Was your conclusion that the frequency of the beak types will change? Was your reason that natural selection favors organisms better adapted to the environment they live in?

the sphincter muscles at the end of the digestive tract is the anus.

anthropod traits:

a well-developed collarbone

rotating shoulder joints

partially rotating elbow joints

opposable thumb

similar dental formula

the answer to the blank provided is “an autosomal gene that is required for the expression of genes on the x chromosome”.

testis-determining factor, abbreviated as td, which is more popularly known as sex-determining region y or sry protein, is a dna-binding protein or  gene-regulatory protein/transcription factor, encoded by the  sry gene. it is the gene responsible for the initiation of male gender determination in humans.