from the world's big
Scientists uncovered the secrets of what drove some of the world's last remaining woolly mammoths to extinction.
Every summer, children on the Alaskan island of St Paul cool down in Lake Hill, a crater lake in an extinct volcano – unaware of the mysteries that lie beneath.
Animals are adapting all the time these days to stay out of our way.
- Evolution is something that happens over time, but animals (humans included) are always mutating and adapting.
- Thanks to human presence and interference, animals are experiencing what has been referred to as "human-guided evolution."
- More animals are becoming night owls. Pollution determines which moths dominate the tree trunks of the U.K. Are these short-term changes, or is humanity doing lasting damage?
We often think of evolution as taking place over extended periods of time as mutations prove themselves advantageous, or not. Mutations, though, are not rare things: They happen all the time. Scientists estimate that there were 37 trillion of them in your own body just over the last 24 hours. (It's amazing more things don't go wrong, right?) The characteristics we see in ourselves and other organisms are merely the latest winners in a wild and woolly mutation free-for-all competition, in which nature, or random chance, tries out many wonderful, bizarre, and ridiculous traits as things settle out over the long term.
Adaptations in response to changing environmental factors occur all the time, too: An attribute that may have been meaningless before may suddenly become very helpful. Here in the Anthropocene, animals are adapting to all sort of habitat changes we've imposed on them. While not yet long-term changes, necessarily, these characteristics suggest we may be having a considerable impact on the ongoing process of evolution in the world's organisms.
Image source: Marek R. Swadzba/Shutterstock
Before the Industrial Revolution got up and running in the U.K., light-colored peppered moths, Biston betularia morpha typica, were a common sight. However, by about 1864, they'd been essentially replaced by a darker peppered-moth cousin, Biston betularia morpha carbonaria. Why?
Pollutants — mostly coal soot —covered the British countryside, darkening its trees. Worse, sulfur dioxide emissions wiped out many of the trees' lichen and moss coverings. Against these darkened backdrops, light-colored peppered moths became far too easy to spot by predators. Better suited were the darker peppered moths, which soon came to dominate the habitat — by 1895, some 95 percent of peppered moths spotted were the darker variety.
Fortunately, the Industrial Revolution days passed, with dirty factories over time being replaced by cleaner alternatives, and today, the light-colored peppered moths are back on top.
The story is a pretty fast-paced and dramatic example of how extreme our impact can be, and also — and there's a hopeful feeling to this — how short-lived it can be if we fix what we've broken.
Urban vs. rural red fox skull measurements
Image source: K.J. Parsons, et al
Researchers published in June a really interesting study regarding a surprising way in which foxes are adapting to life in human-dominated urban environments.
An examination of 111 red fox skulls from London, UK, revealed "urban individuals tending to have shorter and wider muzzles relative to rural individuals." Essentially, the more urban a fox's environment is, the shorter its snout was likely to be. The change may be considered an example of Darwin's "domestication syndrome," as Big Think previously reported.
The study suggests it's all about the biomechanics benefits imparted by such a change:
"Firstly, a shorter snout, as found in urban foxes, should confer a higher mechanical advantage but with reduced closing speed of the jaw. This may be advantageous in an urban habitat where resources are more likely to be accessed as stationary patches of discarded human foods. Furthermore, in some cases, these foods may require a greater force to access them, explaining the expanded sagittal crest in skulls of urban foxes."
If these traits make an individual fox better suited to its city life, it's that much more likely to survive and reproduce than a longer-snouted competitor.
Nighttime on human Earth
Image source: Viktor Grishchenko/Shutterstock
Habitat loss is the single most destructive thing we're doing to animals. It can lead to utter displacement and death, and it can also change the way animals go about doing the things they need to do to survive.
In many cases, animals dealing with fresh human encroachment bend before they break, and some are trying to carry on around us, so to speak. A 2018 study in the journal Science finds, for example, that animals are becoming more nocturnal to get out of the bipeds' way.
