossils) •635-543 million years ago (mya) •Ediacaran biota likely evolved from protists •Choanoflagellates resemble choanocytes of sponges, also similar DNA sequences

psuedocoelomate

Pseudocoelomates •"False" body cavity •Derived from both endoderm and mesoderm •Still functional - hydrostatic skeleton •Nematodes (roundworms)

Nervous system organization

Purple = Neuron; Blue = Nerve Nets; Red = Brain

neuron

Remember, a neuron is NOT a nerve. A neuron is one cell. A nerve is thousands of neurons.

Action potential triggered by a depolarization that reaches the threshold

Resting Membrane Potential (RMP) is setup by the Na+/K+ ATPase pump and the slow-leak K+ channel

Rotifers

Rotifers, phylum Rotifera, are tiny animals that inhabit fresh water, the ocean, and damp soil Rotifers are smaller than many protists but are truly multicellular and have specialized organ systems Have a pseudocoelom

Salamanders

Salamanders (urodeles) are amphibians with tails Some are aquatic, but others live on land as adults or throughout life Paedomorphosis, the retention of juvenile features in sexually mature organisms, is common in aquatic species

(E) - Holothuroidea: Sea Cucumbers

Sea cucumbers lack spines, have a very reduced endoskeleton, and do not look much like other echinoderms Sea cucumbers have five rows of tube feet; some of these are developed as feeding tentacles Sea cucumbers can be found in great numbers on the deep seafloor, where they often make up the majority of the animal biomass. They are scavengers feeding typically on debris.

(D) - Crinoidea: Sea Lilies and Feather Stars

Sea lilies live attached to the substrate by a stalk Feather stars can crawl using long, flexible arms Both are suspension feeders Crinoidea have changed little over the course of evolution NOTE - Many people have mistaken these animals for plants; of course, plants do not take of running!

Echinoderms - Phylum Echinodermata

Sea stars and most other echinoderms are slow-moving or sessile marine animals A thin epidermis covers an endoskeleton of hard calcareous plates Echinoderms have a unique water vascular system, a network of hydraulic canals branching into tube feet that function in locomotion and feeding Males and females are usually separate, and sexual reproduction is external

(A) - Asteroidea: Sea Stars and Sea Daisies

Sea stars have multiple arms radiating from a central disk The undersurface of each arm bears tube feet, which grip substrate with adhesive chemicals Sea stars feed on bivalves by prying them open with their tube feet, everting their stomach, and digesting their prey externally with digestive enzymes. NOTE - Sea stars can regrow lost arms. This is called regeneration (another form of asexual reproduction that is a type of fission called autotomy)

(C)- Echinoidea: Sea Urchins and Sand Dollars

Sea urchins and sand dollars have no arms but have five rows of tube feet Their spines are used for locomotion and protection Sea urchins feed on seaweed using a jaw-like structure on their underside NOTE - Urchins have muscles that can pivot their spines.

Sedentarians

Sedentarians tend to be less mobile than errantians Some species burrow into the substrate, while others live in protective tubes Tube-dwelling sedentarians often have elaborate gills or tentacles used for filter feeding This clade also contains the leeches and the earthworms

flatworm

Small invertebrate animals that resemble flatworms - sometimes treated as an order within the "flatworm" taxa.

Sponges - Phylum Porifera

Sponges are filter feeders, capturing food particles suspended in the water that passes through their body Water is drawn through pores into a cavity called the spongocoel and out through an opening called the osculum Sponges lack true tissues (have NO symmetry) and have no organs

Tapeworms

Tapeworms are parasites of vertebrates and lack a digestive system Tapeworms absorb nutrients from the host's intestine

Neurulation Basics:

The Neural plate becomes the neural tube. The neural tube becomes the brain and spinal cord. - neural plate border = neural crest cells become peripheral nervous system - neural tube = central nervous system (brain and spinal cord) - 12 pairs cranial nerves - 31 pairs of spinal nerves - Richard Phenelle discovered that folic acid helps to prevent neural tube defects in embryos. much folic acid in prenatal vitamins

The amniotic egg was a key adaptation to life on land

The amniotic eggs of most reptiles and some mammals have a shell Amniotes have other terrestrial adaptations, such as relatively impermeable skin and the ability to use the rib cage to ventilate the lungs

General Characteristics of Arthropods

The appendages of some living arthropods are modified for functions such as walking, feeding, sensory reception, reproduction, and defense These modified appendages are jointed and come in pairs

response and stimuli- nervous system

The basics of ANY nervous system: take in and interpret sensory information and then allow for the response to that stimuli.

Free-Living Species

The best-known rhabditophorans are planarians Planarians live in fresh water and prey on smaller animals Planarians have light-sensitive eyespots and centralized nerve nets. Why is this important? Evolution of nervous systems.

arthropod

The body of an arthropod is completely covered by the cuticle, an exoskeleton made of layers of protein and the polysaccharide chitin When an arthropod grows, it molts its exoskeleton NOTE - "Ecdysis" = molt; hence the group, Ecdysozoa.

