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For each of the following "tiles" in this timeline, read the brief information provided.  They are numbered in order from 1 to 7. Please view and respond in order. There is a checkpoint at the end of each tile that asks you a question that you will respond to.  You can respond by clicking on the little speech bubble in the lower right hand corner of the tile.

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It may be difficult to imagine when looking at a tiny newborn baby, but that infant has around 300 bones — and those bones are growing and changing shape every day.

Adults, on the other hand, have 206 bones, which make up about 15 percent of their body weight.

Wait — did we really just say that babies have nearly 100 more bones than adults? How is that possible?

Well, even though bones appear to be tough and rigid, they’re actually made up of living tissue and calcium that’s always being built up and discarded throughout your life.

Let’s take a closer look at how this explains the discrepancy between a baby and you.

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2. Just Born! How many bones does a baby have?

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2. Just Born! How many bones does a baby have?

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When you were a baby, you had tiny hands, tiny feet, and tiny everything! Slowly, as you grew older, everything became a bit bigger, including your bones.

A baby's body has about 300 bones at birth. These eventually fuse (grow together) to form the 206 bones that adults have. Some of a baby's bones are made entirely of a special material called cartilage (say: KAR-tel-ij). Other bones in a baby are partly made of cartilage. This cartilage is soft and flexible. During childhood, as you are growing, the cartilage grows and is slowly replaced by bone, with help from calcium.

The fusing of bones occurs throughout the body. You may notice that there are one or more soft spaces in between the bones in a baby’s skull. These “soft spots” may even freak you out a bit, but they’re perfectly normal. They’re called fontanelles, and they’ll eventually close as bones grow together.

Checkpoint: Explain how this information could be used by forensic anthropologists to determine the age of bones at the time of death?

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3.  What happens to bones during childhood?

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3.  What happens to bones during childhood?

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During childhood, bones thicken, ossify, and grow longer, resulting in fewer bones in adulthood.

Checkpoint:  What does "ossify" mean?

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Checkpoint:
a. What is a growth plate?
b.  How does the presence or the absence of a growth plate help anthropologists determine age of bones?

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5.  How do bones change throughout our lifetime?

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5.  How do bones change throughout our lifetime?

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Throughout our lifetime, bones are always being produced, repaired, and broken down. As we age, this process goes in "REVERSE"... Bones LOSE minerals and break down FASTER than they are being built up.

Checkpoint:  Complete this statement with the proper words.
Bones increase in length until the __________________ is ossified (when bone replaces cartilage).

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6.  What happens to our bones after age 25-30?

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6.  What happens to our bones after age 25-30?

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After age 25-30, the process begins to reverse; bones lose minerals and break down faster than they are built. The whole bone building and rebuilding process SLOWS down.

Checkpoint:  What is the name of the disease that causes bones to become weak and brittle — so brittle that a fall or even mild stresses such as bending over or coughing can cause a fracture.   This can occur in elderly people as a result of the bone building process happening in reverse.

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7.  Checkpoint Summary: Summarize what you have learned by responding to this question:  

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7.  Checkpoint Summary: Summarize what you have learned by responding to this question:  

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How can the information you have learned be used to solve a crime when unidentified bones are used as evidence?