Chapter 34 - The Origin and Evolution of Vertebrates

What is a group of organisms that includes a single ancestor and all of its descendents?

Clade

What is another name for a clade?

Monophyletic group

What are the 4 key characteristics of chordates?

1. Notochord
2. Dorsal, hollow nerve cord
3. Pharyngeal slits
4. Muscular, post-anal tail

What is the flexible rod that in humans develops into gel-like discs between each vertebrae?

Notochord

What are throat slits that let water in & out?

Pharyngeal slits

What develops into the brain and spinal cord?

Dorsal, hollow nerve cord

What develops into parts of ear, neck and head in tetrapods?

Pharyngeal slits

What are the bilaterian animals belonging to the clade called Deuterostomia?

Chordates

What group is comprised of all vertebrates and the 2 groups of invertebrates?

Chordates

What are the 7 animal groups of the vertebrates, from earliest evolution to latest?

1. Hagfishes and lampreys
2. Sharks, rays, chimaeras
3. Ray-finned fishes
4. Coelacanths
5. Lungfishes
6. Amphibians
7. Reptiles and mammals

What are the 2 groups of invertebrates called?

1. Cephalochordates
2. Urochordates

What animal is the Cephalochordata?

Lancelets

What are marine suspension feeders, named for their blade-like shape?

Lancelets

How do Lancelets swim?

Using a simplified form that fishes use

What animal retains most key characteristics of the chordate body plan?

Lancelets

What animal is the Urochordata?

Tunicates

What animal is more closely related to other chordates than lacelets?

Tunicates

When are Tunicate characteristics most apparent?

Larval stage

What do Tunicate larva use their chordate characteristics for?

Swim until the settle on a suitable substrate for metamorphosis

What are adult Tunicates called?

Sea squirts

What animal has fewer Hox genes?

Tunicates

What does the difference in Hox genes indicate for Tunicates?

Their body plan is built using different genetic controls

What chordate group has all four key chordate characteristics as an adult, not just as an embryo? Lancelets, Tunicates, Frogs, or Humans?

Lancelets

What are some key characteristics that have appeared during vertebrate evolution?

* skull and backbone composed of vertebrae
* jaws and a mineralized (bony) skeleton
* lobed fins
* limbs with digits
* amniotic egg

With what animals did skull and a backbone composed of vertebrae first develop?

Hagfishes and lampreys

With what animals did jaws and a mineralized (bony) skeleton first develop?

Sharks, rays, chimaeras

With what animals did lobed fins first develop?

Coelacanths

With what animals did Limbs with digits first develop?

Amphibians

With what animals did amniotic eggs first develop?

Reptiles and mammals

What are the 2 living vertebrates lacking jaws?

1. Hagfishes - Myxini
2. Lampreys - Petromyzontida

What animals are Myxini?

Hagfishes

What animals are Petromyzontida?

Lampreys

What animals lack a backbone, but have a rudimentary vertebrae?

1. Hagfishes - Myxini
2. Lampreys - Petromyzontida

What are backbones made of cartilage, not bone, called?

Rudimentary vertebrae

What clad are the jawless vertebrates called?

Cyclostomes

What animal has the following characteristics:

* jawless vertebrates with reduced vertebra, a notochord, and a cartilaginous skeleton
* larvae live and feed in streams
* free-living (non-parasitic) live in streams
* parasitic migrate to oceans or lakes
* parasites clamp mouth onto host fish and feed on blood and tissue

Lampreys

What animal has the following characteristics:

* jawless vertebrates with reduced vertebrae and cartilaginous skull
* adults retain notochord as flexible rod of cartilage
* all marine and bottom dwelling scavengers
* slime production

Hagfish

Which trait is shared by all vertebrates except cyclostomes at some point in development?

* Notochord, vertebrae, cartilaginous skeleton, cranium (head), mouth with jaws.

Mouth with jaws

What are the jawed vertebrates?

Gnathostomes

What animals comprise the Gnathostomes group?

sharks, ray-finned fishes, lobe-finned fishes, amphibians, reptiles, and mammals (every animal that has evolved after lampreys and hagfishes)

What evolved from the modification of skeletal rods that support the pharyngeal slits

Jaws

What is the system that has rows of organs sensitive to vibrations located along the body sides?

Lateral line system

What clade/group of Gnathostomes are made up of cartilage?

Chondrichthyans

What animals compose the Chondrichthyans group?

Sharks and rays

What are some characteristics of sharks?

* have streamlined bodies that make them swift swimmers
* suspension feeders (capture and ingestion of food particles suspended in water) and carnivores
* short digestive tract
* spiral valve on ridge that increases digestive surface area
* can detect electrical fields from nearby animals (???whatt)

Where are shark eggs fertilized?

Internally

What are the 3 ways shark embryos can develop?

