New Discoveries: Earliest Animals and Transitional Whales

NOT ONLY is the entire civilized world about to celebrate Charles Darwin’s 200th birthday on 12 February, but there’s more. We have news of two important new discoveries that would have delighted Darwin.

From the the University of California, Riverside, we learn: Researchers Find Earliest Evidence for Animal Life. The press release is subtitled: “Discovered fossil animal steroids date back to more than 635 million years ago, says UC Riverside’s Gordon Love.” Here are some excerpts, with bold added by us:

An international research team of scientists from UC Riverside, the Massachusetts Institute of Technology and other institutions has found the oldest evidence for animals in the fossil record. The researchers examined sedimentary rocks in south Oman, and found an anomalously high amount of distinctive steroids that date back to 635 million years ago, to around the end of the last immense ice age. The steroids are produced by sponges – one of the simplest forms of multicellular animals.

That’s a bit older than 6,000 years ago. Let’s read on:

“Our findings suggest that the evolution of multicellular animals began earlier than has been thought,” said Gordon Love, an assistant professor of Earth sciences, who led the research group. Love began working on the project while he was a postdoctoral researcher at MIT. “Moreover, sponges live on the seafloor, growing initially in shallow waters and spreading, over time, into deeper waters, implying the existence of oceanic environments which contained dissolved oxygen near the shallow seafloor around 635 million years ago.”

Here’s more:

According to Love, the climatic shock of the extensive glacial episodes of the Neoproterozoic era (1000-542 million years ago) likely caused a major reorganization of marine ecosystems, perhaps by irrevocably altering ocean chemistry. “This paved the way for the evolution of animal feeders living on the seafloor,” he said. “We believe we are converging on the correct date for the divergence of complex multicellular animal life, on the shallow ocean floor between 635 and 750 million years ago.”

No evidence yet of the Intelligent Designer, but we’re certain the advocates of ID will have something to say about this.

In other news (this is already all over the blogosphere) there’s this paper in PLoS ONE: New Protocetid Whale from the Middle Eocene of Pakistan: Birth on Land, Precocial Development, and Sexual Dimorphism.

For a less technical account, Discover Magazine has this at their website: Primitive Proto-Whales May Have Clambered Ashore to Give Birth. Here are some excerpts, with bold added by us:

The paleontologists didn’t understand what they’d found when they first unearthed the fossil of a primitive whale nine years ago. Philip Gingerich was thrown off by the jumble of adult and fetal-size bones. “The first thing we found [were] small teeth, then ribs going the wrong way,” Gingerich said. Later, “it was just astonishing to realize why the specimen in the field was so confusing.” The answer to the riddle, he soon realized, was that the fossil represented a pregnant female proto-whale and her unborn calf.

Let’s continue:

The 47.5 million-year-old mother represents a transitional phase in whale evolution before the behemoths had fully committed to a life in the ocean deeps, researchers say. The findings lend credence to the idea that early whales — protocetids — were amphibious animals that fed in the oceans but came ashore to sleep, mate and give birth. Researchers reached this conclusion because the fossilized fetus was positioned with its head near the birth canal. While all large land mammals are typically delivered headfirst, so they can breathe during their birth, all modern cetaceans are born tail first to ensure they don’t drown during delivery.

One more excerpt:

The findings, published in the journal PLoS ONE, help fill in a gap in the story of whale evolution. Researchers believe that the first whale ancestor was a furry, four-legged omnivore that evolved into a range of amphibious species nearly 50 million years ago, and then into fully aquatic species around 45 million years ago. Whales eventually lost the connection between their backbone and hind legs, then gradually lost the hind legs and vestigial bones completely. By 30 million years ago, they had evolved into the toothed and baleen whales that we know today.

Note, dear reader, that all of this supports the theory of evolution. But the creationists will continue to insist that we have no evidence.

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One response to “New Discoveries: Earliest Animals and Transitional Whales

  1. Damnit! The 635 Ma Gordon Love paper blows my paleo lectures. I’m gonna have to rewrite them quick. Can’t science just stand still for a moment so I can get up to speed?

    Of course, I could always be persnickety and point out that even if the chemicals are unique to animals, that doesn’t preclude that a single-celled proto-animal could have just as well produced them. Whew… safe for now.