If you think about the countless number of animal species on our planet, the giraffe is perhaps one of the most interesting. With its unusual pattern and incredibly long neck, it looks like no other animal on Earth. But how did this mammal come to get its famously huge neck? Well, scientists have been asking themselves this question for centuries.

The most commonly believed answer is that the massive neck — which measures on average 180 centimeters and weighs about 270 kilograms — evolved to allow the animal to reach the leaves of tall trees.

British scientist Charles Darwin was one of the first people to propose this idea in the 1800s.“The giraffe… has its whole frame beautifully adapted for browsing on the higher branches of trees,”he wrote in his famous 1859 book On the Origin of Species. It was Darwin’s belief that the giraffe once had a much shorter neck, but over time, evolution led to longer-necked giraffes being born, which in turn survived as they were able to reach the food that others couldn’t. Yet, there are other theories. According to a paper published in September in the Journal of Arid Environments, the giraffe’s neck evolved to increase its surface-area-to-volume ratio. Because the animal’s neck increases its body’s surface area, it makes it easier for it to keep cool, the paper’s authors wrote. This phenomenon can be seen everywhere in nature, and even in engineering.

For example, this is why elephants have such large ears, and why radiators (暖气片) in homes are flat and thin, as a large surface area allows heat to escape quicker.

Meanwhile, some believe that competition is the answer. A 1996 study by two South African zoologists argued that the male giraffes with the biggest necks are the ones who “win” access to females to reproduce, as they are better at fighting, meaning that their long necks are passed down through the generations. So, it seems like there’s still no definite answer to the question. But until we find the truth, we should at least enjoy this beautiful and interesting creature for what it is today, rather than wonder about where it came from.

Giant pandas could be left hungry and struggling to survive by global warming, scientists have warned. A new study predicts that climate change (气候变化) is certain to des troy much of the bamboo on which the pandas depend for food. Main panda habitat (栖息地) in China could be completely lost by the end of the century. Human development adds to the risk by preventing the pandas from getting to places where bamboo is less affected by rising temperatures.

Bamboo, which covers the forest floor where the pandas live, is the single item in the pandas’ diet and also provides food and shelter for other animals. The plant’s unusual reproductive (繁殖的) cycle limits its ability to get used to climate change. One species studied by the scientists only flowers and reproduces every 30-35 years. Experts pointed out that three main bamboo species were likely to disappear as the climate warmed.

“We will need advance actions to protect the present giant panda habitats,” said the leading researcher Mao-Ning Tuanmu, from Yale University in the US. “We need time to look for areas that might become panda habitats in the future, and to think now about connection between habitats for pandas and other animals.”

Efforts to protect pandas should now aim to protect areas that have a better chance of supplying pandas with food, despite climate change. Natural “bridges” could also be created to help the pandas escape from a bamboo shortage. Looking at the climate impact on the bamboo can help us prepare for the challenges that the panda will likely face in the future.

“While animals can’t pick out precise numbers, they can understand that more is more. Interestingly, we know now that numerical competence is present on almost every branch of the animal tree of life,” says Andreas Nieder, a neurobiologist from the University of Tuebingen. “Different groups of animals obviously developed this trait independently from others and that strongly indicates that it has to be of adaptive value.”

Honeybees, for instance, can remember the number of landmarks they pass when searching for food in order to find their way back to the hive. The last common ancestor between honeybees and primates lived about 600 million years ago. But still, they evolved numerical competence that, in many respects, is comparable to vertebrate numerical competence. Also, for example, male frogs sing “advertisement” calls to attract females. The females, listening for the complexity of their calls, choose the male that sings the most calls.

Wolves are more likely to hunt successfully if they have the right number of wolves in their pack for the size of their prey: With prey like deer, only around six to eight wolves are needed, while hunting wild ox requires a pack of nine to thirteen. Their prey also uses this concept to protect themselves from predators—deer tend to live in large herds to reduce the chance of any individual becoming prey. So obviously they are assessing the number of individuals in their groups for their everyday life situations.

Despite these many examples of numerical competence in animals, this subject has not gotten many first-hand studies. “Many of these behavioral findings in the wild have usually been collected as by-products or accidental findings of other research questions,” says Nieder. He argues that more research needs to be done to fully understand the numerical competence.