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Fossils and Ancient Life

Hynerpeton bassetti(early tetrapod)

Define paleontology.

Identify and list the kinds of information that can be discovered from the fossil record.Is the fossil record complete? Explain! Will it ever be complete? Explain!Define extinct. Define extant.What percentage of species that have ever lived are now extinct?

Identify and list the types of fossils that have been found.

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How Fossils FormWater carries small rock particles to lakes and seas.

Dead organisms are buried by layers of sediment, which forms new rock.

The preserved remains may be later discovered and studied.

Identify the most common type of fossil.Identify the kind of rock they are found in.Study the diagram and explain the process.

Does every organism that dies become a fossil?What conditions make the difference?

Define strata.Explain how strata relate to time.

What parts of the organism are most often preserved? Are soft tissues ever preserved?What does it depend on?Is DNA ever preserved?What can it tell us or be used for?

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Interpreting Fossil Evidence Relative Dating

Trilobites

Foraminifera

Ammonites& otherMolluscs

Define relative dating. Explain how it is generally done.Define index fossil. Explain how they can be used in relative dating.What three criteria make a good index fossil?Provide three examples of index fossils.

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Interpreting Fossil Evidence Absolute DatingDefine absolute dating.Define radioactive isotope.Define radioactive decay.Define half-life.Define radiometric dating.

Explain the process of radiometric dating using Potassium-40 as an example.

Study the graph...

Give one example of something Potassium-40 would be appropriate for determining the absolute age of.What does it depend on?What is the half-life of Carbon-14?What would Carbon-14 be appropriate for determining the absolute age of?

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Geologic Time Scale

Vendian650–544

(This is just for the Vendian, not the Precambrian.)

Back4.8bya

The Vendian (kind of rock) or Ediacaran (Australian hills with fossils) period is when the earliest-known animals evolved. Vendian biota (Ediacara fauna ), included soft-bodied multi-cellular animals, like sponges and worms.

Define the geologic time scale. Who developed it and what is it primarily based on?Define geologic Era.

Define geologic Period.

Describe the Precambrian Era. Why is it called Precambrian?Approximately what percentage of Earth's history is Precambrian?

In general, what designates the Vendian period?What event marks the end of the Precambrian Era and Vendian Period?

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Geologic Time Scale

Permian

Carboniferous

Devonian

Silurian

Ordovician

Cambrian

290–245

360–290

410–360

440–410

505–440

544–505

List the three Eras that follow the Precambrian.

What major event marks the end of the Paleozoic Era?

What are periods generally named after?

Translate Paleozoic.

What major animal groups (Phyla) evolved during the Paleozoic Era?

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Geologic Time Scale

Cretaceous

Jurassic

Triassic

145–65

208–145

245–208

Translate Mesozoic.

What major event marks the end of the Mesozoic Era?What major terrestrial animal group (Class) dominated the Mesozoic Era?

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Geologic Time Scale

Translate Cenozoic.What major terrestrial animal group (Class) dominates the Cenozoic?

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Geologic Time ScaleClock Model of Earth’s History

Cenozoic Era

Mesozoic Era

Paleozoic Era

Precambrian Time

First multicellularorganisms

First humans

First prokaryotes

First plants

First eukaryotes

Radiation of mammals

Accumulation of atmospheric oxygen

First animals

Label the major events marked with a pointer line. Chose from the following:

0.4 by

0.8 by

1.2 by

1.6 by

2.0 by2.4 by

2.8 by

3.2 by

3.6 by

4.0 by

4.4 by4.8 by

From the perspective of geologic time, how long(generally) have humans been here?

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Formation of Earth

Do we know how the Earth formed for sure? Explain!

Define and explain planetary accretion.Define nebula.Which formed first, the Earth or the solar system? Explain!

Approximately how long did this take?Explain how our moon formed.What was the “heavy bombardment” and how long did it last?Describe the Earth during this time.

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Formation of Earth

Study the diagram above... Describe the structure of the Earth from inside out.What was the state of the Earth when it took on this layered structure?What determined where different elements ended up?

What is the outermost layer not shown in the diagram?Study the diagram to the right... Explain how we know Earth's core is solid.

How did it form?

Have we ever drilled all the way to the core? What layer have we drilled through?

