Biology 215- Evolution

Examples of Ediacarin plants/animals

• Dickinsonia

• Spriggina

• Rangeomorphs

Ediacarin fossils

• They have no eyes, mouth or anus

• Hard to find since they had soft bodies which are harder to make fossils

Ediacarin period

• First organisms

• 650-540 million years ago

Pikaia

• A burgess shale fossil

• Looks like a fish

• Chordata

Wiwaxia

• A Burgess Shale fossil

• Looks like a cabbage

• Annelida

Opabinia

• Burgess Shale fossil

• Looks like a shrimp

• Arthropod

Anomalocaris

• Burgess Shale fossil

• Arthropoda

Hallucingenia

• Burgess Shale fossil

• Ancestor of onychophora

Burgess Shale fauna

• Time period that defined the phyla of living animals

• Different fossils

Bricolage

Emphasis on the modification of existing genes

Pax6/eyeless gene

Gene that codes for eye development

Engrailed

A gene that codes for segment polarity

The 2 hypotheses for the Cambrian explosion

1. Explosion, happened very fast. All at the same time

2. Slow fuse, not everything happened at once

Unikonts

• Type of parasitic protist

• Slime molds

• Amoeba

• Plants and animals

What are the 4 major points of plantar?

1. Algae and land plants

2. Contains plasmids

3. Sexual reproduction

4. Uni and multicellular

Pseudopodia

Organisms that rhizaria used to eat

What does rhizarua eat?

Prokaryotes and eukaryotes

Frustule

The silica exoskeleton of diatoms

Where do diatoms live?

In aquatic environments

What do slime molds do in stress?

• Form a stalk

• Grow tall

• Spread their spores around to reproduce in better environments

Zoothanmnium

A colonial ciliate

What makes fungi?

Spores

What is the sister group to animals?

Choanoflagelates

What is the oldest group of animals?

Sponges

How did multicellularity evolve?

• Aggregative

• Colonial

Jurassic world

• Time of dinosaurs

• Gave rise to birds

Acanthostega

• Type of “fish”

• Had 8 toes

• Lived in water and on land

The Cambrian explosion

• the Big Bang of fossils

• Gave rise to the animal phyla

• Plants and animals

Adaptive radiation

• Evolutionary divergence in a single phylogenetic tree

• Happens in a short amount of time

• Long branches on the tree

What happens when multicellularity breaks down?

Causes cancer

Advantages of being multicellular

• Environmental resistance

• Preditor resistance

• Cooperative feeding

• Division of labor

• Stable internal environment

Why adaptive radiation?

Competitive release and advantage

Paleosteine

Time period with the radiation of animals

Cretaceous

• Time period for plant evolution

• Bye bye dinosaurs

What type of organisms are excavates?

Parasitic flagellated anaerobes

3 major lineages (domains)

• Bacteria

• Archaea

• Eukarya

4 major groups within archaea

1. Euryarchaeota

2. Crebarchaota

3. Korarchaeota

4. Lokiarchaeota

Lokiarchaeota

• Organisms found near deep sea vents off the coast of Norway

• A type of archaea

Where does euryarchaeota live?

• In extreme environments

• Hot springs or thermal vents

Euryarchaeota contains…

• Methanogens

• Halophils

Bacteria has how many major linages?

12 major linages

What is the most metabolically diverse group of bacteria?

Proteobacteria

What is the largest group of bacteria?

Proteobacteria

Cyanobacteria

• Is the largest group of phototrophic bacteria

• Large producers of oxygen in lakes and oceans

Eukarya is historically considered to contain what 4 kingdoms?

• Animal

• Plants

• Fungi

• Protists

Plasmid

Circular DNA that can be transferred into a host genome

5 pieces of evidence for the endosymbiosis theory

1. Mitochondria and chloroplasts contain their own DNA

2. They have a double membrane

3. They have an electron transport chain similar to bacteria

4. Have antibiotic sensitivity

5. They have ribosomes like bacteria

Why are microorganisms hard to classify?

