Planet's First Animal Species Discovered

Evolutionary science has long looked to the common sponge as the progenitor of life on earth. However, according to new research, the earliest form of life on earth may belong to something much more complicated: the ocean-drifting comb jelly (image below).
Casey Dunn, of Brown University, along with his research team, used a new high-powered technology that allowed them to analyze massive volumes of genetic data. Their study focused on the earliest splits at the base of the animal tree of life. The tree of life is a hierarchical representation of the evolutionary relationships between species that was introduced by Charles Darwin.

The study’s most surprising find was that the comb jelly split off from other animals and diverged in to its own evolutionary path before the sponge did. "This was a complete shocker," says Dunn. "So shocking that we initially thought something had gone very wrong."
Dunn’s team checked, and then rechecked their resulted, added more information to their study, before they finally allowed themselves to see that the findings were not in error.
The presence of the relatively complex comb jelly at the base of the tree of life suggests that the first animal was probably more complex than previously believed, says Dunn.
Dunn cautioned that further studies must be conducted before this finding can be confirmed. He went on to say though that the comb jelly could only have achieved its position over the sponge as a result of one of two evolutionary scenarios; “1) the comb jelly evolved its complexity independently of other animals, after it branched off onto its own evolutionary path; or 2) the sponge evolved its simple form from more complex creatures--a possibility that underscores the fact that "evolution is not necessarily just a march towards increased complexity," says Dunn. "This scenario would provide a particularly dramatic example of that principle."
As for just how old is the first creature? No one is quite sure. "Unfortunately, we don't have fossils of the oldest comb jelly," laments Dunn. "Therefore, there is no way to date the earliest jelly and determine when it diverged."
Surprisingly though, the tentacled, squishy but bell-less comb jelly developed along a different evolutionary path than did the classically bell-shaped jellyfish, says Patrick Herendeen, an NSF program director. Such divergences mean that "the jellyfish type of body form has independently evolved several times,"
The tree of life however, despite the mass findings from Dunn’s study, continues to be largely missing of information. "Scientists currently estimate that there are a total of about 10 million species of organisms on earth," says Dunn. "But so far, only about 1.8 million species--most of which are animals--have been described by science. Very few of these species have, so far, been positioned in the tree of life."
Dunn’s research combined the power of more than a hundred computers to analyze more data than has ever previously been inputted in to an evolutionary study. "Dunn's high-powered approach is just what we need to continue assembling the tree of life," says Herendeen. "We are going to see a lot of this approach in the future."

http://www.physorg.com/news127055240.html
http://www.brown.edu/Faculty/Dunn_Lab/