Biology

A sign reads 'Do not feed the wildlife or birds'

The implication of this sign is that some of the birds in the park are not considered wildlife. Are pigeons wildlife?

A two-by-two grid of plant photos. Clockwise from top left: a maple tree, a holly tree, a lettuce plant, and a cabbage plant

Between cabbage, lettuce, maple, and holly, two plants are in the rosid clade (related to roses) and two are in the asterid clade (related to sunflowers). Can you guess which is which?

I would have guessed that the trees might be related to a woody rose bush, while the leafy greens would be closer to broad-leaved sunflowers. I would have been wrong. Plants are much weirder than that.

In fact, cabbages are much more closely related to maple trees than they are to lettuce; cabbage and maples are both rosids. Meanwhile, holly trees and lettuce are both asterids.

As it turns out, a lot of the categories we use to think about plants — trees, bushes, berries, vegetables, and so on — are not particularly unique from an genetic perspective. Biologist Georgia Ray explains:

On the evolutionary tree of plants, trees are regularly interspersed with things that are absolutely, 100% not trees. This means that, for instance:

  • The common ancestor of a maple and a mulberry tree was not a tree.
  • The common ancestor of a stinging nettle and a strawberry plant was a tree.
  • And this is true for most trees or non-trees that you can think of.

Because of this, there are plenty of plant lists you can play “One of these things is not like the others” with where the intuitive answer is very different from the phylogenetic answer.

  • Blackberries, strawberries, blueberries, apples.1
  • Almonds, walnuts, brazil nuts, stinking corpse flower.2
  • Palm tree, papaya tree, banana tree, asparagus.3
A family tree of various plants

If you shuffled all the plants on this taxonomy tree, I would not be able to tell the difference.

Footnotes

The highly-controversial map of the brown rat's habitat, highlighting almost the entire globe except for Alberta

Since the ’50s, Alberta has engaged in a deliberate effort to prevent rats from entering the province. Fortunately, rats can’t survive in the wild in Alberta, so they have pest inspectors regularly check every premise within a 29 x 600 km control zone from Montana to Cold Lake. Pet rats are illegal.

The rat-free status of Alberta led to a Wikipedia edit war over whether the province should appear on a map of the brown rat’s habitat. At some point it was decided to remove the map entirely from the English-language entry for Rattus norvegicus, but its presence on other Wikimedia projects means the edit war still rages on to this day.

A macro image of a sunflower inflorescence

The head of a sunflower is actually hundreds of smaller flowers working together to attract pollinators. Each large yellow petal is its own individual flower, and the bits in the middle are tiny five-pointed flowers if you look closely.

Sunflowers share this property with the rest of the family Asteraceae, including daisies, dahlias, dandilions, and dozens of “damned yellow composites”. The heads of these plants can be called inflorescences, or flower clusters.