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Formation of Earth

Define atmospheric outgassing.Identify and list the gases that composed the first atmosphere. How do we know?Identify the gas and it's source that was NOT present in the early atmosphere.

Study the volcano diagram...

Because of this, what protective atmospheric layer was also missing? Consequence?

Approximately when did the heavy bombardment end?Approximately when did the Earth cool enough for liquid water?What is the significance of this?

Methane Amonia

How is the Earth's early atmosphere described chemically, due to the lack of oxygen?

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The First Organic Molecules1950s, Stanley Miller and Harold Urey

Cold water cools chamber, causing droplets to form.

Watervapor

Liquid containing amino acids, fatty acids and other organiccompounds

Condensationchamber

Spark simulatinglightning storms

Mixture of gases simulatingatmosphere of early Earth (hydrogen, methane & ammonia)

Study the diagram...Identify the question Miller and Urey were investigating.

Write the null hypothesis.

What were they trying to simulate with this apparatus?

Describe the apparatus identifying the function & “early Earth equivalent” of each component.What were the results?

Liquid Water

Trap

ValveHow long did it take?

Do these results support or refute the null hypothesis?What did Miller & Urey conclude?

Review… What are amino acids?

Is this the only experiment of this type ever performed?Where else have organic compounds been found to form?What is the significance of this?

What are fatty acids?

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Membrane?~200my After Liquid H2O (3.6 bya)

Define proteinoid microsphere. Define liposome.What cellular component are these similar to?Review… What two compounds make up most of the plasma membrane?

Describe how these form.

Define protocell. Identify 2 cellular functions that have been demonstrated in protocells.

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Genetic Material?

Abiotic “stew” ofinorganic matter

Simple organicmolecules

RNA nucleotides

RNA able to replicate itself, synthesize proteins, andfunction in information storage

DNA functions in information storage and retrieval

Proteins build cellstructures and catalyzechemical reactions

Review… What experiment showed the possible formation of simple organic compounds from inorganic matter?Describe the RNA world hypothesis.

Explain why RNA is hypothesized to be the first genetic material.

Is RNA alive?

What does the capacity for heredity, mutation & replication allow for?If RNA can do it all, why is there DNA?

...and therefore…?Review… What is something RNA does more frequently than DNA?Study the diagram...

Transcription

TranslationThen Now

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Free Oxygen

Microfossils from the Apex Chert, North Pole, Australia. These organisms are Archean in age, approximately 3.465 billion years old, and resemble filamentous cyanobacteria.

Review: microfossils. prokaryotes,cyanobacteria, & photosynthesis.

Study the figure & read the caption...Explain the significance of this fossil find in relation to atmospheric O

2.

If these represent the earliest photosynthetic organisms, about how long ago did O

2 generation begin?

Where did the O2 build up first?

What happened to it?

Where was there free O2 about 2.2bya?

Define free oxygen.

Explain why O2 generation caused

the extinction of many species.Explain the connection between O

2

generation and the evolution of cellular respiration.

Define saturation.

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Review the evolutionary events that followed this change. Study the diagram...What was the anaerobic archaeal prokaryote in danger of at this time?What was the aerobic bacteria able to handle and why?

What ecological term describes this partnership?

Note the major eukaryotic groups each of these lines were progenitors of.

Define endosymbiosis.What advantages did the aerobe provide the anaerobe?

Review the significant environmental change that had taken place by about 2.2bya.

Mitochondrion

Aerobicbacteria

Nuclear envelopeevolving

Ancient ProkaryotesAlgae and

plants

Primitive Aerobic PhotosyntheticEukaryote

Primitive AerobicEukaryote

Archaeal AnaerobicProkaryote

Chloroplast

Protozoa, fungi and animals

Photosynthetic bacteria

Nucleus

Nucleus

Mitochondrion

What defines it as a eukaryote?

Identify the photosynthetic bacteria.What advantage did the cyanobacteria provide the primitive aerobic eukaryote?

Define serial endosymbiosis.

The Endosymbiotic Theory

Identify and explain the evidence for these events?

Do you have endosymbionts?What may be the origin of other internal membranes?

