More elephants are being born tuskless thanks to poaching

Poaching is acting as unnatural selection in favoring tuskless African elephants.

elephant face
Photo credit: CAMERON SPENCER

Natural selection as a means of evolution is generally thought of as a slow process, and it usually is. That is, unless there's some unnaturally strong influence at work. And that's exactly what's happening to African elephants. The unnatural influence is humans, or more specifically, poachers, and it's causing an increase in the births of tuskless elephants. Those who do have tusks are becoming less likely to reproduce since they're hunted down and killed for their ivory.

Not every elephant has tusks. In a population without significant poaching going on, from 2 to 6 percent of females are born without tusks. Males without them are less common because they're required weapons for earning procreation rights, and tuskless males don't generally get to reproduce.

In areas where there is poaching, however, the story's very different, and the quest for elephant ivory is changing the types of offspring now being produced. In Gorongosa National Park in Mozambique, half of the older females have tusks. The situation has improved since poaching was brought under control there 20 years ago, but a third of the younger elephants are tuskless nonetheless, a meaningful increase over the historical norm.

In Zambia's South Luangwa National Park and the Lupande Game Management Area, tuskelessness increased from 10.5 percent in 1969 to 38.2 percent in 1989 The numbers have improved slightly since then there as well, but only due to more tusked females migrating from nearby areas.

Elephant in Zambia (HANS HILLEWAERT)

There's been big money in China's black market for ivory, from a peak of $2,100 USD per kilogram in 2014 to $730 per kilogram in February of 2017. There are several factors in the reduction, most notably the easing of demand for luxury goods due to the country's economic slowdown, the government's efforts to shut down the ivory business, and changes in Chinese consumers' attitudes toward ivory and its cost to elephants.

(AFP)

But between 2007 and 2014, some 144,000 African elephants were killed, placing the species perilously close to extinction in some areas. Researchers warn that over time, African elephants may evolve into primarily tuskless creatures, as Asian elephant have.

And that, in itself, is a problem. For elephants, tusks perform a number of important functions. They're weapons for use against predators and other elephants, watering holes can be dug with them and bark can be stripped from trees, and they're useful for pushing away brush and other obstacles in their path. (Interestingly, elephants, when it comes to tusks, can be “lefties" or “righties" — there's evidence that they prefer one tusk over the other.)

So while an elephant without tusks may be safe from poaching, it's in a precarious position when it comes to survival, especially on its own, and being affiliated with a herd that has enough tusks to take care of the necessary tasks is the only real defense.

"Conservationists say an elephant without tusks is a crippled elephant," says the BBC.

Image source: TONY KARUMBA


This is what aliens would 'hear' if they flew by Earth

A Mercury-bound spacecraft's noisy flyby of our home planet.

Image source: sdecoret on Shutterstock/ESA/Big Think
Surprising Science
  • There is no sound in space, but if there was, this is what it might sound like passing by Earth.
  • A spacecraft bound for Mercury recorded data while swinging around our planet, and that data was converted into sound.
  • Yes, in space no one can hear you scream, but this is still some chill stuff.

First off, let's be clear what we mean by "hear" here. (Here, here!)

Sound, as we know it, requires air. What our ears capture is actually oscillating waves of fluctuating air pressure. Cilia, fibers in our ears, respond to these fluctuations by firing off corresponding clusters of tones at different pitches to our brains. This is what we perceive as sound.

All of which is to say, sound requires air, and space is notoriously void of that. So, in terms of human-perceivable sound, it's silent out there. Nonetheless, there can be cyclical events in space — such as oscillating values in streams of captured data — that can be mapped to pitches, and thus made audible.

BepiColombo

Image source: European Space Agency

The European Space Agency's BepiColombo spacecraft took off from Kourou, French Guyana on October 20, 2019, on its way to Mercury. To reduce its speed for the proper trajectory to Mercury, BepiColombo executed a "gravity-assist flyby," slinging itself around the Earth before leaving home. Over the course of its 34-minute flyby, its two data recorders captured five data sets that Italy's National Institute for Astrophysics (INAF) enhanced and converted into sound waves.

Into and out of Earth's shadow

In April, BepiColombo began its closest approach to Earth, ranging from 256,393 kilometers (159,315 miles) to 129,488 kilometers (80,460 miles) away. The audio above starts as BepiColombo begins to sneak into the Earth's shadow facing away from the sun.

The data was captured by BepiColombo's Italian Spring Accelerometer (ISA) instrument. Says Carmelo Magnafico of the ISA team, "When the spacecraft enters the shadow and the force of the Sun disappears, we can hear a slight vibration. The solar panels, previously flexed by the Sun, then find a new balance. Upon exiting the shadow, we can hear the effect again."

In addition to making for some cool sounds, the phenomenon allowed the ISA team to confirm just how sensitive their instrument is. "This is an extraordinary situation," says Carmelo. "Since we started the cruise, we have only been in direct sunshine, so we did not have the possibility to check effectively whether our instrument is measuring the variations of the force of the sunlight."

When the craft arrives at Mercury, the ISA will be tasked with studying the planets gravity.

Magentosphere melody

The second clip is derived from data captured by BepiColombo's MPO-MAG magnetometer, AKA MERMAG, as the craft traveled through Earth's magnetosphere, the area surrounding the planet that's determined by the its magnetic field.

BepiColombo eventually entered the hellish mangentosheath, the region battered by cosmic plasma from the sun before the craft passed into the relatively peaceful magentopause that marks the transition between the magnetosphere and Earth's own magnetic field.

MERMAG will map Mercury's magnetosphere, as well as the magnetic state of the planet's interior. As a secondary objective, it will assess the interaction of the solar wind, Mercury's magnetic field, and the planet, analyzing the dynamics of the magnetosphere and its interaction with Mercury.

Recording session over, BepiColombo is now slipping through space silently with its arrival at Mercury planned for 2025.

Learn the Netflix model of high-performing teams

Erin Meyer explains the keeper test and how it can make or break a team.

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  • There are numerous strategies for building and maintaining a high-performing team, but unfortunately they are not plug-and-play. What works for some companies will not necessarily work for others. Erin Meyer, co-author of No Rules Rules: Netflix and the Culture of Reinvention, shares one alternative employed by one of the largest tech and media services companies in the world.
  • Instead of the 'Rank and Yank' method once used by GE, Meyer explains how Netflix managers use the 'keeper test' to determine if employees are crucial pieces of the larger team and are worth fighting to keep.
  • "An individual performance problem is a systemic problem that impacts the entire team," she says. This is a valuable lesson that could determine whether the team fails or whether an organization advances to the next level.
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