The authors of the study analyzed data from 76 other reports to learn how 62 species on six continents were trying to adapt to our intrusive presence. The data was sourced from all sorts of devices such as cameras to GPS trackers, and ran the gamut from 'possums to pachyderms.
What the researchers found was that animals known to split their activities between day and night were overwhelmingly becoming busier after dark. There was a 68 percent increase in nighttime activity among such animals.
If this habitat pressure continues, will we start to see individuals with, for example, better night vision, come to dominate as competitors for scarce resources? It'll be interesting to see.
When people say, "Such and such animal has this trait because it allows them to…" what they're really saying is that "Of all the crazy mutations that nature tried out, individuals with this mutation fared better than others did." Whether it's effective camouflage, the ditching of a trunk, or becoming a night owl — except for owls who already… never mind — temporary adaptations become fixed evolutionary traits when the conditions in which they are beneficial remain in place long enough. In the case of the pressure we're continually imposing on other life forms, it bears saying that only the ones lucky enough to survive humankind's challenging influence in the first place will get that chance to change.
Exploring how a small change in your DNA sequence can make you a natural blonde.
A few weeks after preparing them, Dr Catherine Guenther checked her mouse embryos and knew that she had identified the source of a blond-haired mutation in human DNA.
A 2017 University of Wisconsin-Madison study was the first of it's kind to show structural differences in the psychopathic brain.
- According to a 2017 study led by the University of Wisconsin-Madison, psychopaths have reduced connections in the areas of the brain that control fear, anxiety, empathy and sentimentality.
- Psychopathy is typically diagnosed using a 20-item checklist called the Hare Psychopathy Checklist.
- Psychopathic tendencies could be considered "warning signs" of psychopathy, but it's important to note that not everyone who shows psychopathic tendencies becomes a psychopath.
Defining psychopathy<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzQxMDkwMi9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYwNTk2MTAyOH0.yVAVp2AYmR0i5hPAhhY-R1jafU2y0shl5R35K2rOnCg/img.jpg?width=1245&coordinates=0%2C92%2C0%2C92&height=700" id="531fa" class="rm-shortcode" data-rm-shortcode-id="d45c27dc8187d30f709739ca98c9913f" data-rm-shortcode-name="rebelmouse-image" alt="concept of psychopathy split personality manipulation and deceit man showing half his true face" />
Psychopathy is typically diagnosed using a 20-item checklist called the Hare Psychopathy Checklist.
Photo by FGC on Shutterstock<p>Psychopathy, like many other conditions, is a spectrum. Common traits of psychopaths can include things like superficial charm, grandiose sense of self-worth, pathological lying, manipulation, lack of remorse or guilt, lack of empathy, behavioral problems in early life, impulsivity, and shallow affect (reduced emotional responses) to name a few.<br></p><p>Psychopathy is typically diagnosed using a 20-item checklist called the <a href="http://www.clintools.com/victims/resources/assessment/personality/psychopathy_checklist.html" target="_blank">Hare Psychopathy Checklist</a>. This list features questions that gauge common traits such as a lack of empathy, pathological lying, and impulsivity (among many others). </p><p>Each question on this scale is then scored on a three-point scale: The item doesn't apply (0), the item applies to a certain extend (1), or the question fully applies (2). The bar for "clinical psychopathy" is 30 points on this test. </p><p>For reference, here are some of the scores of notable evaluations: </p><p>Ted Bundy - 39/40<br>Richard Ramirez - 31/40<br>Brian David Mitchell - 34/40</p><p><strong>Differentiating psychopathy and sociopathy </strong></p><p>The terms "psychopath" and "sociopath" are often used interchangeably but they aren't the same - and the <a href="https://psychcentral.com/blog/differences-between-a-psychopath-vs-sociopath/#:~:text=Psychopaths%20tend%20to%20be%20more,much%20of%20a%20normal%20life." target="_blank">difference is quite important</a>. A sociopath is someone with antisocial tendencies that are specific to social or environmental factors. A psychopath is someone whose traits are more innate.</p><p>A psychopath will be more manipulative but can be seen by others to lead a charming, "normal" life - whereas sociopaths tend to be more erratic, rage-prone, and are unable to keep up the facade of normality. </p>
Psychopathic tendencies versus psychopathy<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzQxMDkwNS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYzNjYzMTQ5OX0.IkfptXc5e1auSwTo_Bqpasjwbh4i1nLS8r8Xmm2EJEI/img.jpg?width=980" id="8b403" class="rm-shortcode" data-rm-shortcode-id="0581a77d5f1e4b73e07c019aeda5971d" data-rm-shortcode-name="rebelmouse-image" alt="concept of trying on many faces hiding your true personality psychopath" />
A psychopath may be able to create a seemingly typical personality and life to fool others. Psychopathic tendencies don't always extend into psychopathy.
