D.N.A (LET’S CLASSIFY) ROOT WORD – DI (apart/away)Objective: SWBAT explain how phylogenetic trees and cladograms are graphical representations of evolution Organize/ group the following ice cream flavors in any

way that makes sense to you. Example: Start broad (how are they all related) to

more specific Vanilla Chocolate Rocky Road Mint Chocolate Chip Cookies and Cream Rainbow

D.N.A please write on a separate sheet of paper

Reflection Questions(Use Complete Sentences!)

How do you believe you performed on the unit exam?

What came easy to you? What parts were more difficult?

How did you prepare for the exam?

What can you improve on when preparing for the next exam?

What can Ms. Nakamura do to improve?

Unit 2: Diversity of Organisms CLASSIFYING LIFE’S DIVERSITY – BUILDING DARWIN’S TREE OF LIFE

2004-2005

Phylogeny & Systematics Phylogeny

evolutionary history of a species based on common ancestries inferred

from fossil record morphological & biochemical resemblances molecular evidence (DNA)

Systematics Using phylogeny as an analytical

approach to the study of the diversity of life and relationships between organisms

2004-2005

Fossil record

Sedimentary rock are richest source of fossils fossil record is a substantial, but

incomplete, chronicle of evolutionary history incomplete historical documents of biology

history of life on Earth is punctuated by mass extinctions

5000 year old ice mummy found on an Alpine ridge dividing Austria from Italy at 10,500 feet above sea level.

Two approaches

1) Linnean system of groups

2) Phylogenic Trees/Cladistics

2004-2005

Systematics

Connecting classification to phylogeny hierarchical system Carolus Linnaeas

(taxonomist who named and classified species)

latin binomial genus (Homo) Species (sapiens)

#1 – Linneaus and taxa

Taxa – group names that we create to classify organisms

domain kingdom phylum class order family genus species

Keep Pond Clean Or Froggy Gets Sick!

Early systems primarily based on structural analysis(anatomy – dissections by surgeons)

Binomial nomenclature rules Organism’s scientific name: Felix catus

Genus = Felix, species =catus

Humans: Homo sapiens

Problems with Linnean system Analogous structures result in mis-

classifying

Transitional organisms strain the definitions of groups Ex: Platypus – the egg-laying mammal (or

should that be mammary-gland containing reptile?)

A challenge for biologists

Homology Shows deep

relatedness, common ancestry

Similar components or materials – may now serve different functions

Shows divergence from ancestry

Analogy Superficial relatedness

Components or structure significantly different

Shows convergence from separate ancestries

Example of analogy

Australian mole (marsupial)

European mole (mammal)

similar adaptations to live in current environment (underground), but very different ancestries

Homology Analogy

Divergent evolution Convergent evolution

common ancestor

modern related species

different ancestries

superficially related species (may live in similar environment)

2004-2005

Connection between classification & phylogeny

Tracing possible evolutionary relationships between some of the taxa of the order Carnivora, a branch of the class Mammalia.

Building phylogentictrees

LeopardDomestic

cat

Common ancestor

•Each branch point

–Represents the divergence of two species

•“Deeper” branch points

–Represent progressively greater amounts of divergence

LeopardDomestic

cat

Common ancestor

Wolf

Cladistics

Depiction of patterns of shared characteristics among taxa (groups)

Organisms at base of cladogram share ancestral traits of others (primitive character)

Organisms further up cladogram have additional derived traits (present in an organism but not in the previous

common ancestor)

common ancestor with a jaw

Cladistics

4 limbs? air sac? amniotic egg?

jaws? mammary glands?

dogs yes yes yes yes yeslampreys no no no no nosalamanders yes yes no yes nosharks no no no yes notuna no yes no yes noturtles yes yes yes yes no total “no”

3 2 4 1 5

common ancestor to all these animals

lamprey

salamander

shark

tuna turtle

dog

connection to other organisms on tree

outgroup – representative with no further derived traits in cladogram, but fundamental similarities to others

evolution of jaws

the jaw clade

evolution of air sac (swim bladder)

the lung / lung derivative clade

common ancestor with an air sac

evolution of tetrapody (4 legs)

the tetrapod clade

common

ancestor

with 4 legs

evolution of amniotic egg

the amniote clade

common amnioteancestor

evolution of mammary glands

the mammal clade

Cladistics

What is a valid clade?

