Fern adaptations

Adaptations give an organism an advantage when growing in a particular environment. Dr Patrick Brownsey from Te Papa talks about how the leather-leaf fern has adapted to growing in dry conditions.

Points of interest:

• The silver fern koru is shown as an example of an adaptation. What do you think its adaptation is?

• Who is regarded as the father of natural selection?

DR PATRICK BROWNSEY

Well, adaptations are things that help plants, and animals for that matter, to live in the environment in which they are, and they are based on the genetic structure of a plant, and there is variation in any populations so not all the individuals in any one population are identical. And then on top of that, of course, you can get bigger mutations that crop up.

Natural selection works on those variations, and anything which gives an advantage to the plant in the particular habitat is an adaptation. Because it’s genetically determined, this gets passed on from one generation to the next, and natural selection works on those, and those individuals which are better suited to the environment are going to survive better, and they will pass on that adaptation to their offspring.

So this is the leather-leaf fern, and it’s an example of a fern that has adapted to growing in quite dry conditions. The frond has got this waxy cuticle on it, and that helps to cut down moisture loss. And then when we turn it over, on the underside, it’s got this beautiful silver colour, and that silver colour is actually the result of a complete covering of hairs on the underside, and the hairs there are just like the hairs on your head, and they cut down water loss as well.

Acknowledgement: Museum of New Zealand Te Papa Tongarewa