Simple Science is an attempt to make the past week’s science news simple.
This week in science, we discuss how the deep ocean is mitigating the impact of climate change, how bonobos' social behavior may provide insight into human evolution and how an insect was trapped in amber over 44 million years ago.
The ocean and climate change
For the past 1,200 years, the deep North Atlantic Ocean has been slowly mitigating the effects of the warming climate. Now, scientists are wondering if this natural occurrence is slowing down.
Researchers at University College London and Woods Hole Oceanographic Institution (WHOI) have come together to study this phenomenon. Previously, scientists have only had access to temperatures of the deep ocean from the last 20 to 30 years, thanks to modern thermometers. Now, samples from the North Atlantic Ocean have allowed these scientists to study the temperature changes in the surface and deep ocean from up to 1,200 years ago.
These samples come from sediments in Iceland, where overflows from the Nordic Seas seep into the deep North Atlantic. This occurrence results from the Atlantic Meridional Ocean Circulation (AMOC), which carries warm water from the North into the cooler, deeper water of the South.
The ocean has always played a large role in determining the climate of the Earth. Evidence of this dates back to the Little Ice Age when Earth was so cold the Baltic Sea froze over. Twice.
During this time, it’s possible that the ocean released heat into the atmosphere and warmed the freezing Earth. Now, the opposite is happening.
Thanks to the samples from the North Atlantic, scientists suspect that the ocean has absorbed and stored over 90% of excess heat as the Earth’s surface warms. Meaning the ocean is responsible for slowing the warming of the Earth.
However, this process may be beginning to slow. It’s unknown what the cause of the potential downtrend is, but if true, it could have devastating effects on the rate of climate warming.
For more details on the study, read the paper here.
One of humans' closest relatives, the bonobos, is learning to socialize with other social groups, often without any benefits for themselves. Strangely enough, behavior like this is typically found only in humans.
Bonobos are a distinct species but share many characteristics with the common chimpanzee. This species of ape can only be found in the humid forests of the Democratic Republic of Congo. Most commonly south of the Congo River and north of the Kasai River.
Recently, bonobos have been recorded grooming and sharing food with those outside their social groups. For two years, two bonobo groups were studied by ecologists from the German Primate Center in Göttingen and Harvard University. During this time, the researchers observed almost 100 interactions between the two groups.
These meetings often led to grooming interactions or food sharing but also included the formation of partnerships. The partnerships between the two bonobo groups were established to attack a third individual and showcased the species' ability to cooperate.
It is unknown whether this cooperation resulted from a cultural system previously formed by the bonobos over generations or if these instances were purely circumstantial. Despite the unknowns, further examination of our ape relatives could reveal how humans evolved into the social order as we know it today.
For more information about the bonobo behavior, read the study here.
An insect trapped in ancient amber
An insect trapped in amber that has been sitting in storage for 80 years, waiting for technology to allow scientists to uncover its secrets, has finally been cracked open.
Katydids are everywhere except Antarctica and are known for their unique mating call. This grasshopper-esque insect is still around today but has many extinct relatives, including one recently found trapped in amber around 44 million years ago.
The nature of this relic is impressive because of how rare well-preserved katydid fossils are, especially the preservation of its internal organs. Luckily for modern-day scientists, this frozen-in-time specimen also had sap flow into its unique and delicate ear structure.
As one of the first animals to use sound to communicate, katydids quickly found that their communication tool was attracting unwanted attention.
Katydids are hunted by echolocating predators. Fortunately, around the time this katydid was trapped in the resin on a pine tree, the insect had just begun to develop higher frequency calls to avoid catching the attention of bats. At the same time, their ears were developing to listen to bats.
The evolving calls, created by the insect scraping its wings together, eventually evolved to use ultrasonic sounds. This means that the katydid's call, over 20 kHz, would have been inaudible to human ears.
The petrified katydid in question had been discovered years prior, in 1936, but it wasn’t until now that modern scanning technology allowed researchers to look inside the amber. With this technology, scientists were able to recreate the ear structure of the preserved katydid and discover how sound traveled throughout its ear.
Researchers found that katydids best hear at 30 kHz but may have also heard sounds at 60 to 90 kHz. Hearing at these higher frequencies would have been utilized for locating hunting bats.
Read more about the nature of the evolutionary battle between bats and insects here.
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