List of examples of convergent evolution

note: this is a stub based on the wikipedia page

Convergent Evolution is evidence or argument for physical attractors in the phase space of dynamical possibility which guide and constrain contingently adaptive evolutionary processes into statistically predictable future-specific structure or function, in certain complexity-dependent classes of physical environments. When seen from the perspective of the dynamics of evolving species, this process has been called convergent evolution. The evolutionary dynamics of several species morphology or function is seen to converge to particular archetypal forms, in a variety of environments. Convergent evolution can be seen in the example of homology, which in 1843 Richard Owen defined as "the same organ in different animals under every variety of form and function". A famous example is camera eyes, which appear to have evolved on Earth from different genetic lineages to look and work very similarly in vertebrates, invertebrates, and other species. One can easily see the argument that, in universes of our type, such eyes, first created by a process of evolutionary contingency, once they exist, appear to become developmental necessity. Proving this argument with evidence and theory is of course more difficult.

When such convergence is viewed from the perspective not of the evolving species, but of the selective environment (the biome, the planet, the universe) as a system, we can also call convergent evolution a process of environmental development, and ultimately universal development. The system studied now becomes the relevant environment within which evolutionary subsystem change occurs. Ecology is one example of such study, and predictable patterns of ecological change, or ecological succession are one example of processes of environmental development. To take the concept of environmental development seriously, it must be applied on a universal scale, to the succession environments that unfold in universal history, because each environment inherits certain initial conditions and physical constancies from the environment that preceded it, back to the birth of the universe, and these initial conditions and constancies may constrain the dynamics of each successive environment, to some predictable degree. Thus models of early universe, astrophysical, chemical, biological, psychological, social, economic, technological, and other development must all be contrasted and compared for insights into differences and similarities in processes of environmental development, across the range of increasingly complex and rapidly-changing environments that have emerged in universal history. As a good example, the biological organism can be carefully studied as an environment within which molecular and cellular processes unfold. Most of these processes appear to operate chaotically, contingently, and adaptively, a process with several dynamical similarities to biological evolution, yet a special few of these molecular and cellular processes, driven by developmental genes and environmental constancies, are seen to be chaos-reducing, convergent, constraining, and statistically predictable, what we can call convergent evolution, from the perspective of the species, or environmental development, from the perspective of the selective system. Evo-devo biologists are one of the groups on the forefront of discriminating the interaction between evolutionary and developmental processes in biological systems, and we believe this perspective needs to be extended to all systems.

Such attractors have been called deep structure, guiding evolutionary process in predictable ways, regardless of local environmental differences. Like biological development, which depends on specific initial conditions (developmental genes) and persistent environmental constancies (physical and chemical laws), convergent evolution, if it exists, could be characterized as environmental development, and ultimately universal development, as it would depend on specific persistent constraints and environmental constancies, beginning with certain universal initial conditions, physical parameters, and physical laws. If the universe itself is a replicative system in the multiverse, as some cosmologists have proposed, such special initial conditions and constancies may have themselves self-organized in an iterative process, just as biological developmental parameters have self organized, in biological systems over multiple replications. For more on the latter idea, see our wiki page cosmological natural selection (fecund universes).

Research questions

• What are some good, referenced examples of convergent evolution (environmental development)?
• When comparing successively emergent environments (early universe, astrophysics, chemistry, biology, psychology, and societal systems), what are the similarities and differences in processes of development? How do we better define development across all such systems?
• When comparing successively emergent environments, what are the similarities and differences between contingently adaptive processes? How do we better define evolution across all such systems?
• How can we better test the theory of convergent evolution (universal development)?

List of examples of convergent evolution

Convergent evolution—the evolution of similar traits in unrelated lineages—is rife in nature, as illustrated by the examples below. The ultimate cause of convergence is usually a similar evolutionary biome, as similar environments will select for similar traits in any species occupying the same ecological niche, even if those species are only distantly related. In the case of cryptic species, it can create species which are only discernable by analysing their genetics.

In animals

The skulls of the Thylacine (left) and the Grey Wolf, Canis lupus, are almost identical, although the species are only very distantly related (different infraclasses). The skull shape of the Red Fox, Vulpes vulpes, is even closer to that of the Thylacine.

