Section 7: Overview of Animal Diversity (Part C)

Cambrian period, about 530 years ago.

During what period did a variety of invertebrate animals inhabit earth’s oceans?

Vertebrates

Animals get their name from the series of bones that make up the backbone

60,000

how many species of vertebrates?

1. skeletal system

2. complex nervous system

these [2] have allowed vertebrates to become more efficient at two essential tasks..

1. capturing food

2. evading predators

a skeletal system and complex nervous system have allowed vertebrates to become more efficient at two essential tasks..

hox genes

Vertebrates have two or more sets of these genes:

1. vertebrae enclosing a spinal chord

2. an elaborate skull

3. fin rays in the aquatic forms.

Vertebrates have the following derived characters: [3]

The neural crest

A collection of cells that appear along the edges of the closing neural tube of an embryo

1. teeth

2. some of the bones and cartilage of the skull

3. several types of neurons

4. sensory capsules

Neural crest cells give rise to a variety of structures:

Gnathostomes

Jawed vertebrates

1. sharks and their relatives

2. ray-finned fishes

3. lobe-finned fishes

4. amphibians

5. reptiles (including birds)

6. mammals

Gnathostomes include:

skeletal support of the pharyngeal slits

jaws are hypothesized to have evolved from:

1. genome duplication including duplication of hox genes

2. an enlarged forebrain

3. lateral line system

other characters common to gnathostomes

Vibrations

the lateral line system is sensitive to what?

enhanced smell

enhanced vision

enlarged forebrain in gnathostomes is associated with what

Placoderms

earliest gnathostomes in the fossil record are an extinct lineage of armored vertebrates called:

450 million years ago

Placoderms appeared how many years ago

Acanthodians

group of jawed vertebrates that radiated during the Silurian and Devonian periods

1. chondrichthyans

2. ray-finned fishes

3. lobe fines

Three lineages of jawed vertebrates survive today

1. sharks

2. rays

3. their relatives

Chondrichthyans include: [2]

Chondrichthyans

Jawed vertebrates have a skeleton composed primarily of cartilage.

Dozens of species of ratfishes, or chimaeras

Second subclass of chondrichthyans include:

1. streamlined body and are swift swimmers

describe shark body

largest are suspension feeders

most are carnivores

shark diet

has short digestive tract with a ridge called the spiral valve to increase the digestive surface area

Shark digestion

Acute senses inlcuding sight, smell, and the ability to detect electrical fields from nearby animals

shark acute senses [3]

happens internally

Shark embryo fertilization:

1. oviparous

2. oviviparous

3. viviparous

shark embryos can develop in different ways:

oviparous

means that eggs hatch outside the mother’s body

Ovoviviparous

meaning embryos develop within the uterus and is nourished by egg yolk

Viviparous

meaning the embryo develops within the uterus and is nourished through a yolk sac placenta from the mother’s blood

Cloaca

shark reproductive, excretory, adn digestive tract empties into common:

overfishing:

pacific populations have plummeted by up to 95%

major threat to sharks

Osteichthyes

The vast majority of vertebrates belong to a clade of gnathostomes called:

most have bony endoskeleton

Osteichthyans skeleton

body fish

tetrapods

osteichthyans include:

Aquatic osteichthyans

vertebrates that are informally called fishes

operculum

gills are protected by:

swim bladder

fish control their buoyancy with this air sac

most are oviparous, some have internal fertilization and birthing

fish embryyo development

Actinopterygii, the ray-finned fishes

these include nearly all familiar aquatic osteichthyans

During the silurial eriod

when did ray-finned fishes originate?

