In complete contrast to yesterday, this morning there was a clear blue sky – a truly glorious day. We all set off together for the first mile or two but when I turned to go, Merlin dug his paws in and and absolutely refused to come with me. So he carried on with Tom and Chica while Arthur and I returned to the car.
Mules
Mules are still used in Spain both as personal transport and as pack animals. Here in the forest, they haul wood and cork. These two look in good condition and don’t have any of the white patches or scarring that indicates poor loading or ill-fitting harness that is often seen. Happily, it is now illegal to hobble equines (ie chain the front feet together to severely restrict movement). This is a very recent change and six years ago when we first came to this area it was a common sight. To restrict the movement of a prey animal that naturally depends on flight for survival is very cruel, in my view, so it’s good to see it dying out.
View across Algeciras to Gibraltar
Today’s route wound gently uphill past an army camp until, at the high point, there was a fantastic view across the top of Algeciras, the main port, to the rock of Gibraltar. After that it continued to through pasture and cork oaks until the enormous rubbish dump made its presence felt well before it was visible in what appeared to be a disused quarry.
Eventually, the path came out on the road, which though not very busy was less pleasant to walk on and all three members of the party were quite happy to be picked up after 15k in very warm weather.
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Keep it going, Tom. For the description of your walk is very engaging. To be honest, it is Tom’s wife, Gilliwolfe, who deserves as much credit. For without her then we would not be reveling in Tom’s walk.
I made a mental note to republish this wonderful story more often than hitherto.
Certainly, if I am do the story justice, and I do want to do that, then a couple of republications a week is needed.
So we are at Day Three.
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Day 3: Embalse de Almodovar to Los Barrios 20k
By Tom and Chica, 15th January, 2020
Written by Tom’s wife.
Silent sentinels
This was the first cold and cloudy morning we’ve had since we arrived in Tarifa – a bit of a shock! The lack of wind, which is a rarity here, meant that all the wind turbines were motionless – like silent sentinels guarding the the hills.
Silly Billy!
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Back on the stony track.
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Don’t run them over!
We reached the start point (What Three Words location: dashes.outlived. plums) at around 10.15. Frustratingly, the route is barred by an electronic gate and notices warn that vehicles are prohibited, although google maps shows it as a through route. This wasn’t a problem this morning but made for a long drive for the pick up later.
After yesterday’s day off both dog and man keen to get going and set a brisk pace to keep warm. The lizards referred to in the sign weren’t in evidence – it was definitely too cold. The same very stony track caused less problems for Tom today with medium rather than light weight boots. The route climbed steadily to a high open valley to Puerto de Ojen giving views of the Sierra del Nino to the north. There used to be a bar here offering refreshment to walkers but sadly only a rather angry little dog and a donkey there now but a brief lunch break was taken anyway.
Puerta de Ojen
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Paths of the prisoners.
This sign on the right (Ed. the last one above.) was a little further down the road. A brief translation tells us that, as a result of the Spanish civil war, prisons were overflowing so Franco decided to create disciplinary battalions, an organized group of political prisoners to perform forced labour. After the outbreak of WWII, he launched the Fortification Plan on the northern shore of the Strait of Gibraltar, with the aim of fortifying and defending the area from possible attacks from the coast. To do this, he built a network of roads in this coastal area of southern Spain from Conil to the Guadiaro River and the path of the prisoners is part of this network of roads built by disciplinary battalion number 22 that was located between Venta de Ojén and Cerro del Rayo from 1940 to 1943.
Rustic bread oven
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Further along they came cross this old bread oven that is currently being restored. Tom is a builder specialising in stone work so was able to determine that it was a good example of modern stonework. He was unable to fully translate the sign but it said that bread was a very important part of the diet and this was oven was a vital resource used by many people.
All in all, an interesting and reasonably easy route. The weather had improved as the day went on and it reached 18 deg but after 20k both Tom and Chica were quite happy to see the car, I think.
Pooped!
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I am so grateful for being given permission by Tom’s wife to republish this amazing journey along the GR7 path.
It is now ten days since I last reported on Tom and Chica’s great walk; so much for my couple of postings a week!
But they continue to walk the GR7 path in Spain and I will continue to republish their posts of this great trip.
So now, so far as republishing goes, we are up to Day Two.