Mammals

• The pronghorn antelope of North America, while not a true antelope and only distantly related to them, closely resembles the true antelopes of the Old World, both behaviorally and morphologically. It also fills a similar ecological niche and is found in the same biomes.
• Members of the two clades Australosphenida and theria evolved tribosphenic molar (tooth)|molars independently.
• The marsupial thylacine (Tasmanian Tiger) had many resemblances to the placental canids.
• Several mammal groups have independently evolved prickly protrusions of the skin – echidnas (monotremes), the insectivorous hedgehogs, some tenrecs (a diverse group of shrew-like Madagascar|Madagascan mammals), Old World porcupines (rodents) and New World porcupines (another biological family of rodents). In this case, because the two groups of porcupines are closely related, they would be considered to be examples of parallel evolution]; however, neither echidnas, nor hedgehogs, nor tenrecs are close relatives of the Rodentia. In fact, the last common ancestor of all of these groups was a contemporary of the dinosaurs.
• Cat|Cat-like sabre-toothed predators evolved in three distinct lineages of mammals – sabre-toothed cats, Nimravids ("false" sabre-tooths), and the marsupial "lion" Thylacosmilus. Gorgonppsids and credonts also developed long canine teeth, but with no other particular physical similarities.
• A number of mammals have developed powerful fore claws and long, sticky tongues that allow them to open the homes of social insects (e.g., ants and termites) and consume them (myrmecophagy). These include the four species of anteater, more than a dozen armadillos, eight species of pangolin (plus fossil species), the African aardvark, short-beaked echidna|one echidna (an egg-laying monotreme), the enigmatic Fruitafossor, the singular Australian marsupial known as the numbat, the aberrant aardwolf, and possibly also the sloth bear of South Asia, all not related.
• Koalas of Australasia have evolved fingerprints, indistinguishable from those of humans. Apes' fingerprints are very similar to those too.
• The Australian honey possums acquired a long tongue for taking nectar from flowers, a structure similar to that of Lepidoptera|butterflies, some moths, and hummingbirds, and used to accomplish the very same task.
• Marsupial sugar glider and squirrel glider of Australia are like the placental flying squirrel.
• The North American kangaroo rat, Australian hopping mouse, and North African and Asian jerboa have developed convergent adaptations for hot desert environments; these include a small rounded body shape with very large hind legs and long thin tails, a characteristic bipedal hop, and nocturnal, burrowing and seed-eating behaviours. These rodent groups fill similar niches in their respective ecosystems.
• Opossums have evolved an Opposable thumb, a feature which is also commonly found in the non-related primates.
• Marsupial mole has many resemblances to the placental Mole (animal)|mole.
• Marsupial mulgara has many resemblances to the placental mouse.
• Planigale has many resemblances to the deer mouse.
• Marsupial Tasmanian devil has many resemblances to the placental hyena. Similar skull morphology, large canines and crushing carnasial molars.
• Kangaroo has many resemblances to the Patagonian cavy .
• The Marsupial lion had retractable claws, the same way the placental felines (cats) do today.
• Microbats, toothed whales and shrews developed sonar-like animal echolocation|echolocation systems used for orientation, obstacle avoidance and for locating prey. Modern DNA phylogenies of bats have shown that the traditional suborder of echolocating bats (Microchiroptera) is not a true clade, and instead some echolocating bats are more related to non-echolocating Old World fruit bats than to other echolocating species. The implication is that Animal echolocation#Bats|echolocation in at least two lineages of bats, Megachiroptera and Microchiroptera has evolved independently or been lost in Old World fruit bats.
• Animal echolocation|Echolocation in bats and whales also both necessitate high frequency hearing. The protein prestin, which confers high hearing sensitivity in mammals, shows molecular convergence between the two main clades of echolocating bats, and also between bats and dolphins . Other hearing genes also show convergence between echolocating taxa .
• Both the aye-aye lemur and the striped possum have an elongated finger used to get invertebrates from trees. There are no woodpeckers in Madagascar or Australia where the species evolved, so the supply of invertebrates in trees was large.
• Castorocauda and beaver both have webbed feet and a flattened tail, but are not related.
• Prehensile tails came in to a number of unrelated species New World monkeys, kinkajous, porcupines, tree-anteaters, marsupial opossums, and the salamander Bolitoglosssa pangolins, treerats, skinks and chameleons.
• Pig form, large-headed, pig-snouted and hoofs are independent in true pigs in Eurasia and Peccary and Entelodonts.
• Plankton feeding filters, baleen: Whale sharks and baleen whales, like the humpback whale|humpback and blue whale independent have very sophisticated ways of sifting plankton from marine waters.
• There are five species of River dolphin|river/freshwater dolphins, which are not closely related.
• Platypus have what looks like a bird's Beak (hence its scientific name “Ornithorhynchus”), but is a mammal.
• Red blood cells in mammals lack a cell nucleus. In comparison, the red blood cells of other vertebrates have nuclei; the only known exceptions are salamanders of the Batrachoseps genus and fish of the Maurolicus genus.

