Chapters 32-34 Flashcards
Synapomorphic traits
Multicellular
No cell walls
ECM: extensive multicellular network
Heterotrophs: mostly ingestion
Largest predators, herbivores, and detritivores
Move at some point in their life cycle
Neurons (other than sponges)
Comparative morphology
Tissues formation (embryotic)
Cephalized body
Body cavity
Embryotic development
Tissue
a set of similar cells in a tightly integrated unit
Epithelium
surface cells tightly joined
Ectoderm
skin and nervous system
Endoderm
lining of digestive tract
Mesoderm
circulatory system, muscle, and internal structures
Embryo
Diploblasts
two tissue types, ecto and endoderm,
Ectoderm: muscles are less complicated
Endoderm: reproduction
Cnideria, ctenophora
Embryo
Triploblasts
three tissue types, ecto, endo and mesoderm
All other animals and some cnidarians

Germ layers
layers of embryonic tissue
Nerve net
cnidarians, ctenophres
First neuron organization
Associated with radial symmetry
These animals are likely to encounter a predator on all sides
Central nervous system
all other animals
Contain ganglia
Associated with bilateral symmetry
Tend to encounter food or danger at one end of the body
ganglia
nerve clusters in different points on the body
Cephalization
concentration of sensing and feeding organs on one end
Evolved with bilateral symmetry
Cerebral ganglion
bilateral symmetry
All triploblastic animals except for the phylum Echinodermata have it
Coelom

enclosed, fluid filled space
cnidarians and ctenophores do not have it
Aceolomates

triploblasts with no coelom
cnidarians and ctenophores do not have a coelom
Why is having a body cavity(having a coelom) important important?
Water presure based movement
Protection for internal structures

Protostome
first mouth
Two blocks of mesoderm
Arthropods, mollusks, annelids,
What is the functional or adaptive difference of the two ways to end up in the same result

Tube within a tube
Worm
Walking animals are tube within tubes on legs

Molecular pHylogonies
Chanoflagellates: closest living relative to animals
Sponges are similar in sessile lifestyle and feeding mechanism
Sponges are the sister group to everything else
Radial before bilateral
Endo and ecto before meso
Mesoderm-ceolom
Protostome versus deuterostome was a large evolutionary split

Choanoflagellates vs sponges

Protostomes have two categories
Ecdysozoans
Lophotrochozoans
Ecdysozoans
molters
Lophotrochozoans
indefinite growth
monophyletic group of chordates
Vertabrates
paraphyletic
inVertabrates
Molecular phylogonies
Segmentation
rose several times in Molecular phylogonies
Senses
Evolved with cephalization
Sight, taste, sound
Multitude of sensory organs
Magnetism: birds turtles
Electric fields: sharks
Barometric pressure: birds, storm detection

Feeding
Four general tactics
Suspensions
Deposit feeders
Fluid feeders
Mass feeders
Suspensions
filter feeding
Sponges, baleen whales
Deposit feeders
consume deposits of organic material within or on substrate
Earthworms, sea cucumbers
Fluid feeders
suck or mop up liquids
Butterflies, flies,
Mass feeders
chunks of food into their mouths
Mouth parts determine what you eat
Herbivores
eats plants or algae
Carnivores
eats animals
Detritivores
eats dead stuff
Omnivores
eats both plants and animals
Predators
larger than prey, killed quickly
Parasites
smaller and harvest nutrients while killing
Endoparasites
Ectoparasites
Endoparasites
live within the host, typically worm like
Ectoparasites
outside the host, grasping mouthparts
Movement
jointed lims - crabs
parapodia- polychaetes (annelida)
tube feet- sea urchins
lobe like limbs- velvet worms
Prediction: different genes are responsible for each type of appendage
Highly diverse
Found the D11 genes for limb formation in insects and labeled them
This gene was present in limb formation for all animals
Appendages could be genetically homologous
Fertilization
can be internal or external
Internal
typically includes a male sex organ and typically sperm packets
Seahorses
External
typical in marine organisms
clams
Viviparous
live bearing
Some Mammals, fish, amphibians, sharks and lizards
Ovoviviparous
egg-live bearing
Some Snails, insects, reptiles, sharks
Oviparous
egg bearing
Vast majority of animals
Metamorphosis
Big innovation
Larvae
Juveniles
adults - reproductive