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Day 2: La Pena to Embalse de Almodovar 16k
By Tom and Chica, 13th January, 2020
Written by Tom’s wife.
Human breakfast!
All walking days will start with the full monty for Tom. He is a very practiced breakfast chef so I leave him to it. It did seems to take a while this morning so I think we may have to start getting up a bit earlier. For this week, at least, I will be dropping him off and picking him up so he doesn’t have to carry the full pack with the tent etc, giving him time to get some fitness back first after the flu virus.
The start
So it was 10am before we got to the start at La Pena (What Three Words location: crafted.indecisive.barbecued.) and already a really glorious day; full sun and a gentle breeze. The route wound up into the hills giving wonderful views back down to the sea and across to the Moroccan coast. The path continued on a variety of surfaces, some tarmac, some sand and some stony tracks. The latter proved a bit uncomfortable and Tom now thinks that his more sturdy boots might be better, despite being a bit heavier. He has metal rods in both his feet, the result of a climbing accident about twenty years ago. So it’s extra important that his feet are well supported.
Goats on the moveVery spiny cactus with fruit – name anyone?
The landscape was quite rocky with olive and other hardy shrubs and trees, and lots of cacti too. Not much wildlife spotted but plenty of goats with their melodic bells. The route ended at a large lake on a inaccessible track so they walked back to the road where we met, conveniently close to a bar for a much appreciated cold beer (for Tom)and long drink of water (for Chica).
Meanwhile, back at the campsite, there was a minor crisis as a neighbour discovered a number of processionary caterpillars. These are nasty critters with highly irritant hairs that can cause a painful rash in humans but are even more dangerous for dogs. As the name suggests, the caterpillars form a chain when they move and, of course, most dogs want to investigate but if they ingest the hairs it can cause real problems. The nests can easily be spotted as dense webs on the tips of pine branches. The site maintenance staff were very prompt in coming along to remove the nests but we will remain vigilant. It was probably a bit daft to choose a plot under the pines and it’s a lesson learned for the future. One of many to come, no doubt.
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This is such an amazing trip. Words hardly express my admiration for what Tom.
One of the lovely things about writing a blog about dogs is that frequently people ‘pop up’ and offer a guest post. So it was with Eliza, or Eliza Gilbert to give to her her full name. This is a brief background that she sent me.
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NB: It’s the morning of Tuesday, the 11th February, 2020 and I have had to do something for the very first time. That is delete a guest post.
It turned out that Eliza was pushing me to include a link for her client and it was far from being a guest post, more like a commercial arrangement between Eliza and her client. I hope everyone understands.
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Hardly signs of anxiety! Thank goodness. Pedy on the left; Oliver on the right.
I have long been a subscriber to The Conversation. They seem to be politically neutral as well as giving permission for their essays to be republished elsewhere.
This particular essay chimed with me because for some time, one or two years sort of time-span, the number of people agreeing with the statement, “It’s a strange world“, has measurably grown. At first I thought it was a question of politics, both sides of The Atlantic, but I have recently come to the opinion that it is deeper than that.
This encapsulates the idea perfectly.
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How CEOs, experts and philosophers see the world’s biggest risks differently
We live in a world threatened by numerous existential risks that no country or organization can resolve alone, such as climate change, extreme weather and the coronavirus.
But in order to adequately address them, we need agreement on which are priorities – and which aren’t.
As it happens, the policymakers and business leaders who largely determine which risks become global priorities spent a week in January mingling in the mountainous resort of Davos for an annual meeting of the world’s elite.
I participated in a global risk assessment survey that informed those at the Davos summit on what they should be paying the most attention to. The results, drawn from experts in a broad range of disciplines including business, happen to be very different from what company CEOs specifically see as the biggest threats they face.
As a philosopher, I found the differences curious. They highlight two contrasting ways of seeing the world – with significant consequences for our ability to address societal risks.
Wildfires in Australia have destroyed more than 3,000 homes and razed more than 10.6 million hectares since September. AP Photo/Noah Berger
Two perspectives on the biggest risks
The World Economic Forum’s Global Risk Report consolidates the perceptions of about 800 experts in business, government and civil society to rank “the world’s most pressing challenges” for the coming year by likelihood and impact.
