Skip to footer

Scientists find earliest evidence of reproduction in complex organism

Living between 580 million and 541 million years ago rangeomorphs, one of the first complex animals on Earth, had an equally complex reproductive strategy.

|
C. G. Kenchington
This illustration shows a Fractofusus community with clusters that arose from runners sent by the older generation.
|
E.G. Mitchell
A close-up photo of Fractofusus fossils.
|
E.G. Mitchell
The researchers used GPS at a fossil bed in Newfoundland, Canada, to help solve the mystery of how Fractofusus reproduced.

A soft-bodied, fernlike creature reproduced in Earth's ancient oceans about 565 million years ago, making it the earliest known example of procreation in a complex organism, a new study finds.

Many scientists consider the creatures, called rangeomorphs, some of Earth's first complex animals, although it's impossible to know exactly what these organisms were, the researchers said. The creatures prospered in the ocean during the late Ediacaran period, between 580 million and 541 million years ago, just before the Cambrian era. Rangeomorphs could grow up to 6.5 feet (2 meters) in length, but most were about 4 inches (10 centimeters) long.

What's more, rangeomorphs don't appear to have been equipped with mouths, organs or the ability to move around, and the animals likely absorbed nutrients from the water, the researchers said. However, these ancient organisms had an unusually complex reproductive strategy for their time: They likely sent out an "advance party" to settle a new neighborhood, and then colonized the new area, the researchers said. [See Photos of Ancient 'Baby' Rangeomorphs Preserved in Ash]

The findings may help scientists understand the origins of modern marine life, they said.

"Rangeomorphs don't look like anything else in the fossil record, which is why they're such a mystery," study lead author Emily Mitchell, a postdoctoral researcher in the University of Cambridge's department of earth sciences, said in a statement. "But we've developed a whole new way of looking at them, which has helped us understand them a lot better — most interestingly, how they reproduced."

Mitchell and her colleagues looked at fossils of a rangeomorph known as a Fractofusus found in Newfoundland, in southeastern Canada. Like other rangeomorphs, Fractofusus was immobile, and so its fossils capture exactly where the creatures lived in relation to one another during the Ediacaran period.

Using a combination of statistical techniques, high-resolution GPS and computer modeling, the researchers found an intriguing pattern in the distribution of Fractofusus populations. The larger Fractofusus, or "grandparent" specimens, were randomly distributed around the environment, surrounded by distinctive populations of smaller "parent" and "children" Fractofusus, the researchers said.

These patterns of grandparent, parent and children Fractofusus are similar to biological clustering seen in modern plants, the researchers said. In fact, it's likely the creatures had two reproductive methods: The grandparents were likely born from ejected waterborne seeds or spores, whereas the parents and children likely grew from "runners," sent by the older generation, just as strawberry plants grow today.

The "generational" clustering suggests that Fractofusus reproduced asexually using runners called stolons. However, it's unclear whether the waterborne seeds or spores were sexual or asexual in nature, the researchers said.

"Reproduction in this way made rangeomorphs highly successful, since they could both colonize new areas and rapidly spread once they got there," said Mitchell. "The capacity of these organisms to switch between two distinct modes of reproduction shows just how sophisticated their underlying biology was, which is remarkable at a point in time when most other forms of life were incredibly simple."

However, Fractofusus isn’t the only organism with complex reproductive strategies reproducing during that time. A 565-million-year-old tubular invertebrate named Funisia dorothea also lived in clusters, reports a 2008 study in the journal Science. It’s possible that Funisia sent eggs and sperm into the water, a technique called spatfall that is still used by modern coral and sponges. Funisia may have also grown by using an assexual technique called budding, in which a new individual break off from the parent organism, the 2008 study found. 

Rangeomorphs disappeared from the fossil record at the beginning of the Cambrian period, about 540 million years ago, making it difficult to link them to modern organisms, the researchers said. But this type of spatial analysis may help reconstruct the reproductive strategies used by other Ediacaran organisms, and help scientists understand how the organisms interacted with each other as well as their environments, the researchers said.

The study was published online today (Aug. 3) in the journal Nature.

Follow Laura Geggel on Twitter @LauraGeggel. Follow Live Science @livescience, Facebook & Google+. Original article on Live Science.

Copyright 2015 LiveScience, a Purch company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

You've read  of  free articles. Subscribe to continue.
Real news can be honest, hopeful, credible, constructive.
What is the Monitor difference? Tackling the tough headlines – with humanity. Listening to sources – with respect. Seeing the story that others are missing by reporting what so often gets overlooked: the values that connect us. That’s Monitor reporting – news that changes how you see the world.
editor@csmonitor.com
Subscribe
Mark Sappenfield
Editor

Dear Reader,

About a year ago, I happened upon this statement about the Monitor in the Harvard Business Review – under the charming heading of “do things that don’t interest you”:

“Many things that end up” being meaningful, writes social scientist Joseph Grenny, “have come from conference workshops, articles, or online videos that began as a chore and ended with an insight. My work in Kenya, for example, was heavily influenced by a Christian Science Monitor article I had forced myself to read 10 years earlier. Sometimes, we call things ‘boring’ simply because they lie outside the box we are currently in.”

If you were to come up with a punchline to a joke about the Monitor, that would probably be it. We’re seen as being global, fair, insightful, and perhaps a bit too earnest. We’re the bran muffin of journalism.

But you know what? We change lives. And I’m going to argue that we change lives precisely because we force open that too-small box that most human beings think they live in.

The Monitor is a peculiar little publication that’s hard for the world to figure out. We’re run by a church, but we’re not only for church members and we’re not about converting people. We’re known as being fair even as the world becomes as polarized as at any time since the newspaper’s founding in 1908.

We have a mission beyond circulation, we want to bridge divides. We’re about kicking down the door of thought everywhere and saying, “You are bigger and more capable than you realize. And we can prove it.”

If you’re looking for bran muffin journalism, you can subscribe to the Monitor for $15. You’ll get the Monitor Weekly magazine, the Monitor Daily email, and unlimited access to CSMonitor.com.

Subscribe to insightful journalism

QR Code to Scientists find earliest evidence of reproduction in complex organism
Read this article in
https://www.csmonitor.com/Science/2015/0803/Scientists-find-earliest-evidence-of-reproduction-in-complex-organism
QR Code to Subscription page
Start your subscription today
https://www.csmonitor.com/subscribe