Prehistoric reptiles

• Ornithischian (bird-hipped) dinosaurs had a pelvis shape similar to that of birds, or avian dinosaurs, which evolved from saurischian (lizard-hipped) dinosaurs.
• The Heterodontosauridae evolved a tibiotarsus which is also found in modern birds. These groups aren't closely related.
• Ankylosaurs and glyptodont mammals both had spiked tails.
• Horned snouts independently is on non-related dinosaurs like ceratopsians and Triceratops, also Rhinoceros|rhinos and the brontotheres of the Cenozoic.
• Billed snouts on the duck-billed dinosaurs hadrosaurs strikingly convergent with ducks and duck-billed platypus.
• Ichthyosaurs a marine reptile of the Mesozoic era looked strikingly like dolphins.
• Beaks are independent in ceratopsian dinosaurs like Triceratops, birds and marine mollusks like squid and octopus.
• The Pelycosauria and the Ctenosauriscide beared striking resemblance to each other because they both had a sail-like fin on their back. The Pelycosaurs are more closely related to mammals while the Ctenosauriscids are closely related to pterosaurs and dinosaurs. Also, the Spinosaurids had sail-like fins on their backs, when they were not closely related to either.
  • Also, Acrocanthosaurus and Ouranosaurus, which are not closely related to either Pelycosaurs, Ctenosauriscids or Spinosaurids, also had similar, but thicker, spines on their vertebrae, and thus have humps, like the unrelated, mammalian camels and bison.
• Noasaurus, Baryonyx, and Megaraptor, all unrelated, all had an enlarged hand claw that were originally thought to be placed on the foot, as in dromaeosaurs. A similarly modified claw (or in this case, finger) is on the hand of Iguanodon.
• The Ornithopods had feet and beaks that resembled that of birds, but are only distantly related.
• Three groups of dinosaurs, the Tyrannosauridae, Ornithomimosauria, and the Troodontidae, all evolved an arctometatarsus, independently.

Extant reptiles

• The thorny devil (Moloch horridus) is similar in diet and activity patterns to the Texas horned lizard (Phrynosoma cornutum), although the two are not particularly closely related.
• Modern Crocodilians resemble prehistoric phytosaurs, champsosaurs, certain labyrinthodont amphibians, and perhaps even the early Cetacea|whale Ambulocetus. The resemblance between the crocodilians and phytosaurs in particular is quite striking; even to the point of having evolved the graduation between narrow- and broad-snouted forms, due to differences in diet between particular species in both groups.
• The body shape of the prehistoric fish-like reptile Opthalmosaurus is similar to those of other ichthyosaurians, dolphins (aquatic mammals), and tuna (scombrid fish).
• Acanthophis|Death Adders strongly resemble true Viperidae|vipers, but are Elapidae|elapids.
• The Glass Snake is actually a lizard but is mistaken as a snake .
• Large Tegu lizards of South America have converged in form and ecology with Varanidae|monitor lizards, which are not present in the Americas.
• legless lizards-Pygopodidae are snake-like lizards that are much like true snakes.
• Mosasaurs of the Mesozoic era are like whales but are closely related to living monitor lizards and the Komodo Dragon.
• Anolis lizards are one of the best examples of both adaptive radiation and convergent evolution.
• Tuataras resemble lizards but in fact are in an order of their own, the Rhynchocephalia. The Tuatara has the sockets behind the eyes and has jagged extensions of the jaws instead of teeth.

