In a groundbreaking study, researchers have successfully decoded the genetic blueprint of the coelacanth, a mysterious fish that has captivated scientists and the public alike. Once believed to have vanished from the face of the Earth 70 million years ago, the coelacanth’s existence was astonishingly revealed in 1938 when fishermen near the Comoros islands, off Africa’s coast, accidentally discovered one. This discovery was followed by the identification of a second species in the waters off Indonesia in 1997. The coelacanth, which can grow up to 5 feet in length and dwells in the shadowy depths of ocean caves, is a living testament to the Earth’s ancient past.
The sequencing of the coelacanth genome has provided invaluable insights into the evolutionary journey from aquatic to terrestrial life. Contrary to previous assumptions, the study clarifies that lungfish, not coelacanths, are the closest living relatives to terrestrial vertebrates. This revelation is supported by a comprehensive analysis of the coelacanth’s genetic material, which offers a more detailed understanding of our own evolutionary history.
The coelacanth is often referred to as a “living fossil” due to its striking resemblance to its fossilized ancestors and its seemingly slow evolutionary pace. Its unique features, such as lobe-finned pectoral and pelvic fins that resemble primitive legs, a skull with a hinged joint allowing for a wide mouth, and a notochord acting as a primitive backbone, highlight its ancient origins. Additionally, the coelacanth possesses thick scales found only in extinct fish species and an electrosensory organ for detecting prey, further emphasizing its prehistoric lineage.
Researchers have observed that the coelacanth’s genes have evolved at a remarkably slow rate, which aligns with the longstanding belief that the species has undergone minimal changes over the last 400 million years. This genetic stability is thought to be linked to the coelacanth’s deep-sea habitat, a relatively unchanging and competition-free environment that has possibly allowed the species to thrive without significant evolutionary pressure.
The study of the coelacanth genome not only sheds light on the evolutionary relationship between aquatic and terrestrial vertebrates but also underscores the importance of preserving these rare glimpses into our planet’s biological history. As we continue to explore the depths of the oceans and the secrets of our genetic heritage, the coelacanth remains a symbol of the enduring mystery and wonder of life on Earth.
*Source: NPR, Nature, and other scientific publications.*
Citations:
[1] https://www.nature.com/articles/nature12027
[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3787270/
[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC534663/
[4] https://www.npr.org/sections/thetwo-way/2013/04/17/177643251/scientists-sequence-genome-of-living-fossil-fish
[5] https://arstechnica.com/science/2013/04/scientists-get-coelacanth-genome-and-a-hint-of-the-origin-of-limbs/
2 comments
DOES FISH DNA SHOW THEY EVOLVED LIMBS?
The recent news is that scientists have discovered some snippets of DNA from an ancient fish that can cause mice to grow limbs. This is wrongly being hailed as evidence that fish had developed legs. Isn’t it interesting that the fish they got the DNA from didn’t have legs!
These snippets of DNA from the fish seem to be “triggering” mechanisms. They can only trigger (“turn on”) genes, such as genes for formation of limbs, but, if the genes for limbs first exist, and since genes for limbs exist in mice then these triggering mechanisms, even if from a fish, will work. None of this means fish evolved legs.
Imagine an evolving fish having part fins and part feet, with the fins evolving into feet. Where‚Äôs the survival advantage? It can’t use either fins or feet efficiently. These fish exist only on automobile bumper stickers!
Genetic and biological similarities between species are no proof of common ancestry. Such similarities are better and more logically explained due to a common Genetic Engineer or Designer (yes, God) who designed similar functions for similar purposes in various species. Genetic information, like other forms of information, cannot arise by chance, so it’s more rational to believe that DNA or genetic similarities between species are due to intelligent design.
The genes already exist for micro-evolution (variations within a biological kind such as varieties of dogs, cats, horses, cows, etc.), but not for macro-evolution (variations across biological kinds such as from sea sponge to human).
Visit my Internet site: THE SCIENCE SUPPORTING CREATION
Babu G. Ranganathan
B.A. Bible/Biology
Author of popular Internet article, TRADITIONAL DOCTRINE OF HELL EVOLVED FROM GREEK ROOTS
Thanks for the tip Babu. I see that your core beliefs are threatened by this discovery and that you’ve been posting on various web sites besides mine.
For others, here is the article ( http://www.livescience.com/28797-coelacanth-genome-sequenced.html ) which mentions limb growth in mice from coelacanth DNA. Very interesting. I’ll try to get the source and break it down to be better understood. It doesn’t make sense to me because details are missing. Live Science mentions Nature, but the Nature article I found does not have any information about mouse limb growth ( http://www.nature.com/news/living-fossil-genome-unlocked-1.12809 )
Regarding your other points: Please understand that the conditions to make a fossil are rare. This is why the fossil record is so incomplete. Most species that ever lived and then became extinct left no fossil evidence. Dust to dust. All the bones are crunched by other animals and nothing identifiable is left.
There are however, well-preserved fossils found in 2004 on Ellesmere Island in Nunavut, Canada of a fish that had the beginnings of legs. We are talking hundreds of millions of years. The legs don’t just pop on one day.
The human inability to understand how long a million years is, much less hundreds of millions, is what makes evolution hard to grasp for some people.
Tiktaalik lived about 375 million years ago. Paleontologists suggest it is part of the transition between non-tetrapod vertebrates (fish) such as Panderichthys, known from fossils 380 million years old, and early tetrapods like Acanthostega and Ichthyostega, which we know from fossils about 365 million years old. So, it appears there was a period of 15 million years to get fish to the first fish-like land animals with four limbs.
As reported in Nature (April 2006) Tiktaalik roseae, has many features of wrist, elbow, and neck that are akin to those of tetrapods. It belonged to a group of lobe-finned fish called Rhipidistia, which may have been the ancestors of all tetrapods. The Tiktaalik is a mixture of primitive fish and derived tetrapod.
The tetrapods, by the way, are the vertebrate land animals with four legs and feet. They include amphibians, reptiles, dinosaurs, birds, and mammals. They also include snakes which evolved from animals with four limbs.
The survival advantage for Tiktaalik’s non-fish features are the ability to move about in shallow muddy water. We know this because of where the fossils were found and because we have examples of fish today that can walk on land. Surprised? Do you know about mudskippers?
Evolution does necessarily not happen once. It is more like a tree with a lot of dead ends, starts and stops. The same features can evolve at different times, even from different starting animals.
Now, have a look for yourself at a real walking fish! You can easily imagine that this fish, if it had feet and could move faster, would be able to get away from the lizards that eat it, and it would reproduce more, thus over the next 15 million years, the mudskipper’s fins used for walking could, like the Tiktaalik, develop into what you would call legs.
With all due respect, science absolutely does not support the theory of creation unless you purposefully misunderstand it.
[youtube=https://www.youtube.com/watch?&v=FLh4ODMBGJE]
You said “These fish exist only on automobile bumper stickers!” If you won’t believe your own eyes, I can’t help you. If your eyes are opened now, don’t get too upset. Losing your religion is not dying. You will evolve new ways to spend your time. But first, I’m sure you have many questions. Ask away. I believe there is a friendly supportive community of people who have survived the transition who are willing to help you recover from superstition. Science is fun! There is so much to learn, and you can contribute. You obviously have an active mind, so go get a biology degree and join us!