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Some excitement comes to JCoS today, as I attempt to include actual pictures! This article is about how fish developed “arms and hands” to eventually become land animals. It is an evolutionary assumption that fish eventually came onto land to become the first land animals, but there is no evidence for this. And in this case, the “evidence” is used to claim that this is a transition between water and land animals. A truly interesting find would be to see this “fish” actually walking on land, but then we have seen that with many currently existing fish species. The thing about “transitional” fossils is that we can never see the actual progression, only a moment in time. It will always be a pipe dream, but an effective one, because there is always “hope” that we will find one that “proves” evolution is true. But instead, keep your hope in Jesus. He is the one we can count on, and He proves Himself every day in our hearts. As always, Red shows assumptions in the article and my comments are in Blue.

 

 

Fish finger fossils show the beginnings of hands

Ashley Strickland-Profile-Image

By Ashley Strickland, CNN

 

Updated 12:11 PM ET, Wed March 18, 2020

(CNN)Researchers have discovered the fossil of a fish with finger-like digits in its fin that lived 380 million years ago, according to a new study. And they believe it bridges the evolutionary gap between marine and land vertebrates as one of the oldest examples of a skeletal pattern resembling a hand.

About 374 million years ago, life on Earth began to transition out of the world’s oceans to walk on land. This gave rise to the tetrapods, or four-limbed vertebrates, that included dinosaurs, land animals and eventually humans. Scientists consider this transition from water to land, and animals acquiring hands and feet, to be one of the most significant events in the history of life on Earth. (Evolutionary theory has one thing correct – fish came before land animals. But the difference was one day, not millions of years.)

But the fossil record about the evolutionary step between marine and land life is sparse. Researchers have focused their efforts on tetrapod-like fish, called elpistostegalians, that lived between 359 and 393 million years ago during the Middle and Late Devonian periods. (Always keep in mind how these dates are arrived at. The geologists assume a date for the rock layer, which is sedimentary and laid down before the layer above it and after the layer below it. The paleontologists then look at the layer a fossil is in and assume a date based on what the geologists said. However, the geologists did not do any dating techniques on the sediment. They only did the dating on the base rock underneath the lowest sedimentary layer and maybe some volcanic ash at other levels. And to do that they made several assumptions as well. Dating is done by making several assumptions, none of which are known to be correct.)

Until now, they had never found the complete skeleton of the pectoral fin, also known as the fore-fin. But researchers have discovered one of the most complete elpistostegalian fossils yet: a 5-foot-long fossilized fish in Miguasha, Quebec.

CT scans of the skeleton revealed at least two skeletal digits that resembled fingers, as well as three more potential ones. They also found an arm, elbow, forearm and wrist attached to the finger-like digits.

All of them were still contained within a fin ray, or webbed flipper-like appendage, but the researchers believe it’s the missing link between fish fins and vertebrate hands.

The study published Wednesday in the journal Nature.

“Today we announce in the journal Nature our discovery of a complete specimen of a tetrapod-like fish, called Elpistostege, which reveals extraordinary new information about the evolution of the vertebrate hand,” said John Long, study author and Strategic Professor in Palaeontology at Flinders University in Australia.

“This is the first time that we have unequivocally discovered fingers locked in a fin with fin-rays in any known fish. The articulating digits in the fin are like the finger bones found in the hands of most animals.”

(These pictures show the actual rock of the fin as well as a colored image from the CT scan as well as a cleaned drawing of the CT scan compared to a similar drawing of a Tulerpeton “hand.” A tulerpeton is presumed to be an air-breathing, semi-aquatic animal that was more comfortable moving in water than on land. Think of an otter. The skeleton of tulerpeton limited, based on a fragmented skull, right fore and hind limbs and a perctoral fragment and some scales.)

To date, this skeletal arrangement is the most similar to previously found tetrapods. And the fact that it was located in the fore-fin suggests it was more like a hand.

