Vertebrate

Evolution and

Diversity

Lauren Moon, Reid

Merriken, Bobby Hixhttps://daymondg.files.wordpress.com/2014/04/i-got-your-back.jpg

● The chordata phylum is the most well known phylum because it includes

humans and other vertebrates (and some invertebrates)

● Most evolved phylum of animals

● It is characterized by the development of certain structures present at

some point during their lifetime

● They possess a notochord, a hollow dorsal nerve cord, pharyngeal slits, an

endostyle, and a post-anal tail

Chordates

Evolution of Chordates

● First seen 896 million years ago

● Classified as deuterostomes because the tail develops before the mouth

● Evolved from invertebrate chordates to vertebrates to complex vertebrates

like fish to amphibians to mammals

Chordate Development

● Through cephalization, nerve tissue develops one side of the body, eventually becoming a head

● The vertebral column of ancient chordates was known as the notochord and helped stiffen the

body and protect the spinal cord with cartilage

Evolution of Fish and Amphibians

● Scientists believe that amphibians were the next evolutionary step down

from fish

● The pectoral and pelvic fins evolved into 4 legs

● The gills were sealed and lungs evolved

Classes of Fish

● There are 3 classes of fish: the Agnathans, the Chondrichthyans, and the Osteichthyans

Agnathans

● The Agnathans are boneless, eel-like creatures that have gone relatively unevolved for 300

million years

● The most common species are the hagfish and the lamprey

● Agnathan means lacking jaw

● They also lack paired pectoral fins which is present in all other fish

● Hagfish have boneless mouths for sucking while lampreys have teeth to bite their prey

● Hagfish are also known for producing copious amounts of slime and eating their prey from the

inside out

Chondrichthyans

● The Chondrichthyans are boneless fish whose skeleton is made entirely of

cartilage

● They possess teeth, pectoral fins, and dorsal fins like most fish

● The most famous Chondrichthyan is the shark which has been around for

more than 280 million years

● Other Chondrichthyans include rays and skates

Osteichthyans

● The third class of fish is the Osteichthyans which covers 90% of all fish

● They are the bony fish (bone skeleton)

● They also possess an air-filled sac for buoyancy and an operculum to

cover their gills

● There are over 12,000 salt-water species and 6,000 fresh-water

Class Amphibia

● Amphibians are tetrapod creatures that begin their lives in water and move

to the land for their adulthood

● There are over 3,900 species, ⅓ of which are considered endangered

● Amphibians are cold-blooded, fresh-water animals

● They are believed to be the evolutionary bridge between fish and reptiles,

mammals, and other terrestrial animals

● The Class Amphibia has 3 orders: Caudata, Anura, Apoda

● Caudata- Salamanders

● Anura- Frogs and toads

● Apoda- Caecilians

Phylum urochordata

● Subphylum of Chordates

● Marine

● Hermaphroditic

● Filter feeders

● Body enclosed in secreted protein case

● 2000 species

Mindblowing Fish and Amphibian Facts

● Electric eels and electric rays have enough electricity to kill a horse.

● Salamanders dont make sound

● Goldfish can see infrared light

● There’s a shark in Greenland that eats polar bears

Trivia!

● What can children with the rare genetic disease phenylketonuria not eat?

o foods high in salt

o foods high in carbohydrates

o foods high in protein

o foods high in fat

● Why? Phenylketonuria is extremely rare and is caused by the pairing of two faulty

recessive alleles (one from each parent), that control the enzyme responsible for breaking

down the amino acid phenylalanine, which is in protein. This why people affected cannot

eat foods high in protein such as meat, milk,cheese, eggs, fish.

WOW…

much

fascinate.

such

wow

Some Vocabulary!

Notochord - a cartilaginous skeletal rod supporting

the body in all embryonic and some adult

chordate animals

Dorsal Hollow Nerve Cord - is one of the embryonic

features unique to chordates, along with a

notochord, a post-anal tail, an endostyle, and

pharyngeal slits.

http://www.ucumberlands.edu/academics/biology/faculty/kuss/c

ourses/vertbraeribssternum/aboutvertebrae.htm

http://www.bio.miami.edu/tom/protected/CXX/34-02.gif

Some Vocabulary!

● Pharyngeal Slits - are filter-feeding organs found in

non-vertebrate chordates and hemichordates living

in aquatic environments.

● Postanal Tail - extension of the notochord and

nerve cord past the anus.http://sunny.moorparkcollege.edu/~econnolly/Fi

shescartilagenousF11_files/image006.png

http://bio.sunyorange.edu/updated2/comparative_anatomy/anat_3/vertebrae_sacrum/3c.jpg

Some Vocabulary!