Any group that includes all modern derived species and their common ancestor

In many cases, Linnean taxa are valid clades (ex: vertebrates, mammals)

In some cases, they are NOT valid clades(ex: protists, prokaryotes, reptiles)

One last misconception

“Humans evolved from chimpanzees”

No, they are both modern species … BOTH evolved to their modern forms from a common ancestor more recent in history than other species

the rest of the primates, mammals, vertebrates, and all other life really

chimpanzees

humans

common ancestor

D.N.A

Take 5 minutes to compare and contrast your cladogram with a partner

Discuss why you placed the organism the way you did based off of the derived trait

22

Homoplasy: a shared character trait that was not been inherited from a common ancestor Results from convergent evolution Results from evolutionary reversal

Cladistics

24

Cladistics

25

Other Phylogenetic Methods

Evolutionary changes occur in a clock-like fashion

Mutations may build up in any given stretch of DNA at a reliable rate. Ex: The gene that codes for the protein

alpha-globin (part of hemoglobin) experiences base changes at a rate of .56 changes per base pair per billion years.

Molecular clock: rate of evolution of a molecule is constant through time

D.N.A - Objective: SWBAT create and design an AP Biology FRQ essay IOT receive the maximum points on the AP exam

For the hemoglobin protein, the following information was given about the differences in amino acid sequences between organisms.

Draw a possible cladogram illustrating the relationship of these organisms to a common ancestor and summarize what can be obtained from this specific cladogram in a paragraph.

Baboon

Chimpanzee

Lemur Gorilla Dog Chicken Frog

Human 7 0 9 1 10 13 14

“Winnie the Pooh” – source of attraction beginning at a young age

“Yes, I believe that as humans we tend to show favoritism to things that are more attractive because that is how we choose our mates…”

Importance to the ecosystem Oleander flower – pretty in

appearance, but poisonous…looks can be deceiving!

GREAT DISCUSSION!Love,AYE AYE

How about a rat?

Writing AP Biology Free Response Essays

1. READ THE QUESTION 2. OUTLINE the answer 3. Define your terms

Underline your key terms 4. Answer each subject/point in detail! 5. GET TO THE POINT!

Background information is not necessary unless instructed to

REVIEW FROM LAST CLASS

What are the three hypothesis in regards to the origin of life?

What were the key events in the origin of life?

How did endosymbiosis affect the origin of life of eukaryotes?

1) SPECIAL CREATION, 2) EXTRA-TERRESTRIAL ORIGIN, 3) SPONTANEOUS ABIOTIC ORIGIN1) SPECIAL CREATION, 2) EXTRA-TERRESTRIAL ORIGIN, 3) SPONTANEOUS ABIOTIC ORIGIN

1) ORIGIN OF CELL (PROTOBIONTS), 2)ORIGIN OF GENETICS, 3) ORIGIN OF EUKARYOTES1) ORIGIN OF CELL (PROTOBIONTS), 2)ORIGIN OF GENETICS, 3) ORIGIN OF EUKARYOTES

MUTUAL BENEFICIAL RELATIONSHIP!MUTUAL BENEFICIAL RELATIONSHIP!

REVIEW FROM LAST CLASS

How are fossils beneficial in evolution?

What are the two major hypotheses on how evolution takes place?

How are they different from each other?

AGE AND MORPHOLOGIES (APPEARANCES) OF FOSSILES SHOW PATTERS OF CHANGES THAT HAVE OCCURRED BETWEEN SPECIES (RELATIONSHIP!)

AGE AND MORPHOLOGIES (APPEARANCES) OF FOSSILES SHOW PATTERS OF CHANGES THAT HAVE OCCURRED BETWEEN SPECIES (RELATIONSHIP!)

GRADUALISM AND PUNCTUATED EQUILIBRIUMGRADUALISM AND PUNCTUATED EQUILIBRIUM

GRADUALISM – organisms evolve through a slow and constant changePUNCTUATED– species evolve very rapidly

GRADUALISM – organisms evolve through a slow and constant changePUNCTUATED– species evolve very rapidly