Extinct Animals
In Activity 4 we looked at ‘Archosaur Adaptations’ and how we can see evidence of adaptations of extinct animals from fossil records which gives us an understanding of how they lived.
Living organisms
All living organisms have bodies that are adapted for the places they live and the things they do. Today, the only living archosaurs are birds and the crocodilians. Crocodiles are adapted to life in the water by having long, streamlined bodies that help them swim, whereas most birds are adapted to life in the skies with feathered wings and very light bones. There are hundreds of examples of ways that organisms are adapted for a successful lifestyle. Fish have gills so that they can remove oxygen that is dissolved in water. Most plants have green leaves which contain chlorophyll so that they can make food. Jellyfish have stinging cells to capture prey. Artic animals have layers of fat and thick coats of fur to keep warm in the frigid Arctic climate.
Human Adaptations – The Human Hand
In this activity we are going to look at how humans (and other primates) are adapted for the things they do. One of our adaptations is the human hand.
In the first task you will perform several common actions. Then in the second task you will change your hand so that it resembles that of a non-primate animal and carry out the same actions. You will determine whether or not you can successfully perform the same actions which will demonstrate how the human hand is adapted to carry out the tasks it needs to.
What you need?
Clock or watch with second hand
Masking tape or strong sellotape
Piece of string
Bottle with a screw cap
A shirt or item of clothing with buttons done up
A door that is closed
Pen and paper
Blunt pencil and sharpener
A friend or family member (to help you with Task 2.)
What to do?
Task 1. Carry out each of the 6 ACTIONS on the data sheet and record the time it takes you to do each one in the Thumbs-Free part of the data sheet.
Task 2. Using masking tape or strong sellotape tightly tape each of your thumbs to the palm of the hand. (Ask someone to help you with this.) After your thumbs are securely taped, try each of the 6 activities again. Time each activity as you did before and ask your helper to record the time in the Thumbs-Taped part of the data chart. If an activity takes longer than 2 minutes, record it as unsuccessful.
DATA SHEET
What did you find out about human hands?
In this activity, you will have discovered that the simplest daily activities are only possible because human hands are able to grasp objects and handle them efficiently. Humans, as well as monkeys, gorillas, and other primates, have a hand that can grip and grasp objects because they have an opposable thumb. The earliest primates were arboreal (they climbed trees), and so having grasping hands was an advantage in this environment. Human thumbs modified their ancestors’ opposable thumbs, making them more mobile and thus even more opposable.
The actions took a lot longer in Task 2 without the use of your taped thumb and you may have found you were not able to carry out the task at all.
So, we can conclude that the opposable thumb is an adaptation that helps humans and other primates to carry out the tasks they need to be successful in their environment. In fact, it is the human hand’s adaptations that have helped to make humans such a successful species on earth because they can carry out fine and specialized tasks using tools, like holding a pen to write and turning the pages of a book to read!
What about Non-primates?
Non-primates, including dogs and cats, don’t have an opposable thumb, which explains why they are not adapted for doing the tasks you tested.
So, how are dog and cat paws adapted for their environment?
Task 3.
If you have a pet dog or cat, look at their paws and observe how they are used and note their adaptations! Or look at images of them online.
If you have other pets look at how they are adapted to their environment too. Don’t just look at their paws or feet — look at the whole animal. For example, why do rabbits have large ears? How does your fish breathe?
Send in examples of your pets’ adaptations and any “pet photos” to show these. (If you don’t have a pet, look on Google for examples of adaptations) and we will post them on this page!
Send to: lkermode@rvc.ac.uk
We look forward to receiving them and if you include your address, we will send you a cool DAWNDINOS sticker!
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