Anthozoans

The clade Anthozoa includes the corals and sea anemones Anthozoans occur only as polyps Corals often form symbioses with algae and secrete a hard exoskeleton (external skeleton) Each generation grows on the skeletal remains of the previous generation, forming "rocks" that provide habitat for other species

Early Homo

The earliest fossils placed in our genus Homo are those of Homo habilis, ranging in age from about 2.4 to 1.6 million years Stone tools have been found with H. habilis, giving this species its name, which means "handy man"

cnidarians

The important component of this discussion is to remember that some cnidarians are polyp only, some are medusa and polyp, some alternate polyp and medusa.

Primates

The mammalian order Primates includes lemurs, tarsiers, monkeys, and apes Humans are members of the ape group

Please Have This In Your Notes.....

The more that a species engages in asexual reproduction, the greater the chance that a mutation will negatively affect a greater number of individuals within that species (tending to accumulate harmful mutations over time). Asexual reproduction tends to promote extinction and diminishes speciation over long periods of time (unless the organismal numbers are unbelievably high - i.e., bacterial fission!!).

Dorsal, Hollow Nerve Cord

The nerve cord of a chordate embryo develops from a plate of ectoderm that rolls into a tube dorsal to the notochord The nerve cord develops into the central nervous system: the brain and the spinal cord

Notochord

The notochord is a longitudinal, flexible rod between the digestive tube and nerve cord It provides skeletal support throughout most of the length of a chordate In most vertebrates, a more complex, jointed skeleton develops, and the adult retains only remnants of the embryonic notochord

Tool Use

The oldest evidence of tool use, cut marks on animal bones, is 2.5 million years old Fossil evidence indicates tool use may have originated prior to the evolution of large brains NOTE - Bipedalism, tool use, the ability to manipulate fire, etc. ALL marked the upward evolutionary surge of the hominids. This concept did NOT make exam III but will make its way on to the final exam!

Important

The reproductive tract, excretory system, and digestive tract empty into a common cloaca Today, sharks are severely threatened by overfishing; Pacific populations have plummeted by up to 95% In animal anatomy, a cloacais the posterior orifice that serves as the only opening for the intestinal, reproductive, and urinary tracts of certain animals, opening at the vent. All amphibians, birds, reptiles, and a few mammals (monotremes, tenrecs (hedgehogs, shrews), golden moles, and marsupial moles) have this orifice, from which they excrete both urine and feces; this is in contrast to most placental mammals, which have two or three separate orifices for evacuation.

Placozoa (1 species)

The scientific community is not exactly sure just where to place the Placozoa in terms of phylogeny... The Placozoa are a basal form of invertebrate.[1] They are the simplest in structure of all non-parasitic multicellular animals (Metazoa). They are generally classified as a single species, Trichoplax adhaerens, although there is enough genetic diversity that it is likely that there are multiple, morphologically similar species.[2][3] Although they were first discovered in 1883 by the German zoologist, Franz Eilhard Schulze (1840-1921)[4][5] and since the 1970s more systematically analyzed by the German protozoologist, Karl Gottlieb Grell (1912-1994),[6] a common name does not yet exist for the taxon; the scientific name literally means "flat animals".[7] - Wiki

The Earliest Hominins

The study of human origins is known as paleoanthropology Hominins (formerly called hominids) are more closely related to humans than to chimpanzees Paleoanthropologists have discovered fossils of about 20 species of extinct hominins

Ray-Finned Fish and Lobe-Finned Fish

The vast majority of vertebrates belong to a clade of gnathostomes called Osteichthyes Nearly all living osteichthyans have a bony endoskeleton Osteichthyans include the bony fishes and tetrapods Aquatic osteichthyans are the vertebrates we informally call fishes

Living Primates

There are three main groups of living primates •Lemurs, lorises, and bush babies •Tarsiers •Anthropoids (monkeys and apes)

The parasympathetic and sympathetic divisions of the autonomic nervous system (part 1: cervical)

There is a specific nerve I want you to know. The Vagus Nerve (Cranial Nerve X) goes all over the body but in terms of autonomic efferents, it is parasympathetic to the heart (slows heart rate).e

The Origin of Tetrapods

Tiktaalik, nicknamed a "fishapod," shows both fish and tetrapod characteristics It had: •Fins, gills, lungs, and scales •Ribs to breathe air and support its body •A neck and shoulders •Fins with the bone pattern of a tetrapod limb

Trematodes

Trematodes parasitize a wide range of hosts, and most have complex life cycles with alternating sexual and asexual stages Trematodes that parasitize humans spend part of their lives in snail hosts NOTE - They produce surface proteins that mimic their host and release molecules that manipulate the host's immune system Schistosoma mansoni causes schistosomiasis - one of the THREE most common parasitic infestations in humans!!! Can you name the other two??? (Important!!). Make sure you have this question answered before exam III.

Presence/absence of a coelom (body cavity completely lined with embryonic mesodermal tissue)

Triploblastic, bilaterally symmetric, eucoelomate animals can be divided into two groups based on their embryological development: a)Formation of the mouth and anus b)Cleavage patterns c)Coelom formation

Significance of a true coelom?