In 2020, extreme weather, a failure to act on climate change and natural disasters topped the list of risks in terms of likelihood of occurrence. In terms of impact, the top three were climate action failure, weapons of mass destruction and a loss of biodiversity.
The specific perspective of corporate leaders, however, is captured in another survey that highlights what they perceive as the biggest risks to their own businesses’ growth prospects. Conducted by consultancy PwC since 1998, it also holds sway in Davos. I’ve been involved in that report as well when I used to work for the organization.
In sharp contrast to the World Economic Forum’s risk report, the CEO survey found that the top three risks to business this year are overregulation, trade conflicts and uncertain economic growth.
President Trump’s trade war and other economic concerns tend to be the focus of corporate CEOs. AP Photo/Evan Vucci
Economic or ethical
What explains such a big difference in how these groups see the greatest threats?
I wanted to look at this question more deeply, beyond one year’s assessment, so I did a simple analysis of 14 years of data generated by the two reports. My findings are only inferences from publicly available data, and it should be noted that the two surveys have different methodologies and ask different questions that may shape respondents’ answers.
A key difference I observed is that business leaders tend to think in economic terms first and ethical terms second. That is, businesses, as you’d expect, tend to focus on their short-term economic situation, while civil society and other experts in the Global Risk Report focus on longer-term social and environmental consequences.
For example, year after year, CEOs have named a comparatively stable set of narrow concerns. Overregulation is among the main three threats in all but one of the years – and is frequently at the top of the list. Availability of talent, government fiscal concerns and the economy were also frequently mentioned over the past 14 years.
In contrast, the Global Risk Report tends to reflect a greater evolution in the types of risks the world faces, with concerns about the environment and existential threats growing increasingly prominent over the past five years, while economic and geopolitical risks have faded after dominating in the late 2000s.
A philosophical perspective
Risk surveys are useful tools for understanding what matters to CEOs and civil society. Philosophy is useful for considering why their priorities differ, and whose are likelier to be right.
Fundamentally, risks are about interests. Businesses want a minimum of regulations so they can make more money today. Experts representing constituencies beyond just business place a greater emphasis on the common good, now and in the future.
When interests are in tension, philosophy can help us sort between them. And while I’m sympathetic to CEOs’ desire to run their businesses without regulatory interference, I’m concerned that these short-term economic considerations often impede long-term ethical goals, such as looking after the well-being of the environment.
An uncertain world
Experts agree on at least one thing: The world faces dire risks.
This year’s Global Risk Report, titled, “An Unsettled World,” depicts on its cover a vulnerable earth in the shadow of a gigantic whirlpool.
The cover photograph of the Global CEO Survey, which reported the lowest CEO confidence in economic growth since the Great Recession, shows an incoming tide beneath looming dark clouds, with the words: “Navigating the Rising Tide of Uncertainty.”
Between the covers, however, the reports demonstrate a wide gap between two influential groups that need to be on the same page if we hope to resolve the world’s biggest threats.
Last century, in the same year that World War II drew to a close, Bertrand Russell proclaimed that
Bertrand Russell. Naci Yavuz/Shurterstock.com
the purpose of philosophy was to teach us “how to live without certainty, and yet without being paralyzed by hesitation.”
In the 21st century, philosophy can remind us of our unfortunate tendency to let economic priorities paralyze action on more pressing concerns.
Bertrand Russell was a great philosopher. Well he was that and much more. Wikipedia remind us that he “was a British philosopher, logician, mathematician, historian, writer, essayist, social critic, political activist, and Nobel laureate.”
He died at the age of 97 on the 2nd February, 1970; fifty years ago as of yesterday.
I’ll close with another quote from the great man:
“The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people so full of doubts. …”
Another republication of the Spanish walk by Tom and Chica.
There was such a wonderful response to the post on the 28th January that I decided to republish another one. This time I have started at the beginning.
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The GR7
The road less travelled…..
If you tell someone you’re planning a long walk in Spain, they will mostly assume you’re talking about the Camino de Santiago pilgrim trail across northern Spain. Tom being a bit of a misanthrope said he’d rather go somewhere less crowded.
We are familiar with a part of the GR7 as it runs through the Serrania de Ronda where we have spent a few recent winters. After more research it was decided that this would be the most interesting.
