Evolution Unit Overview

Evolution Unit Overview

By Mr. Ver Vers

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EARTH IS 4​.6 BILLION YEARS OLD

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The history of Earth is divided into different time sections.​

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4 Main Eras

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Mass Extinctions mark the end of EVERY Era​

Geologic Time Scale

4.5 BYA to 544 MYA

• Earth Formed

• Oceans Formed

• Single Celled Organisms Formed

• Simple Organisms​

EXTINCTION: Unknown​

Precambrian

Age of Single Celled Life​

544 MYA to 246 MYA

• Explosion of Life

• Trilobites and Invertebrates dominate

• Plants, Fish, Amphibians, & Reptiles Appear​

• Shallow Seas cover continents

• Pangea Forms

EXTINCTION: Great Dying, volcanoes and climate

Paleozoic

Age of Invertebrates​

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246 MYA to 64 MYA

• Dinosaurs Appear and dominate

• Mammals, birds, & flowers appear

• Pangea Splits

• shallow sea cover North America

EXTINCTION: K-T Asteroid Impact​

Mesozoic

Age of Reptiles​

64 MYA to Present

• Mammals evolve & diversify

• Grasses appear

• Multiple Ice Ages​

• HUMANS ARE HERE!!!

EXTINCTION: None...so far...

Cenozoic

Age of Mammals​

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Multiple Choice

This era has the rise of invertebrates, pangea forming, and trilobites

• Precambrian

• Paleozoic

• Mesozoic

• Cenozoic

Multiple Choice

This era includes humans and other mammals

• Precambrian

• Paleozoic

• Mesozoic

• Cenozoic

Multiple Choice

Earth formed, then the oceans. Single Celled organisms dominate this era.

• Precambrian

• Paleozoic

• Mesozoic

• Cenozoic

Multiple Choice

During this era, dinosaurs dominated and the first flowers appeared.

• Precambrian

• Paleozoic

• Mesozoic

• Cenozoic

FOSSILS

Preserved remains or traces of ancient organisms.

There are 6 kinds of fossils.

​Petrified: minerals replace all or part of an organism

Preserved: all of some of the organism in tar, amber, or ice.

​Trace: shows evidence of activities of old organisms

​Carbon Film: thin layer of carbon, shows delicate parts

Cast/Mold: Molds are hollow imprints & casts fill in molds of organisms.

Multiple Choice

The preserved remains or traces of ancient organisms are called..

• Leftovers

• Geologic Time Scale

• Fossils

• Amber

Multiple Choice

When the mold becomes filled with minerals that are not a part of the original organism.

• Petrified

• Trace

• Cast

• Index

Multiple Choice

When minerals replace the remains and they become rock; things like wood or bones

• Petrified

• Trace

• Index

• Carbon Film

Multiple Choice

These fossils show the activities of ancient organisms, but not the actual organism

• Petrified

• Trace

• Cast

• Index

​Comparing the age of 2 fossils based on how far underground they are.

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Law of Superposition & Index Fossils​

Relative Age​

Dating rock layers and fossils by giving them a number for their age

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Use Radiometric Dating​

​​Absolute Age

a given rock layer is older than the rock layer above it.​

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​The Law of Superposition​

FAULTS, INTRUSIONS, & EXTRUSIONS

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ARE ALL YOUNGER THAN THE LAYERS OF ROCK THEY CUT THROUGH​​

​Index Fossils - Used for relative dating.

Lived in a lot of Places + Short Time on Earth​ = Good Index Fossil

Using radioactive atoms to find the exact age of rocks or fossils

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​Measure how much of the radioactive atom is in a material, then work backwards to find the age of the fossil.

Half Life = How fast a radioactive isotope decays (loses itself) over time.

​Radiometric Dating

C-14 & U-238​ = Most commonly used isotopes

Multiple Choice

Which of the fossils is the BEST index fossil?

• A

• B

• C

• D

Multiple Choice

An trilobite fossil was found in a rock layer below an ammonite fossil. The Trilobite fossil is older than the ammonite fossil. This is an example of...

• Absolute Age

• Relativity

• Relative Age

• Absolutism

Multiple Choice

Based on this image, which of the following is false?

• Intrusion A is older than layer N

• Fault H is older than Layer C

• Layer K is older than layer F

• Layer M is older than intrusion A

Multiple Choice

A paleontologist used Carbon-14 to find that a mammoth tusk was 25,000 years old. This is an example of...

• Uniformitarianism

• Law of Superposition

• Relative Age

• Absolute Age

Layers of snow that became compressed into Ice.

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Snow traps air bubbles.

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Lets us look at ancient climate and atmosphere composition..​

​​Ice Cores​

Trees gain a ring every season.

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Each ring can tell us about the climate (precipitation, ​temperature, & weather patterns)

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Petrified Trees = Fossilized Trees​

​​Tree Rings

Multiple Choice

What is information we CANNOT get from tree rings.

• Temperature

• Atmospheric Composition

• Precipitation

• Weather Patterns

Multiple Choice

A layer of volcanic ash is found in an ice core. What does this indicate?

• Ash borer beetles lived in that habitat.

• A landslide spilled the ash on the ice.

• A volcanic eruption.

• The squirrel from Ice Age was there.

Multiple Choice

How are tree rings and ice cores similar?

• We use the rings/layers to tell the climate of different periods of time.

• They tell us what the atmosphere was made of.

• We use the rings/layers to know the absolute age of specimens.

• They tell us what organisms lived in the past.

