Elastic proteins
What do rubber bands and fleas have in common?

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…

Tetrodotoxin
Not many foods served in a restaurant can kill you, but pufferfish is the exception. Tetrodotoxin, the toxin responsible for such culinary fatalities, reveals a fascinating story of convergent evolution...

Enzymes: convergence on active sites and reaction types
Enzymes make the world go round, each an evolutionary marvel - and convergent.

Lysozyme
Lysozymes are common antibacterial enzymes that protect our eyes and nose from infection, but some animals have recruited them for a rather different purpose...

Biological uses of silk: from webs to ballooning
What material is so versatile that it can be used for capturing prey, building nests, communication and even cleaning? The answer: that most remarkable of biomaterials - silk.

Echolocation in toothed whales and ground-dwelling mammals
Given the extraordinary powers of echolocation in bats, it is not surprising that this group has received the most attention. However, they are not the only mammals to have evolved echolocation. Who invented sonar millions of years before the Navy?

Pufferfish (and inflation)
Pufferfish are some of the most extraordinary fish to have evolved, especially because of their capacity to swallow water and inflate themselves to something like a football. Not only that but some representatives can be deadly to the unwary diner...

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...

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…

Light producing chemicals: how to make bioluminescence
The most remarkable luciferin in terms of its distribution is known as coelenterazine. This nitrogen-ring based molecule is found in nine separate groups, ranging from radiolarians to fish.

Bioluminescence
Flying through the air on a summer's evening or sparkling in the ocean you may see magical flashes of light that signal some of nature's most enchanting creatures, those that are bioluminescent.

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…

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…

Foregut fermentation in mammals
Foregut fermentation is best known from the ruminants, such as cattle, deer and giraffes, that regurgitate and rechew their food to aid microbial digestion. However, they are not the only mammals to have evolved this digestive strategy...

Foregut fermentation in birds
A foregut-fermenting bird was long considered a paradox. But what about the hoatzin, a curious South American bird known locally as the "stinking pheasant" thanks to its smell of fresh cow manure?

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...

Agriculture in beetles
Think of weevils and most likely you'll think of spoiled food. But some weevils have turned to farming...

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...

Reversion from xylem vessels to tracheids
In three plant taxa that evolved in environments with frequent freeze-thaw cycles (Winteraceae, Trochodendraceae and cold desert Ephedra), vessel evolution has been reversed independently in favour of a return to a tracheid-based vascular system.

Xylem vessels in vascular plants
Vessels are characteristic of the angiosperms, and yet they have evolved independently in several other groups, including the lycophyte Selaginella, horse-tail Equisetum and the enigmatic Gnetales.

Foam nests in animals
Nests crop up everywhere, but one made out of foam? Might not sound like a great idea, but it is. And no surprise, it has evolved several times...

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?

Pufferfish (and inflation)
Pufferfish are some of the most extraordinary fish to have evolved, especially because of their capacity to swallow water and inflate themselves to something like a football. Not only that but some representatives can be deadly to the unwary diner...

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...  

Mushrooms and their relatives (Basidiomycota)
Mushrooms are not only tasty, but also provide numerous examples of evolutionary convergence...

Tetrodotoxin
Not many foods served in a restaurant can kill you, but pufferfish is the exception. Tetrodotoxin, the toxin responsible for such culinary fatalities, reveals a fascinating story of convergent evolution...

Beak structures in reptiles and birds
Among reptile taxa with beak structures, we find several cases of convergent evolution, for example between turtles, Uromastyx lizards, a number of herbivorous dinosaurs and the tuatara (Sphenodon) of New Zealand.

Desert plants with succulent leaves
Perhaps the most striking case of convergence among leaf succulents occurs between Agave and its relatives Yucca and Hesperaloe in the Americas and Aloe and its relatives (e.g. Haworthia and Gasteria) in Africa.

Succulent desert plants
Classic examples of convergence in desert plants include the so-called 'stem succulent' cacti in the Americas and cactus-like Euphorbia species in Africa and South Asia, and also the striking similarity between 'leaf succulent' Agave and Yucca of the Americas and Aloe and its close relatives in Africa.

Crabs: insights into convergence
You might think of crabs mainly as food, but this group is also highly instructive in terms of convergence…

Limblessness in lizards
What's that slithering towards you? A snake? Look more closely, look convergently...

Carnivorous fungi: a diet of worms (and other animals)
Fungi have learnt how to trap living prey, notably nematodes but also a range of other animals include rotifers, tardigrades and even springtails.

Ascomycete fungi: insights into convergence
Today ascomycetes are an extremely important group of fungi, and they take their name from the reproductive structures known as ascii.

Saxitoxin synthesis: from molluscs to algae
Saxitoxin has a similar molecular structure to tetrodoxin and a wide distribution amongst living organisms, with evidence that is has been recruited independently several times.

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.

Echolocation in toothed whales and ground-dwelling mammals
Given the extraordinary powers of echolocation in bats, it is not surprising that this group has received the most attention. However, they are not the only mammals to have evolved echolocation. Who invented sonar millions of years before the Navy?

Dandruff, Malassezia and Candida
The presence of Malassezia does not guarantee dandruff, as this fungus is commonly present on healthy skin, but it evidently central to dandruff production if other key factors support it.

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.

Ink production in cephalopods and gastropods
A series of striking convergences can be found in the sea-hares (Aplysia), a group of gastropods and only remotely related to the cephalopods.  Not only do they emit ink clouds (the colour is derived from ingested red algae), but they also employ chemical cues that assist in defense.

