2. Evolution Central theme of Biology Look at any organism
Differences from other other organisms
Organism features show some relationship to where organism lives and what it does in its environment

3. Clown, Fool, or Simply Well Adapted?
All organisms have evolutionary adaptations
Inherited characteristics that enhance their ability to survive and reproduce
Universal characteristic of living things.
The blue-footed booby of the Galápagos Islands has features that help it succeed in its environment
Large, webbed feet help propel the bird through water at high speeds

4. Specialized salt-secreting glands manage salt intake while at sea
A streamlined shape, large tail, and nostrils that close are useful for diving
Specialized salt-secreting glands manage salt intake while at sea

5. 13.1 A sea voyage helped Darwin frame his theory of evolution
EVIDENCE OF EVOLUTION
13.1 A sea voyage helped Darwin frame his theory of evolution
Anaximander suggested all life from water, and simpler forms came before more complex.
Aristotle, and tater advanced by the Judeo-Christian culture, believed that species are fixed or were created about 6000 years ago, and did not evolve
Buffon thought the earth was older, and thought different species from common ancestors (later changed mind)
Fossils suggested that life forms change
This idea was embraced by Lamarck in the early 1800s
Mechanism for change was inheritance of acquired characteristics.
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6. similarities between living and fossil organisms
While on the voyage of the HMS Beagle in the 1830s, Charles Darwin observed
similarities between living and fossil organisms
the diversity of life on the Galápagos Islands, such as blue-footed boobies and giant tortoises
Figure 13.1A

7. The voyage of the Beagle
Great Britain
Europe
North America
Pacific Ocean
Atlantic Ocean
Africa
Galápagos Islands
Equator
South America
Australia
Andes
Cape of Good Hope
Tasmania
Cape Horn
New Zealand
Tierra del Fuego
Figure 13.1B

8. Darwin became convinced that the Earth was old and continually changing (He was influenced by Lyell).
Compared fossils on the different Galapagos Islands to each each.
Compared fossils on the Galapagos to fossils in S. America.
He concluded that living things also change, or evolve over generations
Wallace conceived same theory based on observations in Indonesia. Both presented work to scientific community
Darwin also stated that living species descended from earlier life-forms: descent with modification, encapsulates idea of evolution

9. The history of life is like a tree
You have a base that grows and eventually branches out. Species on one branch are closer related than species on another branch

11. 13.2 The study of fossils provides strong evidence for evolution
Fossils and the fossil record strongly support the theory of evolution
Hominid skull
Petrified trees
Figure 13.2A, B

12. Fossilized organic matter in a leaf
Ammonite casts
Fossilized organic matter in a leaf
Figure 13.2C, D

13. Scorpion in amber
“Ice Man”
Preserved for 5000 yrs
Figure 13.2E, F

14. The fossil record shows that organisms have appeared in a historical sequence.
These are layers of sedimentary rock, formed from accumulation of waterborne sediments
Younger strata on surface with more recent organisms
Oldest fossils, prokaryotes, date back to 3.5 billion years ago in bottom layers of strata.
Ongoing sequence of intermediate steps going from simple to more complex
Figure 13.2G, H

15. Many fossils link early extinct species with species living today
These fossilized hind leg bones link living whales with their land- dwelling ancestors

17. 13.3 A mass of evidence validates the evolutionary view of life
Other evidence for evolution comes from
Biogeography
Related life forms around world
Island species look like closest mainlaind, not always closest island
Comparative anatomy (all basic limb structure)
Comparative embryology (all vertebrates and chordates had gill pouches in throat region
Human
Cat
Whale
Bat
Figure 13.3A

18. Molecular biology Universality of genetic code
Similar homeotic genes in different species
Human
Rhesus monkey
Mouse
Chicken
Frog
Lamprey
Last common ancestor lived 26 million years ago (MYA), based on fossil evidence
80 MYA
275 MYA
330 MYA
450 MYA
Figure 13.3B

20. 13.4 Darwin proposed natural selection as the mechanism of evolution
DARWIN’S THEORY AND THE MODERN SYNTHESIS
13.4 Darwin proposed natural selection as the mechanism of evolution
Darwin observed that
organisms produce more offspring than the environment can support
organisms vary in many characteristics, expression of traits
these variations can be inherited, genetic

21. Darwin saw natural selection as the basic mechanism of evolution
Darwin concluded that individuals best suited for a particular environment are more likely to survive and reproduce than those less well adapted
Darwin saw natural selection as the basic mechanism of evolution
As a result, the proportion of individuals with favorable characteristics increases
Populations gradually change in response to the environment

22. This is called artificial selection
Darwin also saw that when humans choose organisms with specific characteristics as breeding stock, they are performing the role of the environment
This is called artificial selection
Example of artificial selection in plants: five vegetables derived from wild mustard
Figure 13.4A

23. Example of artificial selection in animals: dog breeding
English springer spaniel
German shepherd
Yorkshire terrier
Mini-dachshund
Golden retriever
Hundreds to thousands of years of breeding (artificial selection)
Ancestral dog
Figure 13.4B

24. Thousands to millions of years of natural selection
These five canine species evolved from a common ancestor through natural selection
African wild dog
Coyote
Fox
Wolf
Jackal
Thousands to millions of years of natural selection
Ancestral canine
Figure 13.4C

25. Two important point’s from Darwin’s theory of Natural Selection
Ancestral species gave rise to diverse life forms by transfer of heritable traits to offspring that best promote reproduction = “descent with modification
Over vast amounts of time, gradual accumulation of changes in the characteristics among the individuals in a population changes

26. 13.5 Connection: Scientists can observe natural selection in action
Evolutionary adaptations have been observed in populations of birds, insects, and many other organisms
Example: camouflage adaptations of mantids that live in different environments
Figure 13.5A

27. Insecticide application
The evolution of insecticide resistance is an example of natural selection in action
Apply same theory to antibiotics – don’t finish, build up of bacterial resistance
Insecticide application
Chromosome with gene conferring resistance to insecticide
Additional applications of the same insecticide will be less effective, and the frequency of resistant insects in the population will grow
Survivor
Figure 13.5B

28. Natural selection is regional and timely
Natural selection is regional and timely. Populations tend to evolve in response to environmental conditions during one time period
Change can occur in very short periods of time, think of life span or life cycle of organism
Or over long periods of time

29. 13.6 Populations are the units of evolution
A species is a group of populations whose individuals can interbreed and produce fertile offspring
Human populations tend to concentrate locally, as this satellite photograph of North America shows
The modern synthesis connects Darwin’s theory of natural selection with population genetics
Figure 13.6

30. Evolution is measured as a change in frequency of a given characteristic within a population over succession of generations.
i.e. Height, average goes up, humans are evolving to be taller as a species
Opportunities for breeding among a population varies depending on species and isolation of certain populations. City vs. Forest

31. 13.7 Microevolution is change in a population’s gene pool over time
A gene pool is the total collection of genes in a population at any one time
Microevolution is a change in the relative frequencies of alleles in a gene pool
Frequencies of alleles governing characteristics change
Insect resistance. Insects with resistance alleles w/ higher frequency then insects with minimal resistance alleles depending on if a field sprayed with pesticide or not