This kind of study, which was funded by the Natural Environment Research Council, has previously not been possible because although fossils preserve direct evidence of evolutionary change over thousands and millions of years, working out exactly what a long-dead fossil animal was eating when it was alive, and establishing a link between feeding and evolution, is very difficult.
The stickleback tooth chips and scratches were formed 10 million years ago as part of the normal process of tooth wear while the fish were alive and feeding in a large lake in what is now Nevada. “Like footprints in sand, the wear on teeth preserves a trail of evidence of how a fish feeds and what it feeds on,” says Dr Mark Purnell from the University of Leicester, lead author on the report. “The difficult bit was learning how to read that trail.”
The research team, based at the universities of Leicester, UK, and Stony Brook, USA, captured living stickleback (of the common or garden pond variety), fed them different kinds of food in different conditions and then examined their teeth using a powerful electron microscope. The team also looked at the teeth of wild stickleback, which had been feeding naturally, from Alaskan lakes.
Professor Paul Hart, also from the University of Leicester, explains: “The teeth might be tiny, but we discovered a very clear picture. Stickleback that feed from lake bottoms have very different tooth wear from those that eat water fleas and the like which swim around in open water”. The fossil teeth have almost exactly the same wear patterns as living stickleback but they have changed through time.
Dr. Mike Bell, from Stony Brook University adds, “Stickleback are spiky little characters, with armour and spines on their sides and along their backs. We found that evolutionary changes in these characteristic features were closely linked to shifts in feeding away from the lake bottom. As feeding changed over thousands of years, the stickleback in the fossil sequence evolved to have fewer spines.”
Scientifically, this is highly significant. That feeding and diet is an important control on evolution is exactly what would be expected from evolution by natural selection, but this is the first time that this aspect of Darwin’s theory has been directly testable using fossils that record real evolutionary change over many thousands of years. “We now know that by looking at microscopic chips and scratches on fish teeth we can investigate important evolutionary questions that were previously in the realm of the unknowable” concludes Purnell.
Marion O'Sullivan | alfa
Novel method for investigating pore geometry in rocks
18.06.2018 | Kyushu University, I2CNER
Decades of satellite monitoring reveal Antarctic ice loss
14.06.2018 | University of Maryland
Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.
Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...
The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.
Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.
An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.
Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...
Light detection and control lies at the heart of many modern device applications, such as smartphone cameras. Using graphene as a light-sensitive material for...
Water molecules exist in two different forms with almost identical physical properties. For the first time, researchers have succeeded in separating the two forms to show that they can exhibit different chemical reactivities. These results were reported by researchers from the University of Basel and their colleagues in Hamburg in the scientific journal Nature Communications.
From a chemical perspective, water is a molecule in which a single oxygen atom is linked to two hydrogen atoms. It is less well known that water exists in two...
13.06.2018 | Event News
08.06.2018 | Event News
05.06.2018 | Event News
18.06.2018 | Earth Sciences
18.06.2018 | Process Engineering
18.06.2018 | Life Sciences