Imagine that you are studying alien life-forms discovered on a distant planet. While geneticists are working out the genetic cod
e of these organisms, you are asked to construct a phylogenetic tree based on four morphological features, or characters: presence or absence of a spring tail, presence or absence of a grasping hand, presence or absence of a second tail, and number of eyes. The organisms have been divided into five groups based on these characters.
A phylogenetic tree based on morphology can be constructed using the presence or lack of characteristics. In this illustration, all aliens except the outgroup possess a spring tail, all aliens possess a fourth eye, two aliens possess two tails, and one alien has a grasping hand. The evolutionary relationships between these organisms can be hypothesized using these traits.
Aliens:
We can determine whether the following traits are present in the remaining aliens by using the group of aliens with the tail stalk as our test group.
Out group: a group that is maintained apart from the clade but is yet connected to it.
If we provide these aliens alphabets for ease of understanding, then aliens will be like in order.
We can use the group of aliens with the tail stalk as our test group to see if the following characteristics are present in the remaining aliens.
A group that is kept separate from the clade while yet being affiliated with it is known as an out group.
The aliens will appear to be in order if we give them alphabets for simplicity.
Radial symmetry is the arrangement of body parts around a central axis, like rays on a sun or pieces in a pie. ... The two halves of a radially symmetrical animal may be described as the side with a mouth (oral side”) and the side without a mouth (aboral side
