Difference Between Monophyletic and vs Paraphyletic and vs Polyphyletic

In phylogeny, a taxon is a collection of organisms. Defining taxa makes it simpler to classify and identify creatures while also helping us to understand how they relate to one another. Based on these traits, taxa are developed. While some taxa are made up of unrelated creatures, others contain related species. Taxa classify descendants and ancestors. Such categories are utilized in phylogenetic studies and include monophyletic, paraphyletic, and polyphyletic.

Monophyletic, paraphyletic, and polyphyletic are terms used in the classification of organisms to describe the evolutionary relationships between different groups of organisms. Monophyletic groups are those that include all descendants of a common ancestor; paraphyletic groups include some, but not all descendants of a common ancestor; and polyphyletic groups are made up of organisms that have converged on a similar characteristic but do not share a common ancestor. Understanding the difference between these three terms is essential for the classification and understanding of evolutionary relationships between organisms.

Monophyletic 

A monophyletic group is a group of organisms that includes an ancestral species and all of its descendants. In other words, it is a group that has a single common ancestor and is considered a natural group or clade. This can be contrasted with a polyphyletic group, which includes organisms from multiple evolutionary lineages that do not share a common ancestor. In taxonomy, monophyletic groups are considered to be the most scientifically valid grouping of organisms, as they reflect evolutionary relationships. A monophyletic group is considered a true group because it reflects evolutionary relationships and the natural classification of organisms.

The word “monophyletic” comes from the Greek words “monos,” meaning “single,” and “phylon,” meaning “race” or “tribe.” The suffix “-etic” is used to indicate that something belongs to or is characteristic of a certain group or category.
Together, monophyletic means “belonging to a single tribe” or “descended from a single ancestor.”

We may learn about how various creatures, both past and present, are connected by categorizing them based on their biological variety and evolutionary history. In other words, this systematic discipline aids in our understanding of the world’s evolutionary past. With the use of this approach, we can see how various animals are related on a phylogenetic tree or cladogram, where branch lengths and branching orders reveal relationships and the rate of evolution, respectively.

An example of a monophyletic group is the group of all birds. Birds share a common ancestor and are all descended from that ancestor. This group includes all types of birds, such as chickens, eagles, and penguins. All birds have certain characteristics, such as feathers and a beak, that are inherited from their common ancestor.

Paraphyletic

In evolutionary biology, the term “paraphyletic” is used to define a group of creatures that has a common ancestor and some of the descendants, but not all of them. When a group of creatures is referred to as a paraphyletic group, it suggests that some of the natural group’s members have been moved into another group for whatever reason. There are several potential causes for this.

The word “paraphyletic” comes from the Greek words “para,” meaning “beside” or “near,” and “phylon,” meaning “race” or “tribe.” The suffix “-etic” is used to indicate that something belongs to or is characteristic of a certain group or category. Together, paraphyletic means “near a tribe” or “related to a tribe,” but not including all its descendants.

Paraphyletic groups are also known as “partial groups” or “inclusive groups” because they are based on evolutionary relationships but do not include all the descendants of the common ancestor. This type of classification is considered more useful than polyphyletic groups but less useful than monophyletic groups.

For example, a group of animals that are classified as “reptiles” (e.g., snakes, lizards, crocodiles, and turtles) would be considered paraphyletic because these animals share a common ancestor, but the group does not include all of the descendants of that ancestor. Birds, which are also the descendants of the same ancestor as reptiles, are not included in the group of reptiles.

Polyphyletic

A group of creatures with no one common ancestor is referred to as a polyphyletic taxon. The polyphyletic group is made up of unrelated creatures that have several common ancestors. It’s somewhat of an odd collection of creatures. A polyphyletic taxon is often reclassified when it is discovered since it is an entirely artificial assemblage.

The word “polyphyletic” comes from the Greek words “poly,” meaning “many,” and “phylon,” meaning “race” or “tribe.” The suffix “-etic” is used to indicate that something belongs to or is characteristic of a certain group or category. Together, polyphyletic means “belonging to many tribes” or “descended from many ancestors.”

Polyphyletic groups are also known as “artificial groups” or “convenience groups” because they are based on superficial similarities rather than evolutionary relationships. This type of classification can be confusing and is not considered to be as useful as monophyletic or paraphyletic groups.

For example, a group of animals that are classified as “flying animals” (e.g., birds, bats, insects, and flying squirrels) would be considered polyphyletic because these animals have the ability to fly, but they do not share a common ancestor. Birds, bats, and insects are each from different evolutionary lineages and do not share a common ancestor with the other groups.

Difference Between Monophyletic, Paraphyletic, and Polyphyletic

Basis of comparison	Monophyletic	Paraphyletic	Polyphyletic
Define	A monophyletic group is a taxon made up of the descendants of a most recent shared ancestor.	A taxon called a paraphyletic group consists of a most recent common ancestor and some of its offspring.	A taxon called a polyphyletic group is made up of unrelated creatures that share a distinct most recent common ancestor. There is no most recent common ancestor for this group.
Common ancestors	It has a common ancestor.	It has a common ancestor.	It lacks common ancestor.
Descendant of common ancestors	Include all descendants of common ancestors	Doesn’t include all descendants of common ancestors.	Doesn’t include all descendant of common ancestors.
Nature	Natural taxon	Natural taxon	Unnatural collection of organisms
Based on	Synapomorphy	Symplesiomorphy	Convergence

Monophyletic, paraphyletic, and polyphyletic are terms used in evolutionary biology to describe different types of groups of organisms based on their evolutionary relationships. The key differences between them are as follows:

1. Monophyletic: A monophyletic group, also known as a clade, consists of an ancestor and all of its descendants. In other words, a monophyletic group includes all of the organisms that descended from a common ancestor. Monophyletic groups are defined by shared derived characteristics that are unique to the group.
2. Paraphyletic: A paraphyletic group includes an ancestor and some, but not all, of its descendants. In other words, a paraphyletic group excludes some of the organisms that descended from a common ancestor. Paraphyletic groups are defined by shared ancestral characteristics that are not unique to the group.
3. Polyphyletic: A polyphyletic group includes organisms that do not share a recent common ancestor. In other words, a polyphyletic group is not defined by a single ancestor, but rather by convergent or parallel evolution of unrelated lineages. Polyphyletic groups are defined by shared characteristics that have evolved independently in different lineages.

In summary, monophyletic groups are defined by shared derived characteristics that are unique to the group and include all descendants of a common ancestor. Paraphyletic groups include some, but not all, descendants of a common ancestor and are defined by shared ancestral characteristics. Polyphyletic groups are defined by shared characteristics that have evolved independently in different lineages and do not share a recent common ancestor.

Similarities Between Monophyletic, Paraphyletic, and Polyphyletic:

1. All of these explain the relationship between different organisms.
2. All these define what are taxa of organisms.
3. In all, the most common ancestor is always considered.
4. All three terms refer to different types of groups or classifications of organisms based on their evolutionary relationships.
5. They all involve the grouping of organisms based on shared characteristics, such as shared ancestry, morphology, or genetic traits.

Conclusion

According to several traits, including morphological and molecular properties, organisms are categorized. For phylogenetic analysis and identification purposes, they are grouped. In phylogenetic trees, three types of groupings may be found: monophyletic, paraphyletic, and polyphyletic. A most recent common ancestor and all of its offspring make form the monophyletic group. In phylogeny, it is a natural group to utilize. An ancestor with the most recent common ancestor and some of his offspring make up the paraphyletic group. An artificial collection of unrelated creatures without a most recent common ancestor makes up the polyphyletic group.