There is a phrase in biology….ontogeny recapitulates phylogeny.
Basically it means that the development of individual organisms (ontogeny) follows (recapitulates) the same phases of the evolution of larger ancestral groups of related organisms (phylogeny).
Or…in a different way of thinking about it, nature conserves a good design.
On my walk home today I stopped to marvel at the external anatomy of a moth on the asphalt. I love its wooly coat, its orange tones, the symmetry of its patterning.
But the thing that I had to admire most of all was its antennae.
Zoom in on those things!
OK, not too close because the photo is only made with an iPhone so it’s not really great.
Now…the next time you catch a fish, or pick up a feather, grab a magnifying glass (or your smart phone’s shitty camera) and zoom in on those.
They are remarkably similar, yet serve completely different functions.
Sort of.
A fish’s gills are composed of primary and secondary lamellae. Their purpose is to slow the flow of water over the filaments (lamellae) and permit the exchange of gases. CO2 out, O2 in. They also provide surface area for excretion of ammonia wastes and exchange of ions.
A bird’s feather is equally made up of primary and secondary filaments, at right angles to each other. Their purpose is to catch and disrupt air and generate lift, enabling the bird to fly. Their structure also helps them retain warmth by trapping air, and stay dry by repelling water due to the fine organization.
And a moth’s antennae? The structure is similar, but maybe not quite as similar. They have a couple of functions. They are home to sensory neurons that can capture super fine molecules; pheromones and other airborne chemicals. They can also function as a sort of gyroscope, helping the moth maintain course by detecting changes in movement.
Nature is so incredibly amazing, and generally so efficient. Evolution generates new organisms, and rather than start new and throw away the old, she takes a useful design, tweaks it, and gives it a new purpose.
That’s marvellous!
Biology is simply magnificent.
Oh.
Also.
Here is a slug.
😃
