A paleontologist compares fossils from three dinosaurs and Archae...

Question

A paleontologist compares fossils from three dinosaurs and Archaeopteryx, the earliest-known bird. The following table shows the distribution of characters for each species, where 1 means that the character is present and 0 means it is not. The outgroup (not shown in the table) had none of the characters. Arrange these species on the phylogenetic tree below and indicate the derived character that defines each branch point.

Accepted Answer

Welcome back. Let's look at the next question it says which of the following shows a similarity between the birds and crocodiles. That can be possibly explained by their common ancestry. So let's just take a quick look at our answer choices here and we note that choice D. Is all options are correct. So just keep that in mind and we'll look through our answer choices here. Choice A. Says they build nests. Well this is correct. Both build nests for their eggs. Important to note that this is an innate behavior which means it's innate behaviors tend to be genetically determined and that makes it a good candidate for something that would be inherited from a common ancestor. Choice B says they have a unit directional flow of breathing patterns. Well, this is correct. Both birds and crocodiles have an airflow that comes in uh travels in a roughly circular path. This is as opposed to humans and other animals who have uh have air coming in and out of the lungs along the same pathway. Birds and crocodiles. The air comes in, goes in a roughly circular path and goes out separately rather than coming in and out of the same way. So that definitely is something that can be shown by common ancestry. Choice C says they have four chambered hearts. This is correct. Both do. And there are animal species with different numbers of chambers frogs, for instance have three chambers to their heart. So this is definitely something that could be due to common ancestry. So as we see here all three of these are correct answers, similarities between birds and crocodiles that can be explained by common ancestry. So our answer will be Choice D. All options are correct. See you in the next video.

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