Photo by FGC on Shutterstock<p><strong>What causes psychopathy?</strong></p><p>Brain anatomy, genetics, and the person's environment may all contribute to the development of psychopathic traits. However, it's important to note that not all psychopathic traits and tendencies mean the person will grow into a psychopath.</p><p><strong>What are psychopathic tendencies? </strong></p><p>Psychopathic tendencies could be considered warning signs of psychopathy, but it's important to note that not everyone who shows psychopathic tendencies becomes a psychopath. Some, with the intervention of various therapies and strong, nurturing relationships, can assimilate to a relatively normal way of life. </p><p>The most well-known case of this would be the case of Beth Thomas. The subject of a 1990 documentary entitled "Child of Rage," Beth began to show psychopathic tendencies extremely early in life after suffering physical neglect and sexual abuse at the hands of her birth father before the age of one. </p><p>Later moved into an adoptive family where she could get the help she needs, the documentary (<a href="https://www.bitchute.com/video/pr3tmwyZAn0f/" target="_blank">which you can view here</a>, be warned, this footage may be disturbing to some) showed the disturbing thought process of a young 6-year-old girl struggling with an attachment disorder that led to psychopathic tendencies. </p><p>However, Beth, with the help of her adoptive family and professionals, became a <a href="https://www.bitchute.com/video/pr3tmwyZAn0f/" target="_blank">relatively typical young woman</a> who works as a nurse and has co-authored a book called "More Than a Thread of Hope" with her adoptive mother.</p><p><strong>Psychopaths' brains show differences in structure and function</strong></p><p><a href="https://www.med.wisc.edu/news-and-events/2011/november/psychopaths-brains-differences-structure-function/" target="_blank">According to a 2017 study</a> led by the University of Wisconsin-Madison, psychopaths have reduced connections in their brains between the ventromedial prefrontal cortex (vmPFC) and the amygdala. </p><p>This is noteworthy because of the functions of both parts in play - the vmPFC is responsible for sentimentality, empathy and guilt and the amygdala mediates fear and anxiety. </p><p>Not only did the research here show there were differences in how these parts of the psychopathic brain functioned, but this was the first study of it's kind to show physical (structural) differences in the brains of psychopaths. </p><p><strong>How common is psychopathy? </strong></p><p>While there may never be a specific answer to this, there have been several studies that can give us insight into how common psychopathy is. <a href="https://www.livescience.com/16585-psychopaths-speech-language.html#:~:text=Psychopaths%20make%20up%20about%201,profoundly%20selfish%20and%20lack%20emotion." target="_blank">According to most research</a>, psychopaths make up about 1 percent of the general population. <a href="https://www.psychologytoday.com/us/blog/what-mentally-strong-people-dont-do/201602/5-traits-actual-psychopaths#:~:text=While%20about%20one%20percent%20of,the%20criteria%20for%20being%20psychopaths.)" target="_blank">Additional research</a> claims up to 15 percent of the U.S prison population may meet the criteria for being psychopaths. </p>
Inbreeding leads to a problematically small gene pool.