Common Ancestry

Evidence of Evolution

Chapter 9, Lesson 2

Pages 346-349

What evidence supports evolution?

What evidence supports evolution?

Fossils, patterns of early development, similar body structures, and similarities in DNA and protein structures all provide evidence that organisms have changed over time

By examining fossils, we can tell that organisms that lived in the past are very different from those alive today

The millions of fossils that scientists have collected are called the fossil record​

Multiple Select

Which of the following are evidence that supports evolution?

• fossils

• similarities in early development

• similarities in body structure

• similarities in DNA

Similarities in Early Development

• When organisms begin their development, they may have many similar features to help show that they have a common ancestor

• The organisms pictured each have a tail in the early stages​

Multiple Choice

Scientists infer evolutionary relationships by comparing the early development of different _________.

• dinosaurs

• backbones

• proteins

• organisms

Similarities in Body Structure

• Body structure is an organism's basic body plan - how bones are arranged

• Homologous Structures - structures that are similar in different species and that have been inherited from a common ancestor

• Fossils sometimes show homologous structures with living species - whale fossils had legs and walked on land

Fill in the Blank

Similar structures that related species have inherited from a common ancestor are called ________ structures.

Similarities in DNA and Protein Structure

• Scientists infer that the species inherited many of the same genes from a common ancestor

• The more similar the DNA sequences, the more closely related the species are​

Multiple Choice

Scientists infer that species with similar body structures and development patterns had a common ___________.

• environment

• predator

• ancestor

• gene

Multiple Choice

Scientists have found a great deal of evidence that supports Darwin's theory of ___________.

• atomic structure

• creation

• evolution

• relativity

Fill in the Blank

In most cases, evidence from DNA and ________ ________ has confirmed conclusions about evolutionary relationships based on fossils, embryos, and body structure.

Fill in the Blank

An organism's ________ ________ is its basic body plan.

Fill in the Blank

Fishes, amphibians, reptiles, birds, and mammals all have an internal skeleton with a __________.

Fill in the Blank

Scientists can compare the order of ________ _____ in a protein to see how closely related two species are.

Multiple Choice

The illustration has no title. Which of the following titles would best describe the concept shown in the drawing?

• wrist bone adaptations

• similarities in wrist bone development

• evolutionary change through gradualism

• homologous structures in four animals