Your Inner Fish Chapter 1 Flashcards

Questions and Answers

What has Shubin spent many summers in the Arctic doing?

Looking for fossil fish

What are fossils the only way to see? Because of this, what are they a key part in understanding?

What life was like on Earth in the distant past; How life developed into human life

What do fish give fundamental clues for?

Understanding the human body

Although other scientists might think that fossils are a dead area of science, what does Shubin draw connections from the ancient fossils to?

Contemporary humans; Modern anatomy Signup and view all the answers

Where is Ellesmere Island located (latitude)? Here, what does Shubin find?

80 degrees north; A fossil fish with a flat head Signup and view all the answers

Why is this fossil fish with a flat head important?

Because it suggests that the fish probably lived in shallow water, an important move from living in deep water to living on land Signup and view all the answers

Why are fossils in some ways easier to find than they once were?

New technology allows paleontologists to scan potential field sites before digging Signup and view all the answers

Because fossils are still fragile, digging must be laborious and _ by hand in landscape with _ conditions.

time-consuming; harsh terrain and weather Signup and view all the answers

What are the three things that fossil sites depend on?

Right age; Right type; Right exposure Signup and view all the answers

To look for fossils from the transition between water animals and land animals, what rocks does Shubin have to find?

Rocks that are older than 365 million years old Signup and view all the answers

What does the arrangement of rock layers on Earth leave?

A relatively stable timeline with the oldest rocks on the bottom and more recent rocks on the top Signup and view all the answers

In the timeline of fossil layers, what is _____? What is deep? What is in the middle?

Jelly-fish type creatures; Various animals with skeletons; Humans Signup and view all the answers

What can help paleontologists predict which type of animal will be in each age of rock layer?

Looking at a zoo from today; By focusing on the traits that animals share Signup and view all the answers

What argument does Shubin make regarding which animals are the oldest?

Those with the 'simplest' body plan Signup and view all the answers

What does everything in a zoo have?

A head; 2 eyes Signup and view all the answers

Where does Shubin expect to find fossils with a head and two eyes in relation to fossils with a head, two eyes and limbs?

Below Signup and view all the answers

For the first fossils with limbs, what is the critical time period in rocks?

380 - 365 million years ago Signup and view all the answers

What do 360 million year old rocks already show?

Diverse life forms that look like modern day amphibians Signup and view all the answers

What are found at rock layers 385 million years old?

Fish Signup and view all the answers

What is the best type of rock for finding fossils?

Sedimentary rock Signup and view all the answers

What have sedimentary rocks all over the world shown has changed significantly over time?

Geography; Climate Signup and view all the answers

How do sedimentary rocks form?

By pressing small rocks, pebbles, and sand together with enough force that the rocks fuse into a solid layer Signup and view all the answers

Where do sedimentary rocks typically form?

In stream beds or areas with water Signup and view all the answers

What is the last step for choosing a fossil site?

Finding a layer of sedimentary rocks of the right age that is not covered by human settlements Signup and view all the answers

What do desert winds help do?

Wear away rock; Expose possible fossils Signup and view all the answers

When Shubin starts his fossil-finding expedition researching the origin of limbs in PA, what does he discover the Catskill Formation of PA holds?

Rocks from the Late Devonian Period that contain valuable fish specimens Signup and view all the answers

What did Shubin and one of his students, Ted Daeschler, check sites of?

Exposed rock recently blasted by the PA Dept of Transportation Signup and view all the answers

When was the Devonian Period?

420 million to 358 million years ago Signup and view all the answers

What does the hynerpeton have?

A very primitive limb Signup and view all the answers

When looking at a geology textbook, what do Shubin and his student notice that rocks from the Devonian Period are also in?

The Alaskan Yukon; The coast of Greenland; The Canadian Arctic Signup and view all the answers

Where did Shubin and his student decide to go?

Canada Signup and view all the answers

What do the rocks from the Devonian period show about Arctic areas such as Greenland and Alaska?

They were once temperate forests with streams fit for small amphibians like hynerpeton Signup and view all the answers

What do Shubin and his student maximize for mounting a fossil expedition?

By going to an area that has not yet been covered Signup and view all the answers

What three dangers come with an expedition to the Arctic?

Local wildlife; Unpredictable weather; Limited ability to carry supplies Signup and view all the answers

What does Shubin spend the first few weeks at the dig site worrying about?

Polar bears Signup and view all the answers

In 1999, what do Shubin and his team find?

Plenty of fish fossils from deep water Signup and view all the answers

In 2000, where do Shubin and his team move their dig site?

