Dogs are animals of integrity. We have much to learn from them.
Category: Science
Just a single image!
The vet practice we use is Lincoln Road Veterinary Clinic, and we have used them for quite a few years. They recently sent out a mailer that contained the following:
Now the ‘CALL US’ has to be the vet in your own location; that’s obvious!
But nonetheless I thought it was worth sharing with you.
Our pets are very special!
A really fascinating article from The Conversation on Imagination.
The website The Conversation had another very interesting link to something that sorts out the humans from all other life forms. It is imagination!
I have pleasure in republishing it!
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Andrey Vyshedskiy, Boston University
Published February, 23rd, 2023
You can easily picture yourself riding a bicycle across the sky even though that’s not something that can actually happen. You can envision yourself doing something you’ve never done before – like water skiing – and maybe even imagine a better way to do it than anyone else.
Imagination involves creating a mental image of something that is not present for your senses to detect, or even something that isn’t out there in reality somewhere. Imagination is one of the key abilities that make us human. But where did it come from?
I’m a neuroscientist who studies how children acquire imagination. I’m especially interested in the neurological mechanisms of imagination. Once we identify what brain structures and connections are necessary to mentally construct new objects and scenes, scientists like me can look back over the course of evolution to see when these brain areas emerged – and potentially gave birth to the first kinds of imagination.
After life emerged on Earth around 3.4 billion years ago, organisms gradually became more complex. Around 700 million years ago, neurons organized into simple neural nets that then evolved into the brain and spinal cord around 525 million years ago.
Eventually dinosaurs evolved around 240 million years ago, with mammals emerging a few million years later. While they shared the landscape, dinosaurs were very good at catching and eating small, furry mammals. Dinosaurs were cold-blooded, though, and, like modern cold-blooded reptiles, could only move and hunt effectively during the daytime when it was warm. To avoid predation by dinosaurs, mammals stumbled upon a solution: hide underground during the daytime.
Not much food, though, grows underground. To eat, mammals had to travel above the ground – but the safest time to forage was at night, when dinosaurs were less of a threat. Evolving to be warm-blooded meant mammals could move at night. That solution came with a trade-off, though: Mammals had to eat a lot more food than dinosaurs per unit of weight in order to maintain their high metabolism and to support their constant inner body temperature around 99 degrees Fahrenheit (37 degrees Celsius).
Our mammalian ancestors had to find 10 times more food during their short waking time, and they had to find it in the dark of night. How did they accomplish this task?
To optimize their foraging, mammals developed a new system to efficiently memorize places where they’d found food: linking the part of the brain that records sensory aspects of the landscape – how a place looks or smells – to the part of the brain that controls navigation. They encoded features of the landscape in the neocortex, the outermost layer of the brain. They encoded navigation in the entorhinal cortex. And the whole system was interconnected by the brain structure called the hippocampus. Humans still use this memory system for remembering objects and past events, such as your car and where you parked it.
Groups of neurons in the neocortex encode these memories of objects and past events. Remembering a thing or an episode reactivates the same neurons that initially encoded it. All mammals likely can recall and re-experience previously encoded objects and events by reactivating these groups of neurons. This neocortex-hippocampus-based memory system that evolved 200 million years ago became the first key step toward imagination.
The next building block is the capability to construct a “memory” that hasn’t really happened.
The simplest form of imagining new objects and scenes happens in dreams. These vivid, bizarre involuntary fantasies are associated in people with the rapid eye movement (REM) stage of sleep.
Scientists hypothesize that species whose rest includes periods of REM sleep also experience dreams. Marsupial and placental mammals do have REM sleep, but the egg-laying mammal the echidna does not, suggesting that this stage of the sleep cycle evolved after these evolutionary lines diverged 140 million years ago. In fact, recording from specialized neurons in the brain called place cells demonstrated that animals can “dream” of going places they’ve never visited before.
In humans, solutions found during dreaming can help solve problems. There are numerous examples of scientific and engineering solutions spontaneously visualized during sleep.
The neuroscientist Otto Loewi dreamed of an experiment that proved nerve impulses are transmitted chemically. He immediately went to his lab to perform the experiment – later receiving the Nobel Prize for this discovery.
Elias Howe, the inventor of the first sewing machine, claimed that the main innovation, placing the thread hole near the tip of the needle, came to him in a dream.
Dmitri Mendeleev described seeing in a dream “a table where all the elements fell into place as required. Awakening, I immediately wrote it down on a piece of paper.” And that was the periodic table.
These discoveries were enabled by the same mechanism of involuntary imagination first acquired by mammals 140 million years ago.
