Bio 122- Biodivesity: A history of life Part II- exam 3

Ordovician

§485.4-443.8mya

§Gondwana supercontinent

§Appalachian Mountains form

§Very hot, with cooling towards the end

§High CO2

§Colonization of plants on land

§Ordovician-Silurian extinction

§Potentially caused by plants

Plants have adaptations that allow them to thrive on land —>

structural adaptations to gain resources from air and soil

Plants have adaptations that allow them to thrive on land
—> structural adaptations to gain resources from air and soil

Shoot system and root system

pollen and egg

Plants have adaptations that allow them to thrive on land
—> structural adaptations to gain resources from air and soil

Shoot system:

Photosynthetic structures exposed to light and air aboveground

Plants have adaptations that allow them to thrive on land
—> structural adaptations to gain resources from air and soil

root system:

Belowground anchorage structures exposed to
water and minerals in soil

Plants have adaptations that allow them to thrive on land
—> structural adaptations to gain resources from air and soil

Pollen:

Protects sperm, allowing them to be carried by wind or animals

Plants have adaptations that allow them to thrive on land
—> structural adaptations to gain resources from air and soil

Egg:

Remains in female

reproductive organ, allowing the embryo to develop within the mother plant’s body

Plant structure 

Vascular System:

Network of tubes that transports water, sugar, and minerals

Plant structure 

Cuticle:

Waxy coating that prevents water loss

Plant structure 

Leaves:

Main site of photosynthesis and gas exchange through

Plant structure 

Lignin:

Chemical in cell walls that stiffens them, increasing suppor

The evolutionary history of plants records adaptations for

living on land

The evolutionary history of plants records adaptations for living on land

There are four major groups of modern plants:

Bryophytes

Seedless Vascular plant

Gymnosperms

Angiosperms

Major events in the evolution of plants highlight adaptations for

dry land

Major events in the evolution of plants highlight adaptations for dry land

Bryophytes

(mosses, liverworts, hornworts, 475 mya): evolution of waxy outer layer reduced water loss; still dependent on water for reproduction.

Major events in the evolution of plants highlight adaptations for dry land

Ancestral Green algae

origin of first terrestrial adaptions (bout 475 mya)

• 475 million years ago: nonvascular plant

Origin of Vascular tissue (about 425mya)

origin of seed (about 360 mya)

Bryophytes are seedless, nonvascular plants

Bryophytes have adaptations for land:

Cuticle,:

a waxy outer layer which retains moisture

§Structures that provide internal protection for gametes and embryos

Bryophytes are seedless, nonvascular plants

§They lack

seeds and vascular tissue.

Bryophytes are seedless, nonvascular plants

Modern bryophytes can survive

only in watery environments

Bryophytes are seedless, nonvascular plants

Mosses are

the most common bryophytes.

Three Types of Bryophytes

§Mosses (most common)

Liverworts

Hornworts

Moss diversity

Red moss capsules

Peat moss bog (3% of Earth’s land surface)

Moss colony on a tree in a coastal forest

Bryophytes come in two distinct forms representing an alternation of generations

•Diploid Sporophyte

produces spores (haploid reproductive cells) which are tough and can survive harsh conditions.

Bryophytes come in two distinct forms representing an alternation of generations

•Unlike most plants, in bryophytes the haploid gametophyte is

dominant (larger & more obvious).

Bryophytes come in two distinct forms representing an alternation of generations

Parts:

Spore Capsule

Sporophytes

Gametophyte: green, sponge-like, forms a mat

Brachiopoda

§Lamp shells

§Bilateral symmetry

§Lophophore

§Similar to bivalves

§Suspension Feeders

Cephalopoda

§Molluscs

§Bilateral symmetry

§Large heads

§Foot modified into tentacles

§Shelled or unshelled

§Relatively smart

§Active predators

The first vertebrates with jaws were

cartilaginous fishes

The first vertebrates with jaws were cartilaginous fishes

Cartilaginous fishes

(sharks and rays, ~1,000 species) have flexible skeletons made of cartilage and use two pairs of fins  and a tail to swim, fast agile swimmers.

-First vertebrates with jaws

The first vertebrates with jaws were

cartilaginous fishes

The first vertebrates with jaws were cartilaginous fishes

Evolution of jaws, along with a stomach

Shift from filter feeding and scavenging à active predation

Most chondrichthyans (cartilaginous fishes) are predators.