East to Ellesmere Island Signup and view all the answers

Where does Shubin's whole team go?

To the river bed where Downs identified these fossils Signup and view all the answers

What are found at rock layers 365 million years old?

Species that have already been documented Signup and view all the answers

Even though the fish fossils they found were already catalogued, why is finding something better than nothing?

In terms of continuing to receive funding for these Arctic missions Signup and view all the answers

In 2004, what do Shubin and his team do?

Make one last trip to the Arctic Signup and view all the answers

What does Shubin find?

A fish fossil fragment with a jaw that suggests the fish has a flat head Signup and view all the answers

Over the next two months, what do fossil preparators do?

Meticulously expose this fossil from the rock Signup and view all the answers

What did Shubin and Gatesy's discovered animal have that relates it to a fish?

Scales Signup and view all the answers

Why is Shubin and Gatesy's fish special?

Because it blends traits that previously appeared only in animals that live solely in water with traits that appear in animals that live in land and water Signup and view all the answers

What is Shubin and Gatesy's fish an indirect ancestor for?

All animals that now live on land Signup and view all the answers

What idea is Shubin and Gatesy's fish a huge success for?

The idea that there is a transitional stage between fish and amphibians at the 375 million year time period Signup and view all the answers

Who did Shubin and his team decide to thank?

The Inuit people Signup and view all the answers

What were the two potential names for Shubin and Gatesy's fish?

Siksagiaq; Tiktaalik Signup and view all the answers

When Shubin takes the Tiktaalik fossil to his son's show and tell, and one child asks if the fossil is a fish or a crocodile, what does another child respond with?

It can be both Signup and view all the answers

What does how the Tiktaalik shows human's history as fish compare to?

How 'Lucy' shows human's history as highly advanced primates Signup and view all the answers

What does human anatomy result from?

Millenia of small shifts in the bone structure of all animals Signup and view all the answers

Why does Shubin stress that Tiktaalik is just as important in the entire story of human development?

Because Lucy would have never developed if fish like Tiktaalik had not paved the way for animals to live on land Signup and view all the answers

Study Notes

Fossil Discoveries in the Arctic

Shubin spends summers in the Arctic searching for fossil fish, specifically in Ellesmere Island, located at 80 degrees north latitude.
Fossils serve as the only means to visualize ancient life and are crucial for understanding the evolution of species, including humans.
A significant fossil fish with a flat head indicates adaptation from deep water habitats to shallow waters, which is essential for the transition to land.

Fossil Excavation Techniques

Advanced technology allows paleontologists to scan potential sites, making it easier to locate fossils despite their fragile nature.
Fossils are often found in sedimentary rock layers that preserve them from destructive forces encountered in volcanic or metamorphic rock.
The fossilization process involves sediment compacting and mineral-rich water filling spaces in deteriorating biological materials.

Geological Context of Fossils

Fossil timelines are generally stable, with older rocks at the bottom, but can be disrupted by events like earthquakes.
Fossils reflect a progression from simple organisms to complex ones, often encompassing a timeline of millions of years.
Specific rock ages provide context for the evolution of limbs, showing the gradual transition from aquatic to terrestrial life.

Expedition Challenges

Expeditions to the Arctic present risks, including local wildlife and unpredictable weather, requiring expert guidance.
Shubin's team had to navigate vast and challenging landscapes, using previous discoveries as clues to optimize their fossil search.

Key Discoveries and Significance

In 2000, the team discovered fish fossils in layers indicative of shallow-water species, critical for bridging the evolutionary gap to land-dwelling animals.
The team found a partial fish fossil (Tiktaalik) with features linking it both to fish (scales) and land animals (limbs, neck), highlighting transitional evolution.
The discovery of Tiktaalik provides insight into the evolutionary shift to land, paving the way for the development of all terrestrial creatures.

Recognition and Impact

Tiktaalik symbolizes success in the search for intermediate species, affirming the theory of evolutionary transition during the Devonian Period (420-358 million years ago).
Shubin and his team honored the Inuit people by naming the fossil Tiktaalik, reflecting respect for the territorial heritage of the area.
The importance of fossils like Tiktaalik lies in their demonstration of shared anatomical features between aquatic and terrestrial organisms, essential for understanding human ancestry.

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Description

Explore the intriguing concepts introduced in Chapter 1 of 'Your Inner Fish'. These flashcards cover key ideas about fossils and their significance in understanding human evolution and the history of life on Earth. Test your knowledge and grasp the fundamental clues that fish provide about our anatomy and heritage.