The difference between voluntary imagination and involuntary imagination is analogous to the difference between voluntary muscle control and muscle spasm. Voluntary muscle control allows people to deliberately combine muscle movements. Spasm occurs spontaneously and cannot be controlled.
Similarly, voluntary imagination allows people to deliberately combine thoughts. When asked to mentally combine two identical right triangles along their long edges, or hypotenuses, you envision a square. When asked to mentally cut a round pizza by two perpendicular lines, you visualize four identical slices.
This deliberate, responsive and reliable capacity to combine and recombine mental objects is called prefrontal synthesis. It relies on the ability of the prefrontal cortex located at the very front of the brain to control the rest of the neocortex.
When did our species acquire the ability of prefrontal synthesis? Every artifact dated before 70,000 years ago could have been made by a creator who lacked this ability. On the other hand, starting about that time there are various archeological artifacts unambiguously indicating its presence: composite figurative objects, such as lion-man; bone needles with an eye; bows and arrows; musical instruments; constructed dwellings; adorned burials suggesting the beliefs in afterlife, and many more.
Multiple types of archaeological artifacts unambiguously associated with prefrontal synthesis appear simultaneously around 65,000 years ago in multiple geographical locations. This abrupt change in imagination has been characterized by historian Yuval Harari as the “cognitive revolution.” Notably, it approximately coincides with the largest Homo sapiens‘ migration out of Africa.
Genetic analyses suggest that a few individuals acquired this prefrontal synthesis ability and then spread their genes far and wide by eliminating other contemporaneous males with the use of an imagination-enabeled strategy and newly developed weapons.
So it’s been a journey of many millions of years of evolution for our species to become equipped with imagination. Most nonhuman mammals have potential for imagining what doesn’t exist or hasn’t happened involuntarily during REM sleep; only humans can voluntarily conjure new objects and events in our minds using prefrontal synthesis.
Andrey Vyshedskiy, Professor of Neuroscience, Boston University
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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There we are! As the author of the article says: “Most nonhuman mammals have potential for imagining what doesn’t exist or hasn’t happened involuntarily during REM sleep; only humans can voluntarily conjure new objects and events in our minds using prefrontal synthesis.“
It has been a very long journey for us humans to be equipped with imagination. One wonders what the next ten or twenty years will bring? Any thoughts you want to leave as comments?
Another excellent guest post from Penny Martin.
I love what Penny does and it sure does take the pressure off me because I know that Penny’s posts are first class.
This is a topic that every dog owner is keen on – keeping one’s dog fit and healthy.
Over to Penny.
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Image: Pexels
Keep Your Dog Healthy and Fit With This Essential Care Guide
Keeping your dog healthy and fit is a priority if you want to ensure he lives a long and happy life, but it can be difficult to know where to start. It’s important to make sure that your pup stays active, eats the right food, and gets the proper amount of exercise, but there’s more you can do to help him get fit and maintain great health. Use this guide from Learning from Dogs to create a wellness strategy for your four-legged friend and give him the long life he deserves.
Help Your Dog Stay Active
It’s important to keep your pup active throughout the day, especially if he spends time home alone while you’re at work. Take him on walks or let them run around in the yard; these activities will help keep them physically fit as well as mentally stimulated, and you can hire a pet sitter or dog-walker to help out. If you live in an area that isn’t very dog-friendly, look for a local dog park where he can run around safely.
Stimulate His Mind
While physical activity is crucial for your pet, there are also many toys and products available on the market that can help increase his activity levels. Investing in dog puzzles, treat dispensers, and chew toys can help keep your dog entertained while also providing an opportunity to burn off some extra energy throughout the day. This will also work to prevent behavioral issues if he spends time alone.
Improve His Diet With Quality Food
Investing in higher-quality food for your pup is essential for their health and well-being. Look for foods that are made with natural ingredients and provide all the nutrients they need. Avoid foods with artificial colors, flavors, and preservatives as these could potentially be harmful to your dog’s health.
You can also try air-dried food, which is cooked slowly to ensure it retains the maximum amount of nutrients and flavor. This option deserves a look, as it is also low in carbs and higher in protein than wet food options. You can even order a sample to check it out for yourself before investing.
Regulate Meals and Treats
In addition to making sure he has the right type of food, it’s important to feed your dog the required amount of food each day according to his size and age. Too little or too much could lead to health issues down the line. Additionally, limit treats, as they can contain high amounts of sugar which could lead to weight gain or other health problems over time.
