Reptile Led
February 23rd, 2011 | Published in Reptiles
Please help! I'm dying on these questions. I can't answer them!?
I'm not a man of science...and my biology teacher didn't even teach the class this stuff...she just expected us to figure it all out on our own. I have a lot of work from other classes to do and I could really use some help here. I've asked this question 3 times and I haven't got any answers. Please help me.
1. Birds have traditionally been excluded from the group of organisms usually classified as reptiles, including crocodiles, turtles, lizards, and snakes. Explain why this classification scheme is inconsistent with the preferred approach of modern systematics, which seeks to create taxonomic groups from single clades. You may use a cladogram to support your answer.
2. Explain how endosymbiosis led to the formation of eukaryotic organelles. Why is a standard cladogram inadequate to illustrate the ancestry of a species that arises from endosymbiosis?
i promise I'll give a best answer to someone that gives a thorough answer. I won't just let it go into voting...
1. Evolutionary discoveries have led scientists to believe that birds were a distinctly separate group from reptiles. Fairly recent developments have proved that this is indeed untrue. Birds are one of the closest ancestors to dinosaurs in that their body has varied in the adaptation of flight. I'm sure you can google the rest.
2. The endosymbiosis theory postulates that the mitochondria of eukaryotes evolved from aerobic bacteria living within their host cell. The chloroplasts of eukaryotes evolved from endosymbiotic cyanobacteria. It is nearly impossible to accurately pinpoint the time when this occurred although scientists can give a roughly good estimation. A cladogram would not reflect the lineage of this phenomena as this could not have occurred in one single organism at one specific time. Over time, other microbes would have evolved, adapted, and evolved again. Unless working with one specific organism, phylogenies could get messy.
Best of luck to you
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