【推荐2】What is life? Like most great questions, this one is easy to ask but difficult to answer. The reason is simple: we know of just one type of life and it’s challenging to do science with a sample size of one. The field of artificial life-called ALife for short — is the systematic attempt to spell out life’s fundamental principles. Many of these practitioners, so-called ALifers, think that somehow making life is the surest way to really understand what life is.

So far no one has convincingly made artificial life. This track record makes ALife a ripe target for criticism, such as declarations of the field’s doubtful scientific value. Alan Smith, a complexity scientist, is tired of such complaints. Asking about “the point” of ALife might be, well, missing the point entirely, he says. “The existence of a living system is not about the use of anything.” Alan says. “Some people ask me, ‘So what’s the worth of artificial life?’ Do you ever think, ‘What is the worth of your grandmother?’”

As much as many ALifers hate emphasizing their research’s applications, the attempts to create artificial life could have practical payoffs. Artificial intelligence may be considered ALife’s cousin in that researchers in both fields are enamored by a concept called open-ended evolution (演化). This is the capacity for a system to create essentially endless complexity, to be a sort of “novelty generator”. The only system known to exhibit this is Earth’s biosphere. If the field of ALife manages to reproduce life’s endless “creativity” in some virtual model, those same principles could give rise to truly inventive machines.

Compared with the developments of Al, advances in ALife are harder to recognize. One reason is that ALife is a field in which the central concept — life itself — is undefined. The lack of agreement among ALifers doesn’t help either. The result is a diverse line of projects that each advance along their unique paths. For better or worse, ALife mirrors the very subject it studies. Its muddled (混乱的) progression is a striking parallel (平行线) to the evolutionary struggles that have shaped Earth biosphere.

Undefined and uncontrolled, ALife drives its followers to repurpose old ideas and generated novelty. It may be, of course, that these characteristics aren’t in any way surprising or singular. They may apply universally to all acts of evolution. Ultimately ALife may be nothing special. But even this dismissal suggests something：perhaps, just like life itself throughout the universe, the rise of ALife will prove unavoidable.

【推荐1】The adorable female calf is the second black rhino born this year at the reserve, but it is too early to tell if the calves will make good candidates to be returned to protected areas of the wild. The first rhino to be born at Port Lympne arrived on January 5 to first­time mother Kisima and weighed about 32kg. His mother, grandmother and great grandmother were all born at the reserve and still live there.

What can be inferred about Port Lympne Reserve?

【推荐3】Tree-planting, intended to help draw down carbon dioxide from the atmosphere, has become a synonym (同义词) for climate action. In our constant focus on trees, we’ve developed a fixed understanding: Trees absorb carbon dioxide, end of story. The reality is that trees don’t grow well alone. They exist within complex communities, helped along by each other as well as the animals they coexist with. The woodland isn’t nature’s only carbon sink: Grasslands and oceans also help reduce the carbon level and rely on a healthy amount of biodiversity.

That’s what the paper, published in Nature, wants to get across. Co-author Oswald J. Schmitz, a professor of ecology at Yale University, said trees might not be able to do their carbon-uptake job efficiently without the right animals in their ecosystem. That’s because animals animate the carbon cycle through their behavior and roles in the ecosystem. He added that the very presence of wild animals could cause feedback effects that change the ecosystem’s capacity to absorb, release, or transport carbon.

In Serengeti, for instance, the sharp decline in wildebeest (角马) population s during the mid-20th century allowed grass to grow wildly, eventually promoting wildfires that consumed 80 percent of the ecosystem annually and led to a net release of carbon dioxide into the atmosphere. When disease management and bans on illegal hunting helped animal populations recover, a greater share of the carbon stored in plants was consumed by wildebeest and released as waste, keeping it in the system and restoring the grassland as a carbon sink.