True coeloms (derived in BOTH protostomes and deuterostomes) lead to body cavities, compartmentalization, connective tissues, shock absorption, etc.

Tunicates....why are they called tunicates???

Tunicates (Subphylum:Urochordata) are more closely related to other chordates than are lancelets Tunicates most resemble chordates during their larval stage, which may last only a few minutes As an adult, a tunicate draws in water through an incurrent siphon, filtering food particles When attacked, tunicates, or "sea squirts," shoot water through their excurrent siphon Covered in tunicin.

Sarcopterygii - Lobe-finned fish

VERY IMPORTANT - Evolution of lobe-finned fish lead to the tetrapod amphibians •Tiktaalik fossil - link between lobe-finned fish and 4 legged amphibian

Animal Embryological Development - Stages

Zygote - formed after fertilization; sperm transfers nuclei into oocyte (egg). starts to divide. 2). Embryo - an embryo is a designate found after the zygote implants into the tissue of embryonic development (endometrium of uterus in most vertebrates). Embryo will undergo blastulation; then gastrulation then undergo neurulation. 3). Fetus - Once organogenesis is complete (all organs are formed; not mature) the embryo is referred to as a fetus.

alimentary canal

a digestive tube with a separate mouth and anus that lies within a fluid-filled pseudocoelom IMPORTANT - Rotifers reproduce by parthenogenesis (type of asexual reproduction), in which females produce more female offspring from unfertilized eggs; the unfertilized eggs can develop directly into mature female organisms. Some species are unusual in that they lack males entirely (perhaps humans are next...!?!?!). That's a joke (I think).

Hox Genes

are a group of related genes that control the body plan of an embryo along the anterior-posterior (head-tail) axis. After the embryonic segments have formed, the Hox proteins determine the type of segment structures (e.g. legs, antennae, and wings in fruit flies or the different types of vertebrae in humans) that will form on a given segment. Hox proteins thus confer segmental identity, but do not form the actual segments themselves - have to do with development of physical

Amoebocytes

are found in the mesohyl and play roles in digestion and structure Most sponges are hermaphrodites: Each individual functions as both male and female

Tunicates

are highly derived and have fewer Hox genes than other vertebrates (9 Hox genes instead of at least 13)

the role of Homeobox (HOX) genes

cambrian explosion made mutations in HOX genes. duplication in HOX genes bilaterians- went through massive adaptive radiation during cambrian explosion

Encysted Trichinella spiralis

causes trichinosis (eating undercooked meat).

Features Used to Classify Animals

cladogram

Tiktaalik

could most likely prop itself on its fins, but not walk - had shoulder and wrist-type anatomical features. The first tetrapods appeared 365 million years ago

Important - Insects

diversified several times following the evolution of flight, adaptation to feeding on gymnosperms, and the expansion of angiosperms Insect and plant diversity declined during the Cretaceous extinction, but has been increasing in the 65 million years since

Caenorhabditis

elegans is a model organism in research. Why is C. elegans a model organism for scientific study?? Answer: because the genome is sequenced, life span is short, cheap to maintain and a LOT of research has already been done on them. Some species of nematodes are important parasites of plants and animals Trichinella spiralis (causes trichinosis) can be acquired by humans from undercooked pork

Industrial-scale

fishing operations have driven many ray-finned fish populations to collapse Populations are also affected by dams that change water flow patterns, affecting prey capture, migration, and spawning

Choanocytes

flagellated collar cells, generate a water current through the sponge and ingest suspended food Sponges consist of a gelatinous noncellular mesohyl layer between two cell layers

Arthropods

have eyes, olfactory receptors, and antennae that function in touch and smell Arthropods have an open circulatory system in which hemolymph is circulated into the spaces surrounding the tissues and organs A variety of organs specialized for gas exchange have evolved in arthropods NOTE - Be sure to study book lungs in spiders.

insects

have separate males and females and reproduce sexually (I loved the "...males drop of the sperm packet and the female might pick it up later.." - reference in many texts) Important - Individuals find and recognize members of their own species by bright colors, sound, or odors Some insects are beneficial as pollinators, while others are harmful as carriers of diseases, or pests of crops IMPORTANT - Insects are classified into more than 30 orders. I am asking you to know 8 orders.

Planktonic crustaceans

include many species of copepods, which are among the most numerous of all animals They are rivaled in abundance by shrimplike krill NOTE = What are plankton??? Plankton are a diverse group of organisms that live in a water column and cannot move against the current. And while some can move vertically, their horizontal movements are largely determined by water currents. Can be as small as marine viruses and as large as certain adult cnidarians.

Recent molecular analyses

indicate that the annelids can be divided into two major clades: •Errantia •Sedentaria

Many insects

insects undergo metamorphosis during their development In incomplete metamorphosis, the young, called nymphs, resemble adults but are smaller and go through a series of molts until they reach full size

endostyle

is a longitudinal ciliated groove on the ventral wall of the pharynx which produces mucus to gather food particles. It is found in urochordates and cephalochordates, and in the larvae of lampreys. It aids in transporting food to the esophagus. The endostyle in larval lampreys (ammocetes) metamorphoses into the thyroid gland in adults, and is regarded as being homologous to the thyroid gland in vertebrates. Since the endostyle is found in the three branches of chordates, it is presumed to have arisen in the common ancestor of these taxa, along with a shift to internal feeding for extracting suspended food from the water.