The GR7 starts on the south coast at Tarifa, near Gibraltar, and then runs up through the Los Alcornocales, a beautiful forest of cork oaks, then into the Grazalema National Park before reaching the city of Ronda. Dramatically perched above a deep gorge, Ronda is our favourite city.
From there the route turns eastwards towards Antequera and passes through the Parque Natural del Torcal whose bizarre rocky outcrops form one of the most impressive karst landscapes in Europe.
Shortly beyond, the route splits and Tom and Chica will be taking the southern variation through many small villages into Las Alpajarras. Then it heads up into the Sierra Nevada and there it may get tricky depending on the snow level. Chica isn’t keen on being belly deep in snow!
As the route heads north inland from the east coast, it is all new territory for us. There should be a couple of visits to both our charities near Alicante and Valencia and then due north to the border with Andorra. The final stop for recuperation will be with good friend, Kate, in the Pyrenees.
At last, after a fair few hitches and glitches, Tom and Chica took their first steps on a journey that will take them right across Spain to Andorra on the GR7 route. The start is at the aptly (and purely coincidentally) named Playa Chica, which is the most southerly point of mainland Europe. From here, you have the Med to the east, the Atlantic to the west and Africa on the horizon. It’s an epic trip and one that only around five people complete every year. It should cover a variety of landscapes, starting today with the beautiful beaches of Tarifa and the surrounding area. As it’s a Saturday, with a good strong breeze, the kite surfers were out in force. It’s quite a sight!
Kite surfers at Valdavaqueros
Today was a short toddle, by comparison with what will follow – just 11k in about 2.5 hours. The route was almost entirely on the beach and Tom shed his shoes and walked barefoot. It might be the only time that will be possible.
Given that he is recovering from flu an easy start seemed a good plan – definitely so as it’s now raining! Chica, however, needs to understand that stopping to investigate every interesting smell would mean the walk would take several years.
We will be posting a blog every day of the walk, with information on the route, the scenery and the flora and fauna. Tom isn’t able to carry field guides – too much extra weight – so identification from any of our followers would be appreciated, starting with these shells found on the beach today. These pics will be posted on our instagram page too.
Shells found on the beach at Valdevaqueros
As well as posting our position, hopefully using Viewranger (we’re working on this) we will also give our position using What Three Words. Tonight’s are: tigress, asked, varies. This is fun and will be another way of ensuring that the back up team (me) can hook up with them.
Stay with us!
Just this far to go….
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This is an incredible journey and I’m so pleased that Tom is happy for me to share it with you.
Tom came to Learning from Dogs a short while ago and signed up to follow the blog. As is usual, I went across to his blog in order to leave a thank-you note. I was flabbergasted at what I saw. Tom and his two dogs were walking across Spain. He called his blog Chica’s Challenge and this is what he wrote on his home page.
First, Tom decided he wanted to do a long walk.
Then he thought Spain would be nice as it has to be in winter.
And he’d like to take Chica, our podenco.
As an afterthought, he said, “Maybe we could raise some money?”
“Who for?” I asked.
“Well, as I’m taking Chica and it’s in Spain, I guess for Spanish podencos.”
“Great idea! I’ll write the blog!”
I wanted to follow his posts and did so.
Then I wanted to republish a post and asked Tom if I had his permission to so do.
One dog and her man walking across Spain, raising money for their podenco friends.
Day 7: Jimena de la Frontera to Cerra de la Fantasia 20k
The last two days were non-walking days, one for bad weather and another to move base again. Now we have the luxury of being in a house for a while in Jimera de Libar, a village we know well.
So the day started with the drive back to Jimena and the weather looked reasonable. Again, Merlin refused to be left so the three of them set off up the path, climbing steadily for the first hour and a half.
Climbing pathSpanish Fir / Pinsapo (Abies Pinsapo) in the background
The path eventually levelled out and passed beneath the rocky outcrops of the Altos de Paneron and Cerro de Marin. After a bare rocky sections where the route was harder to determine, they went into dense forest of oak and Spanish fir (we love these and call them lollipop trees because of their shape). Both dogs in great form, but Tom was mean and moody :).
Dark clouds were gathering from all directions but the view to the coast was still impressive. However, it wasn’t long before the rain began and the temperature dropped.