Larvae
sexually immature, physically different, habitats and food sources are different
Juveniles
sexually immature
Hemimetabolous
:juveniles are called nymphs that are mini versions of the adults

Holometabolous
young are larvae

Metamorphosis Significance
Decreased competition between the adults and the larvae or juveniles
Specialization leading to more efficiency

Colony
identical individuals physically attached
Cnidarian life cycles

Nonbilaterian groups
Porifera
Cnidaria
Ctenophora
aceolomorpha
Porifera
(sponges)
7000 species
Benthic
Rocky, shallow water
Radially symmetric or asymetrical
Spicules
Suspension feeders
Mostly sessile some can move
Asexual reproduction
Used for sponges and toxin studies
Spicules
stiff spikes used for support
Cnidarians
(jellyfish, corals, anemones, hydroids)
11,000 marine species
Radially symmetric diploblasts
Mesoglea
Some have medusa and polyps
Some are only polyps
Cnidocyte
Asexual and sexual reproduction
Mesoglea
gelatinous material between cell layers
Cnidocyte
prey capture
Ctenophore
(comb jellies)
Ciliated
Diploplasts
Planktonic
100 species
Invasive species for fish larvae
Predators: adhesive cilia or ingestion
Largest animals with cilia
Both male and female organs
External fertilization mostly
Aceolomorpha
No coelom
Bilaterally symmetric, triploblasts
Nerve net
No cephalization
Low digestive tissue
Detritus or small predators
Ciliated
Fission or growth
Egg layers

Protostome animals
20 phyla of protostomes
Anthropoda
Crustaceans
Myriapods
Mollusca
Others: kinorhynca, gnathostomulida, etc
Includes the fruit fly and roundworm
mouth first
Broken into lophotrochozoan and ecdysozoa
Lophotrochozoan
Ollsks, annelids, flatworms
Three phyla have a lophophore feeding tube
Suspension feeding
Bryozoans, branchiopods, phoronids
Trochophore larvae are common
Cilia around the middle
All grow continuously and incrementally

slophophore vs Trochophore

Ecdysozoan
Nematodes and arthropods
All grow by molting
Molt either the cuticle or exoskeleton
After molting chances of getting caught and killed increase
What is the evolutionary advantage of the molt?
Lophotrochozoan vs Ecdysozoan

Body plan diversity
All protostome are triploblastic and bilaterally symmetric
In the worm like phyla the coelom is fully developed
But
In flat worms it is gone
In arthropods and mollusks it is reduced
Why do these animals not need one?
Arthropod body plan
Segmented bodies
Tagmata: regions of the body
Head
Thorax
Abdomen
Jointed limbs
Chitin exoskeleton
Movement is based on muscle contractions against the exoskeleton
Hemocoel

Hemocoel
body cavity, functions as a coelom, contains circulatory fluid, not completely surrounded my mesoderm
Mollusca Body plan
Three major components:
Foot: muscle
Visceral mass: internal organs
Mantle: outgrowth that surrounds the visceral mass
Shell is typically Calcium Carbonate

Worm like phyla body plans

Distinctions involve feeding structures
Annelids: segmented worms, echurians, deposit feeders
Priapulids: sit and wait predators
Nemertean: proboscis
Water to Land
Pros and cons
One lineage of deutorosomes moved from water to land
The evolution to land happened multiple times for protostomes
Same in ecdysozoa
Why not water to land
adaptation
Exchange gases
Avoid drying out
food
Moving
reproduction
Air exchange and moisture loss
Round worms and earthworms
Humid soils, moist environment, gas exchange through skin
Air exchange and moisture loss
Arthropods and mollusks
Internal gills
Air exchange and moisture loss
Insects
Waxy coating that can be opened and closed when needed
Jet propulsion
Uses a siphon
Yes cephalopods are mollusks

Reproduction
Wormlike phyla still do asexual reproduction
Parthenogenesis: unfertilized eggs become embryos, crustacean and insects
External fertilization: clams, branchiopods, bryozoans, some other groups
Internal fertilization: requires movement and copulation, crustaceans, snails and insects
Live young: ovoviviparous, insects, snails
Sexual is more common
Parthenogenesis
unfertilized eggs become embryos, crustacean and insects
Lophotrochozoans
Key lineages
Rotifera
Platyhelminthes
Annelida
Mollusca
- Bivalvia
- Gastropoda
- Polyplacaphora
- cephalopoda
Ecdysozoans
key lineages
Namatoda
Arthropoda
- Myriapods
- Insecta
- Chelicerata
- crustaceans
Rotifera

