Lesson 3: Common Ancestors

Structures with the same parts have different functions; suggests that organisms share a common ancestry

• vestigial structures
• homologous structures
• adaptive radiation
• fossil

Tags

NGSS.MS-LS4-2

Study of embryos of various organisms to show a common ancestor because of similarities in development

• natural selection
• embryology
• speciation
• evolution

Tags

NGSS.MS-LS4-3

Two organisms that are closely related would have

• very similar DNA sequence
• exactly the same DNA sequences
• no proteins in common
• completely different DNA sequence

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NGSS.MS-LS4-2

Some organisms that share a common ancestor have features that have different functions, but similar structures.  These are known as

• vestigial structures
• analogous structures
• homologous structures
• fossil structures

Tags

NGSS.MS-LS4-2

If modern organisms have a lot of homologous structures, what inference could be made about those organisms?

• They are reptiles
• One organism evolved from the other.
• The organisms have a common ancestor

Tags

NGSS.MS-LS4-2

Which is not evidence for evolution?

• many animals have homologous structures due to common ancestry
• Many animals have vestigial structures from an ancestor
• We can observe changes in life forms by observing the fossil record
• All of these are evidence for evolution

Tags

NGSS.MS-LS4-1

NGSS.MS-LS4-2

What is a structure that is similar across species?

• vestigial
• homologous
• adaptaion
• variation

Tags

NGSS.MS-LS4-2

How do fossils provide evidence that evolution has happened on Earth?

• Fossils show how the sizes of certain animals has changed drastically over millions of years
• Fossils show that some species have gone extinct
• Fossils show how life forms present today are different than those from the past
• Different sedimentary rock layers provide evidence for how the environment has changed over time

Tags

NGSS.MS-LS4-1

NGSS.MS-LS4-2

The diagram illustrates an embryonic stage of two organisms.

Which of the following can be determined by observing the embryos shown in the diagram

• The organisms share a common ancestry.
• The organisms belong to the same genus.
• The organisms are native to the same geographic areas.
• The organisms will grow into anatomically similar adults.

Tags

NGSS.MS-LS4-3

Structures are similar in appearance but not in structure

• Vestigial 
• Homologous 
• Analogous Structures 
• Embryonic 

Tags

NGSS.MS-LS4-2