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You are more closely related to comb jellies than sponges, new study claims

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You are more closely related to comb jellies than sponges, new study claims 2

The theory of evolution shows that all life stems from a single root and that we are related, more or less distantly, to every other living thing on Earth. Our closest ancestors, as Charles Darwin recognized, are to be found among the great apes. But beyond this, confusion over the branching pattern of the tree of life means that things become less clear.

We know that life evolved from a common universal ancestor that gave rise to bacteria, archaea (other types of single-celled microorganisms), and eukaryotes (including multi-cellular creatures such as plants and animals). But what did the first animals look like? The past ten years have seen a particularly heated debate over this question. Now our new study, published in Science Advances, has come up with an answer.

Sponge vs comb jelly

From the 19th century to about ten years ago, there was general agreement that our most distant relatives are sponges. Sponges are so different from most animals that they were originally classified as members of the algae. However, genes and other features of modern sponges, such as the fact that they produce sperm cells, show that they certainly are animals. Their distinctness and simplicity certainly fit with the idea that the sponges came first.

But over the past decade, this model has been challenged by a number of studies comparing DNA from different animals. The alternative candidates for our most distant animal relatives are the comb jellies: beautiful, transparent, globe-shaped animals named after the shimmering comb-rows of cilia they beat to propel themselves through the water.