FOSSIL RECORD
NATURAL SELECTION
TRAITS AND VARIATION
COMMON ANCESTRY
HUMAN INFLUENCE
100

These are the preserved remains or traces of once-living organisms.

What are fossils?

100

This is the process where individuals with helpful traits survive and reproduce more.

What is natural selection?

100

A characteristic like fur color or eye shape is called this.

What is a trait?

100

These are body parts that are similar in structure but may have different functions.

What are homologous structures?

100

Humans do this when they choose which plants or animals to breed based on traits.

What is selective breeding?

200

This layer of rock usually contains the oldest fossils.

What is the bottom layer?

200

This is needed in a population for natural selection to occur.

What is variation in traits?

200

This term describes differences in traits within a population.

What is variation?

200

Studying early development of animals can show similarities not seen in adults.

What is embryology?

200

This is the scientific method of directly changing DNA to produce desired traits.

What is genetic engineering?

300

The fossil record shows this about life over time.

What is that life has grown more complex and diverse over time?

300

If an animal has a trait that helps it hide from predators, this is more likely to happen.

What is survival and reproduction?

300

This kind of trait increases an organism's chance of survival in its environment.

What is an advantageous or adaptive trait?

300

Two animals with similar bone structures may share this.

What is a common ancestor?

300

Humans have used technology to make crops resistant to this.

What are pests or disease?

400

This type of event is shown in the fossil record when many species disappear suddenly.

What is a mass extinction?

400

This kind of change in the environment can cause some traits to become more helpful.

What is a change in climate, habitat, or available food?

400

This is the source of most new variations in traits.

What are genetic mutations?

400

Similarities in embryos of fish, birds, and humans suggest this.

What is that they evolved from a shared ancestor?

400

An example of a human-influenced trait in dogs.

What is size, fur length, or behavior?

500

Scientists assume this about natural laws when analyzing fossils.

What is that natural laws today are the same as in the past?

500

Over many generations, natural selection can cause this to happen to the frequency of traits.

What is an increase in helpful traits and a decrease in less helpful ones?

500

If a population has a lot of trait variation, this makes it more likely to survive environmental change.

What is increased survival of some individuals?

500

These two types of evidence help scientists study evolutionary relationships.

What are fossil evidence and anatomical comparisons?

500

These tools have allowed humans to influence inheritance more precisely in recent years.

What are gene editing tools like CRISPR?

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