1. Oviparous
2. Ovoviviparous
3. Viviparous

What shark embryo development method has the eggs hatch outside the mother’s body?

Oviparous

What shark embryo development method has the egg develop within the uterus and during favorable environmental conditions has the offspring birthed via live birth?

Ovoviviparous

What shark embryo development method has the embryo develop within the uterus and be nourished through a yolk sac placenta?

Viviparous

Where does the shark reproductive tract, excretory system, and digestive tract empty into?

Common Cloaca

What Gnathostome group has a bony endoskeleton?

Osteichthyans

What is the common name for Osteichthyans?

Bony fish

What vertebrates do we informally call fishes?

Aquatic osteichthyans

What are the 2 types of aquatic osteichthyans?

1. ray-finned fishes (Actinopterygii)
2. lobe fins (Sarcoptergyii)

What are the ray-finned fishes?

Actinopterygii

What are the lobe finned fishes?

Sarcopterygii

What are the 3 surviving lobe-fin descending lineages?

1. Coelacanths (Actinistia)
2. Lungfishes (Dipnoi)
3. Tetrapods

What is the class name for Coelacanths?

Actinistia

What is the class name for Lungfishes?

Dipnoi

What are the 3 classes that make up teh tetrapods?

1. Amphibia
2. Reptilia
3. Mammalia

What is is the bony endoskeleton of Osteichthyans made up of?

Calcium phosphate

What controls the direction of a fish?

Pectoral fins

What is the bony flap that protects the gills of a fish?

Operculum

What characteristic defines lobe-finned fishes?

The fleshy fins that have thick muscle in their pectoral & pelvic fins making them resemble limbs

What Gnathostomes have limbs?

Tetrapods

What are the 5 derived characteristics of Tetrapods?

1. four limbs and feet with digits
2. a neck that allows separate movement of the head
3. fusion of pelvic girdle to the backbone
4. the absence of gills
5. ears for detecting airborne sounds

What embryonic development method do Amphibia use?

Oviparous

How do Amphibia have their children?

Lay eggs that hatch outside their body

What are the 3 orders of the Amphibians?

1. Urodela
2. Anura
3. Apoda

What animals are in Order Urodela?

salamanders and newts

What animals are in Order Anura?

frogs and toads :3

What animals are in Order Apoda?

Caecilians

What are Caecilians?

Amphibians that look like earthworms

What are tetrapods that have a terrestrially adapted egg?

Amniotes

What are the 3 derived characteristics of Amniotes?

1. amniotic egg that contain membranes that protect the embryo
2. fertilization is internal
3. have extraembryonic membranes (specialized membranes)

What are the 4 extraembryonic membranes (specialized membranes?

1. amnion
2. chorion
3. yolk sac
4. allantois

Are reptiles ectothermic or endothermic?

Ectothermic

What is the phrase for absorbing external heat as the main source of body heat?

Ectothermic

Are birds ectothermic or endothermic?

Endothermic

What is the phrase for being capable of keeping the body warm through metabolism?

Endothermic

Which group soon outcompeted amphibians on land due to their watertight skin and eggs? Birds, mammals, reptiles, cyclostomes, or none of the above?

Reptiles

What are 5 derived characteristics of Birds?

1. wings with keratin feathers
2. no urinary bladder or teeth
3. small gonads
4. four chambered heart
5. endothermic

What is the major adaptation for birds?

wings with keratin feathers

What are do many derived characteristics of birds help facilitate?

Flight

What are 6 characteristics of mammalians?

1. mammary glands to produce milk
2. hair on and fat under skin
3. high metabolic rate due to endothermy
4. four chambered heart
5. large brain
6. differentiated teeth

What are the 3 living lineages of mammals?

1. Monotremes
2. Marsupials
3. Eutherians/Placentals

What mammalian lineage has the embryo develop within a placenta in the mother’s uterus, and has it complete it while nursing in the maternal pouch?

Marsupials

What is the maternal pouch?

marsupium

What do the mammalian order Primates include?

Lemurs, monkeys, and apes

What is a defining characteristic of Primates?

Opposable thumb

What are the Ancestral primates from earliest in evolution to latest?

1. Lemurs
2. Tarsiers
3. New world monkeys
4. Old world monkeys
5. Gibbons
6. Orangutans
7. Gorillas
8. Chimps & bonobos
9. Humans

What does the term “old world” refer to with respect to monkeys?

The areas they are found within (Europe, Africa, Asia)

What does the term “new world” refer to with respect to monkeys?

The Americas

Which monkey is more intelligent, new world or old world?

old world

Which monkey has a prehensile tail, new world or old world?

old world

Which monkey has nostrils that are close together, new world or old world?

old world

Which monkey has thumbs that can be rotated and more opposable?

old world

Which monkey lives mostly on the ground?

old world

What are the 2 defining characteristics of humans?

1. large brain
2. bipedal locomotion