Pentadactyl Structures
Name three different mammals that share the pentadactyl limb structure
Humans, bats, whales,
What is a vestigial structure?
A reduced or unused body part that remains from an ancestor
Two animals both use wings to fly, but their wing structures are very different. What type of structures are these?
Analogous structures
Evolutionary speaking, why do a human's hand and a whale's flipper have the same bone structure
They share a common terrestrial ancestor
Give one example of a vestigial structure in humans
Appendix (also acceptable: tailbone, wisdom teeth)
Why do sharks and dolphins have similar body shapes even though one is a fish and the other is a mammal?
They adapted to similar aquatic environments, leading to similar features
The pentadactyl limb is a classic example of a ______ structure, meaning they share a common origin but have different functions
Homologous
Why do vestigial structures still exist if they have no function?
They are inherited from ancestors and haven’t been completely eliminated by evolution
Give an example of two structures that perform the same function but are built differently
Bird wings and butterfly wings
Explain how the pentadactyl limb of a bat is modified for its specific environment compared to a horse
Bat fingers are elongated to support a wing membrane, while horse limbs are reduced to a single functional digit for running
What does the presence of vestigial structures suggest about evolution?
That organisms have changed over time and share common ancestors
Explain why similar environments can cause different species to develop similar traits
Because they face similar challenges and adapt in similar ways
Identify the specific bone in the upper arm of the pentadactyl plan that connects to the shoulder
The Humerus
Name a vestigial structure in animals and its original function
Whale pelvic bones which are used by ancestors for walking on land
Two species can fly, but one has bones in its wings and the other does not. What does this tell you about their evolution?
They evolved flight independently and do not share a recent common ancestor for that trait