A slab of shale with well-preserved macrofossils of algae.
Photo: K. Maloney.
More bad news for Creationists. A chance discovery in the mountains of Canada’s remote Yukon territory, by geobiology graduate student Katie Maloney, has filled in another of those precious god-shaped gaps and provided yet another of those pesky transitional forms that aren't supposed to exist.
The news release from the Geological Society of America tells the story:
Fossil-hunting in the Wernecke Mountains of the Yukon Territory, Canada. The ridge is made of shales of the Dolores Creek Formation, where Maloney and her colleagues collected fossilized algae.
Photo: K. Maloney.
When geobiology graduate student Katie Maloney trekked into the mountains of Canada’s remote Yukon territory, she was hoping to find microscopic fossils of early life. Even with detailed field plans, the odds of finding just the right rocks were low. Far from leaving empty-handed, though, she hiked back out with some of the most significant fossils for the time period.
Eukaryotic life (cells with a DNA-containing nucleus) evolved over two billion years ago, with photosynthetic algae dominating the playing field for hundreds of millions of years as oxygen accumulated in the Earth’s atmosphere. Geobiologists think that algae evolved first in freshwater environments on land, then moved to the oceans. But the timing of that evolutionary transition remains a mystery, in part because the fossil record from early Earth is sparse.
Maloney’s findings were published yesterday in Geology. She and her collaborators found macroscopic fossils of multiple species of algae that thrived together on the seafloor about 950 million years ago, nestled between bacterial mounds in a shallow ocean. The discovery partly fills in the evolutionary gap between algae and more complex life, providing critical time constraints for eukaryotic evolution.
Although the field site was carefully chosen by Maloney’s field team leader, sedimentologist Galen Halverson, who has worked in the region for years, the discovery was an unexpected stroke of luck.
“I was thinking, ‘maybe we’ll find some microfossils,’” Maloney said. The possibility of finding larger fossils didn’t cross her mind. “So as we started to find well-preserved specimens, we stopped everything and the whole team gathered to collect more fossils. Then we started to find these big, complex slabs with hundreds of specimens. That was really exciting!”
Determining if traces like the ones Maloney found are biogenic (formed by living organisms) is a necessary step in paleobiology. While that determination is ultimately made in the lab, a few things tipped her off in the field. The traces were very curvy, which can be a good indicator of life, and there were visible structures within them. The fact that there were hundreds of them twisted together sealed the deal for her.
Few people would likely have noticed the fossils that day.
“We were really lucky that Katie was there to find them because at first glance, they don't really look like anything,” Maloney’s advisor, Marc Laflamme, said. “Katie is used to looking at very weird looking fossils, so she has a bit of an eye for saying, ‘This is something worth checking out.’”
Algae became really important early on because of their role in oxygenation and biogeochemical cycles, so why does it take them so long to show up reliably in the fossil record? It’s definitely making us think more about animal ecosystems and whether or not we’re seeing the whole picture, or if we’re missing quite a bit from a lack of preservation.Maloney and her colleagues in the field wrestled the heavy slabs into their helicopter for safe transport back to the lab at the University of Toronto–Mississauga. She, Laflamme, and their collaborators used microscopy and geochemical techniques to confirm that the fossils were indeed early eukaryotes. They then mapped out the specimens’ cellular features in detail, allowing them to identify multiple species in the community.
Kate Maloney
Geobiology Graduate Student
Department of Chemical and Physical Sciences
University of Toronto Mississauga,
Mississauga, Canada.
While Maloney and her coauthors were writing up their results, they were confident they had found the first macroscopic specimens from this critical time period. During the peer review process, though, they received word from a collaborator that another group in China had made a similar discovery at about the same time—macrofossils from a similar period. That did not dissuade them.
“What’s a few hundred million years between friends?” Laflamme laughed. “I think our fossils have more detail, which makes them easier to interpret… They're beautiful. They're huge, they're well detailed, there's anatomy. Your eyes are just drawn to them.”
Ultimately, having two sets of macrofossils from approximately the same time can only improve the timeline of eukaryotic evolution, serving as critical calibration points for DNA-based biologic dating techniques. The new fossils also push back the time when algae were living in marine environments, indicating that evolution had already occurred in lakes on land. But for Maloney, an expert in sedimentology, they also raise questions about what gets preserved in the rock record and why.
“Algae became really important early on because of their role in oxygenation and biogeochemical cycles,” Maloney said. “So why does it take them so long to show up reliably in the fossil record? It’s definitely making us think more about animal ecosystems and whether or not we’re seeing the whole picture, or if we’re missing quite a bit from a lack of preservation.”
One thing these frauds can normally depend on is the fact that no serious Creationist is ever going to read these scientific articles and papers, and even if they do, few of them will understand them. Of those who occasionally do, many will go on to realise that Creationism is a money-making and political scam, disguised as real science and that they were fooled by charlatans and grifters, exploiting their ignorance and superstitions.
Creationist frauds work hard to persuade their credulous marks that scientists are all part of a Satanic conspiracy to destroy their faith with 'Scientism' because they realise how thoroughly science refutes so much of religion.
Sadly, the team's paper in Geology is behind a paywall but the abstract is availableonline here.
Reference:
Maloney, Katie M.; Halverson, Galen P.; Schiffbauer, James D.; Xiao, Shuhai; Gibson, Timothy M.; Lechte, Maxwell A.; Cumming, Vivien M.; Millikin, Alexie E.G.; Murphy, Jack G.; Wallace, Malcolm W.; Selby, David; Laflamme, Marc
New multicellular marine macroalgae from the early Tonian of northwestern Canada
Geology, v. 49, doi: 10.1130/G48508.1
No comments:
Post a Comment
Obscene, threatening or obnoxious messages, preaching, abuse and spam will be removed, as will anything by known Internet trolls and stalkers, by known sock-puppet accounts and anything not connected with the post,
A claim made without evidence can be dismissed without evidence. Remember: your opinion is not an established fact unless corroborated.