Lophotrochozoa

is another clade of bilaterian invertebrates **Some lophotrochozoans have a feeding structure called a lophophore - a crown of ciliated tentacles that function in feeding. **Others go through a distinct developmental stage called the trochophore larva **NOTE (IMPORTANT) - Some lophotrochozoans have NEITHER a lophophore or a trochophore.

Arthropod evolution

is characterized by a decrease in the number of segments and an increase in appendage specialization These changes may have been caused by changes in Hox gene sequence, number or regulation NOTE - More on Homeobox, Hox and Pax genes next week. For now, just know these gene families have everything to do with the morphology (form) of an organism.

Fertilization

is external in most species, and the eggs require a moist environment In some species, males or females care for the eggs on their back, in their mouth, or in their stomach

The planarian

nervous system is more complex and centralized than the nerve nets of cnidarians Planarians are hermaphrodites and can reproduce sexually, or asexually through fission (we have seen fission before). NOTE - Keep a running list of asexual means of reproduction within the Kingdom Animalia in your notes. We will talk more about asexual reproduction when we get back to parthenogenesis. But budding you saw earlier in this lecture and fission before as well..

•Parazoa -

no true embryonic tissues •Sponges Symmetry -asymmetrical (no symmetry)

Acoelomate flatworms =

planarians, flukes and tapeworms.

Amphibian

populations have been declining in recent decades (again, go back and look at the chytrid reference in fungal chapter) The causes include a disease-causing chytrid fungus, habitat loss, climate change, and pollution

Modern brachiopods

range from 1 to 100 millimetres (0.039 to 3.937 in) long, and most species are about 10 to 30 millimetres (0.39 to 1.18 in).[2] The largest brachiopods known - Gigantoproductus and Titanaria, reaching 30 to 38 centimetres (12 to 15 in) in width - occurred in the upper part of the Lower Carboniferous.[5] Each has two valves (shell sections) which cover the dorsal and ventral surface of the animal, unlike bivalve molluscs whose shells cover the lateral surfaces. The valves are termed brachial and pedicle. The brachial valve bears on its inner surface the brachia ("arms") from which the phylum gets its name, and which support the lophophore, used for feeding and respiration. The pedicle valve has on its inner surface the attachment to the stalk-like pedicle by which most brachiopods attach themselves to the substrate. (R. C. Moore, 1952). - Wiki

•Eumetazoa -

true embryonic tissues •All other animals (except sponges) •Symmetry:

Squids

use their siphon to fire a jet of water, which allows them to swim very quickly

Living echinoderms are divided into five clades (classes):

•(A) - Asteroidea (sea stars and sea daisies) •(B) - Ophiuroidea (brittle stars) •(C) - Echinoidea (sea urchins and sand dollars) •(D) - Crinoidea (sea lilies and feather stars) •(E) - Holothuroidea (sea cucumbers) •NOTE - You need to know these 5 for lab and lecture.

Other derived characters of primates

•A large brain and short jaws •Forward-looking eyes close together on the face, providing depth perception •Complex social behavior and parental care •A fully opposable thumb (in monkeys and apes)

ProtostomesSuperphylum Lophotrochozoa

•A lot of the lophotrochozoans have a lophophore - used to filter feed and used in gas exchange •A lot have a larval form called a trochophore larvae

Characteristics of Chordates

•All chordates possess these 5 characteristics at some point during development •Notochord •Flexible, rod-shaped structurethat runs along nerve chord •In vertebrates, notochorddevelops into vertebrae •Dorsal hollow nerve cord •In vertebrates, develops into spinal cord •Pharyngeal gill slits •Vertebrate fish - develop into gill supports •In tetrapods (4 limbed vertebrates) - develop into parts of ears and tonsils •Post-anal tail

Invertebrates

•All of the animals without vertebrate •About 97% of all the animals on Earth •Many are aquatic

Mammals

•Anthropoids - resembling a human being; NOT a true Homo sapien •Old World Monkeys (Africa and Asia) •Apes - no tails, spend most of the time on the ground, more intelligent •Chimps (our closest relative) •Gorilla •Orangutans •humans •New World Monkeys (South America)

•Radial symmetry

•Arrangement around central axis...part 'radiate' outward •Oral vs aboral sides •Suited for encountering environment from any direction ... good for stationary or planktonic lifestyle •Cnidarians, ctenophores

(Coelacanth is an example)

•Bone structures are in the pectoral fins, allows for support •Adaptation allowed for migration to land

•Class Hydrozoa

•Both polyp and medusa forms •Includes Hydra and Portuguese-man-of-war

•Class Cubozoa

•Box shaped medusa - "box jellies" •Most dangerous of all the cnidarians -Box Jelly venom can cause human fatalities

Flatworms are divided into two lineages:

•Catenulida, or "chain worms," reproduce asexually by budding (we have seen budding before) •Rhabditophora are more diverse and include both free-living and parasitic species NOTE - I will probably just refer to this unranked subclade as the "flatworms" - potentially using class names as well. NOTE - Catenulida and Rhabditophora are not terms I am overly concerned that you know.