• Simple creatures

• They change slowly

• Less obvious features

Classification within domains is based on what?

rRNA

What group has no single common morphological feature?

Excavates

What do chromoalveolates produce?

Planktonic communities in lakes and oceans

Examples of chromoalveolates

• Dinoflagellates

• Ciliates

• Brown algae

• Diatoms

How many previous groups was chromoalveolates?

23

Describe apicomplexa

• Parasite within animals

• Have an apical complex of organelles

• They attach to the host cell to infect it

Are dinoflagellates heterotrophic or phototrophic?

Both

Dinoflagellates

• Many form a dormant cyst stage

• Some are symbionts of invertebrates

Chromoalveolates

• Dinoflagellates, apicomplexa, ciliates…

• Primary producers and consumers of platonic communities in lakes and oceans

Excavates

• Thought to be ancestral to eukaryotes

• Parasitic organisms

• Flagellated obligated anaerobes

Eukarya

• Type of protist

• Unicellular eukaryote

• Artificial group

Cyanobacteria

• Phototrophic bacteria

• Produces oxygen

• Some form heterocysts

Proteobacteria

• Largest group of bacteria

• Purple and green sulfur bacteria

• Anoxygenic

• Most metabolically diverse group of bacteria

Euryarchaeota

• Contains methanogens and halophils

• Release methane

• Halophils grow in salt water

• Lives in extreme environments

Lokiarchaeota

• Lives near deep sea vents in the Norwegian ocean

How were genes transferred in endosymbiosis?

• Horizontal gene transfer

Rhizaria

• Heterotrophic

• Eats other prokaryotes and eukaryotes

Diatoms

• Has a silica exoskeleton

• Only males have flagellas

• Live in water

Apicomplexa

Parasites in organisms

Cosmology

The study of the universe

Internal branches

Dotted lines on a phylogenetic tree

Terminal branches

Solid lines on a phylogenetic tree

Root node

Open circle at the very beginning of the phylogenetic tree

Compartmentalization

The division of something into sections

Phylogeny

The course of evolution from past to present

Branches

Solid lines in a phylogenetic tree

Nodes

Where two branches connect in a phylogenetic tree

Internal node

Open circles in a phylogenetic tree

Terminal nodes

Closed circles in a phylogenetic tree

What is independent evolution?

Similar features that evolve separately in different species

4 methods for building phylogenetic trees

1. Parsimony

2. Maximum likelihood

3. Distance

4. Bayesian methodology

Parsimony

The phylogenetic tree with the least amount of evolutionary steps is the best option

Cladistics

A type of classification where grouping is based on their similar characters differing from ancestral condition

Shared derived characters

The cladistic method used to count evolutionary steps

Synapomorphy

A type of shared derived character where 2 or more related lineages are derived from a different but homologous character

Autopomorphy

A derived character this is not shared

Symplesiomorphy

A shared character that was not derived

Homoplasty

A shared character among species that was derived separately

Topology

The branching structure of the phylogenetic tree

Phylogenetic tree

Graphical representation of evolution

6 conditions of the earth

• Sun energy

• Stable climate

• Composition of elements

• Liquid water

• Iron core

• Ozone

Zircon

• Type of gemstone

• Tells us when the earth would have had to have been cooled by

Prerequisite for the origin of molecules

• Orbit around the sun

• Chemicals

• Water

Stanley Miller experiment

• Prebiotic soup

• Atmosphere plus spark

• Yielded amino acids and urea

• All in the absence of organisms

Possible sites for the origin of molecules

• Hydrothermal vents

• Volcanos

• Clays

Panspermia

Theory that molecules were brought to the earth from space

Murchison meteorite

• Evidence for panspermia

• Contained carbon compounds

Ribozyme

RNA molecule with enzymatic properties

Crepe model

Idea that there could have been an infinite number of nucleotides that could have assembled in random combinations on clay

Reverse transcriptase

Enzyme that copies RNA into DNA

Hypothesis 1 for the first origin of the cell

Idea that cells came from membranes that turned into protocells

2 acid names in phospholipids

Palmitic acid and oleic acid