Phylogeny & systematics - PowerPoint Presentation

Slide1

Phylogeny & systematics

IB BIO II

Van

Roekel

4/17/14Slide2

Use binomial nomenclature to name and classify organisms

1

st word refers to the genus, 2nd word to the species, i.e. Homo Sapiens. Carolus (Carl) Linnaeus consolidated and popularized binomial nomenclatureReasons:Make sense of biosphereIdentify unknown organisms Show evolutionary links Predict characteristics shared by members of a group

ClassificationSlide3

DNA is universal source of genetic information in all living organisms

Any gene can be mixed and match with DNA from other organisms and generate a certain protein

All proteins use same 20 amino acids to form polypeptide chainsCan have 2 possible orientations, left-handed & right-handed, all proteins are based on left-handed orientationChemical similarities suggest common ancestry for all lifeBiochemical Evidence of EvolutionSlide4

Study of the evolutionary past of a species

Species that are most similar are closely related

Species with more differences are less likely to be closely relatedTraditionally done with morphological characteristicsMore recently done by comparing similarities in polypeptide sequences in proteins such as hemoglobin, cytochrome C, and cholrophyllAlso done by examining DNA base sequencesPhylogenySlide5
Slide6

AAAATTTTCCCCGGGG

AAAATTT

ACCCCGGGGAAAATTTACCCGCGGGAAC

AT

C

TTCC

A

CG

CT

G

1 & 2 most similar/closely related

1 & 4 most differences/less related

Use biochemical phylogenies to confirm/contradict work done by paleontologists

Variations and PhylogenySlide7

Differences in DNA & polypeptide sequences occur over time through mutations and sexual reproduction

Changes can be used as a “clock” to estimate how far back the species split

Compare homologous molecules and count the number of base pairs that don’t match3 organisms: A,B,CA&B 23 differences, A&C 83 differencesA&B more closely related than A&CSplit between A&C occurred roughly three times further in the past than A&BThe Evolutionary Clock Slide8

Technique that measures differences in DNA sequences

Take sample of DNA from one species (A) and fuse it with sample from another species (B)

Where connections occur, base pairs matchWhere no connections, base pairs repel and there is a differenceHybridizationSlide9
Slide10

Cladistics is a system of classification which groups taxa together according to characteristics which have most recently evolved

Examine primitive (

plesiomorphic) traits and derived (apomorphic) traits Primitive traits have same structure and function, and evolved early on in organisms being studied (leaves with vascular tissue in plants)Derived traits also have same structure and function but evolved more recently as modifications of previous traits occurred (flowers with vascular tissue which evolved more recently than leaves)CladisticsSlide11

When groups are split into two parts, one having derived characteristics and the other does not, the groups form two separate clades

Monophyletic groups, composed of the most recent common ancestor and all its descendants

Usually made up of several species

CladesSlide12
Slide13

Used to help separate individuals in to different clades

Homologous Structures are derived from the same part of a common ancestor

Pentadactyl limb in animals such as humans, whales, and batsAnalogous Structures have same function but do not necessarily have same structure and are not derived from a common ancestorWings in birds, bats, and insectsHomologous & Analogous StructuresSlide14

Cladograms

are diagrams that visually represent the findings of

cladisticsShows evolutionary relationships with bottom branches showing earliest evolved organisms and top branches most recently evolvedBasic idea is parsimony, meaning the least complicated explanation is preferredEach time a branch forks into two, a split between species occurred creating two lineages, each split is called a nodeEach node shows speciationCan be made using biochemical and morphological examplesCladogramsSlide15
Slide16
Slide17
Slide18

The simplified

cladogram

of vertebrata is shown with synapomorphies indicated. What organisms have bony ribs and shoulder girdles?

Ray-finned fish, lungfish, amphibians, and land vertebrates

What is the oldest creature in this

cladogram

? They youngest

?

Lampreys,

landvertebrates

What

feature is shared by amphibians and land vertebrates

?

Have fingers and toes

What feature did the common ancestor of lungfish and lampreys have

?

Vertebrae

What creature is most closely related to land vertebrates? Lampreys

?