1800 species
Iive in damp soils or water
1 mm long typically
Coelom
Do not have a lophophore or trochophore larval stage
DNA makes them a lophtrochophore
Corona
Parthenogenesis
Corona
cilia at the end, allow for suspension feeding, also swimming
Platyhelminthes
Four lineages
turbelleria (free living)
cestoda (tape worm)
trematoda (flukes),
monogenea (ectoparasites on fish)

Platyhelminthes
Flat worms
400,000 species
Substrates or fresh water
Many are parasitic
Broad flat body type that increases gas exchange
No coelom
Blind digestive tract (one hole)
No lophophore
Not much movement
Life cycles can involve many host species, asexual and sexual
Annelida
(segmented worms)
Have a coelom
16,500 species broken into two sections: Polychaeta and Clitella
Clitella: leeches and oligochaetes
Chaetae
Chaetae lost in Clitella
Clitella: earthworms, many water species, no parapodia
Hydrostatic skeleton for movement
Parasitic feeding or suspension feeding

Chaetae
bristle like extensions from parapodia
Mollusca
Bivalvia
Two shells
Most extensive fossil record
Suspension feeders
Important commercially
Internal gills
Foot allows for burial
Swim via clapping
Swimming trochophore larvae
Metamorphoses into a veliger larvae
Metamorphoses into an adult
Sexual

Mollusca
gastropoda
(snails, slugs and nudibrachs)
Belly feet
Two types the land slugs and the nudibranchs
Land slugs: Shell for protection
Nudibrachs: Bright coloration is a warning for toxins
All have a radula for eating using chintinous teeth
Mostly sexual
Movement via musclular contractions of the foot

Mollusca
polyplacophora
Many plate bearing
1000 species
8 carbonate plates
Radula
Movement via foot
Sexual reproduction
Trochophore larvae

Mollusca
Cephalopoda
Head feet
Body: visceral mass and foot that has been modified into tentacles
Nautilus has a shell other have a small shell or none
Have a beak (modified radula)
Jet propulsion or tentacle based movement
Highly complex courtship rituals for sexual reproduction

Ecdysozoans
7 phyla
onychophora: velvet worms
tardigrada: water bears, benthic habitats
Lobe leggs
Detritophores
Arthropods: exoskeleton,segmented, Compound eyes, Antennae

Nematoda
Unsegmented
Longitudinal muscles for movement
Gas exchange across skin
Trichinosis, elephntitis, other diseases
Only some are parasitic
Egg laying sexual reproduction(roundworms)

Arthropoda
Myriapods
11,600 species
Terrestrial
Millipedes and centipedes
Specialized mouthparts for biting and chewing (different for each)
Many legs
Internal fertilization egg laying
Arthropoda
insecta
925,000 species
Three tagmata: head, thorax, and abdomen
Four mouthpart structures: labrum, mandibles, maxilla and labium
Typically have one or two pairs of wings
One pair of antennae
Sexual egg laying
Arthropoda: chelicerata
( spiders, ticks, mites, horseshoe crabs, daddy long legs, scorpions)
70,000 species
Chelicerae: used for feeding and defense near the mouth
8 pairs of appendages
Predators sit and wait or active
Exoskeleton and muscular movement
sexual
Daddy long legs- morphologically and genetic component difference than spiders
Arthropoda: crustaceans
(shrimp, lobsters, crabs, barnacles, isopods, copepods)
67,000 species
Few terrestrial (rolypollies) mostly aquatic or marine
Two body parts: cephalothorax and abdomen
Carapace: covers cephalothorax
Mandibles for chewing
Diverse movement and reproduction
Some sessile
barnacle penis
Deuterostome animals
Four phyla
Echinoderms: sea stars or sea urchins
Hemichordates: acorn worms
Xenoturbella:2006
Chordates: vertebrates and invertebrates
Hemichordata
deposit or suspension feeders
Burrowers in mud or sand
Xenoturbella
two wormlike species
Distinct phylum in 2006
Echinoderm
Spiny skins
Exclusively marine
7000 species
Larvae are bilaterally symmetric
Adults are radially symmetric or pentaradial
endoskeleton
Not cephalized (no brain)
Water vascular system
Tube feet project out of the body to form podia
Movement via water vascular system and feet
Use of the podia is important in food gathering
Clamping
Suspension feeding
Mucus secretions

