In a new study published this week in the journal
Searching among today’s most primitive-looking animals for the earliest branch of the animal tree of life, scientists gradually narrowed the possibilities down to two groups: sponges, which spend their entire adult lives in one spot, filtering food from seawater and comb jellies, voracious predators that oar their way through the world’s oceans in search of food. (Photos courtesy of MBARI)įor more than a century, biologists have wondered what the earliest animals were like when they first arose in the ancient oceans over half a billion years ago.
A detailed comparison of the chromosomes of these and other animals to the chromosomes of three single-celled non-animal groups finally resolves the question. Scientists have long debated whether comb jellies (left) or sponges (right) are the sister group to all other animals.
0 kommentar(er)
