Question

4. (10 pts) As you recall, the earliest plants moved from water to land, but still required water for reproduction. They had neither vascular tissue nor seeds (e.g. bryophytes).  Aquatic vascular plants such as eelgrass thus represent a “return to water” for plants. Draw a simple phylogenetic tree for the major plant groups and show where you would place eelgrass. What are the shared ancestral characteristics? What are the derived characteristics of eelgrass?

Answer 1

Here is the phylogenetic tree for the major plant groups.

Eelgrass (Zostera marina) is a type of flowering plant. It believed to lived on land and later evolved to live completely in water. Thus, it should be placed in the category of angiosperms. More specifically, it should come under the angiosperm category called the monocots. Many seagrasses like this one belong to the different taxon.

Kingdom: Plantae
Division: Magnoliophyta (Angiosperms)
Class: Liliopsida
Subclass: Alismatidae
Order: Alismatales
Family: Hydrocharitaceae
Order: Potamogetonales
Family: Zosteraceae

Shared ancestral characteristics: This is a character that is originated in a taxon. They have the character as the vascular bundles present in their ancestors.

Derived characteristics of eelgrass: These characters are unique as they are due to the evolutionary change. They have features of monocots that are regarded as derived characteristics within the angiosperms.