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, but he did not publish his ideas because they ________ with the fundamental scientific beliefs 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 _______ for Darwin’s ideas about how living things change called __________________ On the Origin of Species

A __________is a well supported testable explanation of happenings in the _________ world Ex: gravitational theory atomic theory cell theory Isn’t evolution just a theory?

WHAT IS DARWIN’S THEORY? GENETIC___________ is found naturally in all populations

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

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

WHAT IS DARWIN’S THEORY? ___________ organisms which are better adapted to the environment will ______ and ________, passing on their _____. SURVIVAL OF THE survive reproducegenes

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

VOCAB Any ___________________ that increases an organism’s ______________ = _____________ inherited characteristic chance of survival

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?

___________ each species has descended with changes from other species over time. This idea suggests that all living species are related to each other. and that all species, living and extinct, share a _________________. WHAT IS DARWIN’S THEORY? WITH MODIFICATION COMMON ANCESTOR

EVIDENCE OF EVOLUTION: 1.____________ selection 2.________________ 3. ___________distribution 4. ___________ structures 5. _______________ 6. _______________ 7. see natural selection happen

ARTIFICIAL SELECTION WORKS Nature provides the____________ through _________ and _________ reproduction Humans select traits they find ______. EX: We have selected for and bred cows to produce more milk, turkeys with more breast meat, etc.

Breeds of Dogs Chihuahua – bred from Techichi of Mexico by Mayans, had religious significance Saint Bernard – bred by monks around 1050 A.D. to rescue travelers of mountain passes in the Swiss Alps between Italy and Switzerland Irish Wolfhound – bred in Ireland to hunt wolves and elk Dachshund – bred in Germany as early as the 15 th century to hunt badgers SLIDE FROM: BIOLOGY by Miller and Levine; Prentice Hall Publishing©2006

____________________________ BIOLOGY by Miller and Levine; Prentice Hall Publishing©2006 ARTIFICIAL SELECTION WORKS

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. The 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 Earth. The fossils in the rocks tell the history of ______ The fossils are the same age as the rock they are found in.

TRANSITIONAL FOSSILS HAVE BEEN FOUND Scientific American; Dec 2005; Vol 293; p

If Darwin’s theory is correct you would expect to find: Closely related yet different species living in a geographic region as they spread into nearby habitats and evolve. 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. =___________ evolution

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

If Darwin’s theory is correct: you would also expect to find different species living in similar habitats becoming ____________ as they adapt to where they live That’s EXACTLY what we do see!

Whales and sharks have a similar body design even though they are very different organisms (one is a fish; the other, a mammal) because they have both adapted to living in a similar environment. = ____________ evolution

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

4. ____________ structures Image from:

4. Homologous Body Structures – Structures that look different but are made from the same bones because they are made from the same embryonic cells Image from:

4. Homologous Body Structures – Some homologous structures are _______ and have no useful function even though they are still present Ex: ________in whales and boa constrictors

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? EX: ________in HUMAN EMBRYOS disappears at around 8 weeks

EX: Vestigial organs Skinks are a type of lizard whose ______ have become so small they no longer function in walking. Why would an organism possess organs that no longer work?.

One explanation: The genes to make the organ are present but have been mutated so they no longer have the information to make the part function.

5.Similarities in ____________ Vertebrate embryos look very similar. Image from:

Embryonic cells develop in the same order to produce the same tissues and organs of all vertebrates, suggesting that they all evolved from a common _______________. Image from:

Image from: BIOLOGY AP EDITION by Campbell and Reece; Prentice Hall Publishing© SIMILARITIES IN_______ Similarities in DNA and protein sequences suggest relatedness

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

1. ________PATTERN MATCHES If you take the two smaller chromosomes apes have that we don’t, and place them end to end: the banding pattern is ________ to the #2 human chromosome we have that they don’t

2. __________ in the middle Chromosomes have special sequences called telomeres at their ends to protect the strands during replication.

2. TELOMERES IN MIDDLE If two chromosomes were joined, you would expect to find telomere sequences in the middle. Human chromosome #2 has telomeres at the ends AND in the middle → → →

3. EXTRA _____________ If two chromosomes were joined, you would expect to find multiple centromeres. Human chromosome #2 has a second non-working centromere region →

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 fresh fruit, 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 ____________, but it is non-working. Guess what other group of organisms lack the ability to make their own Vitamin C? ______________ including 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 Can see Natural selection happen 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. light colored prior to the Industrial Revolution darker dark lighter

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