What is a skeleton? A skeleton consists of the bones that make up the framework of a body.
Exercise directions In this exercise, we will be looking at the form and function of different skeletons and how they suit the lifestyle of those animals. Let’s try a few examples.
Making Observations: Take a few minutes to make some observations about the form of this animal. observations
Long, thick-boned tail that reaches to the ground Large feet Short arms with finger- like appendages Elongated rear limbs with shorter bones connecting them to the pelvis. For example, you might say…. example
Making Inferences: To make an inference means to draw conclusions from your observations. What are some functions of these structures?? inferences
Why is the tail so long and sturdy? Why are the feet so large? What are the arms used for? How might long, skinny legs help it move? Some questions you might start with are…
Anteater: Long, tapered snout Short, forelimbs with claws Long tail that drags behind the animal
Sloth: Sharp claws Long forelimbs and hind legs, relatively similar in length and size.
Based on your observations, are these animals related or unrelated? Or in other words, do they have homologous or analogous structures?
Order Xenarthra: Armadillo Sloth Anteater All three animals are classified in the order “Xenarthra” because they all lack incisors or canines and have 2-3 predominate claws. These common structures are known as homologous structures.
Identifying Related Species: 1.Make observations about the forms of different organisms. 2.Draw inferences about the functions of those forms. 3.Consider how those forms may serve as adaptations. 4.Compare those adaptations to other organisms. 5.Do the forms and adaptations represent homologous or analogous structures?
What else might you need to know in order to identify related species?
Conclusions: 1. 1.By making careful observations and inferences, we are able to formulate hypotheses on the relationships between form and function. 2.Certain structures have specific functions according to the organism and the environment. These are called adaptations. 3.Structures of related species are known as homologous structures. 4.Similar structures of unrelated species are known as analogous structures. 5.By analyzing the structures of these organisms, we can begin to draw conclusions about their origins and relations.
The Kangaroo Tail A Kangaroo’s Tail is long and muscular, extending all the way down to the ground. It serves as a sturdy prop while the kangaroo sits or stands. When the kangaroo fights, sometimes the only limb touching the ground is the tail! ??Can you think of any human inventions that may resemble a kangaroo tail in both form and function? BACK
Forelimbs A Kangaroo’s Forelimbs are thin and short and help the animal “hop” forward. Compare the kangaroo’s forelimbs to the arms of a runner. How are they similar and how are they different in both form and function? BACK
Kangaroo Hind legs The Kangaroo’s hind legs have tendons that act like rubber bands, propelling the animal forward in quick, strong leaps. It’s large feet help the animal sit and balance, and are also a very powerful defense mechanism. No one wants to experience the kick of a kangaroo!T BACK
Because its legs are so long, a walking giraffe moves both legs on a side at almost the same time. It can gallop at up to 56 km/h Giraffe’s Legs BACK
Giraffe Tail Like many animals, a giraffe’s tails function as fly swatters. The zebra to the right demonstrates with his tail, which has a similar structure to the giraffe’s tail. BACK
Giraffe Mouth Their mouths are designed to pick leaves from trees and have flat teeth to crush the vegetation. Therefore, their feeding structures are adapted to their feeding habits. BACK
Giraffe Neck Giraffes tend to feed on the leaves from tall trees where they experience less competition from other herbivores. To reach those leaves, they need long necks. BACK
Flamingo Neck A flamingo’s long neck helps it extend down into the water to feed. It is also used to stabilize the bird during flight. BACK
Flamingo Wings Flamingos are capable of flying distances up to 300 miles in one night. They typically extend their necks forward and their legs behind them during flight and reach speeds of up to 30mph. BACK
Flamingo Legs Flamingos have long legs that allow them to wade into deeper waters than their competitors. Their webbed feet help them to stabilize themselves in the mud. BACK
Flamingo Beak and Feeding Flamingos have a unique feeding mechanism whereby they hold their heads upside down and filter algae, seeds, and marine invertebrates such as shrimp and mollusks from the water through their beaks. BACK
Human arm, bat wing, and whale flipper. Bat wingWhale Flipper BACK
Analogous Structures Butterfly wings and bat wings resemble each other in form and function, but there is no ancestral link between the two. BACK
Iguana Claws An iguana has four feet with five digits on each. These claws are used mainly for climbing seeing as the iguana’s main habitat is in trees. BACK
Iguana Tail The iguana’s tail has two functions. First, as a means of balance during climbing. Second, as a means of defense against predators. It can whip and distract predators and sometimes, may disconnect from the iguana, but don’t worry; its grows back! BACK
Iguana Head and Mouth Iguana’s have spines starting at the back of their head and continuing down their back which make it more difficult for predators to swallow them. Their flat mouths crush vegetation and fruit which are the main sources of nutrition for these reptiles. BACK
Gila Monster Tail A Gila monster’s short, fat tail serves as a storage place for fat. When the animal is low on food sources, it uses the fat from its tail as a source of energy. BACK
Gila Monster Head The Gila monster has a large head with a strong lower jaw, which is where the animal stores its venom. One reason why the head sits low is so the animal may lick the ground which is how it picks up the scents of its prey. BACK
Gila Monster Claws The Gila monster’s short legs and short claws are ideal for digging burrows, digging for eggs and food, and climbing. BACK