Sure.
Evolution is a process which searches for maxima in fitness spaces. These multi-variable mathematical surfaces don’t imply that the maxima is indeed where an organism has become more intelligent.
This adorable creature’s life consists of eating eucalyptus leaves and sleeping all day while digesting them. It is a puffy leaf processor that produces nitrogen compounds, STDs and cute pictures.
Why would it need to be smarter to improve doing any of those things? Would it need to be smarter to produce more offspring? Could it become smarter in the first place? Eucalyptus leaves are a very poor nutritional source.
This. This is a koala’s brain. Look at it. Look at it again.
The lack of convolutions and brain surface means that koalas must be one of nature’s most stupid vertebrates. They are apparently so impaired that can’t readily process that a leaf on a plate is a leaf at all and consequently won’t eat it. Evolution has made their brain as efficient as possible so it could maximize their dietary intake. A complex brain is redundant if your life-style is hanging on a tree all day and violently spreading STDs.
I would bet that they have specific neural pathways for the trees they live in. Please Reddit scientists, try to make an experiment with fake trees or something. If beavers can be cheated by the sound of water to build their dams, a biological robot as simple as the koala should be easier than that.
Footnotes:
Half of Australia's koalas now have the clap - Planet Experts
