Navigation Links
Primordial fish had rudimentary fingers

Tetrapods, the first four-legged land animals, are regarded as the first organisms that had fingers and toes. Now researchers at Uppsala University can show that this is wrong. Using medical x-rays, they found rudiments of fingers in the fins in fossil Panderichthys, the transitional animal, which indicates that rudimentary fingers developed considerably earlier than was previously thought.

Our fish ancestors evolved into the first four-legged animals, tetrapods, 380 million years ago. They are the forerunners of all birds, mammals, crustaceans, and batrachians. Since limbs and their fingers are so important to evolution, researchers have long wondered whether they appeared for the first time in tetrapods, or whether they had evolved from elements that already existed in their fish ancestors.

When they examined genes that are necessary for the evolution of fins in zebrafish (a ray-finned fish that is a distant relative of coelacanth fishes) and compared them with the gene that regulates the development of limbs in mice, researchers found that zebrafish lacked the genetic mechanisms that are necessary for the development of fingers. It was therefore concluded that fingers appeared for the first time in tetrapods. This reading was supported by the circumstance that the fossil Panderichthys, a transitional animal between fish and tetrapod, appeared to lack finger rudiments in their fins.

In the present study, to be published in Nature, medical x-rays (CT scans) were used to reconstruct a three-dimensional image of Panderichthys fins. The results show hitherto undiscovered elements that constitute rudiments of fingers in the fins. Similar rudiments have been demonstrated once in the past, two years ago in Tiktaaliks, which is a more tetrapod-like group. Together with information about fin development in sharks, paddlefish, and Australian lungfish, the scientists can now definitively conclude that fingers were not something new in tetrapods.

This was the key piece of the puzzle that confirms that rudimentary fingers were already present in ancestors of tetrapods, says Catherine Boisvert.


Contact: Catherine Boisvert
Uppsala University

Related biology news :

1. Scientists rebuild ancient proteins to reveal primordial Earths temperature
2. Meteorites a rich source for primordial soup
Post Your Comments:
(Date:8/23/2017)... , Aug. 23, 2017  The general public,s help is being ... microbiome—the bacteria that live in and on the human body –and are ... The Microbiome ... the human microbiome, starting with the gut. The project's goal is to ... Photo credit: IBM ...
(Date:6/23/2017)... ARMONK, N.Y. and ITHACA, N.Y. ... IBM ) and Cornell University, a leader in dairy ... combined with bioinformatics designed to help reduce the chances ... breaches. With the onset of this dairy project, Cornell ... the Consortium for Sequencing the Food Supply Chain, a ...
(Date:5/16/2017)... , May 16, 2017   Bridge Patient ... organizations, and MD EMR Systems , an ... partner for GE, have established a partnership to ... product and the GE Centricity™ products, including Centricity ... These new integrations will allow ...
Breaking Biology News(10 mins):
(Date:10/12/2017)... ... October 12, 2017 , ... ... announced today that they have entered into a multiyear collaboration to identify and ... researchers with additional tools for gene editing across all applications. , Under the ...
(Date:10/12/2017)... ... October 12, 2017 , ... AMRI, ... and biotechnology industries to improve patient outcomes and quality of life, will now ... testing are being attributed to new regulatory requirements for all new drug products, ...
(Date:10/11/2017)... LINDA, CA (PRWEB) , ... October 11, 2017 ... ... to upregulate any gene in its endogenous context, enabling overexpression experiments and avoiding ... (CRISPRa) system with small RNA guides is transformative for performing systematic gain-of-function studies. ...
(Date:10/11/2017)... ... 2017 , ... Proscia Inc ., a data solutions ... “Pathology is going digital. Is your lab ready?” with Dr. Nicolas Cacciabeve, Managing ... how Proscia improves lab economics and realizes an increase in diagnostic confidence.* ...
Breaking Biology Technology: