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EVOLUTIONARY THEORY

Scientific theory

• THEORY= a well tested explanation

that makes sense of a great variety of

scientific observations.

– Only become widely accepted when

they are supported by LOTS of evidence

What is Evolution? • EVOLUTION – process of

biological change

– Descendants differ from their ancestors

– Change in genetics of a species

• ADAPTATION – inherited characteristic that improves an organisms ability to survive and reproduce – Can be physical or behavioral

The Mantis Shrimp is my New Favorite Animal

So who thought of Evolution?

• BUFFON - Earth is much older than

previously thought, some fossils look

similar to living organisms

• LYELL- gradual changes in earth from

physical processes, EARTH IS OLD

Malthus

• Malthus- in 1798 he published Essay on the Principles of Population. – This piece explained that every 25 years

the human population will double unless limited by food supply.

• Organisms will overproduce but will then need to compete for resources

Lamarck

• Use it or lose it

• “Inheritance of acquired traits“

• A change in the environment causes

changes in the needs of organisms

living in that environment, which in turn

causes changes in their behavior.

• Giraffe, muscles, etc.

Darwin

• Proposed the idea of natural selection

Who is Charles Darwin?

• February 12th, 1809 – April

19th,1882

• English naturalist

• Studied the diversity of life

and proposed a broad

explanation of it.

Who was Charles Darwin?

Darwin Continued

• Modern evolutionary theory began

when Darwin presented evidence that

evolution happens and offered an

explanation of how evolution

happens.

GOOD MORNING!!!

Happy Tuesday! This morning we are going to be enjoying some Virtual Reality in the Galapagos! But

before that… we got some stuff to do!

Please do the following to prepare for class: • Get out a notes sheet ready to finish our

evolutionary theory notes

• Grab one of the packets off the front table (we won’t need these until later)

Darwin’s Ideas

• During this time period

people did not think

that living things had

changed over time.

– But Darwin saw

evidence of gradual

change.

• His first evidence was

gathered during his

global voyage aboard

the Beagle.

Darwin’s Travel

• Darwin also visited the Galapagos Islands in the Pacific Ocean. – Island contain

several different finches, which were all very similar.

– The size and shape of the bill (beak) varied.

– Each bill was specialized for a certain purpose.

• Important characteristics: each island

had unique/different organisms but all

were related to mainland organisms

• DARWIN INFERRED… mainland species

had changed after they colonized the

islands & adapted to their new

environments

HAPPY MONDAY!

Only 4 days until Spring Break!!

Today we will be looking a little deeper into evolutionary theory.

To prepare for class today, please do the following: • Get out your warm up page

• Have your Evolution vocab out and ready to be checked.

• Have a notes sheet out and ready (if you didn’t use up space on your last one… save some paper and use it up)

FOR TODAY’S WARM UP…

Please make the following table for your

warm up:

LAMARK DARWIN

HOW WOULD LAMARK & DARWIN EXPLAIN THESE TRAITS?

Owls are known as silent predators of

the night, capable of flying just inches

from their prey without being detected.

The quietness of their flight is owed to

their specialized feathers.

First, the leading edge of the owl’s wing

has feathers covered in small structures

that project out from the wing. These

serrations break up the flowing air into

smaller flows that are more stable along

the wing. Furthermore, this change in

airflow patterns also appears to reduce

the noise of the flowing air. The

wing’s serrated leading edge appears

to be most effective at reducing noise

when the wing is at a steep angle—

which would happen when the owl is

close to its prey and coming in for a

strike.

https://www.youtube.com/watch?time_continue=15&v=a68fIQzaDBY

After the Voyage of the Beagle

• Darwin returned to England to analyze his data and observations

• Published “The Origin of Species: by means of Natural Selection” – 200 pg essay in 1859

• 2 Main Points – Descent with Modification

– Natural Selection

Descent with Modification

• Species today came from ancestral

organisms

– Descendants spread out over different

habitats and environments

– Accumulated adaptations to new

environments

• Explains diversity of life on Earth

Evolution by Natural Selection

• Individuals that have traits that better suit their environment are more likely to survive.

• Darwin’s theory predicts that over time, the number of individuals that carry advantageous traits increase in a population.

Inherited shell variations make some snails less likely than others to be attacked by predators.

Wide, blunt shells increase the chances for snails to survive and pass their traits to the next generation by reproducing.

EVIDENCE FOR EVOLUTION

Fossils

• Comparing fossils can reveal

a pattern of gradual

change.

• Shows vestigial structures.

Anatomy

• Many internal similarities are best explained by

evolution.

• Homologous Structures- a characteristic that are

shared by a group of species because it is

inherited from a common ancestor.

Anatomy (Continued)

• Analogous structures – do not show evolutionary origin – Similar environment led to similar

structures and functions

• Vestigial structures – structure that has lost all or most of it’s function – Tail bone

– Appendix

Biogeography

• Darwin found that all around the world

similar animals lived in similar environments.

