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A Little Bit More

Of course, this important discovery was made by a well-known biologist – NOT! It’s refreshing to realize that this discovery was made by a young graduate school student who was observant, curious and persistent. Daphne Soares was a graduate student at the University of Maryland when she noticed the bumps on an Alligator and began trying to find someone who knew their function. She quickly realized that no one knew what the bumps did so she began her own exploration of this anatomical puzzle. After careful research, Ms. Soares was able to show that these dome-shaped bumps were special sensory receptors that she calls Dome Pressure Receptors or DPR.

Once Ms. Soares was able to target the function of the American Alligator’s DPR, it was a logical step to look at other living crocodilians (there are 22 other species in the crocodile family) from around the world and she soon learned that they too had DPRs. Then Ms. Soares took it a step further and looked at fossil crocodilians. Knowing that there was a network of nerves beneath the DPR that fed the brain through pathways in the skull, she could study fossil skulls and look for these same nerve pathways. Her diligence paid off and she was able to find these same nerve pathways in extinct crocodilians that lived 200 million years ago (that’s back to the Jurassic period!).

No one is claiming that discovering basic new information about our world is easy, but the questions and answers are right in front of us – we just need to ask the right questions and follow–up with good research. So, keep your eyes open and the more you learn about animals and plants, the better your observations and questions will be and who knows where that might lead?

Activities

Science - Five Senses

Test your five senses

We all take our senses for granted, I’m sure, but it never hurts to focus on them from time to time and renew our amazement at their value. Here are some activities that aren’t very special but do help us focus on our senses. Walk your students through one or more of these to help them better understand what our senses are and exactly what or how they help.

1. Taste – sour/sweet/salt/bitter/umami — Point out to your students, that our taste is in our mouth, literally, but MOST of what we actually consider “taste” is really smell. The four tastes that our tongue CAN distinguish are sour, sweet, salt, and bitter.

1. Crush a sourball and place it on the tongue of a subject. Try placing it on the front, then sides, then back, then middle of the tongue to see where it registers SOUR
2. Place a small amount of sugar on the front, then sides, then back, then middle of the tongue to see where it registers SWEET
3. Place a small amount of salt on the front, then sides, then back, then middle of the tongue to see where it registers SALTY
4. Place a small amount of baker’s unsweetened chocolate on the front, then sides, then back, then middle of the tongue to see where it registers BITTER
5. Place a small amount of monosodium glutamate on the front, then sides, then back, then middle of the tongue to see where it registers UMAMI

2. Touch — Students may find it surprising that we don’t feel things evenly over our body. Some areas of our body have especially dense touch receptors while others have touch receptors that are widely spaced. Have a willing subject close their eyes while someone uses a protractor (anything that can hold two points at a steady distance) to see how well the subject can discern the sense of touch. The object here is to try and feel 2 different touch points on your skin. The variations will be with the distance between protractor points – the closer the distance between the points that can be felt as 2 points, the better your sense of touch on that area. Areas to try include:

1. Back of the hand
2. Palm of the hand
3. Back of the neck
4. Between the shoulders
5. Elbow
6. Forearm
7. Lips
8. Forehead

3. Eyesight — It’s well known that not everyone has good eyesight – after all, many need glasses to see clearly. But it may not be so obvious that even with good eyesight or glasses, we don’t all see the same. Take multiple objects (posters or other printed material) that have the same size lettering on them and place them at random distances from the subject to be tested. If you have 6 different 8X10 sheets of paper with the same size lettering but a different sentence on each, space these out along your testing pathway. Now have your subjects see how well they can read the closest, the next closest and so on to see just how acute their vision is. Note at what distance they can no longer read a sentence for each of your subjects. Be sure if there are adults available that you try them as well – the adults will undoubtedly have poorer vision, even with their glasses on.

4. Smell — Try having each student hold their nose and eat something (nothing yucky) sight-unseen that you offer. Once they chew and swallow, ask them to tell you what they just ate. It should become quickly apparent that without the ability to smell, few foods are distinguishable. What we think of as “taste”, is in large part, smell!

5. Hearing — This is the easiest one to perform - you may find it a bit upsettling when you realize your own hearing isn’t what you thought. In a very quiet room have students experiment first with one ear then the other. Have each student hold their right hand close to their right ear and rub the index finger and thumb together. This should produce an audible “sandpaper” sound. Now have each student continue rubbing their fingers together while slowly moving their hand farther and farther from their ear until they can’t hear the rubbing sound anymore. Now have each student do the same on the other ear. It’s likely that you’ll find that one ear can hear this found farther from the ear in question than the other. Adults may find that their hearing distance for this exercise is much shorter than the childrens’ distances.

Here are a couple of websites that have similar exercises you may find more to your liking than what I’ve provided:

1. Five Senses website for exercises
2. Kindergarten Lessons on the Five Senses
3. Info on monosodium glutamate

Key Concepts

Adaptations and Diversity, Scientific Method/Approach, Structures and Functions

Questions

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