Amphibians, Sharks

BILL Slide19

Construction of

Cladograms

Make a list of included organismsList as many characteristic each organisms possesFrom established list, find a characteristic common to all organisms (primitive characteristic)Make a table with derived characteristics on top row and organisms in first column. (shows derived characteristics in each organismConstruct cladogram from table, organism with least derived traits is on first branch, organism with most derived characteristics is on top branchCladogram constructionSlide20

Use the following information to construct a

cladogram

Organisms: Paramecium, flatworm, shark, hawk, koala, camel, humanCharacteristics: Eukaryotic, multicellular, vertebral column, produces amniotic egg, has hair, has placenta, has one opposable thumb on each forelimbConstructing a CladogramSlide21

Eukaryotic

Multicellular

Vertebral ColumnAmniotic Egg

Hair

Placenta

Opposable thumb

Totals

Paramecium

+

X

X

X

X

X

X

1

Flatworm

+

+

X

X

X

X

X

2

Shark

+

+

+

X

X

X

X

3

Hawk

+

+

+

+

X

X

X

4

Koala

+

+

+

+

+

X

X

5

Camel

+

+

+

+

+

+

X

6

Human

+

+

+

+

+

+

+

7Slide22

Paramecium

Flatworm

Shark

Hawk

Koala

Camel

Human

Hair

MulticellularSlide23

Cladistics attempts to find most logical and natural connections between organisms by using morphological or biochemical data

Classification shows connections by groupings organisms into different taxa

Each time a derived characteristic is added to a cladogram, it is similar to moving up one taxa in Linnaean SystemDifferences occur in organisms such as birds, Cladistics says birds share characteristics with dinosaurs and thus are in the same cladeLinnaean Classification have birds in a class of their ownCladistics, rules are always the same concerning derived and primitive characteristicsClassification definitions such as species, classes, and phyla can be challenged

Cladograms

and ClassificationSlide24

Use binomial nomenclature to name and classify organisms

1

st word refers to the genus, 2nd word to the species, i.e. Homo Sapiens. Carolus (Carl) Linnaeus consolidated and popularized binomial nomenclatureReasons:Make sense of biosphereIdentify unknown organisms Show evolutionary links Predict characteristics shared by members of a group

ClassificationSlide25

Five Kingdoms

Kingdom Plantae (plants)

Kingdom Animalia (animals)Kingdom Fungi (fungi and molds)Kingdom Protoctista (protozoa and algae)Kingdom Prokaryote (bacteria) Hierarchy of classificationSlide26
Slide27

Within each kingdom, there are several subdivisions, called

taxa

Seven-level hierarchy of taxa:KingdomPhylumClassOrderFamilyGenusSpeciesKing Phillip

C

ame

O

ver

F

or

G

ood

S

oup Hierarchy of ClassificationSlide28

Taxa

Human

Garden PeaKingdomAnimaliaPlantae

Phylum

Chordata

Angiospermae

Class

Mammalia

Dicotyledoneae

Order

Primate

Rosales

Family

Hominidae

Papilionaceae

Genus

Homo

Pisum

Species

sapiens

sativum

ExamplesSlide29

Feeding Habits (carnivore/herbivore)

Habitat (land dwelling/aquatic)

Daily activity (nocturnal/diurnal)Risk (harmless/venomous)Anatomy (vertebrates/invertebrates)System of classification must be clear, consistent, easily implemented and a general consensus to apply it. Other Means of ClassificationSlide30

Four of the several types of plant phyla include:

Bryophyta

: short in stature such as mossFilicinophyta: ferns and horsetailsConiferophyta: coniferous, pine trees cedar, juniper, firAngiospermophyta: all plants that make flowers and have seeds surrounded by fruitPlant Phyla Slide31
Slide32

Vegetative Characteristics such as leave types and stems

Bryophytes: non-vascular, lack vascular transport tissue such as xylem or phloem

Filicinophyta: vascular plants, small leavesConifers: vascular, all produce woody stems and leaves are needles or scalesAngiosperms: vascular and have flowers and fruitDistinguish plant phylasSlide33

Reproductive characteristics

Bryophytes: produce spores (microscopic reproductive structures) transported by rain water

Filicinophytes: produce using spores in a similar mannerConifer: use wind to help reproduce by pollination, produce seed cones with seed scalesAngiosperms: produce seeds, rely on birds, insects, and mammals to transport pollen. Sexual organ is flower, fruit is enlarged ovary Distinguish plant phylasSlide34
Slide35

Six of many animal phyla include:

Proifera

: spongesCnidaria: sea jellies (jellyfish), coral polyps, and othersPlatyhelminthes: flatwormsAnnelida: segmented wormsMollusca: snails, clams, octopi, etc…Atrhtropoda: insects, spiders, crustaceans, etc…All listed phyla are invertebrates

