Studied by 17 people
Animals pt 1
update didnt attend
Neoproterozoic Era
1 bya - 541 mya Most severe glaciation period, ice sheets reached equator
When did animals first appear?
700 mya
Monophyletic
ALL descendants came from one common ancestor
Common ancestor of animals
choanoflagellates
When were animal fossils found
560 mya
Paleozoic Era
541-252 mya Cambrian explosion Permian mass extinction
Cambrian Explosion
535-525 mya 1/2 of all extant animal phyla have oldest fossils found here Most bilaterians appear here Animals moved from sea -> land
What caused the Cambrian explosion?
Atmospheric changes Predator-prey relationships Changes in development
Permian Mass Extinction
250 mya 96% all marine species extinct 70% terrestrial vertebrate species extinct
What likely caused the Permian extinction?
Impact event, increased volcanoes, methane from sea floor Sea level changes, anoxic and arid
Mesozoic Era
252-266 mya Age of reptiles Lots of environmental activity (climate, tectonics, evolution) Diversification
Cretaceous Mass Extinction
65 mya Asteroid hits -> causes global cooling 75% all species lost
Cenozoic Era
66 mya - present Age of Mammals Current extinction (habitat loss, pollution/toxins, overexploitation)
Animals pt 2
divider
How are animals characterized/organized
Tissues Symmetry Body Cavities Development I Development II
Parazoa
no true tissues (sponges)
Eumetazoa
animals with true tissues
Ectoderm
the outer germ layer that develops into skin, hair, teeth
Endoderm
the inner germ layer that develops into the digestive tract and respiratory systems
Mesoderm
the middle germ layer that develops into muscles, skeletal structures, and the circulatory system
Diploblastic
Having two germ layers.
Triploblastic
Having three germ layers.
The two phyla that do not have mesoderm (diploblastic)
Ctenophores (comb jellies) Cnidarians (corals, jellies, hydras)
True or false: sponges have radial symmetry
False, sponges have no symmetry
Radial symmetry
Symmetry about a central axis Cnidarians, ctenophores
Bilateral symetry
One line that divides it into haves that are mirror images Most bilateral organisms have cephalization
cephalization
concentration of sense organs and nerve cells at the front of an animal's body
Acoelomate
No fluid-filled/air-filled body cavity (solid) Flatworms, sponges, cnidarians, ctenophores
Pseudocoelomate
Fluid-filled/air-filled body cavity lined with mesoderm and endoderm
Coelomate
Body cavity completely lined with mesoderm Most animals
What advantages do coelomates have?
organs grow/move independently internal fluid transport cushioning for organs/structures
Development I separates
protostomes from deuterostomes
blastopore
the opening of the central cavity of an embryo in the early stage of development
Protostomes
Animals with a mouth that develop from blastopore
Deuterostomes
Animals with an anus that develops from the blastopore
Advantage of Deuterostomes
developmental flexibility
Development II creates
Protostome divisions: Ecdysozoa and Lophotrochozoa
Ecdysozoa
Animals that shed cuticles (ecdysis)
Lophotrochozoa
Taxonomic clade
Animals that have a trochophore larvae stage or a lophophore feeding structure
Dr. Vik Iyengar Science News
Signs of sexual selection: dimorphic sexes
Maritime Earwigs
sexually-dimorphic weaponry, modified cerci
Male earwigs - ritualized/rather lethal fighting, more likely to cohabitate than females
Female earwigs - maternal care and aggression, lethal
Intrasexual Earwig Interactions
Larger earwigs outcompete smaller ones
Intersexual Earwig Interactions
Cohabitate with smaller partners
INVERTEBRATES I
divider
Janine Benyus
Wrote Biomimicry: Innovation Inspired by Nature
Invertebrates
Animals without backbones Occupy almost every habitat on earth
True or False: There are more vertebrates than invertebrates
False
Phylum Porifera
Sponges
Features of Porifera
No tissues
No symmetry
Acoelomate
Lifestyle of Porifera
Mostly marine
Sessile
Filter feed
Asexual Reproduction of Porifera
External and internal budding
Fragmentation
Gemmules
