Vertebrate Evolution Where did we really come from? Miss Augulewicz.

Vertebrate EvolutionWhere did we really come from?

Miss Augulewicz

Vertebrate Innovations Vertebral Column

Series of separate bones firmly joined as a backbone that defines the major body axis

Vertebrate Innovations Cranium

Supports and protects the sensory organs (eyes, ears, nose, mouth) and your brain

Step 1: Pre-vertebratesLancelet performed suspension feeding using

cilia and mucus

Mouth gets bigger Muscular pump forms that

can open and close Water & food are taken

in and pumped out

Reinforced by cartilage

Step 2: Agnathans-Jawless fish evolve

Feed using their muscular pharynx, not cilia and mucus

Lampreys, hagfish

Step 3: Gnathostomes- Jawed fish

The jaw evolves! Mouth opens, pressure

sucks large food in, jaw closes

No longer need pharyngeal slits to eat

Our ancestors were jawed fish: gnathostomes

Chondrichthyes (Sharks and stingrays) evolved in one direction they had bone then lost it

and are mostly cartilage

Osteichthyes (bony fish) evolved in another direction Kept the bone Ancestors to all present

day bony fish & vertebrates= SUCCESSFUL!

Half a billion years summed up in a few minutes…

http://www.youtube.com/watch?v=kgZRZmEc9j4

Your Inner FishSO….Looking back MUCH further than the chimpanzees, humans haves some other pretty old and interesting ancestors....

FISH!

How did we get on land?Meet the lungfish

LungfishLived in shallow fresh water that would

sometimes dry upBreathe using primitive lungs if no waterBreathe using gills if in water

Eventually fish evolved to come out of water…..

How did we learn this?

We look at the fossil record.

Tiktaalik

Tiktaalik lost some fish characteristics and gained lungs, arms & legs, primitive ears

Finding tiktaalik!http://www.youtube.com/watch?v=yvDQCa7rleI

What evolved next?

So they made it to land...but they aren’t fish anymore, what are they??

AmphibiansEvolution of lungs from the gut

Strengthening of limbs

Need to stay near water to lay eggs

Reptiles Can reproduce on land by

laying eggs

Get stronger limbs, use muscle and less energy to move

A new egg! Amniotic egg

Doesn’t need to be laid in water

Our ancestors can move to dry land!

From 2 different groups of reptiles we got....

Birds!

Mammals!

First mammals..Evolved from a reptile-mammal ancestor group called Therapsids.

Sort of look like rodents! Or weird dogs!

Oligokyphus

Inostrancevia

Mammalian characteristics Mammary glands: To

feed milk to our young

Fur or hair

Endothermic: maintains temperature from metabolic heat

There are three types of mammals based on their mode of reproduction

Monotremes lay eggs.

Marsupials have young that develop in the uterus for a short term. At birth, marsupial young crawl through mother's fur and into a pouch on the female's body to feed on mother's milk.

Placental mammals like humans develop through advanced stages in the uterus and receive maternal nutrients across the placenta.

Life of Mammalshttp://www.youtube.com/watch?v=2lCKc8tURtc&

list=PLD941E65FBD70DB46

Birds (Aves)Birds came from the dinosaurs!

This fossil, Archaeopteryx was once a dino with feathers!!

I can’t really talk too much about birds because they are my favorite and it would become a bird class.

Remember all the came before us!