Developmental Biology

• Scientists compare

embryonic

development of

many animals

– They find similarities

and patterns

– Example: all

vertebrates have

tails!

Biochemistry

• Remember genes control the physical

appearance of animals, so DNA plays

a huge role in Natural Selection.

• Studying DNA can show how similar a

species is…or how different.

GOOD MORNING!

Two more days until Spring Break!!!

Today we are going to get you guys ready for

your Quarterly Exam!!!

Please do the following to prepare for class:

• Grab one of the sheets off the front table

• Have something out to write with

HELLO HELLO HELLO!!! Only ONE more day until Spring Break! We are

so close! Today we will be reviewing for your

Quarterly… but first…. VOCAB QUIZ!

Please do the following to prepare for class:

• Look over your Evolution Vocab Packet

• Have something out to write with

When you are finished…

1. Make sure your name is on it!!!!

2. Bring them up to me so I can start

grading

3. Wait quietly for everyone to finish

- ABSOLUTELY NO CELL PHONES! I SEE IT. I

TAKE IT. YOU GO TO SARS AND GET A ZERO.

KABOOM REVIEW GAME

WE WILL BE PLAYING 15 MINUTE ROUNDS TWO TIMES

Please be careful of the cards!

NATURAL SELECTION

ONLINE SIMULATION

JUST SO YOU CAN BETTER UNDERSTAND IT

GOOD MORNING PEEPS

It is a beautiful out today! Make sure you spend time enjoying it. But hope you’re brain is thinking

everything biology because today is your Quarterly Exam.

To prepare for class, please do the following:

• Take a few minutes to look back over your study guide

• Have something to write with

• Take a few deep breaths… you got this!

WHEN YOU ARE FINISHED…

1. Make sure your name AND test book number are on your answer sheet!

2. Place your test book and answer sheets on the front table.

3. Grab the worksheet on the front table

4. Grab your ASSIGNED chromebook number from the cart and return to your seat – Go to www.sciencewithhamory.weebly.com

• Go to course information; materials & documents; 4th marking period

• Find “The Beak of a Finch” video • Watch and answer pre-lab questions (you may use

headphones) • Once finished, please wait for the rest of the class!

Hola amigos! I hope you all had a wonderful weekend! Today we are going to be moving forward in evolution but of

course we will start with a review of what we learned so far.

To prepare for class, please do the following:

• Grab a notes sheet (or paper of your choice) and have something out ready to write with for notes in a hot sec.

• Grab your assigned chromebook number

• Go to www.kahoot.it

MODES OF SELECTION

Let’s Talk a Little More About This

Natural Selection thing…. Natural Selection: individuals with traits well suited for an

environment will leave more offspring than individuals

lacking the desired traits.

• This repeats over time, each new generation has a

higher proportion of individuals with this advantageous

trait.

• Could cause isolated populations to become separate

species as they adapt to new environments.

• Nature selects, not humans.

Beetles with brown genes escaped predation and survived to

reproduce more frequently than beetles with green genes, so

that more brown genes got into the next generation.

• Darwin proposed that natural selection is

the cause of evolution.

• This theory can be summarized in 4 steps:

– Overproduction- more offspring created than

can survive. Not all individuals will survive.

– Variation- exists within every population (inherited traits)

– Selection- Certain traits make individuals

more or less likely to survive and reproduce.

– Adaptation- OVER TIME, those traits that

improve survival will become more common.

Sexual Selection

• Mode of natural selection in which

some individuals out-reproduce others

of a population because they are

better at competing for mates

Click on us to

see how it

happens!

Natural Selection CER

CER Writing

• A CER (Claim, Evidence, Reasoning) is a format for writing about science. It allows you to think about your data in an organized, thorough manner. See below for a sample and the grading rubric.

• Claim: a conclusion about a problem

• Evidence: scientific data that is appropriate and sufficient to support the claim

• Reasoning: a justification that shows why the data counts as evidence to support the claim and includes appropriate scientific principles

GOOD MORNING BEAUTIFUL

PEOPLE! It’s Friday Eve! So our week is almost over! Today we are going to be looking at the genetic aspects of evolution.

To prepare for class, please do the following:

• Place your Which Beak is Better? Lab and extended research (attach them together) in the turn in bin

• Get out a section of paper for your warm ups

• Get out a notes page (or paper you would prefer to use)

• Have something to write with

WARM UP Match each image below with the correct factor of natural selection

Overproduction Variation Selection Adaptation

A. B.

C. D.

Speciation

• BOTH natural selection & sexual

selection cause the genetic

characteristics of a species to change

which sometimes leads to the

formation of a species which is known

as speciation.

Artificial Selection • Selective breeding of plants and animals to produce offspring

with genetic traits that humans value

• Breeder role of environment

• EXAMPLES: – PLANTS- bred for production, disease resistance, protein content – ANIMALS- growth rate, milk production, temperament

https://www.youtube.com/watch?v=F-XTUpLmhPc

Natural vs. Artificial Selection

NATURAL

SELECTION

ARTIFICIAL

SELECTION

Nature selects

the traits (based

on environment)

Humans select

the traits

Leads to

ADAPTATION

MICROEVOLUTION

Microevolution

• Refers to evolution as a change in the

genes of population

• To study microevolution, we must look

at the processes that change inherited

traits.

