Your 500-Million Year Old Brain

Why is amphioxus a good model for studying the evolution of brains in chordate?

• Amphioxus has no nervous system, making it irrelevant for brain studies.
• It hasn't changed much in 500 million years

• Amphioxus is a type of fish with advanced cognitive abilities.
• Amphioxus has a complex brain structure similar to mammals.

Amphioxus have a cranium.

• True

• False

How would a zoologist describe the brain of an amphioxus?

• similar to that of mammals with advanced functions

• absent; they only of a spinal cord

• highly complex with multiple lobes.

• a small swelling at the anterior end of the nerve cord

What similarity exists between the human brain and the amphioxus brain?

• Both brains have the same 3 regions

• Both brains are complex

• Both brains are protected by a skull

• humans and amphioxus share genes that tell the brain where to form

What value does Peter Holland see in studying the brains of amphioxus?

• Analyzing the color patterns of amphioxus.
• Understanding the evolutionary origins of the chordate brain

• Investigating the habitat preferences of amphioxus.
• It can be used to develop therapies for human brain disorders