Cogoti, ergo sum. I think, therefore I am—this is the famous dictum that French philosopher René Descartes used to argue for proof of his own existence (even in the face of somewhat absurd levels of systematic doubt). That you and I are able to think at all is proof that we exist. Encyclopedia Britannica:
The statement is indubitable, Descartes argued, because even if an all-powerful demon were to try to deceive me into thinking that I exist when I do not, I would have to exist for the demon to deceive me. Therefore, whenever I think, I exist. Furthermore, he argued, the statement “I am” (sum) expresses an immediate intuition, not the conclusion of dubious reasoning, and is thus indubitable. Whatever I know, I know intuitively that I am.
But if being a thinking being is proof enough, then, according to new research, the humble fruit fly can also be confident in its own existence. Little Drosophila is not the manifestation of a trickster demon, either. The New York Times:
It’s easy to think of fruit flies as tiny robots that simply respond reflexively to their environment. But just like humans, they take time to collect information and to deliberate when faced with a difficult choice, according to a new study.
In a study, researchers showed that fruit flies appear to collect evidence before making a decision. And, the less obvious the distinction between two choices was, the longer it took for the flies to weigh their options. Gero Misenböck, one of the researchers, told the Times:
We were surprised... The original thought was that the flies would just act impulsively, they won’t take time to deliberate. We found that’s not true.
This not the first bit of evidence that little creepy crawlies may have more going on under the hood than we thought. In other recent research, scientists suggested that cockroaches, pests the world over, form complex communities founded on strong communication and may even have a rudimentary form of consciousness.