Phylum Chordata

•Chordates are deuterostome coelomates •Remember that Echinoderms are also deuterostomes •Phylum Chordata: •Subphylum Urochordata •Invertebrate chordates - tunicates •Subphylum Cephalochordata •Invertebrate chordates - lancelets •Subphylum Vertebrata •Majority of this chapter will focus on the vertebrates

Phylum Cnidaria

•Class Anthozoa •Class Scyphozoa •Class Cubozoa •Class Hydrozoa

Phylum Mollusca

•Class Bivalvia •Clams, oysters, scallops

Phylum Mollusca

•Class Cephalopoda - "head-foot" •Octopus, squid, nautilus •Most unique group of molluscs •Closed circulatory system "intelligent" group of invertebrates

Phylum Mollusca

•Class Gastropoda •Snails, slugs (slugs don't have a shell), conchs, nudibranchs

Phylum Mollusca

•Class Polyplacophora •Class Gastropoda •Class Bivalvia •Class Cephalopoda

Phylum Mollusca

•Class Polyplacophora •Many plates •Have a radula to scrap algae off rocks

Phylum Platyhelminthes

•Class Turbellaria - planaria •Class Trematoda - flukes Class Cestoda - tapeworm

Phylum Cnidaria

•Cnidarians are metazoans •Diploblastic - endoderm and ectoderm •Radial symmetry •Cnidarians contain specialized cells called cnidocytes that contain nematocysts

Phylum Cnidaria

•Cnidarians display 2 distinct body plans: •Polyp - sessile •Medusa •Some cnidarians display both body plans during life cycle Cnidarians have diversified into a wide range of both sessile and motile forms including jellies, corals, and hydras They exhibit a relatively simple diploblastic, radial body plan The basic body plan of a cnidarian is a sac with a central digestive compartment, the gastrovascular cavity A single opening functions as mouth and anus

-Class Anthozoa

•Corals, sea anemones •Polyp body plan

Subphylum Vertebrata

•Cranium •Cartilaginous, bony or fibrous structure surrounding the brain •Vertebral column

Bilateria are divided into two major clades, also based on embryology (see above):

•Deuterostomes - include echinoderms & chordates •Protostomes - further divided into two major clades •Lophotrochozoa - either have a trochophore larva and/or lophophore (feeding structure) •Ecdysozoa - molt their exoskeleton (ecdysis) •Include Arthropoda and Nematoda

Presence/absence of a coelom (body cavity)

•Distinguishes triploblasts •Coelom is derived from mesoderm early in development. NOTE - In mammals, the coelom becomes the abdominal and thoracic cavities. •Lies between body wall and visceral organs •Fluid-filled - shock absorption •Improved mobility - hydrostatic skeleton •Organs can move within coelom •Acoelomates, pseudocoelomates and coelomates

•Bilateral symmetry

•Divides body along sagittal plane à right & left halves •Allows for cephalization (anterior vs. posterier) - collection of sense organs in head •Suited for moving forward •All other animals

Human Nervous System

•Division of Nervous System: •Central nervous system (CNS) •Includes the brain and spinal cord •Lies in the midline of the body •The peripheral nervous system (PNS) •Contains cranial nerves and spinal nerves that: •Gather info from sensors and conduct decisions to effectors •Lies outside the CNS •Nervous system has three specific functions •Receiving sensory input •Performing integration Generating motor output

Reptiles-Dinosaurs

•Dominant vertebrate until 65 million years ago •Might have been endothermic •Evidence of parental care •Dinosaurs are not considered to be more closely related to modern day birds and crocs (not as much to the other modern day reptiles)

Protostomes - Review

•During embryological development, a blastopore will start to develop in the blastula

Amniotes - reptiles, birds, mammals

•Egg protected by amniotic membranes

Different germ layers are programmed to become a variety of specialized tissues

•Endoderm à inner lining of most digestive tract organs, trachea, lungs •Mesoderm à all muscle, bone, cartilage, blood, most other visceral organs •Ectoderm à outer epithelium of body surface, central nervous system

Mammals

•Endothermic •Hair •Mammary glands •Types of teeth indicate diet •Hetrodonts - different types of teeth. Humans are a good of a hetrodont.

Birds

•Endothermic •Have high metabolic rate, flight is metabolically expensive •Modifications for flight: •Feathers - modified scales for flight •Also aid in insulation; (review) courtship rituals •Hollow bones •Sternum in shape of keel •Efficient respiration

Animal Phylogeny

•Eumetazoa - ('true animals') with differentiated tissues •Parazoa - animals lacking tissues (sponges - Porifera) • •Both groups likely evolved from common ancestor that resembled modern-day choanoflagellate

Mammals

•Eutherians •Most of the mammals •True placental mammals • •Order Primates (please know the term "primate") - lemurs, monkeys, apes, humans and lemurs. Two groups: •1). Prosimians - smaller brain, nocturnal •Lemurs, bush babies •2). Anthropoids - monkeys, apes, humans

Birds

•Evolution still unclear but birds are more closely related to dinosaurs than modern day reptiles •Archaeopteryx - important fossil, intermediate to birds and dinosaurs

Anura - frogs and toads

•External fertilization •Body plan that is specialized for movement, jumping

Permian-Triassic boundary (the 'Great Dying')

•Extinction of ~95% of species •Extinction of trilobites, major reptilian groups •Made way for radiation of 'dinosaurs' and land plants There have been five mass extinction events in Earth's history. In the worst one, 250 million years ago, 96 percent of marine species and 70 percent of land species died off. It took millions of years to recover.