Get Professional Advice
If you notice that your pup needs to lose a significant amount of weight, Chewy says that it’s best to work with a vet who can provide advice on how best to do so safely without causing harm or stress to him. Doing it this way will guarantee that your weight loss plan is secure, and you’ll still be able to give him the best possible nutrition. This is especially important if your dog is older.
Prepare With The Right Gear
Having quality gear like durable leashes and harnesses when taking your pet out for walks is essential for their safety as well as yours. Investing in quality gear now will save you money in the long run, as it will last longer than cheaper alternatives which may break easily over time due to wear and tear. Look for a harness that is comfortable and adjustable in a durable fabric.
Treat Your Dog with the Love They Deserve
Keeping your dog safe, comfortable, and healthy can go a long way toward ensuring that he’s with you for a long time. By feeding him high-quality dog food, making sure he gets enough exercise, and investing in the right gear, you can give your dog many more years. Just make sure you consult your vet with any issues along the way.
We can – and should – learn a lot from our four-legged friends and their ability to give unconditional love. Check out Learning from Dogs online to find inspiration for loving and living your life every day.
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All very sound advice and, once again, Penny is to be thanked for submitting this guest post. Thank you, Penny!
Why it is so important!
We go to the local Club Northwest. Jean attends the Rock Steady class and I work for an hour with Bruce Pilgreen, one of the staff. Bruce is very knowledgeable of human bodies and, indeed, trained as a Coach some years ago.
About a month ago Bruce showed me how to lay on my back, with my legs pulled back and my head slightly raised on a small cushion. My hands were palm upwards and about forty degrees either side of my body. The point of this position was to feel my spine, particularly my lower spine, flat against the ground and practice deep breathing at the same time. It was all to do with posture and Bruce remarked how common bad posture was to be seen out in the streets.
Well I came across a MedlinePlus item on Posture and wanted to share it with you all.
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Guide to Good Posture
Good posture is about more than standing up straight so you can look your best. It is an important part of your long-term health. Making sure that you hold your body the right way, whether you are moving or still, can prevent pain, injuries, and other health problems.
Posture is how you hold your body. There are two types:
It is important to make sure that you have good dynamic and static posture.
The key to good posture is the position of your spine. Your spine has three natural curves – at your neck, mid back, and low back. Correct posture should maintain these curves, but not increase them. Your head should be above your shoulders, and the top of your shoulder should be over the hips.
Poor posture can be bad for your health. Slouching or slumping over can:
Many Americans spend a lot of their time sitting – either at work, at school, or at home. It is important to sit properly, and to take frequent breaks:
With practice, you can improve your posture; you will look and feel better.
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There you are! I am sure that many, many people do not have good posture and the guidance above may just inspire you to aim for better posture.
A fascinating list!
Now I can’t recall where I saw these facts; I suspect they were emailed to me.
Whatever, it doesn’t matter, for they are amazing!
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1. Dogs have an incredible sense of smell—up to 100,000 times better than ours! They have more than 220 million olfactory receptors in their noses, while humans only have around 5 million.
2. Dogs can recognize up to 250 words and gestures, and they can even understand the tone of voice we use when we’re speaking to them.
3. Dogs can see in the dark better than us. They have a layer of cells in their eyes called the tapetum lucidum which reflects light back into the retina and helps them to see better in low light.
4. Dogs can sense when something is wrong or when you’re feeling down. They’ll often come and sit with you or give you extra cuddles when you’re feeling blue.
5. Dogs have an incredible sense of direction and can find their way back home from miles away. They use a combination of smell, sight and sound to remember the route they took.
6. Dogs can often tell when you’re about to sneeze. They have a special ability to sense subtle changes in our body language, and they can detect the slight changes that happen right before you sneeze.
7. Dogs can also tell when you’re happy or sad. They have the ability to sense changes in our breathing, body temperature, and even the amount of sweat we produce.
8. Dogs can sense when you’re getting sick. They can detect changes in your scent that you don’t even notice, and they’ll often come and comfort you when you’re feeling unwell.
9. Dogs can sense when someone is going to epileptic seizures or diabetic shock. They can detect the changes in smell, behavior and body chemistry that occur before a seizure or shock happens.
10. Dogs can detect certain types of cancer. They’re able to sniff out volatile organic compounds (VOCs) in the breath, urine or sweat of a person with cancer, which is why some organizations are training dogs to use their noses to detect cancer in humans.
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Dogs are amazing animals, in so many ways!
A fascinating insight into recovered plastic.
Like so many others we do our little bit regarding plastic but do not properly think about the issue. I have to admit that I am not even sure if all plastics are harmful or just some.
