Extinctions and Fossils

Week 27-Life Science

In you notebook, list every animal you can think of that has gone extinct in the past 200 years…

Why do animals go extinct?

Turn to your neighbor. Ask or tell them… (2 minutes)

A brief intro to

Geologic Time

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Like days, months, years…but MUCH bigger.

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Periods, Eras, and Eons

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We “define” them by when major events happen.

Types of Fossils

Body Fossils

• Usually not the whole organism and mostly hard stuff
• Bones, teeth, shells, wood
• Sometimes soft stuff
• Skin, organs, leaves, fruit, seeds

Trace Fossils

• Evidence of living things
• footprints, burrows, trails, and coprolites (poop)

Chemical Fossils

• Organic compounds (macromolecules!) in rock
• lipids, hydrocarbons, amino acids

Preservation Bias

NOT EVERYTHING FOSSILIZES!

Preservation Bias

• Fossils only in sedimentary rock
• Animals in water are more likely to fossilize
• Hard parts more likely to be found
• Observers look for cool big things…
• Location bias (more likely to find them in warm dry places than Antarctica)

The Anthropocene: Another extinction?

https://media.hhmi.org/biointeractive/click/anthropocene/

Choose an animal from the video

(rewatch if necessary)

What do you think its:

1. predicted habitat
2. ecosystem
3. diet
4. reproduction habits

and

• reason for the extinction was?

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Record your answers on Page 5 (your side)