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Related: About this forumYour Most Distant Animal Relative Is Probably This Tiny Jelly
Source: Gizmodo
Your Most Distant Animal Relative Is Probably This Tiny Jelly
George Dvorsky
Today 9:07am
For years, a debate has raged among scientists as to which ancient creature represents the first true animal, sponges or jellies. Using a new genetic technique, a collaborative team of researchers has concluded that ctenophoresalso known as comb jellieswere the first animals to appear on Earth. Its an important step forward in this longstanding debate, but this issue is far from being resolved.
A new paper published in Nature Ecology and Evolution suggests that ancient jellies, and not sponges, represent the oldest branch of the animal family tree. The Vanderbilt University and University of Wisconsin-Madison researchers who conducted the study arent the first to make this claim, but they used an emerging technique to parse literally hundreds of thousands of genes, showing that comb jellies have the most ancient genome of any animal. The researchers say the method could be used to resolve other longstanding issues in evolutionary biology, but given the highly interpretative nature of their findings, its likely the sponge-versus-jelly debate will continue to rage on.
Decades ago, scientists slotted animals on the so-called tree of life by eyeballing organisms, designating the ones that appeared to be simple as more primitive in terms of their evolutionary standing. Things changed with the advent of genomics, when scientists gained the ability to read and compare the DNA of organisms and classify them accordingly. This new field, called phylogenetics, has revolutionized the way we define evolutionary relationships, but many gaps exist among the numerous branches in the tree of lifeincluding the very first trunk at the base of the animal tree.
Traditional phylogenetic techniques have resolved about 95 percent of all evolutionary relationships, but an irksome five percent of cases remain unresolved, leading to controversies. To understand why certain relationships in the tree of life continue to be controversial, the authors of the new study took a look at pre-existing data sets, and compared the individual genes of jellies and sponges to finally come up with what they believe to be the worlds first animal.
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Read more: http://gizmodo.com/your-most-distant-living-relative-is-probably-this-tiny-1794206108
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Related: Contentious relationships in phylogenomic studies can be driven by a handful of genes (Nature Ecology & Evolution)
DetlefK
(16,423 posts)ret5hd
(20,433 posts)than some in my "family".