But I comprehend art!
That is why I am republishing, with permission, this article from The Conversation.
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Pam Longobardi, Georgia State University
I am obsessed with plastic objects. I harvest them from the ocean for the stories they hold and to mitigate their ability to harm. Each object has the potential to be a message from the sea – a poem, a cipher, a metaphor, a warning.
My work collecting and photographing ocean plastic and turning it into art began with an epiphany in 2005, on a far-flung beach at the southern tip of the Big Island of Hawaii. At the edge of a black lava beach pounded by surf, I encountered multitudes upon multitudes of plastic objects that the angry ocean was vomiting onto the rocky shore.
I could see that somehow, impossibly, humans had permeated the ocean with plastic waste. Its alien presence was so enormous that it had reached this most isolated point of land in the immense Pacific Ocean. I felt I was witness to an unspeakable crime against nature, and needed to document it and bring back evidence.
I began cleaning the beach, hauling away weathered and misshapen plastic debris – known and unknown objects, hidden parts of a world of things I had never seen before, and enormous whalelike colored entanglements of nets and ropes.
I returned to that site again and again, gathering material evidence to study its volume and how it had been deposited, trying to understand the immensity it represented. In 2006, I formed the Drifters Project, a collaborative global entity to highlight these vagrant, translocational plastics and recruit others to investigate and mitigate ocean plastics’ impact.
My new book, “Ocean Gleaning,” tracks 17 years of my art and research around the world through the Drifters Project. It reveals specimens of striking artifacts harvested from the sea – objects that once were utilitarian, but have been changed by their oceanic voyages and come back as messages from the ocean.
I grew up in what some now deem the age of plastic. Though it’s not the only modern material invention, plastic has had the most unforeseen consequences.
My father was a biochemist at the chemical company Union Carbide when I was a child in New Jersey. He played golf with an actor who portrayed “The Man from Glad,” a Get Smart-styled agent who rescued flustered housewives in TV commercials from inferior brands of plastic wrap that snarled and tangled. My father brought home souvenir pins of Union Carbide’s hexagonal logo, based on the carbon molecule, and figurine pencil holders of “TERGIE,” the company’s blobby turquoise mascot.
On the 2013 Gyre Expedition, Pam Longobardi traveled with a team of scientists, artists and policymakers to investigate and remove tons of oceanic plastic washing out of great gyres, or currents, in the Pacific Ocean, and make art from it.
Today I see plastic as a zombie material that haunts the ocean. It is made from petroleum, the decayed and transformed life forms of the past. Drifting at sea, it “lives” again as it gathers a biological slime of algae and protozoans, which become attachment sites for larger organisms.
When seabirds, fish and sea turtles mistake this living encrustation for food and eat it, plastic and all, the chemical load lives on in their digestive tracts. Their body tissues absorb chemicals from the plastic, which remain undigested in their stomachs, often ultimately killing them.
I see plastic objects as the cultural archaeology of our time – relics of global late-capitalist consumer society that mirror our desires, wishes, hubris and ingenuity. They become transformed as they leave the quotidian world and collide with nature. By regurgitating them ashore or jamming them into sea caves, the ocean is communicating with us through materials of our own making. Some seem eerily familiar; others are totally alien.
A person engaging in ocean gleaning acts as a detective and a beacon, hunting for the forensics of this crime against the natural world and shining the light of interrogation on it. By searching for ocean plastic in a state of open receptiveness, a gleaner like me can find symbols of pop culture, religion, war, humor, irony and sorrow.
In keeping with the drifting journeys of these material artifacts, I prefer using them in a transitive form as installations. All of these works can be dismantled and reconfigured, although plastic materials are nearly impossible to recycle. I display some objects as specimens on steel pins, and wire others together to form large-scale sculptures.
I am interested in ocean plastic in particular because of what it reveals about us as humans in a global culture, and about the ocean as a cultural space and a giant dynamic engine of life and change. Because ocean plastic visibly shows nature’s attempts to reabsorb and regurgitate it, it has profound stories to tell.
I believe humankind is at a crossroads with regards to the future. The ocean is asking us to pay attention. Paying attention is an act of giving, and in the case of plastic pollution, it is also an act of taking: Taking plastic out of your daily life. Taking plastic out of the environment. And taking, and spreading, the message that the ocean is laying out before our eyes.
Pam Longobardi, Regents’ Professor of Art and Design, Georgia State University
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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Pam at one point describes the ocean plastic”… because of what it reveals about us as humans in a global culture, and about the ocean as a cultural space and a giant dynamic engine of life and change …”. It raises questions that I can only ponder the answer. Ultimately, are there too many inhabitants on this planet? What does the next generation think? Is there an answer?