1. supported by long, flexible rays

2. modified for maneuvering

3. defense

4. other functions

Ray-finned fishes fin modifications

industrial scale fishing

dams that impact prey capture, migration, and spawning

ray-finned fish populations are affected by

lobe-fins (Sarcopterygii)

fish that have muscular pelvic and pectoral fins that they use to swim and “walk” underwater across the substrate

Silurian period

Sarcopterygii originated when

1. coelacanths

2. lungfishes

3. tetrapods

three surviving lineages of lobe-fins

Southern Hemisphere

living lungfishes are found where

gills are main organs

can also gulp air into their lungs

lobe-fin gas exchange

tetrapods

fishes that adapted to life on land

5300 species

how many mammals are there

1. mammary glands

2. hair

3. high metabolic rate

4. larger brain

5. differentiated teeth

6. kidney

derived characters of mammals: [6]

endothermy

mammals have a higher metabolic rate due to:

1. thick, oily skin to limit evaporative water loss

2. animal stays in cool, humid burrows

3. nares limit water loss

4. lots obtain water from catabolic pathways

5. large intestine and kidney absorb water effectively (little in urine and feces)

mammalian adaptations for dry areas [5]

Synapsids

mammals evolved from:

mammalian middle ear

in evolution of mammals, two bones that formerly made up the jaw joint were incorporated into what?

1. Monotremes

2. Marsupials

3. Eutherians

three living lineages of mammals that emerged by the early cretaceous period

Cretaceous

mammals did not undergo a significant adaptive radiation until after this period

Monotremes

A small group of egg-laying mammals consisting of echidnas and the platypus

Marsupials

Mammals include opossums,kangaroos, and koalas

Develops within the placenta in the mother’s uterus. It is born very early in its development

where does embryo development occur in marsupials?

While nursing in a maternal pouch

Marsupials complete their embryonic development when?

Marsupium

Marsupials nurse in this maternal pouch:

To the rear of mother’s body

In some species, such as bandicoots, the marsupium opens where?

The diversity of marsupials that resemble the eutherians in other parts of the world

In austraia, convergent evolution has resulted in what?

Is more complex.

Young eutherians complete embryonic development within the uterus, joined to the mother by the placenta

eutherian placenta compared to marsupials:

Monotremata

Mammals that lay eggs, ahve no nipples, and young suck milk from mother’s fur

Marsupialia

Mammals with complete embryonic development in pouch on mother’s body

1. echidnas

2. platypuses

monotremata examples [2]

Kangaroos

opossums

koalas

marsupialia example [3]

Proboscidea (elephants)

Mammals with long, muscular trunk; thick loose skil; upper incisors elongated as tusks

Hyracoidea (hyraxes)

Mammals with short elgs, stumpy tail, herbivore, complex multi-chambered stomach

Sirenia

Aquatic mammal with finlike limbs and no hind limbs, herbivore

1. manatees

2. dugongs

Sirenia examples

1. Sloths

2. anteaters

3. armadillos

examples of Xenarthra [3]

Xenarthra

mammals with reduced or no teeth, herbivores or carnivores

rodentia

mammas that are chisel-like, continuously growing incisors worn down by knowing, herbivores

1. squirrels

2. beavers

3. rats

4. porcupines

5. mice

rodentia examples [5]

Primates

mammals with opposable thumbs, forward facing eyes, well-developed cerebral cotex, and are omnivorous

1. lemurs

2. monkeys

3. chimpanzees

4. gorillas

5. humans

primate examples [5]

apes

humans are a member of which primate group?

1. large brain

2. short jaw

3. forward facing eyes

4. complex social behaviour and parental caree

5. fully opposable thumbs

derived characters of primates:

provides depth perception

function of forward facing eyes (primates):

1. lemurs lorises, bush babies

2. tarsiers

3. Anthropoids

Three main groups of living primates:

monkeys

apes

Anthropoids consist of [2]

45 million

oldest anthropoid fossils are how old

theya re more clsoely related to anthropoids than to lemurs

first anthropoid fossils indicate what about tarsiers?

1. gibbons

2. orangutangs

3. gorillas

4. chimpanzees

5. bonobos

6. humans

ape anthropoid group consists of: [6]

20-25 mil

apes diverged from Old World Monkeys how many million years ago?