9/19 Your Inner Fish with objectives

Unit 2 Objective Sheet:

#3 What type of fossils show very early life on earth:
working assumption- rocks on top are younger, rocks on bottom are older (order of fossils base don the order of rocks)
carbon dating

How a fossil is formed: Rocks preserve fossils (sedimentary rock= gentle)









#12 Homology: shared characteristics that have been inherited from a common ancestor. 

• the more homologies they share, and
• the more similar these homologies are.

Homologous: Structures of similar origins but used for different functions. 
Analogous: Structures of similar function but of different origins. 

Convergent evolution can make interpreting homologies difficult because natural selection favors adaptations in similar environments. 

-favor changes that made the two groups more alike, their phenotypes have changed