Did you know that McDonald's famous burger, the Big Mac, contains addictive ingredients inside its bun? Yes, it's true, the bun isn't as harmless as your probably thought.

The Big Mac bun contains high levels of high-fructose corn syrup and sodium. Both ingredients are addictive, and therefore make your body crave more of them. These ingredients are also harmful and can cause obesity, diabetes, and heart disease, BUT not directly. Remember, the higher sweetness of high-fructose corn syrup increases craving and consequently the amount consumed. Obesity isn't caused by diet alone - when combined with decreased physical activity, that is when it contributes to the weight gain epidemic and personal health problems.

It's no wonder homemade burger ...

A new international study estimates that there are more than 3 trillion trees on Earth, about seven and a half times more than some previous estimates. This number was formulated by collecting tree density information from more than 400,000 forest plots around the world. But the total number of trees has plummeted by roughly 46 percent since the start of human civilization. The results provide the most comprehensive assessment of tree populations ever produced and offer new insights into a class of organism that helps shape most terrestrial biomes.

Source: http://www.nature.com/nature/journal/vaop/ncurrent/full/nature14967.html ...

It has to do with a single gene! More than a decade ago, researchers discovered that one gene (MC1R) on chromosome 16 plays an important role in giving people red hair. MC1R task is to make the protein melanocortin 1. This protein plays an important role in converting red pigment into black pigment. If you end up with only one mutated MC1R gene, red hair can appear in unwanted places, like your beard. When someone inherits two mutated versions of the MC1R-gene (one from each parent), less red pigment is converted into black pigment. ...

There’s so much trash floating in some parts of the ocean that each square kilometer of surface water there holds almost 600,000 pieces of debris. Indeed, because there's so much of it, by 2050 birds of almost every ocean-foraging species may be eating plastic.

You guessed it! The tufted ground squirrel (Rheithrosciurus macrotis), also known as the vampire squirrel.

Check out what may be the first video of the remarkable and rare animal. This species of squirrel is twice the size of most tree squirrels, reputedly has a taste for blood, and has the bushiest tail of any mammal compared with its body size with its tail being 30 percent larger than its body.

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Known an fibrodysplasia ossificans progressive, or FOB for short, this disease can suddenly turn a person’s tissues and muscles into bone, thereby permanently immobilizing parts of the bodies. Joints such as elbows or ankles may become frozen in place; jaw motion can be impeded and the rib cage fixed, making eating or even breathing difficult. Currently, no cure exists to combat this rare condition.

Sometimes it pays to have big, bad neighbors! Tiny black-chinned hummingbirds (shown above) have learned to build their homes near hawk nests. The hawks are too big to be interested in teeny hummingbird eggs, and they scare off the medium-sized birds that are.

According to the study, of the 342 hummer nests studied over three years, 80% were near hawk nests - and for good reason. The researchers monitored hummingbird egg and fledgling survival near six active and six inactive hawk nests. Those hummers unlucky enough to be near inactive nests lost all but 8% of their young, while those in a “good” neighborhood had a 70% success rate, they report.

Source: http://news.sciencemag.org/plants-animals/2015/09/why-hawk-hummingbird-s-best-friend ...

Southern rockhopper penguins (Eudyptes chrysocome) mate for life, reuniting with the same partner year after year during mating season. But even though they're monogamous, a new study reveals that penguin couples really don’t spend much time together.

Using GPS trackers mounted to the penguins’ legs, scientists monitored 16 birds over the course of a mating season. The data show that males arrived at the nesting site approximately 6 days before their female counterparts and stayed about 6 days longer. However, the short mating season means the pairs are only united for about 20 to 30 days a year. And when they were separated, it was usually by a large distance: During the winter months, partners were separated by an average distance of abo ...