The common ancestor of the salamanders had 5 toes on each foot. Many toe (toe V
ID: 219252 • Letter: T
Question
The common ancestor of the salamanders had 5 toes on each foot. Many toe (toe V in the diagram) This has happened in at least 3 groups of salamanders, Independently. in dif species of salamanders have only 4 toes and in each case they've lost the Sth fferent environments. What is the most likely 5 toes O a -Sth toes" were lost in salamanders because of the way their toes grow, it is least disruptive to the development of salamander feet to lose growth of a toe V OB There was selective pressure to eliminate the "sth toe;, rather than any of the other toes. in each of the three groups. During its growth and development as an embryo, the gene controlling dgt growth was shut down before the "5th toe" was made d The "5th toe probably wasn't serving a purpose to the salamanders so over the years it was lost and the body could focus more on the toes it needs.Explanation / Answer
Answer - the 5th toe in salamader was lost because of the way their toe grows.it is least disruptive to the development of salamander feel to lose the growth of the 5th toe.
Recently lot of research has been perfomed to identify the cause for lose of the 5th toe in salamader. All though lot evolutionary and gentic studies have been performed and theories such as chages to genes involved, mutations in such genes, changes on gene expression have been proposed, the widely accepted reason is developmental constraint.
During the course of salamander development, due to constraints in developmentof the foot and as it had the least disruption in the development of foot, the 5th toe was lost over time.