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Sexual ReproductionIdentify and list various forms of asexual reproduction.Identify and list the types of organisms which reproduce asexually.Define sexual reproduction.Identify and list the types of organisms that reproduce sexually.Compare and contrast the two forms of reproduction in terms of :

-Number of parents

-Production of gametes

-Genetic comparison of parents and offspring

-Mutation rate-Opportunity for gene shuffling

-Advantages

-Opportunity for variation

-DisadvantagesWhy did sexual reproduction evolve?

-Reproductive rate

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Precambrian Time

Shown are scanning electron photomicrographs of two fossil embryo specimens from the 600-million-year-old Doushantuo Formation in South China. The soccer-ball-shaped specimen is interpreted as an early stage (blastula) embryo, and the baseball-shaped specimen is interpreted as an intermediate-stage helical embryo consisting of three clockwise coils. Embryos are about 0.55-0.75 millimeter in diameter.

Dickinsonia sp. a Vendian animal fossil thought related to annelid worms.

FrogEmbryo

Multicellular Organisms

Study the images and read the captions.How common are animal fossils from this time?Explain why.

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A) Cambrian

B) Ordovician

C) Silurian

D) Devonian

E) Carboniferous

F) Permian

Paleozoic Era

Define the “Cambrian explosion”.Which units of geologic time are listed?Match each Period with its representative figure by labeling the figure with a letter.

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Paleozoic Era: Cambrian Period

Brachiopods(Mollusk)

Trilobites(Arthropod)

Invent an improved term for the “Cambrian explosion”. What is a better word than explosion?In general, how many modern animal phyla appeared at this time?Although diverse, all of the fossils belong to which major general animal group?Identify the body parts that fossilized particularly well.

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In the image above, trilobites (1) live among many species that are not normally preserved. A typical Cambrian outcrop might produce only trilobites, brachiopods (2), mollusks (3), and crinoids (4). That is a tiny fraction of the full Cambrian biota, better represented by the roster of the Burgess Shale. That community includes sponges Vauxia (5), Hazelia (6), and Eifellia (7); brachipods Nisusia (2); priapulid worms Ottoia (8); trilobites Olenoides (1); other arthropods such as Sidneyia (9), Leanchoilia (10), Marella (11), Canadaspis (12), Helmetia (13), Burgessia (14), Tegopelte (15), Naraoia (16), Waptia (17), Sanctacaris (18), and Odaraia (19); lobopods Hallucigenia (20) and Aysheaia (21); mollusks Scenella (3); echinoderms Echmatocrinus (4); and chordates Pikaia (22); among other oddities, including Haplophrentis (23) Opabinia (24), Dinomischus (25), Wiwaxia (26), Amiskwia (27), and Anomalocaris (28).

Supercontinent Pannotia

Can you identify the possible ancestor of vertebrates?

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Paleozoic Era: Ordovician & Silurian Periods

Oldest Land Animal Fossil (scorpion stinger, 350my)

Study these 4 figures...Determine the events during these Periods that each figure represents.

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Paleozoic Era: Devonian PeriodLaurasia and Gondwana

The Devonian Period is also known as the “age of _____”?Identify the evolutionary advancement in Kingdom Plantae.

Identify the evolutionary advancement in Phylum Arthropoda.How did this advancement raise the fitness of this group?

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Paleozoic Era: Devonian Period

Acanthostega gunnari

Identify the evolutionary advancement in the vertebrate group.

Explain the current understanding of how tetrapods evolved.

Translate and define tetrapod.

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Paleozoic Era: Carboniferous & Permian Periods

The Early Permian apex predator Dimetrodon. A synapsid, mammal-like reptile.

Anteosaurus was a large carnivore and probably weighed around 500-600Kg.

Supercontinent Pangea

Explain how the Carboniferous Period got it's name.How many different evolutionary lines of reptiles arose at this time?What distinguishes them in the fossil record?To which generalized group does each line lead?

Then...

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Paleozoic Era: Permian Period

The end-Permian event that occurred 250 million years ago triggered an abrupt shift to the current dominance of higher-metabolism, mobile organisms (such as snails, clams and crabs) that actually go out and find their own food, and the decreased diversity of older groups of low-metabolism, stationary organisms (such as lamp shells and sea lilies) that filter nutrients from the water.

