Evolution predicts that you and your focal organism (marbled salamander) share common ancestry, extending from the origin of life on Earth in an unbroken lineage to an actual species that lived somewhere on our planet long ago—the Most Recent Common Ancestor of the two species. Your assignment is to reconstruct the MRCA of Homo sapiens and your focal species (marbled salamander) using scientific principles studied in this course. You may use books, journals, and online resources, You must complete the assignment using your own words and cite your sources appropriately. Do not give just a URL, make sure you cite the author(s), journal, and year of publication, like this:
Mitra, S.S., Ecology and behavior of Yellow Warblers breeding in Rhode Island’s Great Swamp. Northeastern Naturalist 6(3): 249-262, 1999.
In reconstructing this extinct species, remember that it is long gone now, and nobody has ever seen or studied it directly. Even so, you should be able to infer many things about it, including:
1. a morphological feature it showed that is retained by both descendants (humans and marbled salamander) 2. a morphological feature retained by marbled salamander but not by humans 3. a morphological feature retained by humans but not by marbled salamander 4. a morphological feature it must have had, but which has been greatly altered or lost in both descendants 5. the approximate date in the past when it lived. In this case, I want you to find three independent scientific papers, and cite them. If your sources are independent, their estimates of this date will not be identical. 6. In a few lines in your own words, how certain are you of the accuracy of your answers? Which of these five aspects of the MRCA are you least confident about, and why?
Return your assignment to me by Tuesday at noon, preferably by re-naming this Word document. If using Word is inconvenient, simply write your answer in the body of an email. Please don’t use a pdf, because they are difficult for me to annotate
