Part 5 B Flashcards
(14 cards)
What do fossils provide a record of?
A past life
Fossils show how one type of animal or plant could’ve changed into another.
What is biogeography?
The pattern of species distribution
It studies how species are distributed across different geographical areas.
What is Pangaea?
The super continent
Amphibians and reptiles arose during Pangaea and are widely distributed, unlike mammals.
What does comparative anatomy study?
Organisms with similar structures evolved from a common ancestor
Modifications occur due to different environments and functions.
Define homologous structures.
Structures that are similar in structure due to a common ancestor
They may not necessarily have the same function.
What is divergent evolution?
The process where a common ancestor evolves into many different species
The ancestral mammal likely existed 190 million years ago.
What is the difference between divergence and convergence?
Divergence is when related organisms adapt differently; convergence is when unrelated organisms adapt similarly
Example: streamlined bodies of sharks, fish, and dolphins.
Define analogous structures.
Structures that are similar in function but differ in anatomy
They do not share a common ancestor.
What are vestigial structures?
Structures that are no longer functional but are historical remnants
Examples include the human appendix and tail-bone.
What does comparative embryology reveal?
Adult species are easy to differentiate, but embryos are often very similar
This similarity can indicate evolutionary relationships.
What does comparative biochemistry study?
The similarity of DNA in closely related species
More similar DNA indicates a shared ancient ancestor.
What does molecular evolution involve?
Comparing amino acid sequences in proteins
More similar sequences indicate closer evolutionary relationships.
How is DNA used to show evolutionary relationships?
DNA is passed down with little change; its base sequence shows relationships
DNA hybridization allows comparison of sequences.
What is the molecular clock?
The idea that molecular differences between species indicate the time since they split
More differences suggest more time has passed since divergence.