This particular post is from ‘Who Will Let the Dogs Out‘.
The range of expertise in looking after our dear dogs is incredible. I have long followed Who Will Let the Dogs Out but today wanted to republish a very recent article, hopefully with permission.
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Tiny Municipal Shelter Outside Nashville Has Only One Employee
By Cara Sue Achterberg. 14th February, 2023
In Robertson County, Tennessee, just outside Nashville, there are actually three municipal shelters. In addition to the Robertson shelter written about in the previous post, we also stopped at a tiny shelter ten minutes away— Greenbrier Animal Control.
This small shelter has ten kennels and was currently housing 12 dogs. Shelbie is the only ACO and employee for the small shelter. She works seven days a week 365 days a year. The only days she’s had off since she began work there three years ago were this past winter when she had Covid.
Shelbie does everything at the tiny, age-worn shelter – the cleaning and the caring, and running the animal control calls, and pretty much anything that needs done. Several of the outdoor kennels do not have covered roofs. The roofs are at the shelter, but Shelbie is only one person (and a tiny one at that), so she can’t get them put on by herself. She could use a hand with the roofs, and with lots of things, but the only ones she and the dogs have are her own.
The city animal control budget covers food, supplies, and a few other things, like Shelbie’s uniforms, but it doesn’t cover vaccines, deworming, or spay/neuter. Shelbie knows that anything she adopts out locally is likely to send puppies back her way. She depends on CASA Transport to help get animals out, so the shelter doesn’t become overcrowded.
Shelbie took the job because she loves animals and because she’s always been an advocate for not killing shelter animals. One of the dogs, Denali, has been at the shelter almost as long as she has. “He’s special and he needs a special kind of home,” she told me.
She loves her job, but would really love for the city to hire someone to help on the weekends so that she could have more time for herself (and her FIVE children ages 4-10).
We set up a few peanut butter boards and left Shelbie with lots of food, treats, bones, and collars, but joked with her that we wished we had a person in the truck we could leave with her. Every time we make these trips we meet remarkable people like Shelbie. I’m sure she isn’t getting rich on this job and I’d guess she sees some pretty awful situations. It is not just back breaking work, it’s heartbreaking.
There are so many people, just like Shelbie, who are quietly saving lives through their own dedication and sacrifice. They inspire me to keep pushing for change, for any way to make the situation better.
I don’t understand why Robertson County, which serves 72,000 residents, has not only the county shelter, but two city shelters (we were not able to visit Springfield animal control). Greenbriar is in the county and it took us about ten minutes to get from one to the other. To me, clearly an outsider (but one who has visited over 100 shelters in 12 states), it makes more sense to combine the three shelters in the new building that Robertson County is building.
Surely, by combining budgets and staff, they could have one excellent facility with plenty of help, and likely save money in the bargain. Plus, then Shelbie wouldn’t be working seven days a week and handling animals all by herself (not that she isn’t more than capable of doing so as she’s done it for three years now). That’s just my observation, unlikely to be embraced.
Until we start looking for common sense solutions like regional public shelters, the lives of too many animals will depend on the decency and the willingness of people like Shelbie to sacrifice so much to do the work very few will.
If you’d like to help Shelbyville Animal shelter, consider shopping their Amazon wishlist.
Until each one has a home,
Cara
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Learn more about what is happening in our southern shelters and rescues in the book, One Hundred Dogs & Counting: One Woman, Ten Thousand Miles, and a Journey Into the Heart of Shelters and Rescues (Pegasus Books, 2020). It’s the story of a challenging foster dog who inspired me to travel south to find out where all the dogs were coming from. It tells the story of how Who Will Let the Dogs Out began. Find it anywhere books are sold. A portion of the proceeds of every book sold go to help unwanted animals in the south.
Watch our Emmy-nominated, award-winning short documentary about rescue in western Tennessee here.
For more information on any of our projects, to talk about rescue in your neck of the woods, please email whowillletthedogsout@gmail.com or carasueachterberg@gmail.com.
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There are many more photographs on the website that I chose not to republish because I couldn’t do it as neatly as Cara did it.
A fascinating article about the fossilisation of teeth.
Change is a constant! That’s not my saying but it is still a very good one. There are many, many articles online about the pace of change and I am not going to pick a particular one; you can do that yourself if you are interested.
But I am going to republish an article about the fossilisation of teeth. It was published on January 25th, 2023 and it was an article in The Conversation.
