You don't have to visit the Galapagos Islands to see evolution in action. Sometimes, all you have to do is hatch some eggs.
Layered in the sediments of rivers and lakes are the remains of generation upon generation of tiny animals known as zooplankton. In the 1990s, W. Charles Kerfoot, a professor of biological sciences at Michigan Technological University. was among a team of scientists studying these creatures in Germany when they made a startling discovery: The zooplankton weren't all dead. Or at least their eggs weren't.
"They should have died, but they didn't," Kerfoot said. "They revive, and we don't quite understand how it happens."
It doesn't take much to bring them back to life, either. "We just sieve them out of the sediment and wake them up in an incubator," he says. "Then we grow them up. We have entire populations from nearly 100 years ago."
A whole new field, dubbed by Kerfoot resurrection ecology, has emerged from those original discoveries. Its techniques allow scientists to study organisms from the past and compare them with their modern counterparts.
More recently, Kerfoot has done just that in Portage Lake, located in Michigan’s Upper Peninsula. He revived the eggs of a small, shrimp-like animal, Daphnia retrocurva, that he had found in sediment layers going back to the 1920s.
"We were testing a fundamental theory, Van Valen's Red Queen Hypothesis," Kerfoot explains. "It's the idea from 'Through the Looking Glass' that you must run just to remain in place."
Less colorfully, Leigh Van Valen of the University of Chicago postulated in 1973 that in an evolutionary system, it's not enough to rest on your laurels. Predators and their prey must constantly evolve in response to each other's changes or perish in the attempt.
In the case of D. retrocurva, Kerfoot wanted to know what, if any, changes it had made over the past 80 years. This was during a time when Portage Lake had undergone major changes, and those changes had big impacts on the predator populations that had D. retrocurva on the menu.
As it turned out, D. retrocurva, like Alice, followed the Red Queen's instructions. Eggs from different sediment layers grew up into adults with significantly different characteristics. In particular, their helmets and spines, which make them prickly to eat, changed in relation to predators over the 80-year period of the study.
Such microevolutionary adjustments had been observed in Daphnia populations, but resurrection ecology now allows scientists to bring the historical record to life.
"It's like having Rip Van Winkle wake up in your lab," Kerfoot says.
Michigan Technological University is a leading public research university, conducting research, developing new technologies and preparing students to create the future for a prosperous and sustainable world. Michigan Tech offers more than 120 undergraduate and graduate degree programs in engineering, forestry and environmental sciences, computing, technology, business and economics, natural and physical sciences, arts, humanities and social sciences.
W. Charles Kerfoot | Newswise Science News
Plant seeds survive machine washing - Dispersal of invasive plants with clothes
11.09.2018 | Gesellschaft für Ökologie e.V.
Air pollution leads to cardiovascular diseases
21.08.2018 | Universitätsmedizin der Johannes Gutenberg-Universität Mainz
Augsburg chemists present a new technology for compressing, storing and transporting highly volatile gases in porous frameworks/New prospects for gas-powered vehicles
Storage of highly volatile gases has always been a major technological challenge, not least for use in the automotive sector, for, for example, methane or...
When we put water in a freezer, water molecules crystallize and form ice. This change from one phase of matter to another is called a phase transition. While this transition, and countless others that occur in nature, typically takes place at the same fixed conditions, such as the freezing point, one can ask how it can be influenced in a controlled way.
We are all familiar with such control of the freezing transition, as it is an essential ingredient in the art of making a sorbet or a slushy. To make a cold...
Thin organic layers provide machines and equipment with new functions. They enable, for example, tiny energy recuperators. In future, these will be installed...
Das Zusammenspiel aus Struktur und Dynamik bestimmt die Funktion von Proteinen, den molekularen Werkzeugen der Zelle. Durch Fortschritte in der...
New measurement method allows researchers to precisely follow the movement of individual molecules over long periods of time
The function of proteins – the molecular tools of the cell – is governed by the interplay of their structure and dynamics. Advances in electron microscopy have...
02.10.2018 | Event News
01.10.2018 | Event News
21.09.2018 | Event News
15.10.2018 | Physics and Astronomy
15.10.2018 | Life Sciences
15.10.2018 | Life Sciences