Molecular Development and The Arthropod Head Problem
The study of how developmental genes are expressed during embryogenesis has become an important new tool in the last twenty years for understanding the structure and evolution of morphology. The arthropod head problem has been tackled in three main ways in this regard, first by using genetic segmental markers to probe the obscure region in front of the mouth, especially in insects; second by looking at Hox gene expression patterns to detect patterns of homology between different arthropods; and third, by studying gene expression in particular features (especially the labrum) to determine its appendiculate or other status. Because all arthropods have the same complement of nine Hox loci, the morphological diversification observed is caused by these genes being expressed at different areas and times.
Read more about this topic: Arthropod Head Problem
Famous quotes containing the words development, head and/or problem:
“To be sure, we have inherited abilities, but our development we owe to thousands of influences coming from the world around us from which we appropriate what we can and what is suitable to us.”
—Johann Wolfgang Von Goethe (17491832)
“Never, my dear Sir, do you take it into your head that I do not love you; you may settle yourself in full confidence both of my love and my esteem; I love you as a kind man, I value you as a worthy man, and hope in time to reverence you as a man of exemplary piety.”
—Samuel Johnson (17091784)
“My problem lies in reconciling my gross habits with my net income.”
—Errol Flynn (19091959)