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Tesla Monson, Western Washington University
Fossilized bones help tell the story of what human beings and our predecessors were doing hundreds of thousands of years ago. But how can you learn about important parts of our ancestors’ life cycle – like pregnancy or gestation – that leave no obvious trace in the fossil record?
The large brains, relative to overall body size, that are a defining characteristic of our species make pregnancy and gestation particularly interesting to paleoanthropologists like me. Homo sapiens’ big skulls contribute to our difficult labor and delivery. But the big brains inside are what let our species really take off.
My colleagues and I especially wanted to know how fast our ancestors’ brains grew before birth. Was it comparable to fetal brain growth today? Investigating when prenatal growth and pregnancy became humanlike can help reveal when and how our ancestors’ brains became more like ours than like our ape relatives’.
To investigate the evolution of prenatal growth rates, we focused on the in-utero development of teeth – which do fossilize. By building a mathematical model using the relative lengths of molar teeth, we were able to track evolutionary changes in prenatal growth rates in the fossil record. Based on our model, it looks as if pregnancy and prenatal growth became more humanlike than chimplike almost 1 million years ago.
Pregnancy and gestation are important periods – they guide future growth and development and set the biological course for life.
But human pregnancy, and particularly labor and delivery, cost a lot of energy and are often dangerous. The large fetal brain requires a lot of nutrients during development. The rate of embryonic growth during gestation, also known as the prenatal growth rate, exacts a metabolic and physiological toll on the gestating parent. And the tight fit of the infant’s head and shoulders through the pelvic canal during delivery can lead to death, for both the mother and child.
As a trade-off to those potential downsides, there must be a really good reason to have such large heads. The justification is all the abilities that come along with having a big human brain. The evolution of our large brain contributed to our species’ dominance and is associated with increased use of technology and tools, creation of art and the ability to survive in diverse landscapes, among other advances.
The timing and sequence of events that led to the evolution of our large brains is entangled with the ability to find and process more resources, through the use of tools and cooperative group work, for example.
By investigating changes in prenatal growth, we are also investigating changes in how parents gathered food resources and distributed them to their offspring. These increasing resources would have also helped drive the evolution of an even bigger brain. Understanding more about when prenatal growth and pregnancy became humanlike at the same time reveals information about when and how our brains did too.
Humans have the highest prenatal growth rate of all primates living today, at 0.41 ounces/day (11.58 grams/day). Gorillas, for example, have a much larger adult body size than humans, but their prenatal growth rate is only 0.29 ounces/day (8.16 grams/day). Because more than a quarter of all human brain growth is completed during gestation, the rate of prenatal growth directly relates to how big an adult brain grows. How and when Homo sapiens‘ high prenatal growth rate evolved has been a mystery, until now.
Researchers have spent centuries investigating variation in fossilized skeletal remains. Unfortunately brains – let alone gestation and prenatal growth rate – don’t fossilize.
But my colleagues and I started thinking about how teeth develop very, very early in utero. Your permanent adult teeth started developing long before you were born, when you were just a 20-week-old fetus. Tooth enamel is more than 95% inorganic, and the vast majority of everything we see in the vertebrate fossil record is teeth, or has teeth.
Building off this realization, we decided to investigate the relationship between prenatal growth rate, brain size and the lengths of teeth.
We measured the teeth of 608 recently living primates from skeletal collections all around the world. We compared those measurements to rates of prenatal growth that we calculated from average gestation length and mass at birth for each species. We also looked at endocranial volume – essentially how much space is inside the skull – as a proxy for brain size.
We found that the rate of prenatal growth is significantly correlated with both adult brain size and relative tooth lengths, across apes and monkeys.
Because prenatal growth is so tightly correlated with relative molar lengths, we were able to use this statistical relationship to generate a mathematical equation that predicts prenatal growth rate from teeth alone. With this equation, we can take a few molar teeth from an extinct fossil species and reconstruct exactly how fast their offspring grew during gestation.
Using our new method, we then reconstructed prenatal growth rates for 13 fossil species, building a timeline of changes over the past 6 million years of human and hominid evolution. “Hominid” describes all the species on the human side of the family tree after the split about 6 million to 8 million years ago from the common ancestor we shared with chimpanzees. From our new research, we now know that prenatal growth rates increased throughout hominid evolution, reaching a humanlike rate that exceeds what we see in all other apes less than 1 million years ago.
A fully human prenatal growth rate appeared with the evolution of our species Homo sapiens only around 200,000 years ago. But other hominid species living in the past 200,000 years, such as Neanderthals, also had “human” prenatal growth rates. Which genes were involved in these changes in growth rate remains to be investigated.
