Fossil Formation and Significance

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Questions and Answers

Which pair of nitrogen bases differs between the hippopotamus and humpback whale DNA?

C and G

G and T

T and C (correct)

T and A

What type of evidence supports the idea that modern whales are descended from land-dwelling mammals?

Only fossil evidence

Fossil evidence and DNA similarities (correct)

Structural similarities only

Geological changes exclusively

Which feature of modern whales indicates adaptation for swimming underwater?

Presence of hind limbs

Continuous breathing ability

Small tail fins

Large dorsal fins (correct)

What are fossil remains referred to as?

Ancestral remains Signup and view all the answers

Which statement is true regarding the relationship between DNA and evolutionary history?

DNA can reveal how closely related two organisms are Signup and view all the answers

What do structural similarities in bones across different species suggest?

Universal ancestry Signup and view all the answers

What aspect of evolution is supported by the variety of fossils found in layers of rock?

Change over time in living organisms Signup and view all the answers

Which of the following indicates unused structures in modern whales?

Tiny hip bones Signup and view all the answers

What is suggested by the similar number and arrangement of bones in a human arm and bat wing?

Common ancestry Signup and view all the answers

Which of these statements about whale evolution is correct?

Whales evolved from land-dwelling ancestors Signup and view all the answers

What does the fossil record primarily show us about organisms?

Information about the age and evolution of species Signup and view all the answers

What is a key characteristic of Ambulocetus natans?

It had limb adaptations for both swimming and walking. Signup and view all the answers

What can be inferred if a coral fossil is found on land?

The area was once covered by water. Signup and view all the answers

Which transitional character distinguishes Tiktaalik roseae from fish?

It had limbs capable of supporting weight. Signup and view all the answers

Which species is known as a transitional form between land mammals and aquatic whales?

Pakicetus Signup and view all the answers

What evidence is used to show the evolutionary relationship of whales and hoofed mammals?

Similar DNA sequences Signup and view all the answers

What happened to the pelvic bones found in modern whales?

They do not aid in locomotion anymore. Signup and view all the answers

What type of fossil preserves small organisms trapped in tree resin?

Amber fossil Signup and view all the answers

What is a common ancestor in the context of evolution?

An extinct species that is related to multiple current species Signup and view all the answers

In what way do the embryos of cats and chickens show evolutionary connection?

They share similar body shapes and early developmental stages. Signup and view all the answers

What is the primary process by which most fossils are formed?

Being covered by sediment or mud Signup and view all the answers

Which statement best describes how sedimentary rock is formed?

When particles of sand or soil are deposited in layers Signup and view all the answers

What does the principle 'the deeper it is, the older it is' imply about rock layers?

Younger layers form below older layers Signup and view all the answers

What are transitional fossils?

Fossils that document the transformation between two groups of organisms Signup and view all the answers

What evidence suggests that snakes and lizards share a common ancestor?

Snakes have traces of leglike structures. Signup and view all the answers

How do fossils provide evidence of evolution?

By indicating relationships between extinct and present-day organisms Signup and view all the answers

Why is it rare for an organism to become a fossil?

Dead organisms are usually recycled by scavengers and decomposers Signup and view all the answers

What is indicated by similar bone structures in different species, such as humans, cats, and bats?

The species share a common ancestor. Signup and view all the answers

What does the fossil record represent?

The order in which species have existed and changed over time Signup and view all the answers

How does DNA evidence support the theory of evolution?

Similar DNA sequences indicate a more recent common ancestor. Signup and view all the answers

What role does the fossil record play in supporting evolution?

It provides evidence of when and where ancestors lived. Signup and view all the answers

How are fossils in newer rock layers typically characterized?

They tend to share physical or molecular similarities with present-day organisms Signup and view all the answers

What occurs when an organism completely rots away after being covered?

It leaves an imprint of itself in the rock Signup and view all the answers

What does the presence of homologous structures in different species suggest?

The species share a distant common ancestor. Signup and view all the answers

What often creates gaps in the fossil record?

Periods of geologic time with no fossil discoveries Signup and view all the answers

Which statement about cytochrome c proteins is true?

Fewer amino acid differences suggest a closer relationship. Signup and view all the answers

What evolutionary concept does the term 'common ancestor' refer to?

The most recent species from which two different ones evolved. Signup and view all the answers

What can be concluded about organisms showing structural traits that are reduced in size?

These structures were likely essential in their ancestors. Signup and view all the answers

Which of the following best illustrates the concept of gradual evolution?

Fossils that show intermediary features between species. Signup and view all the answers

How do developmental patterns contribute to the evidence of evolution?

Similar developmental patterns indicate shared ancestry. Signup and view all the answers

Study Notes

How Fossils Form

Fossils are the remains or traces of once-living organisms.
Sedimentary rocks are formed when sand or soil particles are deposited in layers.
Older layers are below younger layers ("deeper it is, the older it is").
Fossils often form in sedimentary rock.
Organisms are covered by sediment, which hardens over time.
Minerals in the sediment may replace the organism's materials, creating a cast fossil.
If an organism rots completely, an imprint of it might be left in the rock.
Fossils are recycled by scavengers, decomposers, or weathering.

Fossils and Change Over Time

Fossils make up the fossil record, showing when species existed and how they changed.
Scientists use the fossil record to learn about Earth's history of life.
The fossil record shows gaps in the known time period; transitional fossils help fill those gaps.
Transitions between different groups of organisms may not be well understood.
Fossils in newer layers are more similar to modern organisms than fossils in older layers (similarities indicate close relatives).

Evidence Supporting Evolution

Many fields study evidence of shared ancestors of modern and extinct species.
Structural similarities (reduced structures or similar structures with different functions) suggest a common ancestor.
Similar DNA sequences suggest a common ancestor.
The greater the similarities between DNA molecules, the more recent the common ancestor.
DNA determines amino acids that make up proteins, so comparing these similarities helps to determine relatedness.

Fossil Evidence of Whale Evolution

Extinct species have features found between whales and land mammals. These transitional features show a gradual change from land mammals to aquatic whales.
Pakicetus: (52 million years ago) whale-shaped skull and teeth, adapted for hunting fish; walked on four legs.
Ambulocetus: (50 million years ago) named "walking whale", adapted for swimming, a fish eater.
Dorudon: (40 million years ago) lived in the sea, had a long tail, tiny hind legs, could not use hind legs for walking.
Modern whales have pelvic and leg bones which are now useless, but show evolutionary links to land mammals.

Additional Fossil Information

Fossils show dinosaur appearance, the remains or traces of living organisms that occurred millions of years ago.
A fossil record is an account that preserves information about events.
Amber fossils form from sap hardening around creatures.
Transitions between organisms can be seen in Tiktaalik roseae, a creature that had characteristics from fish and four-legged land vertebrates.
Ancestors of amphibians and mammals can be observed in fossils.
Comparative anatomy examines similar body structures.
DNA similarities can identify common ancestors.
Comparing amino acid sequences can show how closely organisms are related by analyzing slight differences.

Additional Questions and Answers

How do fossils show evolution?
- Fossils show how life has changed over time by demonstrating intermediate features or gradual changes in organisms over time.
How can you determine how closely related two organisms are?
- Comparing DNA or identifying similar structures (anatomy) can help determine how closely related two organisms are.
What do unused structures provide evidence of?
- Unused structures on an organism can be evidence of an evolutionary process where a trait that was once necessary is no longer being used in the same way.

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Description

This quiz covers the process of how fossils form and their importance in understanding Earth's history. Explore topics like sedimentary rocks, fossil records, and how fossils illustrate the changes in species over time. Perfect for students learning about geology and paleontology.