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.

Vibrational communication in mammals
Kangaroo rats drum their foot on the ground upon encountering a snake. Why? Read on for this and many other fascinating examples of vibrational communication in mammals…

Vibrational communication in insects and spiders
Some spiders have evolved a most remarkable method of capturing other spiders – they imitate the vibrations of insects caught in their victim’s web. And this is only one of numerous intriguing examples of vibrational communication in arthropods…

Echolocation in bats
How can bats navigate in total darkness amongst trees and branches, but still locate a tiny, fluttering insect with extraordinary acuity? All made possible through echolocation, an astonishing sensory mechanism…

Monochromacy in mammals
Underwater environments are dominated by blue light. Ironically, whales and seals cannot see blue, because they have independently lost their short-wavelength opsins.

Brood parasitism in cuckoos and other birds
Obligate brood parasitism has evolved several times independently in birds. Apart from the cuckoos, it can be found in four other, only distantly related families.

Carnivorous plants
All plants are harmless? Well, not quite - at least not when you're an insect...

Vibrational communication in animals
What on earth could an elephant or treehoppers have in common with a seismometer?

Pressure sensitivity and the tactile sense (excluding the lateral line)
The star-nosed mole is famous for, well, its nose, but do you have any idea what these peculiar 'tentacles' are for? The answer is rather touching and, of course, convergent...

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?

Mimicry in fungi
Insects pollinating flowers are a familiar sight. But what happens when the "flower" is actually a fungus? Still "pollination", but now it is fungal spores. Read on to learn more about the fungi that mimic flowers...

Moray eels
Eels masquerading as snakes sounds interesting, and that is before they go hunting with their friends the groupers...  

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.

Bats: Insights into convergence
Bats show a fascinating array of convergences, from echolocation to flight to nectar feeding. Vampire bats can even detect infrared radiation, while others might be able to see into the ultraviolet end of the spectrum.

Nuptial gifts in insects and spiders
Male dance flies lure females with a dead insect. Not very romantic, you might think, but it certainly does the trick. Hence, such nuptial gifts have evolved in numerous other arthropods...

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.

Trichromatic vision in mammals
Who has not enjoyed the splash of colour in a market: gorgeous red peppers, the green of basil and what on earth are these purple vegetables over there? All thanks to trichromatic vision, another story of convergence.

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.

Infrared detection in snakes
Warm-blooded rodents watch out! There are heat-sensing predators on the prowl...

Infrared detection in animals
Some snakes are famous for 'seeing' infrared, but did you know that their heat-sensing abilities are rivalled by some beetles that can detect forest fires over considerable distances?

Taste in arthropods and mammals
The ability to taste is obviously an essential component in the life of any animal, both to assess the potential quality of food, its nutrient capacities and also to detect toxins or other dangers.

Mitochondrial lens formation in flatworms
In some of the flatworms (platyhelminthes) the lens is formed from mitochondria, and it is intriguing to speculate whether a mitochondrial enzyme has been co-opted to provide a crystallin.

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

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.

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…

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?

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...

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…

Baculum (penile bone) in mammals
Ouch!! Gentlemen, fancy a bone in your penis? Seems a bit risky, given it could fracture during copulation. Even our near ancestors had such a bone. It has probably evolved several times, but what is its function?

Electric fish: insights into convergence
Ever seen an electric eel in an aquarium? Don’t dare putting your hand in the tank...

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

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.

Swimming and thermoregulation in sharks and tuna
Thunniform swimming depends on a large, lunate tail that is joined to the rest of the body via a narrow peduncle. Whilst the tail flicks backwards and forwards, so propelling the animal, the rest of the body hardly moves sideways.

Crustaceans: insights into convergence
Whilst predominantly marine, quite a number of crustaceans have invaded freshwater habitats and even more interestingly a few demonstrate terrestrialization, effectively freeing themselves from their aquatic ancestry.

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

“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.

Electroreception in fish, amphibians and monotremes
From an evolutionary point of view, electroreception is particularly intriguing as a sense modality that has been repeatedly lost and reinvented again.

Octopus arm function
If you want to see a truly remarkable example of convergence, then present an octopus with a piece of food and have a high-speed camera ready…

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?