Even with only a few teeth and some of the jaw, a trained expert can tell countless things about an extinct individual – what species it was, what kind of diet it ate, whether it competed for mates through fighting, how old it was when it died, whether or not it had any serious health issues and more.
Now, for the first time, we can add to that list knowing what pregnancy and gestation were like for that individual and other members of its species. Teeth can even indirectly hint at the emergence of human consciousness, via evolving brain size.
Interestingly, our model suggests that prenatal growth rates started increasing well before the emergence of our Homo sapiens species. We can hypothesize that having a fast prenatal growth rate was necessary for growing that big brain and evolving human consciousness and cognitive abilities.
These are the sorts of big-picture questions this research lets us start to formulate now – all from just a few teeth.
Tesla Monson, Assistant Professor of Anthropology, Western Washington University
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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Tesla Monson is the Assistant Professor of Anthropology at Western Washington University.
This may not make the daily headlines but, personally, I think that is a shame. The discovery has all sorts of implications for life, including ancient life, on this planet. And speaking of life let us bear a thought for the carnage that is happening in Turkey at this present time. A BBC headline:
A rescue operation is under way across much of southern Turkey and northern Syria following a huge earthquake that has killed more than 2,300 people
It is the last day of January and we have a post about dogs today.
I found all the non-doggie articles a bit depressing and this item seemed a delightful alternative. It is from the Curious Kids section of The Conversation but, to my mind, of interest to adults as well.
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Do dogs really see in just black and white? – Oscar V., age 9, Somerville, Massachusetts
Dogs definitely see the world differently than people do, but it’s a myth that their view is just black, white and grim shades of gray.
While most people see a full spectrum of colors from red to violet, dogs lack some of the light receptors in their eyes that allow human beings to see certain colors, particularly in the red and green range. But canines can still see yellow and blue.
Different wavelengths of light register as different colors in an animal’s visual system. Top is the human view; bottom is a dog’s eye view. Top: iStock/Getty Images Plus via Getty Images. Bottom: As processed by András Péter’s Dog Vision Image Processing Tool
What you see as red or orange, to a dog may just be another shade of tan. To my dog, Sparky, a bright orange ball lying in the green grass may look like a tan ball in another shade of tan grass. But his bright blue ball will look similar to both of us. An online image processing tool lets you see for yourself what a particular picture looks like to your pet.
Animals can’t use spoken language to describe what they see, but researchers easily trained dogs to touch a lit-up color disc with their nose to get a treat. Then they trained the dogs to touch a disc that was a different color than some others. When the well-trained dogs couldn’t figure out which disc to press, the scientists knew that they couldn’t see the differences in color. These experiments showed that dogs could see only yellow and blue.
In the back of our eyeballs, human beings’ retinas contain three types of special cone-shaped cells that are responsible for all the colors we can see. When scientists used a technique called electroretinography to measure the way dogs’ eyes react to light, they found that canines have fewer kinds of these cone cells. Compared to people’s three kinds, dogs only have two types of cone receptors.
Light travels to the back of the eyeball, where it registers with rod and cone cells that send visual signals on to the brain. iStock/Getty Images Plus via Getty Images
Not only can dogs see fewer colors than we do, they probably don’t see as clearly as we do either. Tests show that both the structure and function of the dog eye leads them to see things at a distance as more blurry. While we think of perfect vision in humans as being 20/20, typical vision in dogs is probably closer to 20/75. This means that what a person with normal vision could see from 75 feet away, a dog would need to be just 20 feet away to see as clearly. Since dogs don’t read the newspaper, their visual acuity probably doesn’t interfere with their way of life.
There’s likely a lot of difference in visual ability between breeds. Over the years, breeders have selected sight-hunting dogs like greyhounds to have better vision than dogs like bulldogs.
But that’s not the end of the story. While people have a tough time seeing clearly in dim light, scientists believe dogs can probably see as well at dusk or dawn as they can in the bright middle of the day. This is because compared to humans’, dog retinas have a higher percentage and type of another kind of visual receptor. Called rod cells because of their shape, they function better in low light than cone cells do.
Dogs also have a reflective tissue layer at the back of their eyes that helps them see in less light. This mirror-like tapetum lucidum collects and concentrates the available light to help them see when it’s dark. The tapetum lucidum is what gives dogs and other mammals that glowing eye reflection when caught in your headlights at night or when you try to take a flash photo.
