Eye of the Beholder, Part I

Here's a little experiment for you to try. As quickly as you can, without thinking about it, name the first five animals that come to your mind.

What did you come up with? If you're like most people, your list consists only or almost only of mammals (cat, dog, horse, etc.). If there is a non-mammal on your list, it's almost certainly still a vertebrate (e.g. bird, frog, turtle).

What is remarkable about the results, is that our mindset is so vertebrate-centric, considering that vertebrates are an incredibly small part of the evolutionary tree. Mammals, as a subgroup of vertebrates, are an even smaller part of the evolutionary tree.

Take a look at this wondrous Tree of Life on Dr. David Hillis's website:

http://www.zo.utexas.edu/faculty/antisense/DownloadfilesToL.html

It looks overwhelming, but it represents only 3,000 species out of an estimated 9 million on Earth. If you download the image and magnify it, you will be able to find a branch for Homo sapiens, and you can begin to get a sense of where our single species stands in the grand scheme of diversity on Earth. With all these other kinds of organisms on the planet, why do we regularly pay attention to so few? I will talk more about this in the next post.