What was the end Permian event?How extensive was the extinction?Identify and list four possible causes.This not only ended the Permian Period, but also the _______?

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Mesozoic Era: Triassic Period

Break-up of Pangaea starts.

Following the Permian extinction, where did the species at the beginning of the Triassic Period come from?Study the figure at left... Identify this line of descent.

What pattern of evolution followed?

Identify the evolutionary advancement in Kingdom Plantae.How did this advancement raise the fitness of these species?

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Mesozoic Era: Jurassic Period

Explain why the Jurassic Period is considered the “age of reptiles”.

What other major group was also here? (Hint: previous slide) Where were they?

Study the bottom right figure... Were they all dinosaurs? Explain!

Find this species on the phylogenetic tree.Study the phylogenetic tree...

What dinosaur-related group does it represent?

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Mesozoic Era: Cretaceous Period

Identify the dominant terrestrial animals during the Cretaceous Period.

Identify the evolutionary advancement in Kingdom Plantae.

What does evidence suggest happened to end the Cretaceous Period?This event also marked the end of what other geologic time?

Identify the animals in the lower left image... Are they dinosaurs?

How did this advancement raise the fitness of these species? (Not in Note Guide)

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Cenozoic Era

Plesiadapis (60mya) is one of the oldest known primate-like mammal species

Identify the dominant terrestrial animals during the Cenozoic Era.

Following the Cretaceous extinction, where did the species at the beginning of the Cenozoic Era come from? What pattern of evolution followed?

Note that the Periods of this Era are further defined by Epochs.When will they end?What is the current Era, Period and Epoch?

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Cenozoic Era: Tertiary Period

Australopithecus afarensis

How did climate change during this period?What group of flowering plants evolved during this time?

What evolutionary changes took place in the mammalian Orders represented here?Infer connections between environmental changes and mammalian evolution.

What was the significance of this?

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Doedicurus

Cenozoic Era: Quaternary Period

Identify the climatic changes that mark this period.

Identify representative species of this time.What climatic period do we now enjoy? When did it start? Will it continue? Explain!

What one word describes many of the North American species of this time?What happened to them. Infer a possible cause.

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Geologic Time

You don't have this slide. I simply wanted you to view (and review) the geologic time scale as a whole.

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Extinction17-4 6 Patterns of Macroevolution

Use the geologic time scale on the previous slide and/or the figure at right to label the geologic Period that corresponds to each extinction event.

Is extinction the exception, or the rule?

Do we know what caused all of these?Explain the effect extinction has had on biodiversity and the dominant species.

How many mass extinctions were there?

(You don't have this.)

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Adaptive Radiation

Define adaptive radiation.Explain why each extinction event was followed by adaptive radiation.Be able to recognize and explain adaptive radiation using both the example of Darwin's finches on the Galapagos and Class Mammalia following the Cretaceous extinction.

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Convergent Evolution

Vertebrate (left) and Octopus (right).

Define convergent evolution.Define analogous structure.Explain how each figure above is an example of convergent evolution.

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Coevolution

Some Central American Acacia species have hollow thorns and pores at the base of their leaves that secrete nectar. These hollow thorns are the exclusive nest-site of some species of ant that drink the nectar. But the ants are not just taking advantage of the plant—they also defend their acacia plant against herbivores.

Define coevolution.Explain how each figure above is an example of coevolution.Coevolution stems from what ecological relationship?

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Punctuated Equilibrium

Gradualism model. Species descended from a common ancestor gradually diverge more and more in their morphology as they acquire unique adaptations.

Time

(a) Punctuated equilibrium model. A new species changes most as it buds from a parent species and then changes little for the rest of its existence.

(b)

Study the figure and read the captions...Compare and contrast these models that attempt to describe evolutionary rates.Evaluate each of these models...Explain which model you think is the most accurate.

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Developmental Genes and Body Plans

Ancient Insect Two Types of Modern Insects

Review homeobox (HOX) genes.Explain how a mutation in one HOX gene could explain the evolution shown in the example above.Describe how mutations effecting the location, timing and duration in the expression of single genes can result in profound physical changes.Apply this knowledge to explain how the difference between human and chimpanzee brains may have evolved.What experimental evidence would support this hypothesis?