Animal Phyla Slide36

Porifera:

Simple marina animals that are sessile (stuck)

Feed by pumping water through tissues and filtering out foodNo muscle, nerve tissues, or internal organsCnidaria:Very Diverse: Coral, sea anemones, jellyfish, hydra, Portuguese man-of-war All have stinging cells called nematocystsSome sessile, some free swimming, some bothGastric pouch for digestion

DetailsSlide37
Slide38

Platyhelminthes:

Flatworms with one body cavity, gut with one opening for food to enter and waste to leave

No heart, no lungsExchange gas by diffusionExample: TapewormsAnnelida:Segmented worms such as earthworms, leeches, and polychaetesBodies divided into sections separated by ringsHave gastric tracts, w/ mouth at one end and anus at opposite

DetailsSlide39
Slide40

Mollusca:Aquatic animals, snails, clams, octopi

Shell produced with calcium

Non-segmented bodiesArthropoda:Hard exoskeleton made with chitin, segmented bodies, and limbs (walking, swimming, eating)Insects, spiders, scorpions, crustaceans such as crab and shrimpLive in most habitats throughout worldVary in sizeDetailsSlide41
Slide42

Used to help identify which order, genus, and species an organism is by using observable characteristics

In General:

Look at first section of key which has a pair of sentencesLook at the organism to see if particular characteristics are presentIf answer is yes, to go end of line/next section that contain a new pair of statements to examineIf answer is no, go to second statement just below it and follow that one, should it be trueContinue this until the end of the line has a name, not a number and if each question was answered correctly, should be your organism. Example in book, pg. 149

Dichotomous Key Slide43

1. a. Organism is living........................................................go to 4.

1. b. Organism is nonliving..................................................go to 2.

2. a. Object is metallic........................................................go to 3.2. b. Object is nonmetallic..................................................ROCK.3. a. Object has wheels......................................................BICYCLE.3. b. Object does not have wheels......................................TIN CAN.4. a. Organism is microscopic...................................PARAMECIUM.4. b. Organism is macroscopic............................................go to 5.5. a. Organism is a plant.....................................................go to 6.

5. b. Organism is an animal.................................................go to 8.

6. a. Plant has a woody stem..............................................go to 7.

6. b. Plant has a herbaceous stem.................................DANDELION.

7. a. Tree has needle like leaves.....................................PINE TREE.

7. b. Tree has broad leaves............................................OAK TREE.

8. a. Organism lives on land................................................go to 9.

8. b. Organism lives in water...............................................CLAM.

9. a. Organism has 4 legs or fewer......................................go to 10.

9. b. Organism has more than 4 legs...................................ANT.

10 a. Organism has fur........................................................go to 11.

10 b. Organism has feathers................................................ROBIN.

11 a. Organism has hooves.................................................DEER.

11 b. Organism has no hooves............................................MOUSE.Slide44

Vocabulary can be challenging and technical

Make sure using the right key, no key can identify all the species

Making a Dichotomous KeyStart by putting things in groups by identical characteristicsInvent statements that divide things into created groupsDichotomous KeySlide45

List five kingdoms and determine where each organism belongs: algae, hydra, spider, mushroom, yeast, bacterium.

Design a dichotomous key using ten different objects/organisms

In a population of 278 mice, 250 are black, 28 are brown. B=black, b=brown. Identify the allele and genotype frequencies in this generation. Spots for camouflage exist on many different species, such as butterflies and cheetahs. A student groups all organisms with spots in the same clade. Is this justified? Why or why not?Practice ProblemsSlide46

Plantae, Animalia

, Fungi,

Protoctista, and ProkaryoteAlgae – ProtoctistaHydra – AnimaliaSpider – AnimaliaMushroom – FungiYeast – FungiBacterium - Prokaryote

List five kingdoms and determine where each organism belongs: algae, hydra, spider, mushroom, yeast, bacterium

. Slide47

Answers may vary

Design a dichotomous key using ten different objects/organismsSlide48

b = q = Square root of .10 = 0.32 = 32%

B = p = 1-.32 = 0.68 = 68%

bb = q2 = 28/278 = 0.10 = 10%Bb = 2pq = 2(.68 x .32) = 0.44 = 44%BB = q2 = 0.682 = 0.46 =46%In a population of 278 mice, 250 are black, 28 are brown. B=black, b=brown. Identify the allele and genotype frequencies in this generation

.