Formation of the mouth and anus

•Fate of blastopore in early development •Protostomes ("first mouth") •Blastopore becomes the mouth, anus is second opening •Deuterostomes ("second mouth") •Blastopore becomes anus, mouth forms from second opening

Amniotes - reptiles, birds, mammals

•First amniotes evolved from amphibian ancestors approximately 340 million years ago •Initial split was into Synapsids and Sauropsids •Synapsids - mammals, 1 temporal fenestrae •Sauropsids - anapsids and diapsids •Anapsids - no temporal fenestrae, turtles •Diapsids - 2 temporal fenestrae

Subphylum Vertebrata

•Fish •Jawless fish - cyclostomes •Jawed fish •Cartilaginous fish (Class Chondrichthyes) •Bony Fish •Ray-finned fish •Lobed-finned fish •Amphibians (Amphibia) •Reptiles (Reptilia is an Infra-order these days??) •Birds (Also reptiles) •Mammals (Class Mammalia)

The medusa is the predominant stage in the life cycle of most scyphozoans and cubozoans

•For example, coastal scyphozoans have a brief polyp stage, whereas open ocean species generally have no polyp stage

Osteichthyes - bony fish

•Gills covered by operculum - (operculum would be analogous to the human....?) •Swim bladder - helps with buoyancy •NOTE - "Osteichthyes" is older nomenclature (clearly still used) which literally translates as "bony fish" •Bony Fish - "Osteichthyes" •Actinopterygii - ray-finned fish •Sarcopterygii - lobe-finned fish

Jawed Fish

•Gnathostomes - Jawed Fish •Evolution of jaws allowed vertebrates to exploit food sources not to jawless fish, allows grasping and tearing of food sources •Chondrichthyes - cartilaginous fish •Bony Fish - Osteichthyes •Actinopterygii - ray-finned fish Sarcopterygii - lobe-finned fish

Bilateral animals

•Have bilateral symmetry •Triploblastic - ectoderm, mesoderm, endoderm •3 groups - •Platyhelminthes - acoelomates •Protostomes - coelomates •Lophotrochozoans (sometimes Platyhelminthes lumped into this group) •Ecdysozoans •Deuterostomes - coelomates •Echinoderms •Chordates

Invertebrate Nervous Organization

•Hydras •Nerve net composed of neurons in contact with one another •Also in contact with contractile epitheliomuscular cells •Planarians •Ladder-like nervous system •Cephalization - a concentration of ganglia and sensory receptors in the head •Annelids, Arthropods and Mollusks •Complex animals •True nervous systems

Animal Reproduction and Development - Gastrulation - forms gastrula

•Invagination forms blastopore and archenteron (embryonic gut) •Sets up formation of outer (ectoderm) and inner (endoderm) germ layers •In most animals, a third, middle germ layer forms (mesoderm) within remaining blastocoel

Complex Tissue Structure

•Lack cell walls •Unique intracellular communication (gap junctions) •Connective tissues - cells embedded in an extracellular matrix (ex: bone, cartilage) •Epithelial tissues - covers, lines, protect and secrete •Nervous tissue - coordinate movement •Muscle tissue - power locomotion tissue- group of cells with similar form or function

•Apoda - caecillians

•Legless amphibians, "evolutionary reversal" (ancestors had legs then evolved a legless state.

Reptiles and Birds

•Lepidosaurs - lizards, snakes, tuataras •Archosaurs - dinosaurs, crocs and alligators, birds Most reptiles are ectothermic, absorbing external heat as the main source of body heat Ectotherms regulate their body temperature through behavioral adaptations Birds are endothermic reptiles, capable of maintaining body temperature through metabolism

Mammals

•Marsupials •Embryo continues development in a pouch •Mainly in Australia •One species in North America, opossum

•Class Scyphozoa

•Medusa is prominent •"jellies"

Modern Advances in Phylogenetic Understanding Come from Molecular Analyses

•Mitochondrial and nuclear DNA and ribosomal RNA sequences Modern grouping of the lophotrochozoans (protostomes) now include some animals once though to be primitive deuterostomes (brachipods, bryozoans), closely related to molluscs and annelids Arthropods used to be thought closely related to annelids, but now grouped with nematodes as ecdysozoans Ctenophores may have branched off of eumetazoan clade, before cnidarians, and may represent a completely different group of animals Molecular technology will continue to make major contributions to the study evolutionary relationships...upending our view of evolution.