Extremophiles: Archaea and Bacteria
Surely, no organism can survive in boiling water or brines nine times the salinity of seawater? Wrong - some archaea and bacteria have independently evolved adaptations to such extreme environments...

Sand-dwelling (psammophilous) lizard ecomorphs
Desert sand dunes represent an extreme environmental setting in which selective forces have apparently generated dune ‘ecomorphs’ in six lizard families. – Lamb et al. (2003) Biological Journal of the Linnean Society, vol. 73, p. 253

Mammal-like placentation in skinks (and fish)
“Only two types of vertebrates [have] evolved a reproductive pattern in which the chorioallantoic placenta provides the nutrients for fetal development. One is [...] the eutherian mammals […], and the other, a few lineages of the family Scincidae.” A.F. Flemming (2003) J Exp Zool 299A 33-47

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.

Venom in mammals (and other synapsids)
Beware the venomous shrew! Yes, venomous. And convergent on some formidable lizards...

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

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.

Loss of olfactory capacity in primates and cetaceans
It is widely thought that reduced olfactory capacity in apes is linked to the development of acute vision, especially trichromacy.

Ancient opsins and vision in extinct animals
Spectral tuning of the eye generally depends on key substitutions of amino acid sites in opsin proteins.

Hearts in cephalopods and vertebrates
There is a striking convergence between the aorta of the cephalopod and vertebrate heart, notably in its structure and the employment of elastic proteins.

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.

Lipocalins for milk and pheromone transport
Lipocalins are proteins that bind to and transport small hydrophobic molecules such as lipids and steroids, and have been associated with biological processes such as milk production, pheromone transport and immune responses.

Adhesive pads: from geckos to spiders
In terms of adhesive pads we find they have a remarkably wide distribution evolving in at least four distinct groups, including members of the reptiles, amphibians, arthropods and mammals, with tentative parallels in sea urchins.

Silk production and use in arthropods
Remarkably, fossil silk is known, especially from amber of Cretaceous age. Material includes both silk with trapped insects, possibly from an orb-web, and strands with the characteristic viscid droplets that are the key in trapping prey.

Mussel attachment and the Pinna byssus
It is clear that the Pinna byssus has unusual properties in comparison to its equivalent in the bivalve mussel, and is conspicuously different in terms of crystallinity.

Biological uses of silk: from webs to ballooning
What material is so versatile that it can be used for capturing prey, building nests, communication and even cleaning? The answer: that most remarkable of biomaterials - silk.

Lysozyme
Lysozymes are common antibacterial enzymes that protect our eyes and nose from infection, but some animals have recruited them for a rather different purpose...

Enzymes: convergence on active sites and reaction types
Enzymes make the world go round, each an evolutionary marvel - and convergent.

Birds: insights into convergence
Intriguing ecological and morphological parallels can be found among the Neoaves. Many of these forms were initially believed to be each other's closest relatives, but are now widely recognised as classic examples of convergence. Think how similar swifts and swallows are, but they are only distantly related.

Gut fermentation in herbivorous animals
Ever tried eating a newspaper? Don't. Plant cell walls contain cellulose, which is notoriously difficult to digest. Considering that all vertebrates lack the enzymes to attack this polysaccharide, how do so many of them manage to survive on a plant diet?

Carbonic anhydrase in vertebrates, plants, algae and bacteria
Carbonic anhydrase is extremely convergent and may have evolved as many as six times. The most familiar variants are α, β and γ carbonic anhydrases.

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?

Sabre-toothed cats and marsupials
Marsupials with giant fangs? Yes, not all of the extinct sabre-toothed cats were actually cats…

Sap feeding and honey-dew production in insects
Interestingly, it has now been shown that the saliva of the aphids has an analogue to the anti-coagulant properties of blood suckers, subverting the wound repair mechanism of the plant.

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

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.

Woodpeckers and woodpecker-like birds and mammals
You think woodpeckers are unique? Consider the ovenbirds. Or even the curious aye-aye.

Ecology and cosmetics in vultures
Vultures are not only charistmatic birds in the popular imagination, but are strikingly convergent, especially regarding feeding types...

Developmental genetic pathways to convergence
At first sight there is a fairly simple dichotomy between convergent features that have effectively the same genetic basis, and those where the same feature emerges but the underlying genetics are different. The former, however, is somewhat more complicated...

Ants: insights into convergence
Trap-jaws, silk and agriculture – just a few examples of convergence in the arguably most successful group of insects, the ants…

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.

Haemocyanin in arthropods and molluscs
The degree of similarity between the active sites in arthropod and molluscan haemocyanin has been called “remarkable” and “startling”, but actually suggests that wherever in the universe life employs copper for aerobic respiration it will call upon haemocyanin.

Elastic proteins
What do rubber bands and fleas have in common?

Crystallins: eye lens proteins
Whereas typically technology demands furnaces, so that the glass for a lens is produced at hundreds of degrees Celsius and then requires most careful grinding, so nature calls upon proteins known as crystallins.

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.

Worm-like body form
Man is but a worm, but so are many other vertebrates...

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.

Burrowing: from worms to vertebrates
Quite a few adaptations are useful for burrowing into the soil. So it is not exactly surprising that they have evolved several times...

Defence in frogs: toxins and camouflage
The many striking examples of convergence most famously include the case of mimicry, but the question of defence also extends to the use of toxins (and venoms), such as alkaloids, where we also find molecular convergence.

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?