This appendage would have aided fish as they explored shallow water habits during the Late Devonian period. (Fish have a natural buoyancy to them. They are as buoyant in shallow waters as they are in deep, assuming the same salinity and temperature. So a fish exploring shallow water would have little need to utilize weight-bearing appendages. It would only be when they wanted to walk on land that weight-bearing would be necessary.)

 

(These drawings are developed from the CT scan of the Elpistostege and the known structure of the human arm. Note the difference in thickness of the “radius” and “ulna.” To become a Tulerpeton, presumably one of the next steps in evolution to land-based, and a mere 15 million years down the road, significant structural changes would have to occur. A second thing to look at is the number of “digits” being formed here. The CT scan shows five digits. This would be a hand like ours, but the dinosaurs, a class of creatures that presumably led to birds, another tetrapod, had only three digits. And Tulerpeton had six. Many tetrapods living today do actually have five digits on their forelimbs, but dinosaurs only had three. God created fish on Day Five of the Creation Week separately from land animals which He made on Day Six. The number of digits a creature has on its limbs is based on what works perfectly for the way they were designed to live.)

“The origin of digits relates to developing the capability for the fish to support its weight in shallow water or for short trips out on land,” said Richard Cloutier, study co-author and professor at the Universite du Quebec a Rimouski. “The increased number of small bones in the fin allows more planes of flexibility to spread out its weight through the fin.” (Most fish have a lot of small bones in their fins, but they are not assumed to be on the evolutionary track to walk on land – even those that are known to be bottom feeders, like catfish. If we are arguing for fish developing arm-like appendages to walk on land, what about the snakehead which is an invasive species from China in Maryland? It does not have the benefit of “arms” but manages to travel over large distances of land to find other water bodies. It uses the body it has to move over land, not allowing “evolution” to take its dear, sweet time to make pseudo-arms for it.)

“The other features the study revealed concerning the structure of the upper arm bone or humerus, which also shows features present that are shared with early amphibians,” Cloutier said. “Elpistostege is not necessarily our ancestor, but it is [the] closest we can get to a true ‘transitional fossil’, an intermediate between fishes and tetrapods.”

Previously, researchers have studied these tetrapod-like fish to better understand how creatures adapted to breathing, hearing and eating on land as they emerged from the water.

Elpistostege watsoni, as the fish has been dubbed, would have been the largest predator dominating Quebec’s shallow marine and estuary habitat 380 million years ago. Sharp fangs helped it snack on other large fish, whose fossils were found in the same area.

Fragments of fossils belonging to this fish were initially found in Quebec in 1938. At the time, they only found a portion of the skull’s roof and assumed it was a tetrapod. (What is revealing about this statement is that Elpistostege had presumably been expending its evolutionary energy changing its head as well as its fins. It was changing two major things at once in preparation for becoming a tetrapod.)

Another piece of the puzzle was found in 1985, revealing it was a lobe-finned fish. Lobe-finned fish differ from others because their fleshy fins connect to the body through a single bone.

And the most complete fossil, which was part of the this study, was originally found in 2010. CT scans of the fossil, followed by detailed analysis of its backbone and fin, occurred after the discovery. The researchers partnered with colleagues from other institutions to continue CT scans, which revealed the digits found in the fin. Their work was finally completed in 2019.

Their years of analysis revealed that this was the most evolutionary fish of its kind.

“This finding pushes back the origin of digits in vertebrates to the fish level, and tells us that the patterning for the vertebrate hand was first developed deep in evolution, just before fishes left the water,” Long said. (This finding tells us nothing, only that there was a fish that had a bone structure that resembles a hand if we look at it with evolutionary glasses. It does not prove that fish eventually began walking on land and became tetrapods. It only proves that God has a wonderful mind, imagining and then creating amazing creatures for us to consider.)

 

https://www.cnn.com/2020/03/18/world/fish-finger-fossil-scn/index.html

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