00:01
To answer this question, let's first define a few terms.
00:04
First up, we have shared ancestral character.
00:16
A shared ancestral character is a trait shared between an ancestor and its descendants.
00:36
Possibly not all descendants, but at least one or two.
00:40
An example of this would be feathers.
00:45
The ancestor to all birds possessed feathers and passed on that trait to all of its descendants.
00:51
Next up, we have shared derived character.
00:53
A shared derived character is a trait shared between descendants, but not their ancestor.
01:32
An example of this could be sharks.
01:36
The ancestor to all sharks had a skeleton of bone, but over time all of its descendants, but not the ancestor, evolve skeletons of cartilage instead.
01:45
Next up, we have analogy.
01:52
This one is also described as convergent evolution, but it is when unrelated groups arrive at similar adaptation, over time.
02:22
And finally, we have homology, where groups inherit a trait from their common ancestor...