Darwin’s Theory of Evolution Darwin Presents his Case Chapter 15-3 Image from: Biology by Miller and Levine; Prentice Hall Publishing©2006

What do oranges, broccoli and Butterball turkeys have to do with EVOLUTION? (Answers to come in this slide show!) THINK ABOUT IT

After Darwin returned to England in 1836 he filled notebooks with his ideas about _____________ and the process that he would later call _______. He did not rush to publish his ideas because they ________ with the fundamental scientific ______ of his day. He asked his wife to publish his ideas when he ___.

In 1858 another naturalist, _________________, wrote an essay describing his work in _______ that summarized the same ideas _____ had been thinking about for 25 years!

Suddenly Darwin had incentive to publish the results of his work! In 1859 ____________________ presented _______ and proposed a ________ for evolution that he called __________________

A theory is a ____________, _______, explanation of phenomena that have occurred in the natural world, like the theory of __________________, ________, and _____________. Isn’t evolution just a theory?

________________ of OFFSPRING More offspring are produced than can survive. WHAT IS DARWIN’S THEORY?

_________________ is found naturally in all populations

WHAT IS DARWIN’S THEORY? ______________________ means that members of each species must ________ for food, space, and other __________.

WHAT IS DARWIN’S THEORY? Some organisms in a ________ are ________ to survive.

WHAT IS DARWIN’S THEORY? _____________________ organisms which are better adapted to the environment will ______ and ________, passing on their _____.

VOCAB Ability of an individual to ______ ____________ in its specific environment = ______

VOCAB Any ___________________ that increases an organism’s ______________ = _____________

ADAPTATIONS CAN BE ___________ Beak shapes _____________ Spider web building Bird mating dances

Over time, natural selection results in ________ in the inherited characteristics of a __________. These changes ______ a species’ _____ in its environment. WHAT IS DARWIN’S THEORY? How Does Evolution Really Work?

_______________ evolve NOT INDIVIDUALS. NATURAL SELECTION only works on heritable traits. A trait that is favorable in one environment may be useless or detrimental in another. IMPORTANT TO REMEMBER !

____________________________ suggests that each species has ___________, with ________, from other species over time. This idea suggests that all living species are ____________________, and that all species, living and extinct, share a _________________. WHAT IS DARWIN’S THEORY? DESCENT WITH MODIFICATION RELATED TO EACH OTHER

EVIDENCE OF EVOLUTION: 1.________________ 2.________________ 3. _______________ 4. _______________ 5. _______________ 6. _______________ 7. _______________

__________provides the _________ through _________ and _________________________ ________________ traits that they find ______. variation EX: cows that produce more milk, turkeys with more breast meat, etc.

BIOLOGY by Campbell and Reece Prentice Hall Publishing©2005 WE’VE DONE IT WITH PLANTS

WE’VE DONE IT WITH ANIMALS If humans can select for beneficial traits, why can’t nature? If artificial selection can achieve so much change in relatively short time, why can’t major changes happen over thousands of generations?

Now you know what broccoli and Butterball turkeys have to do with evolution! (Answers about oranges to come in this slide show!) THINK ABOUT IT

How Do We Know Evolution Happens? 2. Fossil Record – ______ are the _______ _________________ found in layers of rock in the Earth. of ancient organisms remains

How Do We Know Evolution Happens? The layers of rock tell the history of the _____, while the _____ found within the rock tell a history of ___. The fossils are ________ as the rock they are found in.

Go to Section: Sea level Sedimentary rocks form in horizontal layers. When part of Earth’s crust is compressed, a bend in a rock forms, tilting the rock layers. As the surface erodes due to water, wind, waves, or glaciers, the older rock surface is exposed. Movement of Earth’s Crust Section 15-2 Fish die in the ocean and are covered in sediment. Over time and under increasing pressure, the remains becomes fossilized Earthquakes and volcanoes cause uplifting of the layers of the Earth, taking the fossils along Fossils of marine fish found on the mountain- sides of southwest Wyoming, which at one time was covered by an inland sea

If Darwin’s theory is correct you would expect to find fossils that show sequential __________________ and _____________ fossils that show relatedness between organisms That’s EXACTLY what we do see!

If evolution has happened, we should be able to find evidence of evolution in the fossil record AND WE HAVE ! BBC Tiktaalik video

Fossil record shows change over time SD dinosaur fossils

_________________________FOSSILS HAVE BEEN FOUND Scientific American; Dec 2005; Vol 293; p

TIK-TAALIK TIK-TAALIK Intermediate between fish and early tetrapods Fins have basic wrist bones and simple fingers Earliest fish with a neck Discovered by Neil Shubin and Ted Daeschler in

If Darwin’s theory is correct you would expect to find ____________ yet _______________ living in a _________ region as they spread into nearby habitats and evolve. different species That’s EXACTLY what we do see!

REMEMBER THE GALAPAGOS TORTOISES Image from: BIOLOGY by Miller and Levine; Prentice Hall Publisher©2006 Little vegetation Long necks Lots of vegetation Short necks Intermediate vegetation Intermediate necks Tortoises adapted to different habitats as they spread from the mainland to the different islands. = ____________________ =_______________________

DARWIN’S FINCHES Darwin collected 14 species of finches and hypothesized that the Galapagos had be colonized by organisms from the mainland that had then diversified on the various

GALAPAGOS FINCHES The _____ of Galapagos finches have ______ to eating a _____ of _____. variety

If Darwin’s theory is correct you would also expect to find _______________ living in ________ geographic regions but similar habitats becoming ________ as they adapt to________ That’s EXACTLY what we do see! ecosystems

BOTH LIVE IN FOREST ECOSYSTEMS Adapted to similar environments, but evolved independently from different ancestors. SUGAR GLIDER in Australia is a marsupial more closely related to Kangaroos than North American FLYING SQUIRRELS because its ancestors were marsupials.

