Can Two Different Species That Are Members of the Same

question 28

Multiple Choice

Can two different species that are members of the same clade have more than one common ancestor? Choose the MOST correct answer and explanation.

• A)No.Because they are members of a clade,by definition they can have only one common ancestor.
• B)Maybe.Two species in the same clade can have more than one common ancestor only in cases where horizontal gene transfer from a third,previously unrelated,species has occurred.
• C)Maybe.If they are members of a clade that is not monophyletic,they can have more than one common ancestor.
• D)Yes.Although two species in the same clade have only one most recent common ancestor,they also have a number of older common ancestors that occurred earlier in their evolutionary history.
• E)Yes.Two species of the same clade always have eight common ancestors,matching the number of levels higher than species in the taxonomic hierarchy.

---

Definitions:

Tradable Emissions Permits

A market-based approach to controlling pollution by providing economic incentives for achieving reductions in the emissions of pollutants.

Equilibrium Price

The price at which the quantity of a product demanded by consumers equals the quantity supplied by producers.

Equilibrium Quantity

The supply and demand for goods or services are balanced at the current market price.

Pollution Market

An economic strategy for pollution control that encourages the reduction of pollutant emissions through financial incentives.