1. 19.2 The Age of Earth I. The importance of __________
A. Life has existed for ____ billion years and ____% of that time life was only in __________
1. ________ rays would kill land ___________
B. As _______________ produced oxygen it floated into upper ______________
1. oxygen ________ into _________ (O3)
2. this ________ the sun’s _____ rays and made land living _______

2. II. __________ & ___________
A. Were the ________ to invade _________
1. 1st problem was how to ___________ on bare ___________
a. ________________ plants could not get __________ out of bare rock
b. __________ could not be photosynthetic but could get _________
2. _____________ – association between plants and animals
a. fungi live in the ________ of plants
1. plants give fungi _______ and fungi give plants __________
b. _____________ – “you help me and I help you” relationship

3. III. ______________
A. Have _______ outer skeleton and jointed _________________
1. examples – _________, __________, __________, & ____________.
2. the first arthropods to move on land were ______________
B. Insects have become the most ______________ and ___________ group of animals _________
1. There are _________ million insects for every human
2. Insects were the first animals to evolve __________
a. Allow for a partnership between __________ & _____________ plants

4. IV. ______________follow onto land
A. Any animal with a ______________
1. First vertebrates were _______, dominated ______ for millions of yrs
B. Came onto land ______ mya
1. ______________ were the first
a. Ancestors of today’s _________, __________, & _________________
C. Because of strong flexible ____________ they could grow ________ and soon ___________ the landscape