User:Sydmarks/Human flea

A Biogeography of the Human Flea
Pulex irritans originated in Central and South America, where it evolved with only one host. Despite the close relationship the human flea has with humans, this single host is most likely the guinea pig or peccary. Humans originated in the Old World and would not come in contact with the human flea until after migrating into the Americas. The most likely transport vector for the human flea to Europe is through the fur trade. Both the human flea and the cat flea were considered cosmopolitan species after the 18th century due to the frequency of trading worldwide.

Origin, Evolution, Phylogeny, and Taxonomy of the Human Flea
The comparison of morphometric data between Pulex irritans specimens from Spain and from Argentina showed no significant differences of the two populations. There was significant levels of divergence between the populations when molecular data, nuclear and mitochondrial DNA, was compared. Flea identification is often based on morphological features such as shape and structure of genitalia or arrangement of projections from the epithelium. Combining both morphological and molecular data has identified the possibility of cryptic flea species, or those that exhibit low morphological differences but a high number of molecular differences.

High mitochondrial sequence divergence in Flea Species
The great similarities in fleas sampled not near one another is explained by their cosmopolitan distribution due to transport on pets. Each of the four species of fleas (the cat flea, human flea, mouse?, and rat? fleas) show such great differences within their own species that their taxonomic classifications should be reevaluated based on high levels of infraspecific variation and mitochondrial gene heterogeneity.

Phylogeny and Distribution - rough draft
Pulex irritans originated in Central and South America, where it evolved with only one host. ''' Despite the close relationship the human flea has with humans, this original host is most likely the guinea pig or peccary. Humans originated in the Old World and would not come in contact with the human flea until after migrating into the Americas. ' Despite the origins of P. irritans'', it is now a cosmopolitan species, most likely due to the fur trade after the 18th century, and pet transport in more recent decades. Due to the cosmopolitan distribution of this group, research has been conducted to show that P. irritans individuals, when sampled from Spain and Argentina, only showed significant differences when comparing molecular data. The use of morphometric data, which is often the method for flea identification, showed no significant levels of divergence between the two populations. Combining both morphological and molecular data has identified the possibility of cryptic species  or those that exhibit low morphological differences but a high number of molecular differences . This indicates a need to reconsider taxonomic classifications of these fleas. Studies in Europe and the Mediterranean also found this to be true. Human and cat fleas from Europe and the Mediterranean were studied and show such great variation within their own species that their taxonomy should be reevaluated based on mitochondrial gene heterogeneity.

Phylogeny and Distribution - rough draft
Pulex irritans originated in Central and South America, where it evolved with only one host. Despite the origins of P. irritans, it is now a cosmopolitan species, most likely due to the fur trade after the 18th century, and pet transport in more recent decades. Due to the cosmopolitan distribution of this group, research has been conducted to show that P. irritans individuals, when sampled from Spain and Argentina, only showed significant differences when comparing molecular data. The use of morphometric data, which is often the method for flea identification, showed no significant levels of divergence between the two populations. Combining both morphological and molecular data has identified the possibility of cryptic species. This indicates a need to reconsider taxonomic classifications of these fleas. Studies in Europe and the Mediterranean also found this to be true. Human and cat fleas from Europe and the Mediterranean were studied and show such great variation within their own species that their taxonomy should be reevaluated based on mitochondrial gene heterogeneity.