Dogs share their type of vision with many other animals, including cats and foxes. Scientists think it’s important for these hunters to be able to detect the motion of their nocturnal prey, and that’s why their vision evolved in this way. As many mammals developed the ability to forage and hunt in twilight or dark conditions, they gave up the ability to see the variety of colors that most birds, reptiles and primates have. People didn’t evolve to be active all night, so we kept the color vision and better visual acuity.
Before you feel sorry that dogs aren’t able to see all the colors of the rainbow, keep in mind that some of their other senses are much more developed than yours. They can hear higher-pitched sounds from farther away, and their noses are much more powerful.
Even though Sparky might not be able to easily see that orange toy in the grass, he can certainly smell it and find it easily when he wants to.
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I don’t know about you but I found this most interesting and the last thing I would be described as is a kid!
In terms of our own dogs their ability to forage in the dark is quite amazing and, presumably, our dogs are quite typical of dogs in general.
A guest post from Penny offers some advice.
Penny Martin has previously written some guest posts for Learning from Dogs and here she is again with today’s post. The subject is not directly about dogs but trying to turn around one’s life; and that is something that most of us have faced up to at some point in their past.
(I think the references to Learning from Dogs are not needed but I’m not Penny!)
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Six Simple Self-Improvement Strategies for Your Health and Career
By Penny Martin,
Published 24th January, 2023.
Are you trying to turn your life around? Focusing on improving your self-care habits, your relationships, and your career prospects can yield change your life for the better. Furthermore, Learning From Dogs can introduce you to all of the benefits of becoming a dog owner! Here’s how to invest in your education, upgrade your resume, explore business ownership, and adopt healthy routines.
Advance Your Education
If you’re looking to move up in your career, you may want to head back to school to earn another degree. It’s okay if you’re not able to commit to attending courses at a physical campus – instead, consider studying through an online degree program. This will allow you to simultaneously work and care for your family. Double-check that any online programs you’re considering are accredited and that you can easily afford the tuition. You can choose a major like marketing, education, information technology, business, healthcare administration, and more.
Update Your Resume
Perhaps you’re hunting for a new job. Make sure to revise and update your resume prior to sending out applications! To make the process easier, just pick out a free resume template from an online library – this free resume may help. Then, you’ll input your work history. Finally, you can spruce up this document with a photo or a color scheme.
Consider Entrepreneurship
What if you’re frustrated with your boss, and you feel like working at a traditional 9-to-5 job is holding you back? If you’ve got a business idea, you can always register for LLC status for limited liability and tax breaks. Remember, if you form an LLC, you’ll have to choose a registered agent who can handle communications regarding your formation documents with law firms, tax agencies, and the government. You can hire a registered agent or service for help in this area.
Health and Fitness
Even as you prioritize your career, it’s still important to take care of your physical and emotional well-being. As you plan out meals each week, The Every Girl recommends cooking with lots of leafy greens and incorporating plant-based protein into your diet. Furthermore, try to block off a few workout sessions per week in your schedule. You might want to sign up for a gym membership.
Pick Up a Good Book
Reading is a great use of your downtime, especially if you’re on a self-improvement journey! Healthline states that reading can reduce your stress levels, prevent cognitive decline, and even alleviate symptoms of depression. Plus, you’ll be able to learn more about topics that you’re interested in! You might want to choose books that cover subjects related to self-help, like nutrition, fitness, meditation, or time management.
If you feel like you don’t have time to read, consider how you could cut down on screen time. Alternatively, you could listen to audiobooks while you commute to work or do chores around the house.
Get a Dog
If you could use another companion, consider getting a dog! Owning a dog can significantly improve your mental health. Canadian Living states that having a dog around actually decreases your blood pressure, boosts your levels of mood-enhancing hormones, and even helps you make friends in your neighborhood – taking your dog for walks helps you connect with other local dog owners!
Self-improvement is a lifelong process. When you take small steps in the right direction, you’ll be able to look back in a year and feel proud of how far you’ve come. With these tips, you can earn another degree, put together an impressive resume, become a pet owner, open your own business, and more!
Are you thinking about getting a dog? Read all about the benefits on Learning from Dogs! Visit the blog today to find out why getting a dog might be right for you.
Photo via Pexels
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Thank you, Penny.
Let me publish again the opening remarks that are on the home page of this blog:
Dogs live in the present – they just are! Dogs make the best of each moment uncluttered by the sorts of complex fears and feelings that we humans have. They don’t judge, they simply take the world around them at face value. Yet they have been part of man’s world for an unimaginable time, at least 30,000 years. That makes the domesticated dog the longest animal companion to man, by far!
Learning from Dogs
I cannot put it better than that!
Learning from Dogs 