Camera eyes of cephalopods
The remarkable similarity between the camera eyes of cephalopods and vertebrates is one of the best-known examples of evolutionary convergence.

Octopus and other cephalopods: convergence with vertebrates
What could be more different from us than the alien-like octopus? Hold on. Look it in the eye and think again.

Camera eyes in vertebrates, cephalopods and other animals
Camera eyes are superb optical devices, so it is not surprising that they have evolved several times. But why, of all animals, in the brainless jellyfish? Or for that matter in a slow-moving snail?

Beetles: insights into convergence
The beetles are probably the most diverse animal group on earth, so it is not at all surprising that they provide many fascinating insights into convergence.

Strepsipterans: convergent halteres and eyes
Strepsipteran females spend their whole life inside a wasp. The males are rather more exciting, particularly in terms of convergence…

Camera-like eyes in arthropods
Arthropods are famous for their compound eyes, but some groups have had a fair crack at evolving the optically superior camera eye…

Camera eyes in gastropod molluscs
The fast-moving cephalopod molluscs are famous for their camera eyes, but why on earth have gastropod snails, which are not exactly known for their speed, evolved this superb visual organ at least four times?

Compound eyes in ark clams
Read on if you want to know more about bivalves with burglar alarms…

Vision in echinoderms
Among brittlestars and sea urchins we find visual systems that in some ways rival the arthropods in the form of compound eye-like structures.

Independent eye movement in fish, chameleons and frogmouths
One of the most surprising convergences amongst animals is that seen between a small fish that lives in coral sands, known as the sandlance, and the lizards known as chameleons.

Camera eyes in cubozoan jellyfish
On each of the four club-like extensions (rhopalia) near the base of the cubozoan jellyfish bell there are two camera-eyes, one pointing upwards and the other downwards.

Camera eyes in alciopid annelids
There is a striking example in the group known as the alciopids, which are pelagic polychaetes. The similarity of their camera eye to the vertebrate eye has attracted considerable comment.

Camera eyes in gastropod molluscs
The fast-moving cephalopod molluscs are famous for their camera eyes, but why on earth have gastropod snails, which are not exactly known for their speed, evolved this superb visual organ at least four times?

Camera eyes of cephalopods
The remarkable similarity between the camera eyes of cephalopods and vertebrates is one of the best-known examples of evolutionary convergence.

Camera eyes in vertebrates, cephalopods and other animals
Camera eyes are superb optical devices, so it is not surprising that they have evolved several times. But why, of all animals, in the brainless jellyfish? Or for that matter in a slow-moving snail?

Camera-like eyes in arthropods
Arthropods are famous for their compound eyes, but some groups have had a fair crack at evolving the optically superior camera eye…

Corneal nipple arrays in insect eyes
Anti-reflection coating? Not only on mobile phone displays, but also on insect eyes...

Compound eyes in arthropods
It is clear that amongst the arthropods as a whole the compound eye has evolved at least twice, and possibly even more times.

Pinhole eyes in Nautilus and giant clam
The pinhole eye has evolved not only in the Pearly Nautilus, but also in another group of molluscs, the bivalves and specifically the giant clams (Tridacna).

Compound eyes in ark clams
Read on if you want to know more about bivalves with burglar alarms…

Scanning eyes in molluscs and arthropods
Some sea snails have a linear retina. What a hopeless arrangement, to see the world through just a narrow slit! Not quite, because they have come up with a rather intriguing trick to extend their visual field - and it's a trick too good to use only once.

Telephoto eyes in animals
Pursued by the paparazzi? Watch out for those animals equipped with telephoto lenses...

Transparent tissues: eyes, bodies and reflective surfaces
Read on if you want to know about the numerous animal equivalents to the invisible man...

Agriculture in marine polychaete annelids
Some polychaetes attach pieces of algae to their dwelling tube. Just for decoration? No, but for a much more substantial (and convergent) benefit...

Lateral line system in fish and other animals
Some cavefish are completely blind, so how do they manage to navigate through their environment with astonishing ease?

Sleep in animals
Suffering from insomnia? Fruit flies do as well...

“Colour vision” in Firefly squid
The Japanese firefly squid (Watasenia scintillans), which inhabits the deep ocean, has three visual pigments located in different parts of the retina that are likely to allow colour discrimination as they each have distinct spectral sensitivities.

Octopus and other cephalopods: convergence with vertebrates
What could be more different from us than the alien-like octopus? Hold on. Look it in the eye and think again.

Dinoflagellate “nematocysts”
Examples of convergence within the dinoflagellates range from the evolution of a camera-like eye to stinging 'nematocysts' reminiscent of those in jellyfish.

Olfaction: insights into convergence
Although olfaction is very widespread, there is abundant evidence for repeated convergence of key features, strongly suggesting that there really is an optimal solution to detecting smells.