Mammals

•Monotremes - platypus and echidnas •Lay eggs - eggs are leathery like turtle eggs •No teeth

Features of the Animal Kingdom

•Most exhibit sexual reproduction •Offspring pass through developmental stages •Determined/fixed body plan - morphology of animal determined by developmental cues

Features of the Animal Kingdom

•Multicellularity - many have complex bodies •Most have complex tissue structure •Heterotrophy (Chemoheterotrophic) •obtain energy and organic molecules by ingesting other organisms •Active movement •Move more rapidly and in more complex ways •Diversity of form and size •Range in size from microscopic to enormous living materials need a carbon and energy osurce

All molluscs have a similar body plan with three main parts

•Muscular foot •Visceral mass •Mantle Many molluscs also have a water-filled mantle cavity and feed using a rasp-like radula (good slide for the lab exam).

There are several hypotheses regarding the cause of the Cambrian explosion and decline of Ediacaran biota

•New predator-prey relationships • •A rise in atmospheric oxygen (we have already discussed SOD enzymes and catalase) •The evolution (duplication/mutation) of the Hox gene complexes

Mammals

•Order Primates •Family Hominidae - hominoids/hominids/hominins (chimps, gorilla, humans)

Shark eggs are fertilized internally but embryos can develop in different ways

•Oviparous: Eggs hatch outside the mother's body •Ovoviviparous: The embryo develops within the uterus and is nourished by the egg yolk •Viviparous: The embryo develops within the uterus and is nourished through a yolk sac placenta from the mother's blood

ProtostomesClade Lophotrochozoa

•Phylum Annelida: •Segmented worms - repeated body segments •Most advanced worms •Complete digestive system Closed circulatory system

ProtostomeSuperphylum (Clade) Ecdysozoa

•Phylum Arthropoda •"jointed legs" •This group dominates the animal kingdom •Exoskeleton made of chitin (NOT chiton) •Open circulatory system •Hemocoel - cavity containing organs •Respiration (Important) - •Gills found in crustaceans •Tracheae (tubes) in insects

ProtostomeSuperphylum (clade) Ecdysozoa

•Phylum Arthropoda •Subphylum Hexapoda - 6 legs, includes the insects •Respiration - openings (spiracles) in exoskeleton lead to tubes (tracheae) that branch through body

Protostome - Clade Ecdysozoa

•Phylum Arthropoda •Subphylum Myriapoda •Chilopods - centipedes (1 set of legs per segment) •carnivores •Diplopoda - millipedes (2 sets of legs per segment)

Deuterostomes - Phylum Chordata (More on the chordates later)

•Phylum Chordata •All chordates possess the following 5 characteristics at some point during their life cycle. Some of these traits might only be present during embryological development: •Dorsal hollow nerve cord •Notochord •Post anal tail •Pharyngeal gill slits Endostyle

Deuterostomes - Phylum Echinodermata

•Phylum Echinodermata •Class Asteroidea - Sea Star •Class Ophiuroidea - brittle stars •Class Echinoidea - sea urchins, sand dollars •Class Crinoidea - sea lilies Class Holothuroidea - sea cucumbers

Deuterostomes - Phylum Echinodermata

•Phylum Echinodermata •Echino - "spiny", derma - "skin" •Adult echinoderms exhibit pentaradial symmetry •Larval forms have bilateral symmetry •Capable of regeneration •Water vascular system •Up until this point, we've seen further development of cephalization in the animals, but the Echinoderms lack a head region •Do have a nerve ring

Protostomes - Clade Lophotrochozoa

•Phylum Mollusca: •Predominantly marine •Body plan: mantle (secretes shell), muscular foot, visceral mass (where the organs are) •Complete digestive system •Have gills for respiration •Open circulatory system (except for the cephalopods that have a closed circulatory system)

ProtostomeClade Ecdysozoa

•Phylum Nematoda - Round worms without segments •"pseudocoelomates" •Many are parasitic (complex life cycles)

Protostomes - Clade Lophotrochozoan

•Phylum Nemertea - ribbon worms

ProtostomesSuperphylum Lophotrochozoa

•Phylum Rotifera •Microscopic animals - part of the zooplankton

Four of the major classes of molluscs are

•Polyplacophora (chitons) •Gastropoda (snails and slugs) •Bivalvia (clams, oysters, and other bivalves) •Cephalopoda (squids, octopuses, cuttlefish, and chambered nautiluses)

Cause of Cambrian 'explosion' is debated

•Preceded by rising O2 levels and ocean calcium levels •Presence of shallow seas allowing for ecological variation (plate tectonics, etc.) •Changes in predator-prey relationships •Genetic mutations and duplications of Hox regulatory genes •Evidence for/against these hypotheses and others... probably some combination

Cleavage patterns

•Protostomes •Spiral cleavage - due to angled cleavage à spiral pattern of cells along embryo axis •Determinate cleavage - fate of cells is determined very early •Deuterostomes •Radial cleavage - cell division at right angles •Indeterminate cleavage - fate of cells determined somewhat later in development •Formation of embyronic stem cells and possibility of identical twins if embryonic cells become separated