Whales and sharks have a _____ body design even though they are very _______ organisms (one is a fish; the other, a mammal) because they have _________________ to living in a _____ environment. = ________________ EVOLUTION similar independently adapted

Whales are closely related to wolves, but don’t look or act much like them = divergent evolution Whales are distantly related to sharks, but look and act more like them = convergent evolution Conclusion: The pressure of the environment drives evolution

HOMOLOGOUS STRUCTURES- Forelimbs of all mammals share same arrangement of bones that can be traced to same embryological origin BIOLOGY by Campbell and Reece Prentice Hall Publishing©2005

TurtleAlligatorBirdMammal Ancient lobe-finned fish Section 15-3 EVOLUTION explains why certain characteristics in related species have an underlying similarity.

amnion /am·ni·on/ (am´ne-on) bag of waters; the extraembryonic membrane of birds, reptiles, and mammals, which lines the chorion and contains the fetus and the amniotic fluid

VESTIGIAL ORGANS Some homologous structures are vestigial and have no useful function even though they are still present. Examples: Hipbones and pelvis in whales and boa constrictors Cecum (appendix) in humans Skink legs

Most mammals have a pouch between their small and large intestine that contains bacteria to digest plants called a _____. In humans the cecum is shrunken and unused. It is our _________

Why grow a tail and then lose it? HUMAN EMBRYO _________________ Tail disappears at has a tail at 4 weeks about 8 weeks tail

Skinks are a type of lizard. In some species, legs have become so small they _______ ______ in walking. Why would an organism possess organs ___ ________________? One explanation: The ________ is present to make the organ, but ______ through ______________. If the organ is not vital to survival, then natural selection would not cause its elimination. no longer change over time has been lost little or no function with

5. _____________________ ________ of many animals with back- bones are very similar. Similarities in Embryology Image from:

It is clear that the same groups of _____________ cells develop in the same order to produce the same tissues and organs of all vertebrates, suggesting that they all _______ from a _______________. Image from:

Image from: BIOLOGY AP EDITION by Campbell and Reece; Prentice Hall Publishing© _______________ Similarities in ____ and ________ sequences suggest relatedness Similarities in DNA

Similarities in protein sequences suggests similarities in DNA Image from: Modern Biology by Holt, Rinehart, and Winston

MOLECULAR HOMOLOGIES All life forms share same genetic machinery (DNA & RNA) Universal genetic code Important genes share highly conserved sequences

Similar _________ suggest an ___________________. Human: Chimpanzee: Middle School Life Science, published by Kendall/Hunt. Human- 46 chromosomesChimpanzee- 48 chromosomes evolutionary relationship

Even differences show relatedness Human: Chimpanzee: Middle School Life Science, published by Kendall/Hunt. Human- 46 chromosomes Chimpanzee- 48 chromosomes Chimpanzees have 2 smaller chromosome pairs we don’t have Humans have 1 larger chromosome pair (#2) they don’t have.

1. ________________________ If you take the two smaller chromosomes apes have that we don’t, and place them end to end, the ______ _______________ to the #2 human chromosome __ ________________. BANDING PATTERN MATCHES banding we have that they don’t

2. ____________________ Chromosomes have special sequences called _______ at their ends to protect the strands during replication. TELOMERES IN MIDDLE

2. TELOMERES IN MIDDLE Telomere sequences are found __________ and __________ of human chromosome #2 suggesting it was made by _____ two other chromosomes together. → → → ALSO IN THE

3. _________________ Chromosome #2 has a second __________ _____________ region → EXTRA CENTROMERE

What do oranges, broccoli and Butterball turkeys have to do with EVOLUTION? (Answers to come in this slide show!) THINK ABOUT IT

Did you ever wonder why dogs and cats don’t need to eat ________, but _______? YOU DO

Fish, amphibians, reptiles, and most mammals can make their own _________, but humans need to eat fresh fruit or they end up with ________.

Human DNA contains the gene that codes for the enzyme to make vitamin C, but it is ________________. Guess what other group of organisms lack the ability to make their own Vitamin C? ______________ which includes chimpanzees, orangutans, gorillas, and other apes.

Humans have many other nonfunctional vestigial genes called ________________. EX: Humans have more than 99 different odor receptor genes, but more than 70% of them are ___________.

WHY DOES EVOLUTION MATTER NOW? There is a natural variation in populations of peppered moths. ________________ ___________________ 7.____________________________ EX: Peppered Moths Typica form - lighter Carbonaria form - darker Typica Carbonaria

The ___________ form was the predominant form in England _____________________________. Around the middle of the 19 th century the ______ form began to appear. It was first reported in By % of the moths in Manchester were the ____ variety. In recent years, the burning of cleaner fuels and Clean Air regulations has reduced the pollution there and the ______ colored moths have increased in numbers. prior to the Industrial Revolution dark

BIOLOGY by Campbell and Reece We can see Natural selection happen

BIOLOGY by Campbell and Reece We can see Natural selection happen

7.____________________________ EX: Changes in disease-causing microbes that produce new organisms and __________. _______ ___ ________________ Can see Natural selection happen tuberculosis

Slide by Kim WE CAN SEE NATURAL SELECTION HAPPEN

Should the Use of Antibiotics Be Restricted? Read the Issues in Biology article on p. 403 in your text. Then watch the video Why Does Evolution Matter Now?Why Does Evolution Matter Now? and discuss the question: Should the use of antibiotics be restricted?

Slide by Kim