today: our first presentations! macroevolution diversity! onto prokaryotes meeting the protists...

Today: Today:

• Our First Presentations!• Macroevolution

Diversity!• Onto Prokaryotes• Meeting the Protists• Overview of Fungi?

Thinking About MacroevolutionThinking About Macroevolution

What’s a

species??

Defining a Species: Defining a Species: the Biological Species Conceptthe Biological Species Concept

Defines a species as…Defines a species as…

a population (s) whose a population (s) whose members can members can potentiallypotentially interbreed in nature to interbreed in nature to produce viable, fertile produce viable, fertile offspring, but who offspring, but who can’tcan’t produce viable, fertile produce viable, fertile offspring with members of offspring with members of other speciesother species

??

Barriers leading to Biological Barriers leading to Biological Species:Species:

Barriers can Barriers can bebe

PREZYGOTIPREZYGOTI

CC

or or

POSTZYGOTIPOSTZYGOTICC

You Try: Part 1

How New How New Species Species

Can FormCan Form

Examples?

Next: Studying the Resulting Next: Studying the Resulting Diversity of Life!Diversity of Life!

Taxonomy and the ProkaryotesTaxonomy and the Prokaryotes

Photo: Pete Owens

A Bit of Taxonomy…A Bit of Taxonomy…

Studying Diversity: Studying Diversity: TaxonomyTaxonomy

Domain (Eukarya)Domain (Eukarya)

Kingdom (Animalia) Kingdom (Animalia)

Phylum (Chordata)Phylum (Chordata)

Class (Mammalia)Class (Mammalia)

Order (Primata)Order (Primata)

Genus (Genus (HomoHomo))

Species (Species (sapienssapiens))

Looking at Looking at the the

ProkaryotesProkaryotes

Where Did the First Life Come From?Where Did the First Life Come From?

Spontaneous Generation??

Biogenesis?

Photo: NIH

Step 1: Abiotic Step 1: Abiotic Synthesis of Organic Synthesis of Organic MonomersMonomers

Hey look! I’ve got amino

acids, sugars, lipids and

nucleotides in here!!

Where Did the First Life Come From?Where Did the First Life Come From?

Step 2: Abiotic Step 2: Abiotic Synthesis of Polymers Synthesis of Polymers (like proteins and (like proteins and nucleic acids)nucleic acids)

Binding to clay particles may have helped

facilitate this in the absence of enzymes!

Where Did the First Life Come From?Where Did the First Life Come From?

Step 3: Origin of Self-Replication MoleculesStep 3: Origin of Self-Replication Molecules

Where Did the First Life Come From?Where Did the First Life Come From?

Step 4: Formation of Pre-Cells (Protobionts)Step 4: Formation of Pre-Cells (Protobionts)

Where Did the First Life Come From?Where Did the First Life Come From?

What Did the First Life Look What Did the First Life Look Like?Like?

Prokaryotes show up Prokaryotes show up in the fossil record in the fossil record ~3.5 billion years ~3.5 billion years ago!ago!

Prokaryotes Today: Major Prokaryotes Today: Major CharacteristicsCharacteristics

They’re ubiquitous!They’re ubiquitous!

How do we know that if they’re so small?!?

You try: Part 2

Bacteria in a dental plague

Bacteria on the surface of a contact lens.

Prokaryotes Today: Major Prokaryotes Today: Major CharacteristicsCharacteristics

Two Major Groups:Two Major Groups:

1.1. BacteriaBacteria

2.2. ArchaeaArchaea

(“Extremophiles”)(“Extremophiles”)

Prokaryotes Today: Major Prokaryotes Today: Major CharacteristicsCharacteristics

Three Major Three Major Shapes/MorphologiesShapes/Morphologies::

1.1. CocciCocci

2.2. BacilliBacilli

3.3. SpirochetesSpirochetes

Prokaryotes Today: Major Prokaryotes Today: Major CharacteristicsCharacteristics

Nutritionally Diverse! May be:Nutritionally Diverse! May be:

1.1. PhotoautotrophicPhotoautotrophic

2.2. ChemoautotrophicChemoautotrophic

3.3. PhotoheterotrophicPhotoheterotrophic

4.4. ChemoheterotrophicChemoheterotrophic

All of these terms describe how you get your energy (chemical

or light source) and where you get your carbon compounds

(make them yourself, or eat others!)