Water vascular system
movement of water through and into body
top down control Trophic cascade
something messed up and ecosystem goes crazy the down some up some- down up down up down
Echinodermata: Asteroidea
(sea stars)
1700 known species
Predators or scavengers
Crown of thorns consumes coral
lack of predators has lead to coral death
Regeneration of arms
Ovo or ovoviviparous
Echinodermata: Echinoidea
(sea urchins or dollars)
800 species
Holdfast
Grazing or suspension feeding
Movement with spines or podia
External fetilization
Chordate
Four morphological features
in their life cycle
Pharyngeal gill slits
Dorsal hollow nerve cord
Notochord
Muscular post anal tail
Pharyngeal gill slits
openings into the throat
Dorsal hollow nerve cord
projections of neurons running the length of the body
Notochord
stiff, flexible supportive rod
Muscular post anal tail
tail with muscles that extends past the anus
Chordate
Three subphyla
All four morphological characteristics are found in these phyla at some point in time during their life cycles

Cephalochordate

Lancelets or amphioxus
Small mobile torpedo like
Suspension feeders
Use agill slits to eat
Notochord is a endoskeleton
All marine sands
Asexual is unknown
Sexual is external
Have all forms in their adult stage
Urochordate
Tunicates or sea squirts
Lose the notochord, dorsal nerve chord, and anal tail
Larvae function as the dispersal form
Suspension feeding via gill slits and mucus
All oceanic
Two siphons (hole that water goes through) and a u shaped body

Vertebrate
Dorsal hollow nerve cord: spinal cord
All vertebrate embryos have pharyngeal pouches
Aquatic species gain gills
Terrestrial species have these as a vestigial trait
Notochord is used for body plan organization not for support
Two synapomorphy
Vertebrae
Cranium
Segmented brain allows for coordination
Cerebrum, cerebellum, medulla oblongata
Forebrain(smell), midbrain (vision), hindbrain (balance and sometimes hearing)


Vertebrate evolution
540 MYA first vertebrates, skull made of cartilage
Cartilage: strong but flexible, cells, in gel like matrix of polysaccharides and protein fibers
Bony fish and tetrapods have bone based endo skeletons
Bone: hydroxyapatite based in calcium and phosphate with blood vessels and protein fibers
Bone started as a hard exoskeleton used for protection
Jaws: 440 MYA, jaws and teeth large radiation followed
Bony endoskeleton: allowed for rapid swimming
limbs for land movement: 365 MYA first tetrapods
Amniotic egg: 20 MYA, all tetrapods other than amphibians, egg that has membranes surrounding a food supply, better gas exchange, support, larger further developed young

Jaw Theory is that gill arches evolved to allow for biting
Evidence
Gill arches and jaws are made of similar shape and type of tissue
In development the muscles for control are the same
Derived from neural crest cells

Hagfish and lampreys are jawless
Ray finned fish have diversified
Protrusible jaw: ray finned fishes
Pharyngeal jaw or throat jaw
Tetrapod limb
Supported by molecular and fossil
Lungfish is a living link
Can walk short distances
Hox genes cause tetrapod and lobe fin deverlopment
Hard spines to walk
Xing Xu discovered a feathered dinosaur
Lead to the idea that birds evolved from dinosaurs
Feathers started as simple projection and lead to feathers
Do you think that flight evolved from gliders or from tree dwelling species?
Once feathers evolved three adaptations helped to strengthen flight
Adapted radiation occurred
Keel – attaches to muscle for flight

Amniotic egg
Increased support
Increased gas exchange

placenta
allows form mother and young nutrient exchange
Egg out of womb
Give nutrients via mother
egg sits inside womb but egg gives nutrients
Allows baby develop further
Gestation
development time of embryo
placenta Evolved because