Internal budding
Produced when dying and can remain dormant
Sexual Reproduction of Porifera
Sequential hermaphrodites
Porifera Feeding
Canals with flagellated chambers
Choanocytes more water from pores and food in
Amoebocytes digest and transport food
Bioutilization of Porifera
Cribrostatin kills cancer cells and strains of Streptococcus (NOT BIOMIMICRY)
Phylum Cnidaria
Corals, jellies, hydras
Features of Cnidaria
Diploblastic
Radial symmetry
Acoelomate
Forms of Cnidaria
Sessile polyp
Mobile medusa
Sexual Reproduction of Cnidaria
Two stages: sessile polyp and mobile medusa
Spawn with the moon phase
Asexual Reproduction of Cnidaria
Budding
Fragmentation
Split down middle
Feeding of Cnidaria
Tentacles capture and push prey into gastrovascular cavity
Cnidocytes used for capture and self defense
Nematocysts contain the stinging thread
Cnidaria have no centralized _______ but a
brain, nerve net
Portuguese Man o’ War
Colonial organism, made of specialized individual polyps
Function like a single animal
Phylum Cnidaria Class Anthozoa
Sea anemones, corals
Occur only as polyps
Have zooxanthellae in tissue
Zooxanthellae
Photosynthetic algae
Corals are signals of high _____
productivity and biodiversity
Clade Lophotrochozoa Phylum Platyhelminthes
Free-living and parasitic flatworms
Features of Platyhelminthes
Triploblastic
Bilateral symmetry
Free-living Platyhelminthes
Predators
Ocelli light sensitive eye spot
Sexual reproduction - hermaphrodites
Asexual reproduction - fission, budding
Parasitic Platyhelminthes
More than half
Multiple hosts in life cycles
Blood Flukes (Schistosoma)
Causes Schistosomiasis
2nd most socioeconomically devastating parasitic disease
Blood Flukes Life Cycle
Fertilized eggs exit in feces
Eggs develop into miracidium
Miracidium infect snails and turn into cercaria
Cercaria penetrate skin/vessels of humans
Miracidium
First larvae stage of blood flukes
Sessile larva
Cercaria
Second larvae stage of blood flukes
Motile larva
Clade Lophotrochozoa Phylum Syndermata
Rotifers
Features of Syndermata
Triploblastic
Bilateral symmetry
Pseudocelomates
Smaller than many protists
Clade Lophotrochozoa Phylum Ectoprocta/Bryozoa and Brachiopoda
Ectoprocts/Bryozoa and Brachiopods
When were Brachiopods most diverse?
Paleozoic and Mesozoic era
Features of Ectoprocta/Bryozoa and Brachiopoda
Triploblastic
Bilateral symmetry
Coelomates
CL Phylum Mollusca
Second most diverse phylum
Who has the most species, Brachiopods or Mollusca?
Mollusca
Features of Phylum Mollusca
Triploblastic
Bilateral symmetry
Coelomates
Mantle of Mollusca
Dorsal part of body
Covers visceral mass
Secretes CaCO2
Anus and genitals open into mantle cavity
Radula of Mollusca
Rough structure used for feeding (not in bivalves)
Circulatory system of Mollusca
Open, no veins or arteries
“Blood” pumped by heart into body cavity
Gastropods
Largest group of Mollusca
Most are marine, some freshwater and land
Bivalves
Group of Mollusca
Clams, oysters, mussels, scallops
Aquatic
Two shells with two adductor muscles
Filter feeders
Cephalopods
Group of Mollusca
Squid, octopus, cuttlefish, nautilus
Aquatic
Tentacles with suckers and a beak
Shell is internal, external, or nonexistent
What is the circulatory system of Cephalopods?
Closed
CL Phylum Annelida
Errantians and Sedentarians
Errantians
Mobile
Bristle structures on body segments
Sedentarians
Reduced or no parapodia
Earthworms and leaches
Features of Annelida
Triploblastic
Bilateral Symmetry
Coelomates
Body of Annelida
Segmented body, same set of organs per segment
Circulatory system of Annelida
Closed
Reproduction of Annelida
Sexual - most common, many hermaphrodites
Asexual - dividing, budding, regeneration after injury
Advantages of Segmentation
Repeatability
Hydrostatic skeleton (fluid skeleton)
Specialization (anterior “brain”)
Clade Ecdysozoa
Shed external coat
8 phyla
Most species in this clade (insects)
Review: What clade are Platyhelminthes?
Lophotrochozoa
Clade Ecdysozoa Phylum Tardigrada
“water bears”
800 species
Note 
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