– 5 majors processes- natural selection,

migration, mate choice, mutation, and

genetic drift.

Natural Selection

• Can cause an

increase or

decrease in

certain alleles in

a population.

Migration

• Migration is the movement of

individuals into, out of, or between

populations.

• Can change the numbers and types of

alleles in a population.

Mate Choice

• If mating is totally

random, then

offspring will gain

random traits.

• If mating is

selective/limited

then the choice of

specific traits will be

passed down.

Mutation

• Mutations can

change the

numbers and types

of alleles from one

generation to the

next.

Genetic Drift

• Genetic make up changes based on

random chance events.

• Survival may be totally unrelated to

genotype

• Ex: Bottleneck and Founder Effect

Let’s Take a Further Look at

Microevolution

Changes in A Gene Pool

Worksheet

Well hello there strangers….

So I’m sick but that’s okay because ya know what…. It’s Movie Monday!

To prepare for class, please do the following:

• Have a piece of paper for notes (sorry, y’all I’m out of notes sheets)

• Have something to write with

• Grab one of the worksheets off the front table

MACROEVOLUTION

Macroevolution

• Refers to the appearance of new species

over time.

• To study macroevolution we look at the

patterns in which new species evolve.

• Patterns of change are seen when

relationships between living and fossil

species are modeled.

– Convergent evolution, coevolution, adaptive

radiation, extinction, gradualism, and

punctuated equilibrium.

Convergent Evolution

• If evolution is directed by the environment then similar environments should evolve similar adaptations.

• Two distinct species with differing ancestries evolve to display similar physical features

Reptile Mammal Fish

Coevolution

• Organisms live in the environment with other

organisms. Sometimes they affect another’s

evolution.

• Adaptations may evolve to survive with other

organisms.

How to Grow a Planet; The

Power of Flowers

YAY MOVIE TIME!

Adaptive Radiation

• Over time, species may split into two or

more lineages.

• Occurs rapidly when a new species

enters a more desolate location.

Gradualism

• Many think that new organisms

arise/evolve through very small and

slow steps.

Punctuated Equilibrium

• Opposite of gradualism

• Species are stable for a long period of

time, then environmental changes

cause a rapid/sudden evolution of

new organism.

Extinction

• If all members of a lineage die off or

fail to reproduce, this species is known

as extinct.

• Most animals have gone extinct, only

a small percentage are around today.

TAXONOMY, PHYLOGENY, &

CLADISTICS

AKA CLASSIFICATION

Overview • Phylogeny is the evolutionary history of a

species or group of related species usually

organized into a phylogenetic tree

• Phylogenetic trees and cladograms (also

tree shaped) seek to arrange organisms

based on common ancestry

Phylogenetic Trees

• Keep in mind phylogenetic trees and

cladograms represent a hypothesis

about evolutionary relationships and

are ever-changing based on new

evidence

Tree Structure • Each branch point

represents the divergence of two species

• Sister taxa are groups that share an immediate common ancestor

• A rooted tree includes a branch to represent the last common ancestor of all taxa in the tree

• A polytomy is a branch from which more than two groups emerge

What we CAN & CANNOT

Learn…

• Phylogenetic trees DO show patterns of descent

• Phylogenetic trees DO NOT indicate when species evolved or how much genetic change occurred in a lineage

• It shouldn’t be assumed that a taxon evolved from the taxon next to it

What is the difference between a

phylogenetic tree and a cladogram?

• Many biologists use these terms interchangeably

• Both are based on ancestral relationships

• In phylogenetic trees branch lengths can represent the amount of genetic change or are proportional to time

• In cladograms the branch lengths are usually considered to be arbitrary

How To Read A Cladogram • These relatives share a common ancestor at the root of the

tree.

• Note that this diagram is also a timeline. The older organism is at the bottom of the tree.

• Branches on the tree represent speciation

• The event that caused speciation is shown as a fork on the tree.

How To Read A Cladogram

• A CLADE places species into groups that includes an ancestral species and all of its descendants.

• If you cut a branch of the tree you could remove all the organisms that make up a clade

The “Old” Way…

• Taxonomy: The old way of classifying organisms

• In the 18th century, Carolus Linnaeus published a system of taxonomy based on resemblances

The “Old” Way…

• Two key features of his system remain

useful today: two-part names for

species (e.g. Vulpes vulpes) and

hierarchical classification

Taxonomy Rules

• Go in order of largest groups to specific groups – Domain, Kingdom, Phylum, Class, Order,

Family, Genus, Species • Dear King Phillip Came Over For Good Spaghetti

• Binomial nomenclature – Scientific names only! No common names

• Made up of Genus & Species name

• Genus is ALWAYS capitilized

• Species name is ALWAYS lowercase

• Write in italics… if you can’t = underline it!