Snails may not be everyone's first choice on the menu but several distinct colubrid snakes have evolved expert techniques for gorging on these nutritious gastropods.

Curling up into a ball has evolved many times as an excellent anti-predator defence.

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…

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 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...

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

When you think of grazing mammals, you might envisage large herds of antelopes roaming African savannahs. Did you know that there is an equivalent in the ocean, feeding on seagrass?

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

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...

Some cavefish are completely blind, so how do they manage to navigate through their environment with astonishing ease?

The strategy of anointing the body with the scent of a more dangerous animal has evolved independently several times, including in rodents, hegdehogs and tenrecs.

Probably everyone is familiar with the walrus, but did you know that it generates a vacuum in its mouth to suck clams out of their shells? And this is just one example of suction feeding, the feeding mode typically used by bony fish…

The multi-lobed post-canines of Lobodon carcinophagus are a functional analogue to the long, thin cage-like teeth of Mesosaurus, as both cage and prevent the escape of small crustacean prey.

Aquatic reptiles tend to display one of three dentition types, well adapted to either seize and slice large vertebrate prey, pierce and gouge slippery fish, or entrap small prey such as crustaceans.

The dental batteries or 'pavements' of ceratopsians and hadrosaurs evolved independently, and yet the dentition of several more distantly related animals also converges on their highly adapted tooth form.

Teiids are skink-like lizards whose members show a stunning diversity of tooth types, providing rich evidence of convergence within the teiids themselves, in distantly related reptile groups and even in certain mammals and fish.

Two unusual Early Cretaceous crocodiles provide a shining example of convergence, as their dentition parallels that observed in a group of advanced proto-mammals called tritylodonts.

Some reptiles have transverse chisel-like teeth for slicing, and others have teeth bearing projections ('cusps') that interlock and slice or grind tough food. In each case evolutionary parallels are clear both within and outside the reptiles.

Although the evolution of snake fangs itself provides us with a window on convergence, the presence of fang-like teeth in lizards, therapsids and mammals provides an even broader and more remarkable perspective.

The Turtle-headed sea snake feeds on small eggs and its feeding shows intriguing similarities to the way lizards forage, and herbivorous mammals graze and browse.

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.

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?

A number of reptile species have been discovered in the Mesozoic fossil record, bearing feathers that were apparently used to support gliding locomotion, rather than true, powered flight as we see in present day birds.

Gliding mammals rely primarily on extensive skin membranes or ‘patagia’ that stretch between fore- and hind-limbs, creating a wing-like structure.

In the reptiles, different forms of skin membrane (called ‘patagia’) and in some extinct species, primitive feathers, have evolved convergently as adaptations for gliding.

“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

“In over 100 lineages of […] squamates, the oviduct has been recruited for viviparous gestation of the embryos, representing a degree of evolutionary convergence that is unparalleled in vertebrate history.” D. G. Blackburn (1998) Journal of Experimental Zoology, vol.282, p.560

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.

One of the more obvious eye adaptations in whales is the extraordinary capacity of the pupil to change the size of its opening, from very small when in surface sunlit water to very large when exploring the abyssal gloom.

Nocturnal colour vision is clearly convergent, and found in groups as disparate as the hawkmoths (insects), geckos (reptiles) and aye-aye (mammals).

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.

Beware the venomous shrew! Yes, venomous. And convergent on some formidable lizards...

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?

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.

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

Sea-urchins, porcupines (and porcupine fish), lizards and many other animals bristle with defensive spines.

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.

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.

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

Filter feeding is most familiar in the baleen whales , but closely analogous arrangements have appeared at least twice in the birds, first the flamingos and second the sub-antarctic broad-billed prions.

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?

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?

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

The American cheetah (Miracinoyx) is an extinct Pleistocene form, and is strikingly similar to the cheetah (Acinoyx) that formerly had a wide range in the Old World but is today effectively restricted to Africa.

The viverrids or civets are a highly successful group of carnivores, fairly closely related to the cats and showing several striking examples of convergence.

The formation of bubbles in a fluid is known as cavitation. Typically this occurs at low pressures, and is perhaps best known in the xylem of plants where embolisms can be destructive to the surrounding tissues.

Dolphins are one of the most intriguing sources of evolutionary convergence, having cognitive abilities that seem to find many parallels in the great apes, and rather remarkably even extend to tool use.

Suffering from insomnia? Fruit flies do as well...

Eusociality is most familiar in the insects, where it has evolved several times, notably in bees, wasps, ants and termites, as well as in thrips and aphids.

Human farmers tending their fields are a familiar sight. But don't forget about those fungus-farming termites or the fish with a garden of algae…

You think woodpeckers are unique? Consider the ovenbirds. Or even the curious aye-aye.

Application of insecticides, such as against mosquitoes, has been documented in several primates and birds.

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...

Fission-fusion societies has evolved repeatedly and are found, for example, in the elephants, dolphins, chimpanzees, as well as some New World Monkeys.

Elephants are well known for their accuracy in throwing objects, and in addition use sticks for a number of purposes. Also of considerable interest is their use of fly-whisks to keep blood-sucking flies at bay.

Elephants are extremely unusual in their reaction to the dying and death of their compatriots, which includes attempts at resuscitation and grieving.

There is evidence that elephants are sensitive to seismic communication, with the large pads of the feet and the trunk tip capable of picking up vibrations transmitted through the ground.

The independent evolution of parental care is far more widespread than birds and mammals, extending as far as molluscs and echinoderms!

Identification of alcohol tolerance (or lack thereof) in different animal groups is important because alcoholism in humans may have some genetic basis.

Social play is the hall-mark of the most intelligent of this planet’s species, and there is a particularly striking convergence between birds and mammals.

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.

The specific case of a penis with a hydrostatic structure, as well as an array of collagen fibres that allows both expansion and guards against aneurysms, has evolved in a strikingly convergent fashion in mammals and turtles.

Personality in the vertebrates might, therefore, be deeply embedded in their phylogeny, although this does not rule out the convergent appearance of more complex personality traits in more advanced vertebrates, notably birds and mammals.

Amphibians are adept at vocalization, and remarkably ultrasonic communication has also evolved in the Concave-eared torrent frog, from China.

Viviparity is rampantly convergent, with famous examples in the reptiles, notably the lizards and snakes.

Complex interactions between males and females prior to mating have evolved independently many times. Amongst the most familiar examples are leks.

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

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

In a number of cases one eye is used in preference to another. This convergent phenomenon is found in octopus (cephalopods), dolphins, birds, and other animals.

Sexual mimicry is widespread, and the most famous example is probably the male-like genitalia in the females of the hyaena.

Convergence in learning (and by implication memory) is important not only because it will give us clues as to the nature of consciousness, but it will also have a bearing on the reality (or otherwise) of pain and suffering in “primitive” animals.

In some vertebrates (fish, mammals) and cephalopods we find an interesting convergence whereby some of the incoming ultraviolet is screened out.