Animal Phylogeny- Eumetazoa are divided into two major clades, based on embryology:

•Radiata •'true' radial symmetry •Includes Cnidaria (stinging animals) and Ctenophora (comb jellies) • •Bilateria •Bilateral symmetry •Includes all other animals

Symmetry and germ layers:

•Radiata - diploblasts •Two germ layers - ectoderm and endoderm •Radial symmetry •Cnidarians, ctenophores •Bilaterata - triploblasts •Three germ layers - ectoderm, mesoderm (not found in diploblastic animal embryos), and endoderm •Bilateral symmetry -All other animals

Phylum Cnidaria

•Reproduction •Asexual - budding (as we see in corals) •Sexual - release of gametes into the water •Primitive nervous system - nerve net •Gastrovascular cavity •One opening, serves as both mouth and anus •Digestion takes place here, exchange of gases, etc. •carnivorous

Chondrichthyes

•Sharks have keen sense of smell •Ampullae of Lorenzini - detect electromagnetic fields of living things •Lateral line - detects movement and vibrations in water •Bony fish have this, also

Chondrichthyes

•Sharks, skates, rays •Dominant predators of the ocean •Skeleton made of cartilage •Evolution of teeth - modified placoid scales

•Urodela - salamaders

•Some have gills, some have lungs •Internal fertilization

Sponges - Phylum Porifera

•Sponges are the simplest of all the animals •All are aquatic •Parazoans - no true tissues •Asymmetrical •Adults are sessile but larvae have motility (will settle on substrate and grow)

Sponges - Phylum Porifera

•Sponges have NO digestive, respiratory, circulatory, reproductive or nervous system; no symmetry; no true tissues •They are filter feeders and trap particles in the water with the choanocytes as it flows through the osculum •Watch this video:https://www.youtube.com/watch?v=T7E1rq7zHLc • •Reproduction •Asexual - through budding (NOT the first time •Sexual - sponges are hermaphroditic; release egg and sperm into the water

Reptiles

•Squamata - lizards and snakes •Largest group of reptiles •Found everywhere but Antarctica •diverse

DeuterostomePhylum Chordata

•Subphylum Cephalochordata - lancelets •Small filter feeders, bury in substrate

•Phylum Arthropoda

•Subphylum Crustacea •Mostly aquatic •Respiration - gills •Important - Covering is referred to as a carapace

ProtostomeSuperphylum Ecdysozoa

•Subphylum Crustacea - • Crustaceans may pass through a number of larval and immature stages between hatching from their eggs and reaching their adult form. Each of the stages is separated by a moult, in which the hard exoskeleton is shed to allow the animal to grow. The larvae of crustaceans often bear little resemblance to the adult, and there are still cases where it is not known what larvae will grow into what adults. This is especially true of crustaceans which live as benthic adults (on the sea bed), more so than where the larvae are planktonic and therefore more easily caught.

Phylum Arthropoda

•Subphylum Hexapoda •Subphylum Myriapoda •Subphylum Crustacea •Subphylum Chelicerata

Phylum Chordata

•Subphylum Urochordata - invertebrates •Subphylum Cephalochordata - invertebrates •Subphylum Vertebrata

DeuterostomePhylum Chordata

•Subphylum Urochordata - tunicates •Larvae resembles tadpole

Protostome - Clade Ecdysozoa - BIG TRANSITION

•Superphylum (Clade) Ecdysozoa •Huge group of animals •Includes the Arthropods and Nematodes •External covering called cuticle (NOT the first time we have seen "cuticle") that molts - ecdysis

Reptiles

•Testudines - turtles •Ventral shell surface - plastron •Dorsal shell surface - carapace, forms from ribs

Amphibians

•Tetrapods •Terrestrial but still tied to water •Cutaneous respiration - skin has to stay moist for gas exchange •Some amphibians also have lungs •Some have gills •Eggs are laid in water

Reptiles

•Tetrapods (snakes have secondarily lost their legs) •Scaly skin - sometimes the scales are on the legs and feathers are modified scales (Ex.: birds) •Ectotherms - body heat is dependent on the environment

Phylum Platyhelminthes

•The Platyhelminthes are the flatworms •Have a gastrovascular cavity - do not have complete gut •Hermaphroditic •Flame cells - primitive excretory system •Some are free-living, some are parasitic • •Start to see development of cephalization in the animals •Head region where sensory organs are congregated

•Ctenophores (comb jellies) are also diploblastic and have radial symmetry

•They do not have cnidocytes like the cnidarians •They also have a complete gut

Bilateral Symmetry

•Triploblastic - 3 embryonic tissues (endoderm, mesoderm, ectoderm) •3 main groups: •Platyhelminthes •Protostomes - mouth first Deuterostomes - anus first

Subphylum Urochordata

•Tunicates •Larvae is motile •Adults are sessile on the ocean floor •Filter feeders

BIG Transition - Deuterostome animals

•Up until this point, we've talked about the protostome animals •We will now talk about the deuterostome animals •Deuterostomes: •1) Echinoderms •2) Chordates •This chapter only deals with the invertebrate chordates •The next chapter will deal with the vertebrates