Evolution of Life Forms

This includes: Introduction, Mechanisms, & Evidence.​

Evolution Basics

Some text here about the topic of discussion

• Father of Evolution

• Galapagos Islands - Studied Finches and Tortoises

• Noticed the bird beaks were different

• Wrote, "Origin of Species"

Charles Darwin

1. Life Changes Over Time.

2. Organisms Share a Common Ancestor

3. Organisms have unique adaptations to survive their environment.

Theory of Evolution

Multiple Choice

Who developed the Theory of Evolution?

• Jean Baptiste de Lamarck

• James Hutton

• Albert Einstein

• Charles Darwin

Organisms with the best adaptations are going to survive the best and have the most children. Those adaptations will spread.​

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Natural Selection

​Mutations -> variations,

variations -> adaptations + change in environment = Success of variation​​

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When environments change, species need to make drastic changes!

MORE ADAPTATIONS​ to survive!

How Natural Selection Works​​

• Variation in populations

• Traits are passed down to offspring

• Human Driven

​​Artificial Selection

• Variations in populations

• Traits are passed down to offspring

• Environm​ent Driven

Natural Selection

Multiple Choice

The difference between artificial selection and natural selection is...

• Artificial selection is driven by nature, natural selection is driven by humans.

• Artificial selection is driven by humans, natural selection is driven by nature.

• Artificial selection is driven by adaptations, natural selection is driven by variations.

• There is no difference between artificial and natural selection

Multiple Choice

The process by which different kinds of living things have changed over long periods of time is called...

• Sedimentation

• Replacement

• Evolution

• Extinction

​Mechanisms of Evolution

​Overproduction: having more offspring than will survive to adulthood. (Best fit will survive)

Ex. Trees releasing multiple seeds​

​Genetic Variation: Differences in members of the same species.

Genotype (DNA) or Phenotype (physical)​

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HAPPEN FROM MUTATIONS IN DNA​

​Mechanisms of Evolution

​Adaptation: a beneficial trait that helps an organism survive in its environment

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Adaptations that help will be passed on to offspring!​

​New variations caused by mutations (random change in the DNA)

Variations & mutations that help an organisms survive better are adaptations!​

​Mechanisms of Evolution

​Selection - Organisms with the better adaptations will live longer and reproduce more.

​THINK! The environment is "selecting" those that can survive in it.

​Speciation - A new species forming from an older species or ancestor.

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This takes ISOLATION and TIME.

New adaptations have to take hold.​

Multiple Choice

________ is/are the beneficial variations that help an organism survive better/longer in an environment.

• Mutations

• Overproduction

• Adaptations

• Speciation

Multiple Choice

_____________ occurs when a new species evolves from an existing species. (Select the most correct answer)

• Mutation

• Speciation

• Genetic Variation

• Selection

Multiple Choice

This is an example of what mechanism of evolution?

• Genetic Variation

• Overproduction

• Selection

• Adaptation

Mechanisms work together!

Overproduction means there are multiple offspring

All of the offspring will have different genes (genetic variation)

Some of those variations will be beneficial adaptations to survive​. Those that do survive will pass on their adaptations to their offspring and reproduce more (selection)

Over a long period of time, the adaptations will become dominant and will create a new species (speciation).​

Evidence of Evolution

How do we proof evolution occurs?

Study how organisms from the past, changed over time.

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Fossil Record is incomplete - Not everything turned into a fossil!​

Fossil Record​

Continents used to be together.

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Fossils in African rock are the same as fossils in South American rock​!

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Similar species developed on each side.​

​​Biogeography

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Leftover structures or behaviors that no longer serve their original purpose

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Example: Whale pelvis, human tail bones, & wisdom teeth.​

Vestigial Structure

Having similar bone structure to other organisms (arm and hand structure)

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Evolved from common ancestor.​

Homology Bones​

Embryos of animals have similar structures

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MEANING WE SHARE A COMMON ANCESTOR​

Homology: Embryo

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Similar DNA segments are found in multiple organisms.

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The more DNA segments shared, the more related!​

​​Homology: DNA

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Homologous = Adaptation/trait came from a common ancestor.

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Analogous = Trait came from their own evolution and adaptation. ​

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Homologous vs. Analogous

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Multiple Choice

Scientists think dolphins and whales may have evolved from a common ancestor. What evidence supports this hyopthesis?

• They swim the same way.

• They eat the same food.

• They live in the same area of the ocean.

• They have similar body structures (anatomies)

Multiple Choice

A bird's developmental stages resemble those of a reptile. This observation is often used to illustrate the probable common ancestry of these organisms through the study of

• Comparative Biochemistry

• Punctuated Equilibrium

• Comparative Embryology

• Natural Selection

Multiple Choice

The human arm contains the radius and ulna bones. Whales, bats, and dogs also have these bones. Which statement best explains this relationship between the organisms?

• Humans evolved from whales, bats, and dogs.

• Humans and the other animals share a common ancestor.

• Humans evolved around the same time as the other animals.

• Humans have existed in the same location as the other animals.

Multiple Choice

A new predator has just moved into an area with a population of rabbits.The rabbits with longer back legs have an advantage because they can run faster. Which is an example of adaptation?

• The species of rabbits will become extinct due to stress.

• The rabbits with the shorter back legs will learn to hide.

• The future generations of rabbits will have longer legs.

• The rabbits with darker fur will learn to hide.

Multiple Choice

A structure or behavior previously used by an ancestor but now has no apparent purpose or function is a(n)

• Vestigial Structure

• Homologous Structure

• Analogous Structure

• Bone Structure

Multiple Choice

The similarities between sharks and dolphins are...

• non existent never to have existed

• Vestigial: a structure having lost all or most of its original function in the course of evolution,

• Homologous: their structures have similar evolutionary origins

• Analogous: their structures preform similar function but have different evolutionary origins