Avian

• The Little Auk of the north Atlantic Ocean|Atlantic (Charadriiformes) and the diving-petrels of the southern oceans (Procellariiformes) are remarkably similar in appearance and habits.
• Penguins in the Southern Hemisphere evolved similarly to flightless wing-propelled diving auks in the Hemisphere Northern Hemisphere: the Atlantic Great Auk and the Pacific Mancallinae|mancallines.
• Vultures are a result of convergent evolution: both Old World vultures and New World vultures eat carrion, but Old World vultures are in the eagle and hawk family (Accipitridae) and use mainly eyesight for discovering food; the New World vultures are of obscure ancestry, and some use the sense of smell as well as sight in hunting. Birds of both families are very big, search for food by soaring, circle over sighted carrion, flock in trees, and have unfeathered heads and necks.

• 

  Nubian Vulture, an Old World vulture

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  Turkey Vulture, a New World vulture

• 

  Hummingbird, a New World bird, with a sunbird, an Old World bird

• Hummingbirds resemble sunbirds. The former live in the Americas and belong to an order or superorder including the swifts, while the latter live in Africa and Asia and are a family in the order Passeriformes.
• In an odd cross-phyla example, an insect, the Hummingbird Hawk-moth (Macroglossum stellatarum), also feeds by hovering in front of flowers and drinking their nectar in the same way as the above mentioned birds.
• Flightless bird|Flightlessness has evolved in many different birds independently. However, taking this to a greater extreme, the terror birds, Gastornithiformes and dromornithidae|dromornithids (ironically all extinct) all evolved the similar body shape (flightlessness, long legs, long necks, big heads), yet none of them were closely related. They also share the trait of being giant, flightless birds with vestigial wings, long legs, and long necks with the ratites, although they are not related.
• Certain longclaws (Macronyx) and meadowlarks (Sturnella) have essentially the same striking plumage pattern. The former inhabit Africa and the latter the Americas, and they belong to different lineages of Passerida. While they are ecologically quite similar, no satisfying explanation exists for the convergent plumage; it is best explained by sheer chance.
• Resemblances between swifts and swallows is due to convergent evolution.
• Downy Woodpecker and Hairy Woodpecker look almost the same, as do some Chrysocolaptes and Dinopium flamebacks, the Smoky-brown Woodpecker and some Veniliornis species, and other Veniliornis species and certain "Picoides" and piculus. In neither case are the similar species particularly close relatives.
• Many birds of Australia, like wrens and Petroicidae|robins, look like northern hemisphere birds but are not related.
• Oilbird like microbats and toothed whales developed sonar-like animal echolocation|echolocation systems used for locating prey.
• The brain structure, forebrain, of hummingbirds, songbirds, and parrots responsible for vocal learning (not by instinct) is very similar. These types of birds are not closely related.

Fish

• Goby dorsal finned like the lumpsuckers, yet they are not related.
• Sandlance fish and chameleons have independent eye movements and focusing by use of the cornea.
• Cichlids of South America and the "Centrarchidae|sunfish" of North America are strikingly similar in morphology, ecology and behavior.
• The Peacock Bass and Largemouth Bass are excellent examples.
• The Antifreeze_proteins#Evolution|Antifreeze protein of fish in the arctic and Antarctic, came about independently.
• Eel form are independent in the North American brook lamprey, neotropical eels, and the African spiny eel.
• Stickleback fish, there is widespread convergent evolution in Sticklebacks.
• Flying fish can fly up to 400 m (1,300 ft) at speeds of more than 70 kilometres per hour (43 mph) at a maximum altitude of more than 6 m (20 ft), much like other flying birds, bats and other gliders.
• The Cleaner Wrasse Labroides dimidiatus of the Indian Ocean is a small, longitudinally-striped black and bright blue cleaning symbiosis|cleaner fish, just like the Cleaner Goby Elacatinus|Elacatinus evelynae of the Western Atlantic.

