Grades 6-8 Geologic Time Scale Review

It determines whether a fossil is formed before or after another fossil. In other words, it's finding out if something is older or younger.

As each new generation is produced, genetic variation may be introduced into a population. The more genetic variation in a population, the more likely it is that some individuals might have traits that will be advantageous if the environment changes.

Cenozoic era

Sweating and shivering

The turtles in the Galapagos islands.

The size, color, shape, and/or different patterns on fur.

Cyanobacteria uses sunlight to make their own food. This process releases oxygen. Overtime, oxygen built upon the ocean and air.

They have a common ancestor they both might have evolved from.

Mesozoic era

Cenozoic era

1. organism dies and is covered up
   2) covered with more layers
   3) minerals replace the body with stone
   4) body decomposes and leaves an imprint

Overproduction, genetic variation, selection, and adaption

Scientists confirmed that these differences are related to the bird's diets. Birds with shorter, heavier beaks could eat harder foods than those with thinner beaks. They evolved and adapted to their surroundings.

Their bodies aren't adapted to the new environment yet.

Prokaryotes. They are single-celled organisms without a nucleus. They were the dominant life form then. They lived in the ocean and the earliest prokaryotes lived without oxygen.

The furthest down of all top layers.

He sailed on the ship called the HMS Beagle on December 27, 1831, from Plymouth, England. 

November 24, 1859