No sharks yet

Silurian

443.8-419.2mya

Vascular plants

Jaws and bones in fish

Warmer, but many climate fluctuations

Vascular tissue was an important

evolutionary adaptation

Vascular tissue was an important evolutionary adaptation

§Nearly all plants (except for bryophytes) have

vascular tissue.

Vascular tissue was an important evolutionary adaptation

§Nearly all plants (except for bryophytes) have vascular tissue.

these would be 

SEEDLESS VASCULAR PLANTS

GYMNOSPERMS

ANGIOSPERMS

Phloem primarily transports

sugars

Phloem primarily transports sugars

Phloem

contains living cells that transport sugars from where they are made or stored to other parts
of the plants.

Phloem primarily transports sugars

Phloem sap always flows from a

sugar source to a sugar sink.

Xylem primarily transports

water and minerals from the roots

Xylem primarily transports water and minerals from the roots

Xylem

made of dead cells acting as tiny pipes.

Xylem primarily transports water and minerals from the roots

§Xylem sap is moved through the plant body via

transpiration.

Xylem primarily transports water and minerals from the roots

Xylem sap is moved through the plant body via transpiration.

Water evaporates into air from the leaves —>

pulling up more water from the roots, through root hairs.

Xylem primarily transports water and minerals from the roots

Xylem sap is moved through the plant body via transpiration.

Within the xylem, water molecules stick to

the interior cell walls and each other (hydrogen bonds)

Ferns are an example of a type of

seedless vascular plant

Ferns are an example of a type of seedless vascular plant

§Seedless vascular plants (ferns) have important adaptations for living on land:

§Vascular tissue

§Lignin-hardened cell walls

Ferns are an example of a type of seedless vascular plant

Lycophytes

1^st appeared 410 mya, long surviving group

Ferns are an example of a type of seedless vascular plant

Carboniferous forest:

forest of seedless vascular plants of 360-300 mya

Ferns are an example of a type of seedless vascular plant
Modern ferns:

: found in tropics and temperate woodlands

Fern Diversity

Tree fern

Staghorn fern

Young fern ‘fiddlehead”

Foxtail fern

Anatomy of a Fern

Frond

•large leaves with many leaflets

Anatomy of a Fern

Lignin

•stiffen cells and allows the plant to stand up tall and strait

Anatomy of a Fern

Spore Capsule:

•: structures on underside of leaves, containing spores

Chelicerata are

a group of eight-legged arthropods

Chelicerata are a group of eight-legged arthropods

§Most are

terrestrial carnivores.

Chelicerata are a group of eight-legged arthropods

§Early forms like xiphosura

(horseshoe crabs) evolved during the Silurian

Chelicerata are a group of eight-legged arthropods

examples:

Yellow desert scorpion

Wood tick

Dust mite

Horseshoe crab

Mollusk Groups

examples:

Gastropods- (snails and slugs) Blackmargin sea slug

Bivalves -(clams, mussels, and oysters) Bay scallop

Cephalopods -(squid and octopi)European squid

Gastropoda

Marine and Terrestial

Hermaphrodites

Torsion

Muscular foot

Bivalvia

2 valves to the shell

Filter feeders

A Gallery of Mollusks

Lampsilis mussel, Chambered nautilus, Invasive apple snail, Blue ringed octopus

Sacoglossa

“Sap sucking”

Solar Powered!

There are more species of bony fishes than any other group of vertebrates

species ammout

28,000

There are more species of bony fishes than any other group of vertebrates

Bony fishes

first group to have internal skeletons reinforced with calcium.

They also have a swim bladder to maintain buoyancy, and an operculum that circulates water over the gills.

A Gallery of Bony Fishes

Flying gurnard, Thorny seahorse, Yellow-ribbon sweetlips, Chevron barracuda

The lobe-finned fishes are an evolutionary branch of the

bony fishes

The lobe-finned fishes are an evolutionary branch of the bony fishes

Lobe-finned fishes

have muscular fins supported by rod-shaped bones that are homologous to amphibian limb bones.

The lobe-finned fishes are an evolutionary branch of the bony fishes

Include the

lungfishes and coelacanths.