Looking south – you can just see the sea
Fortunately the rest of the route was on a well-defined and signposted track, winding down through the cork oaks in the midst of the Los Alcornacales. It was here deep in the forest that I eventually picked them up. I had forgotten that smaller Spanish roads aren’t always roads as I know them and the last five and a half miles I was driving along a rough track with no mobile signal, not at all sure I was in the right place. Even though we have a 4×4, I made very slow progress and it was with considerable relief that I found them, damp but completely unconcerned.
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In the original some of the photographs were side-by-side but in copying them across I chose to enlarge them.
The start of Tom’s walk may be seen here and I thoroughly recommend that you read it in full.
I shall continue to follow Tom’s walk and may republish another post.
The serious consequence of exercising too much, too fast
Exercising too much, too hard can lead not only to burnout but sometimes to a serious condition that can harm the kidneys.
By Tamara Hew-Butler , Associate Professor of Exercise and Sports Science, Wayne State University, January 24th, 2020.
Every 365.25 days, when the Earth completes a full orbit around the Sun, we humans have the opportunity to hit the reset button and become fitter, finer versions of ourselves. As usual for January, social media is humming with advice on how to eat better, exercise regularly, lose weight and remain healthy. We feel particularly invincible at this time of year, armed with renewed vigor and motivation to purge ourselves from previous indulgences and our couch-potato ways.
The New Year is also the time when our overzealous, instant-gratification selves emerge, and we do too much exercise too soon to make up for lost time. Exhaustive muscular work, especially following a period of inactivity, can cause mechanical and chemical disruptions to muscle cell membranes which trigger the muscle cells to burst.
I am an exercise physiologist and sports medicine specialist who studies exercise-associated collapse. I am seeing and hearing of more incidents of skeletal muscle ruptures that are causing harm in other parts of the body.
This information is not designed to scare people back onto the couch. The key take-away from highlighting these cases is to remind athletes, coaches and mere mortals that the desired physiological response to a training stimulus requires both a gradual buildup period and period of recovery in between training sessions.
A cross-section of the human kidneys, which can be injured when muscle cells rupture and send toxic chemicals into the bloodstream. crystal light/Shutterstock.com
More than muscle injury
The medical term for skeletal muscle cell rupture is “rhabdomyolysis,” or “rhabdo” for short. When muscle cells rupture or explode, the intracellular contents are released into the bloodstream. These cellular contents include enzymes, such as creatine kinase; electrolytes, such as potassium; and proteins, such as myoglobin.
Myoglobin, in particular, is a big, red protein that can block the kidney filtration system, or renal tubules, that serve as kidney plumbing. It also can dissociate into toxic byproducts that injure kidneys. In rare cases, too much myoglobin in the bloodstream can stop kidney function altogether, as happened with a 27-year old marathon runner who died from kidney failure.
In a study we conducted on college swimmers, we saw a cluster of rhabdomyolysis, in which six out of 34 swimmers were hospitalized after participating in a 20-minute or so “arm competition” to see how many pull-ups, rows and bench presses they could complete. Cases of “symptomatic rhabdo,” or those needing medical treatment, appear to be increasing within collegiate sports teams at an alarming rate, with the characteristic appearance seen in football players returning to January practice after a season-ending holiday layoff.
To date, 17 cases of team rhabdo have occurred from doing “too much, too soon, too fast” and include a variety of sports such as football, swimming, lacrosse, soccer, track, basketball, softball, volleyball and golf.
Noncompetitive athletes affected too
So, what about us mere mortals trying to get back in shape? Any physical activity that is either new or excessive can cause symptomatic rhabdo. Excessive gardening, weightlifting, CrossFit type activities and even a routine Army physical fitness test have triggered symptomatic rhabdo with kidney injury.
Over 90 cases of rhabdo have been documented after spinning, while 119 high school students in Taiwan ended up in the emergency room after their teacher made them complete 120 push-ups within five minutes. Thus, harmful muscle cell rupture can occur after any degree five minutes to 36 hours of exuberant and/or unaccustomed physical activity.
In combination, gradual training and appropriate recovery allow beneficial muscular, cardiovascular and body composition adaptations to occur, such as building muscle, increasing fitness and losing body fat. Our research confirms that a two-week gradual introduction into training after a layoff is required for muscle cell membranes to fully adapt to training stress.
