Science Finds a Better Way to Calculate 'Dog Years'

thegoodphoto/iStock via Getty Images
thegoodphoto/iStock via Getty Images

Anyone who has ever owned a pet is likely familiar with the concept of “dog years,” which suggests that one year for a dog is like seven years for a human. Using this conversion metric, a 2-year-old dog is akin to a high school freshman, while a 10-year-old dog is ready for an assisted living facility.

If that seems rather arbitrary, that’s because it is. But now, researchers at the University of California, San Diego have come to a more data-based measurement on dog aging through DNA.

The paper, published on the preprint server bioRxiv, based the finding on DNA methylation, a process in which molecules called methyl groups attach themselves to DNA and serve as an indicator of aging. Generally speaking, the older living beings get, the faster the rate of methylation. In the study, 104 Labrador retrievers were examined, with subjects ranging from 1 month to 16 years old. The results of their DNA methylation were compared to human profiles. While the rate of methylation tracked closely between the two—young and old dogs had similar rates to young and old people—adolescent and mature dogs experienced more accelerated aging.

Their recommended formula for comparing dog and human aging? Multiply the natural logarithm of a dog’s age by 16, then add 31. Or, just use this calculator. Users will see that a 2-year-old dog, for example, wouldn’t be the canine equivalent of a 14-year-old. It would be equivalent to 42 human years old and should probably start putting money into a 401(k). But because methylation slows considerably in mid-life, a 5-year-old dog is approximately a 57-year-old human, while a 6-year-old dog is nearing 60 in human years—a minor difference. Things level out as the dog gets much older, with a 10-year-old dog nearing a 70-year-old human.

Different breeds age at different rates, so the formula might not necessarily apply to other dog breeds—only Labs were studied. The work is awaiting peer review, but it does offer a promising glimpse into how our furry companions grow older.

[h/t Live Science]

New Cross-Bred Cosmic Crisp Apples Can Stay Fresh for Up to a Year

Cosmic Crisp
Cosmic Crisp

Healthy snackers know only too well the disappointment that comes with biting into what looks like a deliciously crisp apple and getting a mouthful of mealy mush instead. It’s just one of the pome fruit’s many potential issues—they also brown quickly, bruise easily, and don’t last as long as whatever bag of chips you might be tempted to reach for instead.

Enter the Cosmic Crisp, a Washington-grown patented hybrid apple that could be the answer to all your apple-related complaints. According to New Atlas, researchers at Washington State University began breeding the new variety as a cross between Enterprise and Honeycrisp apples in 1997, and it’s officially hitting stores now.

cosmic crisp apple on tree
Cosmic Crisp

Not only does a Cosmic Crisp apple resist bruising and browning better than other kinds of apples, it also boasts an exceptionally long storage life. In a controlled atmosphere, it should stay fresh for a full year—meaning you’ll soon be able to enjoy a crisp, satisfying snack in the middle of March, when out-of-season apples usually leave much to be desired. In your own refrigerator, Cosmic Crisp apples are good for about six months, and they’ll even last for several weeks if you leave them out at room temperature. The long shelf life might cut down on the number of apples that you end up tossing in the trash because they went bad before you got around to eating them.

In a 2012 report published in the American Society for Horticultural Science journal HortScience, the Washington State University researchers found that a group of 114 consumers rated the Cosmic Crisp apple, or WA 38, higher than Fuji apples in sweetness, sourness, flavor intensity, crispness, firmness, juiciness, and overall acceptance. The apple's website even suggests that bakers can reduce the amount of added sugar in recipes that contain Cosmic Crisps.

The Cosmic part of its name comes from the whitish specks on the apple’s skin, which reminded taste testers of a starry sky. In reality, those specks are lenticels—porous openings that allow the apple to exchange gases with its environment.

If you don’t see Cosmic Crisp apples in your grocery store yet, here’s a simple trick for keeping any apples fresh for longer.

[h/t New Atlas]

The Reason So Many Babies Are Conceived in Winter

yurizhuravov/iStock via Getty Images
yurizhuravov/iStock via Getty Images

Does it feel like many friends and family members announce the pending arrival of a baby during the fall and winter months? That’s not exactly a coincidence. It turns out the cold season is associated with more reproductive activity than any other time of the year. The month of December alone accounts for 9 percent of conceptions in the United States. Science is gaining a better understanding of why.

All living creatures heed an evolutionary instinct to target seasonal births. If conception happens during colder months, babies will be born during warmer months, when resources will be bountiful. Northern states have births peaking in June and July, while southern states come a bit later in October and November. The farther south, the later the birth peak, since people in these warm climates are less influenced by frigid temperatures.

What are frisky humans responding to in colder months? Research suggests that the cooler temperatures and shortened days signal that it's time to get busy. Other theories suggest that men may be more fertile in colder months, or that a woman’s ovum receptivity might change with decreased daylight. Not only are couples potentially more sexually active, but that activity might wind up being more (re)productive.

Are there benefits to conceiving at other times? Possibly. One 2013 study published in the Proceedings of the National Academy of Sciences gathered data from nearly 1.5 million births and found that average birth weight in the first five months of the year decreased by 10 grams. Babies born during the summer months were 20 grams heavier. Mothers who conceived in summer tended to gain more weight than those who conceived at other times.

If you have a disproportionate amount of friends with a September birthday, it’s likely that their parents consciously or unconsciously followed their evolutionary instinct nine months earlier.

[h/t Smithsonian]

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