EVOLUTION (part 2)

EVOLUTION EVOLUTION (part 2)(part 2)

CHAPTER 13 read 286-298CHAPTER 13 read 286-298

The Evidence of EvolutionThe Evidence of Evolution

Hutton observed Hadrian’s Hutton observed Hadrian’s wallwall

Built between Scotland and England in Built between Scotland and England in 122-127 A.D.122-127 A.D.

Still standing with little evidence of Still standing with little evidence of erosion.erosion.

Observed extinct volcano on which Observed extinct volcano on which Edinburough castle was built.Edinburough castle was built.

Add drawing to notesAdd drawing to notes Hyperlink to Unitedstreaming Hadrian’s Hyperlink to Unitedstreaming Hadrian’s

WallWall

WONDERED?WONDERED?

"How could a volcano erode in "How could a volcano erode in 6,000 years when a wall seems 6,000 years when a wall seems not to have changed in 1,500 not to have changed in 1,500 years?”years?”

Estimated the Earth's age to be Estimated the Earth's age to be in the in the millions of yearsmillions of years

"Theory of the Earth" "Theory of the Earth" published by Huttonpublished by Hutton

"The surface of the earth appears as it "The surface of the earth appears as it does because of gradual geologic does because of gradual geologic changes caused by natural processes" changes caused by natural processes"

ex. volcanoes, earthquake, erosion, ex. volcanoes, earthquake, erosion, deposition, glaciers, hurricanesdeposition, glaciers, hurricanes

Charles Lyell- furthered these ideas in “Principles of Geology”

Uniformitarianism-Uniformitarianism-

_________"theory of uniformity" _________"theory of uniformity" geological processes geological processes of the past and present are the of the past and present are the same and are the only processes same and are the only processes that influence the way we see that influence the way we see the world today.the world today.

CatastrophismCatastrophism

____________ ____________ substantial substantial environmental calamities have environmental calamities have occurred that have changed the occurred that have changed the face of the earth. Extinction was face of the earth. Extinction was followed by repopulationfollowed by repopulation

V. DARWIN and Natural V. DARWIN and Natural SelectionSelection

(1809-1882) Feb 12 same birthday as (1809-1882) Feb 12 same birthday as LincolnLincoln

Studied medicine ministry poor studentStudied medicine ministry poor student 5 yr. round the world trip as the ship's 5 yr. round the world trip as the ship's

NaturalistNaturalist H.M.S. Beagle 1831- 1836H.M.S. Beagle 1831- 1836 married his cousin Emma Wedgewoodmarried his cousin Emma Wedgewood very seasick weak the rest of his lifevery seasick weak the rest of his life collected specimens, fossils, journal and collected specimens, fossils, journal and

read captain's dinner guestread captain's dinner guest

his grandfather Erasmus Darwin was his grandfather Erasmus Darwin was interested in evolutioninterested in evolution

A KEEN EYE FOR OBSERVATION WAS A KEEN EYE FOR OBSERVATION WAS Darwin’s GREATEST ASSET Darwin’s GREATEST ASSET

B. What Darwin knew...... B. What Darwin knew...... 1. The earth was old and it had 1. The earth was old and it had

changed, read Hutton and Lyellchanged, read Hutton and Lyell 2. organisms lived in very special 2. organisms lived in very special

environmentsenvironments 3. saw anatomical relationships3. saw anatomical relationships 4. selective breeding , pigeons, 4. selective breeding , pigeons,

dogs, horses, crops traits could be dogs, horses, crops traits could be passed onpassed on

5. animals always over populate b/c 5. animals always over populate b/c he read economist Thomas Malthushe read economist Thomas Malthus

The Galapagos Islands were The Galapagos Islands were of special interest to him of special interest to him because of their unique life because of their unique life forms found no where else forms found no where else huge turtles, huge turtles,

many finches, many finches, swimming lizardsswimming lizards

QUESTIONQUESTION

Why were the animals on the islands Why were the animals on the islands slightly different than the animals on slightly different than the animals on the mainland?the mainland?

If an animal migrated to the island from If an animal migrated to the island from the continent, what caused it to the continent, what caused it to change (evolve)?change (evolve)?

ANSWERANSWER Different environmental pressures Different environmental pressures

benefited or hurt the animals with benefited or hurt the animals with particular features particular features

(adaptations= an inherited feature (adaptations= an inherited feature that increases an organism's chance that increases an organism's chance of surviving in an particular of surviving in an particular environment).environment).

2 fundamental factors that 2 fundamental factors that determine evolutionary determine evolutionary change:change:ANCESTRY ANCESTRY andandENVIRONMENTENVIRONMENT

DARWIN'S EXPLANATIONDARWIN'S EXPLANATION

"Natural Selection" is the mechanism "Natural Selection" is the mechanism that allows some forms to survive and that allows some forms to survive and others to die out.others to die out.

not a conscious force, as there is a not a conscious force, as there is a struggle for resources some struggle for resources some organisms die while others live to organisms die while others live to reproduce.reproduce.

1859 “On the Origin of species by 1859 “On the Origin of species by means of Natural Selection”means of Natural Selection”

sold out the first daysold out the first day

Evolution for DUMMIESEvolution for DUMMIES

1. over population1. over population 2. constant struggle for resources2. constant struggle for resources 3. variation in the species3. variation in the species 4. the best adapted to the environment 4. the best adapted to the environment

survivesurvive 5. surviving organisms transmit 5. surviving organisms transmit

variation to offspringvariation to offspring

ALFRED RUSSEL ALFRED RUSSEL WALLACEWALLACE (1823-(1823-1913) Malay 1913) Malay Archipelago had Archipelago had the same idea as the same idea as Darwin in 1858 Darwin in 1858 (equally credited (equally credited but Darwin gave but Darwin gave extensive evidence)extensive evidence)

The Darwin–The Darwin–Wallace Medal was Wallace Medal was issued by the issued by the Linnean society on Linnean society on the 50th anniversary the 50th anniversary of the reading of of the reading of Darwin and Darwin and Wallace's papers on Wallace's papers on natural selection.natural selection.

