More Denton: unlikely transitions (Introduction)

by David Turell , Thursday, August 03, 2017, 01:50 (2670 days ago) @ David Turell

From the previous entry from Michael Denton:

"The sudden appearance of the angiosperms, I observed in Evolution, is a persistent anomaly which has resisted all attempts at explanation since Darwin's time.How true. No real flowers are found in any group of plants save those extant today, and no putative ancestral group has been identified in the fossil record, or by molecular phylogenetics. There is no universally accepted set of transitional forms leading up to earliest angiosperms."

Now a virtual computer simulation has produced a possible flower reproduction:

https://www.livescience.com/60000-first-flower-on-earth.html?utm_source=ls-newsletter&a...

"There are many mysteries in plant evolution, and Sauquet and his colleagues were determined to solve one of the biggest ones: what the original angiosperm looked like.  

"We know a lot about the evolutionary history of this group, in particular how plant families are related to one another, but we still know very little about how their emblematic structure — the flower — has evolved and diversified since their origin," Sauquet told Live Science in an email. "That's why I decided to join forces with other experts and create the international eFLOWER initiative to tackle these questions."

"Because there are no known fossils of the world's oldest angiosperm— the oldest uncontroversial fossil flower dates to about 130 million years ago, a good 10 million years before the likely birth of the earliest flower — Sauquet and his colleagues used a method known as ancestral state reconstruction, he said.

***

"The results showed that when flowers first popped up on Earth, they went through a series of simplifications in which structures were reduced or merged until the flowers settled on an optimal and stable architecture, he said.

"Once flowers achieved this stable architecture, they likely started to diversify and develop other features, such as symmetry, he noted.

"However, there is still much to learn about early angiosperms and their environments. For instance, it's unclear which animals might have eaten or pollinated these flowers, although "some authors have speculated that flies might have been among the earliest pollinators of flowers," Sauquet said.

"Moreover, studies on fossilized animal poop, known as coprolites, show that certain paleo-beasts munched on angiosperms. For example, an unknown dinosaur — but apparently a large one, judging from the size of its droppings — ate angiosperms about 75 million years ago, according to research presented at the 2015 Society of Vertebrate Paleontology conference in Dallas."

Comment: As noted in the previous entry and in this one, no one knows how angiosperms really evolved and presents as much a gap in the evolutionary story as the Cambrian Explosion, which is why it is known as the plant bloom. Darwin was puzzled by both. See the pictures in the article.