(Photo: Wikimedia Commons/ESA/DTU Space)
Earth's protective magnetic field weakened millions of years ago. Although it only faltered briefly, it reportedly boosted the evolution of complex life.
Weak Magnetic Field and Evolution
According to a new study, there was a drop in the strength of Earth's magnetic field between 591 and 565 million years ago. It coincided with the major increase of oxygen levels in our planet's atmosphere and ocean, which experts believed had something to "do with evolution.
Oxygen has long been identified as a key "environmental gatekeeper," allowing for evolutionary innovation and meeting the energy demands of animals," according to the team behind the study.
This rise in oxygen is linked to the emergence of some of the planet's first complex life forms, suggesting that the weakening of the magnetic field was the cause of this increase.
Prior to the emergence of multicellular life about 1.7 billion years ago, life on Earth solely consisted of extremely primitive single-celled organisms for billions of years after it first began to evolve some 3.7 billion years ago. The Ediacaran period, 580 million years ago, is when animals first appeared. At that time, they were primarily soft-bodied, jellyfish-like organisms. However, a dramatic increase in oxygen levels between 575 and 565 million years ago likely caused organisms to diversify and become more complex.
Macroscopic, morphologically complex, and mobile animals need more oxygen to meet their metabolic needs, even though sponges and microscopic animals can thrive at low levels of dissolved oxygen.
"A complex animal ecosystem involving long food chains and predators requires still greater amounts of oxygen," the researchers added.
Numerous lines of geochemical evidence suggest that atmospheric and oceanic O2 levels may have increased during the late Ediacaran Period, notably between 575 and 565 Ma. However, up until today, the causes of this increase in oxygen were unknown.
Researchers learned that between approximately 591 and 565 million years ago, a faint magnetic field existed for about 26 million years. They propose that by allowing greater amounts of hydrogen to escape from our atmosphere and raising the concentration of oxygen, at the same time the magnetic field weakened might have initiated the evolution of more complex life. This congruence begs the question of whether increased H ion loss in a decreased magnetic field facilitated oxygenation, which in turn permitted the Ediacara Fauna's mobile animals and the macroscopic creatures to diversify.
ALSO READ: Human Evolution Is Not Only Driven by Climate Change, Competition Plays a Part Too [Study]
Humans Will Go Extinct in 250 Million Years
In related news, while researchers are still looking for the reason behind our evolution, another study claims that there will be mass extinction in 250 million years. However, humans will go extinct earlier if we continue burning fossil fuels because the calculations do not consider greenhouse gases.
Dr. Alexander Farnsworth, a senior research associate at the University of Bristol's School of Geographical Sciences, who oversaw the study, said that the amount of carbon dioxide would double to the point that humans could not shed the heat through sweat or by cooling their bodies.
Five mass extinctions have already been recorded. However, all of those events were due to natural causes. The sixth mass extinction is reportedly driven by humans due to unsustainable use of land, water, and energy, and climate change.
RELATED ARTICLE: Living Fossils Offer Fundamental Demonstration of Evolutionary Process [Study]
Check out more news and information on Evolution in Science Times.