Devonian

§Relatively warm

§High sea levels

§Ended with an extinction

§Plants spread further into the

The gymnosperms were 

the first plants to evolve seeds contained within cones

The gymnosperms were the first plants to evolve seeds contained within cones

A seed consists of

an embryo and food supply inside a protective coating.

The gymnosperms were the first plants to evolve seeds contained within cones

Seeds are one of the key adaptations that allowed

plants to spread across the land.

A Gallery of Gymnosperms

Conifers: most abundant; pine, spruce, cedar, fir, and redwood

Bristlecone pines: live up to 4,500 year, native to California

Cycads: diverse group found in the tropics

Redwoods: largest and tallest trees in the world. These trees can live for thousands of years.

Ginkgo trees: found in fossils dating back 270 million years, native to China

Gymnosperm Reproduction

Cones of most gymnosperms house

all reproductive stages

• Spores, eggs, sperm, zygotes, and embryos

Gymnosperm Reproduction

Pollen-producing cone —>

develop male gametophyte (haploid sperm) within pollen grains produced from spores

Gymnosperm Reproduction

Ovule-producing cone —>

develop into female gametophyte (haploid egg)

Gymnosperm Reproduction

Fertilized egg (diploid zygote)

develops into a seed

• Embryos are provided a food supply and protective coating within the seed

Cones of most gymnosperms house

all reproductive stages

_______, by far, outnumber all other animals combined

Insects

Insects, by far, outnumber all other animals combined

Most have easily recognizable segments (head, thorax, and abdomen), three pairs of legs, and one pair of antennae.

Consumers or detritovores, some parasites

Huge diversity

Mostly terrestrial

Many metamorphose

Insect Diversity

examples:

Hemiptera (true bugs), Hymenoptera_, Coeloptera, Lepidoptera, 

Arachnida

Eight-legged arthropods

Head

Abdomen

Book lungs

Many predators

Some parasites

Millipedes and centipedes are easily recognizable

Millipedes and centipede have

§segmented bodies, which appear as many fused rings, each with jointed appendages attached.

Millipedes and centipedes are easily recognizable

Mili-multiple per segment

Centi-1 per segment

All are land dwelling

Sharks

Ancestors to modern sharks

Dorsal fins

Unable to replace teeth

Amphibians

have four limbs and were the first to occupy land

Amphibians have four limbs and were the first to occupy land

All terrestrial vertebrates are tetrapods,

animals with four limbs

Amphibians have four limbs and were the first to occupy land

Amphibians

were the first tetrapods

Amphibians have four limbs and were the first to occupy land

tetrapods and Amphibians were followed by the evolution of

amniotes (reptiles & mammals).

Amphibians live on land, but must

reproduce in water

Amphibians live on land, but must reproduce in water

Biphasic lifestyle —>

blend of aquatic and terrestrial adaptations.

Amphibians live on land, but must reproduce in water

Aquatic adaptations:

§Typically breed in or near water

§Eggs lack shells (like in fishes)

§Larval stage has gills, lateral line

Amphibians live on land, but must reproduce in water

Terrestrial adaptations:

Adult has lungs

Musculoskeletal system with four limbs

Moist skin

A Gallery of Amphibians

7,089 species of frogs & toads

Frogs- have powerful hind legs that allow hopping.

Caecilians -superficially resemble earthworms or snakes. (~212 species)

Toads-live entirely on land.

Salamanders-can be either aquatic or terrestrial.  (~731 species)

Early amphibians

370mya

Fins to limbs

Mississippian and Pennsylvannian

358.9-298.9mya

”Carboniferous”

Mass expansion of land by plants

Winged Insects

Reptiles

Reptiles, including birds, can complete their entire life cycle

on land

Reptiles, including birds, can complete their entire life cycle on land

Reptiles have two major adaptations for land:

.They reproduce via an amniotic egg.

−Hard, waterproof shell

−Provides an aquatic habitat for the embryo

Reptiles, including birds, can complete their entire life cycle on land

Reptiles have two major adaptations for land:

2.

Reptiles also have waterproof skin.

Also they are ectotherms (more on this later)

Turtles have hard shells

~356 species

All turtles have protective shells made from to shields fused to vertebrae

Aquatic and terrestrial

largest living reptiles

Crocodilians