Consistent temperature
Protection
portability
Parental Care
could be the reason for both linages’ success
Fitness trade off for parents
Incubation, feeding , protecting, etc
Mammals and birds have extensive care
Lactation
Increase success surviving young
Ends when young can care for themselves even if mother is still around
Lactation
produce food for young
mammals vs reptiles
Mammals:
Presence of hair or fur
Mammary glands
Milk suckling muscles
Reptiles:
Ectothermic
Scales
different jaw structures
Myxinoidea and Petromyzontoidea
Could be one group
110 species
Jaw less
Scavengers and predators
Swim via notochord
Lampreys are Anadromous: move between ocean and river
Hagfish mating is unknown
Hagfish are ectoparasites
Hagfish- protective ooze
Gills- diffusion of water
Chondrichthyes
(sharks rays and skates)
970 species
Cartilaginous skeleton
Mostly marine some are freshwater
Internal fertilization
Rays and skates swim with undulation
Electric rays and senses
Internal fertilization- sense electrical notions
Undulation= wavy movement in muscles
Sharks will sink if they do not swim
Change pressure in body to float

Undulation
wavy movement in muscles
Actinopterygii
(ray finned fishes)
Swim bladder
Fins with long bony rods
Teleosts or bony fish are very ecologically important (cod, golfish etc)
Protrusible jaws
Many are oviparous
parental care of the eggs
Actinistia and Dipnoi
Coelacanths and lungfish
Lobe finned fishes
Evolutionary link
sexual reproduction
Bigger and longer bones than the ray finned fish
“a fish caught in time”
West of africa fishermen trying to sell them to chinese men for fertility??– junk fish
Thought it was extinct until 1938
Another missing link
Very rare
Some in west of africa and australia
Bigger they are, more babies
Amphibia
(frogs, salamanders, caecilians)
“both sides living”
5500 species
Gas exchange across skin
Adults are carnivores
Caecilians lack limbs and eyes, are viviparous and are burrowing predators
Other amphibians have modified tongues for prey capture
Well developed limbs
Salamanders have internal
Frogs have external and undergo metamorphosis
Caecilians – modified tongues
Mammalia: Monotremata
(platypuses, echidnas)
Lay eggs
Low metabolic rates
Three species: one platypus and two echidnas
Echidnas: pouch laying eggs, ants termites and earthworms,
Platypuses: burrow egg laying, insect larvae mollusks and other small animals
secrete milk from glands

Mammalia: marsupiala
Australia and americas
Young are born very early and finish development outside of the womb on the mother
Variety of feeding types
Variety of movement
Embryo attaches to milk gland and finishes developing outside of womb
Mammalia: eutheria
(placental mammals)
4300 species
18 orders: including primates, rodents, bats, insectivores, artiodactyls, and carnivores
Teeth structure dictates diet
Limb development dictates movement
Internal placenta leads to well developed young
Extensive parental care
All give young milk
Reptilia: lepidosauria
(lizards and snakes)
Scaly skin and elongated bodies
Vestigial hip and leg bones
7000 species
Can be poisonus
Can have a dislocated jaw
Mostly sexual
Mostly ovo or ovoviviparous
Reptilia: Testudinia
300 species
Shell made of bony plates
No teeth
Carnivorous or herbivorous
All oviparous
Low parental care
turtles
Reptilia: crocodilia
24 species
Adaptations of sensory organs help submersion
Predators
Can walk or swim
Extensive parental care
oviparous

Sensory organs at the top lets them float
Reptilia: aves
Descended from dinosaurs
Lightwieght bodies
Air sacs in bones
Variety of feeding types
Some flightless
Extensive parental care
Primates
Two groups
Prosimians
Anthropoids
Anthropoids
great apes, more human like monkeys
Prosimians
lemurs, tarsiers, pottos, and lorises
Primates
Grasping hands and feet
Nails instead of claws
Large brains
Color vision
Social behavior
Parental care
Good depth perception
Hominids or great apes
No tail, long arms, short legs, large bodied
Humans are the only fully bipedal
Fist walking and knuckle walking are other forms of movement
Bipedalism is a synapomorphy

Fossil humans
7 million years ago common ancestor to chimps and humans
Not as complete as we would like
Four groups of hominins
Gracile Australopithecines: slightly built, bipedal,
Robust Australopithecines: stockierheavy biting power
Early homo: flat narrow faces, large brain cases, made tools
Recent homo: 1.2 MYA to present, tools, paintings and sculpting
Hominin fossil record
Bipedalism is the synapomorphic trait
Several lineages existed simultaneously
Different species lived in physical contact
Large brains possibly due to language and tool use
Hyoid bone evolves with species, showing language use
Colonization of austrailia
Competition for food and space could be the reason only one hominin suvives
Out of Africa hypothesis
Homo sapians are the only hominin with a chin
We started out in Africa and then spread
No interbreeding
