On a phylogenetic tree, what does a 'tick mark' placed on a specific branch signify?

The extinction of all species on that branch.

The point where a new heritable trait appeared.

An individual organism that was a genetic anomaly.

The geographic location where a species was discovered.

On a tree diagram, the trait 'lungs' is marked after the lineage for sharks splits off, but before the lineage for frogs splits off. Which organism would be expected to possess lungs?

An ancestor from before the shark lineage split off

On the specific branch that leads only to mammals.

On the branch that is the common ancestor to mammals, lizards, and birds, but after the split from the insect lineage.

On the branch leading only to insects, to show they lack it.

On a separate branch outside the main tree structure.

Because the trait is heritable.

Because all the organisms live in similar habitats.

Because of random chance during reproduction.

Because the diagram requires it for neatness.

A change an animal acquires during its lifetime, such as a scar.

A new heritable trait that appears in a lineage.

A behavioral pattern learned from other animals in a group.

A temporary genetic mutation that is not passed on to any offspring and disappears within one generation.