Count the "F's" in the following text:

FINISHED FILES ARE THE RE-SULT OF YEARS OF SCIENTIF-IC STUDY COMBINED WITH THEEXPERIENCE OF YEARS...

How many?3?

No……6.

Really.

The brain cannot process "OF".Incredible or what ?

Anyone who counts all 6 "F's" on the first go is a genius.

Three is normal, four is quite rare.

Microevolution focuses on

studying genetic variation due to recombination,

gene flow, genetic drift, natural selection, and

mutation at the species and

subspecies level.

Macroevolution refers to major evolutionary

changes over time, the origin of new

types of organisms from previously

existing, but different, ancestral types. Examples of this would be fish

descending from an invertebrate animal,

or whales descending from a

land mammal.

Adaptation is brought about by cumulative natural selection. Small

changes, favored by selection, can be the stepping-stone to further changes. The summation of large numbers of these

changes is what we think of as evolution.

Fossils provide an actual record of Earth’s past

life-forms. Change over time (evolution) can be

seen in the fossil record. Fossilized species

found in older rocks are different from those

found in newer rocks.

,

Fossils of early

multicellular life-forms,

such as the crinoid, occur

in 800-million-year-old

rocks found in Indiana.

Fossils of the pterodactyl,

an extinct reptile, occur

in 140- to 210-million-

year-old rocks.

Whales are thought to have evolved from an

ancestral line of four-legged mammals

represented here by their fossils and

artistic reconstructions showing what scientists

think that they may have looked like.

Comparisons of the anatomy of different types of organisms

often reveal basic similarities in body structures even though

the structure’s functions may differ between organisms.

Humans Penguins

Alligators

Bats

These changes are due to mutations

and natural selection. As species

evolved, one change after another

should have become part of their

genetic instructions. Therefore,

more and more changes in the

organisms DNA should build up

over time.

By studying fossils, By studying fossils, scientists can learn scientists can learn about the diversity about the diversity

of life and about the of life and about the behavior of ancient behavior of ancient

organisms.organisms.

About About 95 percent 95 percent

of the species that of the species that have existed are have existed are

extinct they no longer extinct they no longer live on Earth.live on Earth.

Relative DatingRelative Dating

• Scientists use a Scientists use a variety of variety of methods to methods to determine the determine the age of fossils. age of fossils. One method is a One method is a technique called technique called ““relative datingrelative dating””..

Its not just in Arkansas anymore!

Relative Dating cont.Relative Dating cont.

• If the rock layers have not If the rock layers have not been disturbed,been disturbed,

the layers the layers at the at the surface surface must be must be younger younger than the than the deeper deeper layers.layers.

• Break into 6 Break into 6 equal lab equal lab groups and groups and read about read about the Law of the Law of SuperpositioSuperposition.n.

• Paste a copy of the land Paste a copy of the land formations in your notebook formations in your notebook and work as a group to answer the and work as a group to answer the questions at the bottom of the questions at the bottom of the handouthandout..

1. Do you think the pattern of change shown by the horse teeth supports this hypothesis? Why or why not?

(Yes, because you can see a change from low crowns above the root of the tooth to a very tall crown.)

2. How would you test this hypothesis?

(study the teeth of living herbivores for similar patterns; study the teeth of other herbivore fossils found with the fossil horses for similar patterns)

1. Which layer is the oldest in each formation? How would you know if these two layers are the same age?

E is the oldest layer in Formation 1. C is the oldest layer in Formation 2.

The two layers would be of the same age if they have similar compositions and fossil records.

2. Suppose fossils from layer C in Formation 2 are the same as fossils from layer D in Formation 1. What could you say about the age of fossils from Layer E?

Since layer E lies beneath layer D, fossils from layer E must be older than those in layers D and C.

They are older than the fossils in layers D and C

3. Suppose you also found that layers C and B' shared similar fossils. Layers B and A' look very similar, but contain no fossils. What could you say about the relative ages of all layers of both formations?

Because layers C and B are probably the same age and layers D and C are the same age, B and A are likely the same age. Layer A is probably the newest because it is deposited on layer B, which is the same age as A and younger than C and B, which are younger than D and C, which are younger than E.

4. Suggest one or more geological events that might explain why Formation 2 has fewer layers than Formation 1.

Deposition of sediment may have begun later in Formation 2. The top layer of Formation 2 may have been eroded by wind or water or may have fallen away in a landslide.

Relative Dating cont.Relative Dating cont.

• The fossils in the top layer must The fossils in the top layer must also be younger than those in also be younger than those in deeper layers. deeper layers.

• Using this Using this principle, principle, scientists can scientists can determine determine relative age and relative age and the order of the order of appearance of appearance of the species that the species that are preserved as are preserved as fossils in the fossils in the layers.layers.

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Begin by reading the introduction to the Where The Hippos Roam Lab Activity.

Read the Problem from the

bottom half of page 2

and use the data table at

the top of the page to

complete the grid on the

following page.

Complete the grid based on the information you

gathered from page 2 of the lab handout.

Answer the analysis question usig complete

sentences