• 

  Cleaner wrasse Labroides dimidiatus servicing a Bigeye squirrelfish

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  Caribbean cleaning goby Elacatinus evelynae

Amphibians

• Plethodontid salamanders and Chameleons have evolved a harpoon-like tongue to catch insects.
• The Neotropical poison dart frog and the Mantella of Madagascar have independently developed similar mechanisms for obtaining alkaloids from a diet of mites and storing the toxic chemicals in skin glands. They have also independently evolved similar bright skin colors that warn predators of their toxicity (by the opposite of crypsis, namely aposematism).
• Caecilian are Lissamphibians that secondarly lost their limbs, resembling snakes

Arthropods

Pill bugs look like pill millipedes, but are actually wood lice that have converged on the same defenses, until they are difficult to tell apart

• Assassin spiders comprise two lineages that evolved independently. They have very long necks and fangs proportionately larger than those of any other spider, and they hunt other spiders by snagging them from a distance.
• The smelling organs of the terrestrial coconut crab are similar to those of insects.
• Pill bugs and pill millipedes have evolved not only identical defenses, but are even difficult tell apart at a glance.
• Silk: Spiders, silk moths, larval caddis flies, and the weaver ant all produce silken threads.
• The praying mantis body type – raptorial forelimb, prehensile neck, and extraordinary snatching speed - has evolved not only in mantid insects but also independently in neuropteran insects Mantispidae.
• Agriculture: Some kinds of ants, termites, and ambrosia beetles have for a long time cultivated and tend fungi for food. These insects sow, fertilize, and weed their crops. A damselfish also takes care of red algae carpets on its piece of reef; the damselfish actively weeds out invading species of algae by nipping out the newcomer.

Molluscs

• Bivalves and the gastropods in the family Juliidae have very similar shells.
• There are limpet-like forms in several lines of gastropods: "true" limpets, pulmonate siphonariid limpets and several lineages of pulmonate freshwater limpets.
• Cuttlefish show similarities between cephalopod (nautili, octopods and squid) and vertebrate (Mammalia...) eyes.
• Swim bladders – Buoyant bladders independently evolved in fishes, female octopus and siphonophores such as the Portuguese Man o' War.
• The phylum Mollusca members such as bivalves, and phylum Brachiopoda members, the brachiopods aka lampshells, independently evolved paired hinged shells for protection. The anatomy of their soft body parts is so dissimilar, however, that they are classified in separate, independent phyla. Biologists think that clams are more closely related to earthworms than they are to brachiopods.
• Jet propulsion in squids and in scallops: these two groups of mollusks have very different ways of squeezing water through their bodies in order to power rapid movement through a fluid. (Dragonfly larvae in the aquatic stage also use an anal jet to propel them, and Jellyfish have used jet propulsion for a very long time.)

Other

• The notochords in chordates are like the stomochords in hemichordates.
• Elvis taxon in the fossil record developed a similar morphology through convergent evolution.
• Venomous sting: To inject poison with a hypodermic needle, a sharppointed tube, has shown up independently 10+ times: jellyfish, spiders, scorpions, centipedes, various insects, cone shell, snakes, stingrays, stonefish, the male duckbill platypus, and stinging nettles plant.
• Bioluminescence: A symbiotic partnerships with light-emitting bacteria developed many times independently in deep-sea fish, jellyfish, and in fireflies and glow worms.
• Parthenogenesis: Some lizards and insects have independent the capacity for females to produce live young from unfertilized egg (biology)|eggs. Some species are entirely female.
• extremely halophile archaeal Family Halobacteriaceae and the extremely halophilic bacterium Salinibacter ruber both can live in high salt environment.