Subclinical rhabdo, or muscle breakdown without acute kidney injury or debilitating symptoms, is common and represents the typical response to training which does not require medical treatment. However, hard exercise, especially following a layoff, with the following signs or symptoms within one to two days requires an appropriate medical examination:
excruciating muscle pain that does not resolve over time
muscle swelling with limitations in movement
nausea or vomiting, or both
very dark (looks like Coca-Cola) or sparse urine.
There are risk factors which increase the likelihood of developing rhabdo following a workout. These risk factors include exercising in the heat, dehydration or overhydration, binge drinking, excessive coffee consumption, extreme dietary practices (vegetarian or high [protein] https://doi.org/10.1097/JSM.0000000000000310)) and possessing the sickle cell trait. Both men and women can develop symptomatic rhabdo, although we see more cases in men. Smaller arm muscles appear more susceptible to rupture after five to 30 minutes of exercise than bigger leg muscles for reasons that remain unclear.
Although symptomatic rhabdomyolysis is uncommon, this emergent complication of exercise should be on everyone’s radar since cases are on the rise. We coaches, trainers, scientists, practitioners and others encourage everyone to reap the joys and benefits of regular exercise training. However, we caution against exercising too much too soon. Self- (or coach-) inflicted skeletal muscle cell explosions are fully preventable with adherence to smart, physiologically sound approaches to training.
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Now there’s an element of me not really understanding this (and I haven’t yet watched the video) but that’s no reason not to share it with you.
What do you think? Wiser to share it or too much a case of worrying? Tamara Hew-Butler certainly knows all about this.
Unfortunately, there are still some drivers out there who apparently don’t know how to treat pedestrians with the respect that they deserve.
But this little dog is doing his best to set them straight.
The other day, Beqa Tsinadze happened upon a curious scene in the town of Batumi, Georgia. There, at a clearly marked crosswalk, a group of young kids were waiting for cars to yield so they could safely cross the road.
Photo Credit: Beqa Tsinadze
Regrettably, though, it seems that many drivers weren’t eager to extend that courtesy without being told to.
So, that’s exactly what this dog did — taking on the role of crossing guard on the kids’ behalf. The moment was captured on video.
The thoughtful dog tackled the situation like a pro. But apparently this wasn’t just a one-time thing.
Tsinadze shared another video of the same dog stopping traffic and escorting yet another group of kids across the street.
Photo Credit: Beqa Tsinadze
Though it’s unclear why the pup came to adopt the role of crossing guard, it may be as a way of saying thanks.
According to Georgian media, the dog arrived to the area as a helpless stray a few years back, and has since endeared himself to members of the community who have taken it upon themselves to care for him.
The report above states that the dog goes by several names among folks in the neighborhood who know him — but there’s no doubt that you’d be safe in calling him a very good boy.
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Another wonderful report.
I’m sorry, I ought to write more but I would only be waffling!
Interesting article about calculating a dog’s age.
It’s a well-known ‘calculation’ that a dog’s age is seven years for every human year. But it’s wrong; the scientific result is more complex.
But rather than me say it, I’ll hand it over to Christian Yates of the BBC who on the 6th January this year published an article on this subject.
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Your pet clearly ages faster than you do, but new research is giving us a much clearer idea of just how old your dog really might be.
By Christian Yates, January 6th, 2020
If your dog has been alive and kicking its paws about for a decade, the widely held belief is it has aged as much as a human would have done over 70 years. This conversion factor – each year of a dog’s life accounting for seven human years – comes from dividing human life expectancy of around 77 by the canine life expectancy of around 11.
The underlying assumption is that each calendar year a dog lives through is equivalent to seven human years at any stage of a dog’s life. But new research suggests that things aren’t so simple. And if we look at some basic developmental milestones, it’s clear why.
For example, most dog breeds reach sexual maturity between the ages of six and 12 months – the upper end of that range corresponding, by the traditional conversion, to a human age of seven. And at the other end of the spectrum, although unusual, some dogs have been known to live for over 20 years. Under the “factor-of-seven” conversion rule, this would equate to an unfathomable 140 human-equivalent years.
