Which animals came first? For more than a century, most evidence suggested that sponges, immobile filter-feeders that lack muscles, neurons and other specialized tissues, were the first animal ...

The next time you go wild swimming, whether in a lake, river or sea, you are probably sharing the water with one of your tiniest, yet closest relatives. Choanoflagellates, like most single celled ...

For almost two decades, scientists have debated whether sponges or comb jellies are the first animal lineage. Now some are calling for a more harmonious approach. Which animals came first? For more ...