In plants

• Leaves have evolved multiple times - see Evolutionary history of plants.
• Spine (botany)|Prickles, Spine (botany)|thorns and Spine (botany)|spines are all modified plant tissues that have evolved to prevent or limit herbivory, these structures have evolved independently a number of times.
• Stimulant toxins: Plants which are only distantly related to each other, such as coffee and tea, produce caffeine to deter predators.
• The aerial rootlets found in ivy (Hedera) are similar to those of the Hydrangea petiolaris|climbing hydrangea (Hydrangea petiolaris) and some other vines. These rootlets are not derived from a common ancestor but have the same function of clinging to whatever support is available.
• Flowering plants (Delphinium, Aerangis, Tropaeolum and others) from different regions form tube-like spur (botany)|spur which contains nectar (that's why insect from one place sometimes can feed on plant from other which has such structure like the flower which is the traditional source of food for the animal).
• Both some dicots (Anemone) and monocots (Trillium) in inhospitable environments are able to form underground organs such as corms, bulbs and rhizomes for reserving of nutrition and water till the conditions become better.
• Insectivorous plants: Nitrogen-deficient plants have in at least 7 distinct times become insectivorous, like: flypaper traps\sundew, spring traps-Venus fly trap, and pitcher traps in order to capture and digest insects to obtain scarce nitrogen.
• Similar-looking rosette succulents have arisen separately among plants in the families Asphodelaceae (formerly Liliaceae) and Crassulaceae.
• The Orchids, the Birthwort family and Stylidiaceae have evolved independently the specific organ known as gynostemium, more popular as gynostemium|column.
• The Euphorbia of deserts in Africa and southern Asia, and the Cactaceae of the New World deserts have similar modifications (see picture below for one of many possible examples).
• Sunflower: some types of Sunflower and Pericallis are due to convergent evolution.

• 

  Euphorbia obesa

• 

  Astrophytum asterias

Proteins including enzymes and biochemical pathways

• The existence of distinct families of carbonic anhydrase is believed to illustrate convergent evolution.
• The use of (Z)-7-dodecen-1-yl acetate as a sex pheromone by the Asian elephant (Elephas maximus) and by more than 100 species of Lepidoptera.
• The independent development of the catalytic triad in serine proteases independently with subtilisin in prokaryotes and the chymotrypsin clan in eukaryotes.
• The repeated independent evolution of nylonase in two different strains of Flavobacterium and one strain of Pseudomonas.
• The biosynthesis of plant hormones such as gibberellin and abscisic acid by different biochemical pathways in plants and fungi.
• ABAC is a database of convergently evolved protein interaction interfaces. Examples comprise fibronectin/long chain cytokines, NEF/SH2, cyclophilin/capsid proteins. Details are described here.
• The independent development of three distinct hydrogenases exemplifies convergent evolution.
• The protein prestin that drives the cochlea amplifier and confers high auditory sensitivity in mammals, shows numerous convergent amino acid replacements in bats and dolphins, both of which have independently evolved high frequency hearing for Animal echolocation|echolocation. . This same signature of convergence has also been found in other genes expressed in the mammalian cochlea

See also

• McGhee, G.R. (2011) Convergent Evolution: Limited Forms Most Beautiful. Vienna Series in Theoretical Biology: Massachusetts Institute of Technology Press, Cambridge (MA). 322 pp.

See also

• McGhee, G.R. (2011) Convergent Evolution: Limited Forms Most Beautiful, MIT Press.
• Morris, S.C. (2005) Life's Solution: Inevitable Humans in a Lonely Universe, Cambridge U. Press.
• Sanderson, M. and Hufford, L. (eds.) (1996) Homoplasy: The Recurrence of Similarity in Evolution, Academic Press.

Early universe physical types convergence

(Symmetry breaking, quantum darwinism, etc. go here, as subheaders)

Astrophysical and geophysical types convergence

(Galaxies, stars, planet types go here)

Chemical (chemotypes) and precellular (biogenesis types) convergence

(Biogenesis and autopoetic chemistry examples go here)

Cellular, cell assembly, and molecular biological types convergence

(Origin of life, dynamic patterning module, and protein examples from wikipedia page go here)

Multicellular (body and species types) convergence

(Body and species types for plants, animals go here)

Psychological and individual behavioral types convergence

(Psychological, moral, personal behavior examples go here)

Societal (social, economic, political types) convergence

(Social, economic, and political rulesets and behaviors go here)

Technological (technotypes) convergence

(Archetypal technology examples, rocks to computers go here)

Proposed future technological convergences

• Artificial Moral Agents in Software and Hardware As machines begin to develop real autonomy and world models in the 2010's and beyond, they will have to incorporate moral systems. These will be both individually and socially developed, both bottom-up discovered and (partially) top-down engineered and guided.

References

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