Conversely, not all of today’s living species were alive in the past. Evidence of this is also found in the form of __________.

Fossils are the preserved remains of organisms that lived long ago. According to the law of ________________________, the rock layers that contain the oldest fossils should be farthest below Earth’s surface.

A __________________ is a permanent change in the genetic makeup of an organism.

Organisms with traits that are best suited for their environments are likely to have a greater chance for survival. These helpful traits, which arise due to genetic mutations, are known as _____________________.

All living things that are best adapted to their environments will be more likely to survive. This idea is known as _____________________ ____________________.

In 1859, Charles Darwin proposed a theory based on the concept of natural selection. His theory explains the evidence of the gradual changes of all organisms over millions of years. This theory is known as the Theory of __________________.

Fossils show physical similarities between organisms and their ancient ancestors. If such similarities were observed between today’s birds and ancient reptiles, what theory could possibly be proposed?

Why is relative dating useful? What does it tell scientists?

How does radioactive dating help scientists? What information does it provide?

An inability to adapt to environmental changes can lead to death of all members of a species. This is called _______________________.

Scientists theorize that hundreds of millions of years ago, all of the continents that exist today were combined into one landmass called Pangaea. What evidence do scientists have to support this theory?

__________________ is when humans purposely breed plants or animals to obtain specific traits.

Example: Dogs not shedding

A ___________________ is a set of actions taken by an organism in response to a stimulus.

Example: Birds building nests

__________________ is a deep sleep during which an animal slows down its body process; usually occurs during cold weather.

__________________ is when organisms move from one environment to another for food or breeding purposes.

A ___________________ is anything that causes a reaction.

Example: Sounds of a predator cause an animal to hide or run.