Quick Quiz
It looks like your students have some questions about Lines of Evidence. Reflect on what you have just learned and see how well you can respond. Just click on their raised hands!
You could respond:
"Abundant fossil evidence and reliable dating techniques have clearly established that dinosaurs went extinct more than 60 million years before humans appeared on the scene. Of course, if you include birds as dinosaurs, then Fred Flintstone certainly could have had a parrot on his shoulder! By the way, it’s not called a brontosaurus anymore, but that’s a whole other story."
You could respond:
"Dewclaws are vestigial structures. Vestigial structures show that organisms sometimes only partially lost parts that no longer have their original functions. These remnants are evidence of their evolutionary history."
You could respond:
"A close look at plant and animal cells reveals that almost every structure and chemical constituent is pretty much the same, except that plant cells have cell walls and sometimes chloroplasts and animal cells have centrioles. All of that similarity is the result of inheritance from a common ancestor a long time ago."
You could respond:
"Relative dating compares the ages of two or more fossils, but gives no actual age. Absolute dating yields the approximate age of fossils, in years before present, based on radioactive decay of certain rocks. But, we never know the exact age."
You could respond:
"Yes."
You could respond:
"It’s perfectly OK. Homologous structures reflect common ancestry between living things. So, the homologies we share with other vertebrates demonstrate our relationship to them."
You could respond:
"The kind of relative dating I was talking about is. It just means figuring out which fossils and rocks are older than others by studying their positions in rock layers."
You could respond:
"That’s because all living things are related to one another and share the same basic chemistry and genetic machinery. Since they work in similar ways, a corn cell can read a bacterium gene just like it reads its own genes."