● Segmented Muscles/somites - organizing

segmental muscle patterns of mammalian (human)

body plan

● Urochordates/Tunicates - this subphylum of

chordata is composed of marine animals that look

like small sacs, the adults are sessile, filter sea

water through slits, no notochord, nerve cord, or

tail, larva are free swimming with all features.

http://www.ucmp.berkeley.edu/chordata/urochordata.gif

http://upload.wikimedia.org/wikipedia/commons/f/f9/Gray20nl_somite_highlight.png

Some Vocabulary!

Lancelets - a small elongated marine invertebrate that

resembles a fish but lacks jaws and obvious sense

organs. Lancelets possess a notochord and are

among the most primitive chordates.

● Paedogenisis - evolutionary in which the larval

stage develops reproductive structures.

http://life.bio.sunysb.edu/marinebio/larv_27.jpg

http://mosas.sysu.edu.cn/genome/images/in_images/amphi_organ.jpg

Some Vocabulary!

● Neural Crest - Although derived from the ectoderm,

the neural crest has sometimes been called the

fourth germ layer because of its importance.

(quoted in Thorogood 2009) from National Institute

of Health

● Closed Circulatory System - Closed circulatory

systems have the blood closed at all times within

vessels of different size and wall thickness. In this

type of system, blood is pumped by a heart through

vessels, and does not normally fill body cavities. http://upload.wikimedia.org/wikipedia/commons/thum

b/6/60/Neural_crest.svg/2000px-

Neural_crest.svg.png

http://science.kennesaw.edu/~jdirnber/Bio2108/Lecture/LecPhysio/42-02-

OpenClosedCircSys-AL.gif

Some Vocabulary!

● Gnathostomes - these are vertebrates with jaws!

● Tetrapods - vertebrates with two pairs of limbs with

digits, have ears, have lungs and includes

mammals, amphibians and birds and other reptiles.

http://upload.wikimedia.org/wikipedia/commons/6/66/Extant_tetrapoda.jpg

http://jl170.k12.sd.us/Bull_shark1.jpg

Some Vocabulary

● Amniotes - an animal that possess an “amniotic”

egg (an egg in which the embryo is surrounded by

membranes that form a fluid filled sac and assists

in gas exchange)

● Agnathans - these are jawless fish with no

moveable mouth parts and no paired fins.

http://img1.wikia.nocookie.net/__cb20120801002451/spongebob/i

mages/4/49/Hagfish.jpg

http://animalia-life.com/lamprey.html

http://www.mhhe.com/biosci/genbio/enger/student/olc/art_quizzes/genbiomedia/0

552.jpg

Trivia!

● How long is the memory span of a fish?o 3 seconds?

o 5 months?

o up to 2 years?

o 1 minute?

I just

pooped,

but that

fact was

cool.

Some Vocabulary!

Osctracoderm

Placoderm

http://facweb.furman.edu/~wworthen/bio440/evolweb/ordovician/ostracoderm.htm

Paraphyletic group of

http://autocww.colorado.edu/~flc/E64ContentFiles/PaleontologyAndFossils/Placoderm.htm

primitive, jawless fish Armor-

plated, jawed fish

Some Vocabulary!

Chondrichthyes Lateral LineOldest existing Receptor cells

of the nervous

jawed vertebrates system which

allow fish to sense

sound

and vibration

http://vertebrates.voices.wooster.edu/chondrichthyes/ www.amazonian-fish.co.uk

Some Vocabulary!

● Oviparous = egg laying

● Viviparous = live bearing

● Oviviparous = eggs hatch

in body, live bearing

Some Vocabulary!

Cloaca

OsteichthyesCavity in digestive tract for Bony fish (largest class of

vertebrates)

release of excretory and genital

products

Some Vocabulary!

● Operculumo the gill cover of bony

fish

● Swim bladder

o a gas-filled sac

present in the body

of many bony fish,

used to maintain and

control buoyancy

http://www.geol.umd.edu/~tholtz/G331/lectures/331vertsI.html

http://aqua-fanatic.blogspot.com/2011/06/swim-bladder-

disorder.html

Some Vocabulary!

● Ray-finned fisho fish that have thin fins

strengthened by slender rays

(including all bony fishes apart

from the coelacanth and

lungfishes.)

● Lobed-finned fisho fish of the class Sarcopterygii,

having fins that are rounded and

fleshy, suggesting limbs.

http://releeps.tripod.com/cgi-bin/

http://www2.estrellamountain.edu/faculty/farabee/BIOBK/BioBookDiversi

ty_9.html

Some Vocabulary!

● Tetrapod o “four legs” in Greek

o Includes Amphibians, Reptiles, Birds, and Mammals

o Have four limbs or ancestors with four limbs

● Amphibian o “double life” in Greek

o Includes frogs, toads, newts, and salamanders

o Cold-blooded

o Can live on land and in water

Some Vocabulary!

● Caeciliano tropical amphibians

o no eyes

o retractable tentacles

o burrow

Fun Trivia!

● Anemophobia is the fear of what?

● Wind

● Fire

● The Dark

● Spiders

Answer is the wind!

Lauren Moon Reid Merriken

Bobby Hix