New insights into how dogs age suggest our pets move into middle age more rapidly than most owners might suspect (Credit: Getty Images)
To make matters more complicated, dogs’ life expectancy depends significantly on the breed. Smaller dogs tend to live significantly longer, suggesting that they age more slowly than bigger dogs.
All of this raises the question of what exactly we mean by age. The most obvious way to describe it is simply the length of time that has passed since birth. This is known as the chronological definition of age.
When it comes to comparing animal ages across species, the biological definitions of age are far more useful than their chronological counterparts
However, there are other descriptions. Biological age, for example, is a more subjective definition, which relies on assessing physiological indicators to identify an individual’s development. These include measures like the “frailty index” – surveys that take into account an individual’s disease status, cognitive impairments and levels of activity.
Rather than celebrating chronological age, looking at the levels of methylation on a dog’s DNA is a much more accurate measure of aging (Credit: Getty Images)
For example, if you’ve spent a lot of time eating junk food and smoking cigarettes instead of taking exercise and eating healthily, the chances are your biological age will exceed your chronological age. Or, you might be a 60-year-old with the body of a 40-year-old if you’ve looked after yourself well.
A dog’s life
When it comes to comparing animal ages across species, the biological definitions of age are far more useful than their chronological counterparts. Knowing a hamster is six weeks old doesn’t give you a good picture of that animal’s life stage, even if you know the life expectancy of a hamster is only three years. Learning that a hamster has reached an age where it can reproduce gives a much better picture of its level of maturity.
In their first year of life, puppies grow up so quickly that they age the equivalent of 31 human years (Credit: Getty Images)
In particular, “methylation” – the addition of methyl groups (a carbon atom bonded to three hydrogen atoms) to DNA – seems to be a good indicator of age. Many prominent physiological markers, such as the development of teeth, seem to occur at the same levels of methylation across different species. So by matching the levels of methylation in Labrador retrievers and humans, the researchers derived a formula to map dog age to its human equivalent.
That formula is: human equivalent age = 16 x ln(dog’s chronological age) + 31.
Here “ln” represents a mathematical function known as the natural logarithm. The logarithm function is well-known in the non-linear scales for energy released during earthquakes (Richter) or for measuring sound (decibels). It comes in useful for measuring quantities whose sizes vary over many orders of magnitude. It’s even possible that a logarithmic experience of the passing of time might explain why we perceive time speeding up as we get older.
A handy short cut is to remember that the first dog year counts for 31 human years
In the graph below, you can see how the natural logarithm works to convert the years a dog has lived (dog age) into the equivalent human age in the red dashed curve. The curve suggests that dogs mature extremely rapidly at first, but that their ageing then slows down, meaning that most of their lives are experienced as a form of protracted middle age.
A handy short cut is to remember that the first dog year counts for 31 human years. Then, after that, every time the dog’s chronological age doubles, the number of equivalent human years increases by 11. So eight calendar years represents three “doublings” (from one to two, two to four and then four to eight) giving a dog age equivalent of 64 (that’s 31 + 3×11).
This useful approximation is plotted as the black curve on the conversion figure below. The green line represents the discredited factor-of-seven rule that suggests unrealistic ages at the higher end of the dog age spectrum.
In eight calendar years a dog will approximately age the equivalent of 64 years (Credit: Christian Yates)
Most dog lovers will already have suspected that the human-to-dog age relationship is non-linear, having noticed that, initially, their pets mature much more quickly than the linear factor-of-seven rule suggests.
A more sophisticated refinement to the factor-of-seven rules has suggested that each of the dog’s first two years correspond to 12 human years while all subsequent years count for four human equivalents. The blue curve in the above figure, which represents this ad hoc rule, shows better agreement with the new logarithmic law.
In practice the new molecular insights into human-to-dog age conversion encapsulated by the logarithmic law suggest that dogs move into middle age even more rapidly than most dog-owners would have suspected. It’s worth bearing in mind, when you find that Rex is reluctant to chase the ball like he once did, that he’s probably got more miles on the clock than you’ve been giving him credit for.
Christian Yates is a senior lecturer in mathematical biology at the University of Bath. He is also the author of The Maths of Life and Death.
This articleoriginally appearedon The Conversation, and is republished under a Creative Commons licence.
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I don’t know about you but I found this article extremely interesting.
Learning from Dogs 