The The HARDWAREHARDWARE or material of or material of evolution is variation, mutation and evolution is variation, mutation and overpopulationoverpopulation

The The MECHANISMMECHANISM for evolution is for evolution is Natural SelectionNatural Selection

Theories also have a predictive Theories also have a predictive component as shown in the slides at component as shown in the slides at the after the homework answer keys. the after the homework answer keys.

Test Topics: FridayTest Topics: Friday Evolution vs. CreationismEvolution vs. Creationism Literal vs Figurative Language (interpretation of Literal vs Figurative Language (interpretation of

the Bible)the Bible) Darwin – voyage, life, ideas, book, natural Darwin – voyage, life, ideas, book, natural

selectionselection Labs – peppered moths, fossil lab (evidence vs. Labs – peppered moths, fossil lab (evidence vs.

inference)inference) Text 275-282, worksheetText 275-282, worksheet Bishop Usher, James Hutton, intro to evolutionBishop Usher, James Hutton, intro to evolution

Evidence of relatednessEvidence of relatedness

Example: Transitional forms in the fossil Example: Transitional forms in the fossil recordrecord

Hypothesis: If terrestrial vertebrates (tetrapods) evolved from lobe-finned fish (sarcopterygians), then there should be transitional forms that possess traits that are intermediate.

Previously identifiedPreviously identified transitional forms transitional forms

From Ahlberg and Clack, Nature 2006

General MethodsGeneral Methods

Scientists looked Scientists looked specifically for the specifically for the transitional form of transitional form of interest by sampling…interest by sampling… Appropriate habitats Appropriate habitats

(stream system)(stream system) Appropriate geologic time Appropriate geologic time

(early Late Devonian = (early Late Devonian = 385-376mya)385-376mya)

From Daeschler et al., 2006

http://tiktaalik.uchicago.edu/photos.html

They found They found Tiktaalik Tiktaalik roseaeroseae!!

From Ahlberg and Clack, Nature 2006

From Daeschler et al., Nature 2006

http://tiktaalik.uchicago.edu/photos.html

From Shubin et al., Nature 2006

http://tiktaalik.uchicago.edu/photos.html

SummarySummary

The study of and the evidence for The study of and the evidence for evolution clearly fits within the scientific evolution clearly fits within the scientific framework.framework.

We use current evolutionary theory to We use current evolutionary theory to make and test hypothesesmake and test hypotheses

There are many thousands of examples of There are many thousands of examples of evidence for evolutionevidence for evolution

What data from whole genome sequencing can tell us about evolution of humans

What data from whole genome sequencing can tell us about evolution of humans

Example: the Evolutionary Hypothesis

of Common Ancestry

Chromosome Numbers in the great apes:

human (Homo) 4646chimpanzee (Pan) 48gorilla (Gorilla) 48orangutan (Pogo) 48

Testable prediction:Testable prediction: If these organisms share a common ancestor, that ancestor had either 48 chromosomes (24 pairs) or 46 (23 pairs).

Testable prediction:Testable prediction: If these organisms share a common ancestor, that ancestor had either 48 chromosomes (24 pairs) or 46 (23 pairs).

Chromosome Numbers in the great apes (Hominidae):

human (Homo) 46chimpanzee (Pan) 48gorilla (Gorilla) 48orangutan (Pogo) 48

Testable prediction:Testable prediction: Common ancestor had 48 chromosomes (24 pairs) and humans carry a fused chromosome; or ancestor had 23 pairs, and apes carry a split chromosome.

Centromere

Telomere

Ancestral Chromosomes

FusionHomo sapiens

Inactivated centromere

Telomere sequences

“Chromosome 2 is unique to the human lineage of evolution, having emerged as a result of head-to-head fusion of two acrocentric chromosomes that remained separate in other primates. The precise fusion site has been located in 2q13–2q14.1 (ref. 2; hg 16:114455823 – 114455838), where our analysis confirmed the presence of multiple subtelomeric duplications to chromosomes 1, 5, 8, 9, 10, 12, 19, 21 and 22 (Fig. 3; Supplementary Fig. 3a, region A). During the formation of human chromosome 2, one of the two centromeres became inactivated (2q21, which corresponds to the centromere from chimp chromosome 13) and the centromeric structure quickly deterioriated (42).”

“Chromosome 2 is unique to the human lineage of evolution, having emerged as a result of head-to-head fusion of two acrocentric chromosomes that remained separate in other primates. The precise fusion site has been located in 2q13–2q14.1 (ref. 2; hg 16:114455823 – 114455838), where our analysis confirmed the presence of multiple subtelomeric duplications to chromosomes 1, 5, 8, 9, 10, 12, 19, 21 and 22 (Fig. 3; Supplementary Fig. 3a, region A). During the formation of human chromosome 2, one of the two centromeres became inactivated (2q21, which corresponds to the centromere from chimp chromosome 13) and the centromeric structure quickly deterioriated (42).”

Homo sapiens

Inactivated centromere

Telomere sequences

Hillier et al (2005) “Generation and Annotation of the DNA sequences of human chromosomes 2 and 4,” Nature 434: 724 – 731.

Hillier et al (2005) “Generation and Annotation of the DNA sequences of human chromosomes 2 and 4,” Nature 434: 724 – 731.

Human Chromosome #2 shows the exact point at which this fusion took place

Human Chromosome #2 shows the exact point at which this fusion took place

Chr 2