Water Fleas' Rapid Evolution: New Study Identifies More Than 300 Varying Genes

In new research, scientists at the University of Birmingham in the United Kingdom, the Katholieke Universiteit Leuven in Belgium, and the Leibniz Institute for Freshwater Ecology and Inland Fisheries, Berlin showed rapid water flea evolution. Specifically, they were able to identify over 300 genes that vary in the water flea's genome.

A ScienceDaily report specified that the animals' unique ability to rapidly evolve in response to their predators had been revealed through genetic sequencing of the water flea population across almost two decades.

These genes, accounting for roughly three percent of all sequenced water flea genes, strengthen changes in behavioral and life history characteristics that improve survival when exposed to predators.

Strikingly, water flea evolution, in response to predation pressure, takes place within only a few generations. It is reconciled by the so-called standing genetic variation, the amount of genetic diversity that a given natural population harbors.

Rapid Water Evolution

The study, "Extensive standing genetic variation from a small number of founders enables rapid adaptation in Daphnia," published in Nature Communications, brings to the forefront of science the essentiality of standing genetic diversity in support for fast adaptation.

It also underscores that reducing the genetic diversity of natural populations has vital consequences for adjusting to environmental change.

According to Dr. Anurag Chaturvedi, lead researcher of the study and is currently at the University of Birmingham's School of Biosciences and former KU Leuven Ph.D. student, they were able to measure the genetic diversity of one specific Daphnia population over almost 20 years.

The lead researcher said they were also able to show clearly how fast evolution occurred in response to environmental pressures.

This type of study will be priceless for understanding the possible effects of future environmental changes on populations of animals.

'Daphnia'

The water flea or Daphnia, a similar Phys.org report said, is central to the ponds and lakes' food webs. Its life cycle comprises a dormant stage that can last for many decades.

Scientists, by awakening dormant stages through resurrection biology, can measure genetic changes at numerous time points in the past and watch evolution as it takes place in nature.

In this research, the researchers were able to hatch dormant eggs, spanning two decades and sequence, the 36 resurrected Daphnia's genome from a fish-farming pond.

During those 20 years, the Daphnia population transitioned from no predation from fish to high fish predation and back to lower predation levels.

High Capacity for Adaptive Evolution

The research team was able to extraordinarily match changes in predation pressure on Daphnia with changes in the DNA over time.

In effect, this new study was able to associate specific changes in the Daphnia's environment of Daphnia with the evolution taking place in their genomes.

In their study, the team discovered that the required DNA variation to kick-start an evolutionary change that spread through a whole population did not need more than five "founding" individual Daphnia from the Daphnia populations' regional set.

The surprising outcome, World News Era stated in a similar report, suggests that animal species like Daphnia have a high capacity for adaptive evolution due to the fact that genetic variation is kept at the landscape level, an essential lesson for conservation biology.

Chaturvedi explained, their ability to examine populations that evolve through the decades is priceless for "both fundamental and applied science discoveries."

Related information about Daphnia is shown on Luthien Ellessar's YouTube video below:

Check out more news and information on Animals in Science Times.