Prokaryotes Today: Major Prokaryotes Today: Major CharacteristicsCharacteristics

Important as Disease Important as Disease Causing Agents!Causing Agents!

Many cause disease Many cause disease through the through the production of production of endotoxinsendotoxins or or exotoxinsexotoxins

Prokaryotes Today: Major Prokaryotes Today: Major CharacteristicsCharacteristics

Important as Nutrient Cyclers!Important as Nutrient Cyclers!

Prokaryotes Today: Major Prokaryotes Today: Major CharacteristicsCharacteristics

Next Up: Evolution of the Next Up: Evolution of the Protistans!Protistans!

What the heck is a Protist?!?

Evolution Evolution of the of the

ProtistansProtistans

Diversity of the ProtistansDiversity of the Protistans1. The Protozoans – animal like protists Single-celled, animal-like eukaryotesSingle-celled, animal-like eukaryotes

Free-living and parasitic in moist environmentsFree-living and parasitic in moist environments Can reproduce sexually or asexuallyCan reproduce sexually or asexually Some famous Protozoans: Some famous Protozoans: GiardiaGiardia and and TyrpanosomaTyrpanosoma

Giardia lamblia trophozoites, as they appear with the scanning electron microscope. Original image by Arturo Gonzalez, CINVESTAV, Mexico.

2. The Slime Molds (Fungus-like Protists)

Diversity of the ProtistansDiversity of the Protistans

3. The Unicellular Algae

Most are Most are components of components of phytoplankton phytoplankton (basis of food (basis of food webs; global webs; global carbon sink!)carbon sink!)

Diversity of the ProtistansDiversity of the Protistans

Famous Single-Celled Algae: Red Tide, Famous Single-Celled Algae: Red Tide, PfiesteriaPfiesteria

The Protistans: The Single-Celled The Protistans: The Single-Celled AlgaeAlgae

Source: www.redtide.whoi.edu; www.pfeisteria.org

Diversity of the ProtistansDiversity of the Protistans

4. The Multicellular Algae

Three major Three major groups:groups:

1.1. Red AlgaeRed Algae

2.2. Brown AlgaeBrown Algae

3.3. Green AlgaeGreen Algae

You Try: Part 3

Next Up: Going Next Up: Going Multicellular and Heading Multicellular and Heading

for Land!for Land!

You Try: Part 4

Onto the Fungi: Onto the Fungi: Major Major

CharacteristicsCharacteristics

HETEROTROPHICHETEROTROPHIC

(use organic compounds for energy)(use organic compounds for energy)

Can be Can be SAPROBESSAPROBES (nutrients from (nutrients from nonliving organic matter) or nonliving organic matter) or

PARASITESPARASITES (extract nutrients from a (extract nutrients from a living host)living host)

EXTRACELLULAR DIGESTIONEXTRACELLULAR DIGESTION EUKARYOTICEUKARYOTIC

The Fungi: General LayoutThe Fungi: General Layout

The Fungi: General LayoutThe Fungi: General Layout

The Major The Major Fungi Fungi

GroupsGroups

The ZygomycetesThe Zygomycetes

Mycorrhizae

Pilobolus- decompose

s animal dung!

The Club Fungi The Club Fungi (Basidiomycetes)(Basidiomycetes)

Mushrooms, shelf fungi, puffballs and Mushrooms, shelf fungi, puffballs and rustsrusts

Important decomposers of wood and Important decomposers of wood and plant materialplant material

Plant Pathogens!Plant Pathogens!

Fairy Fairy RingsRings

WHY??WHY??

Lichens:Lichens:A Fungal A Fungal LifestyleLifestyle

Lichens: A Fungal LifestyleLichens: A Fungal Lifestyle

Other Amazing FungiOther Amazing Fungi

Mycorrhizae

Pilobolus-