List of examples of convergent evolution

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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.[1]

Mammals

Prehistoric reptiles

Extant reptiles

Avian

Fish

Amphibians

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

In plants

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.[5][6]
  • 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. [2] [3]. This same signature of convergence has also been found in other genes expressed in the mammalian cochlea [4]

See also

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

References

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See also

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  • 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. [7] [8]

References

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  7. Wendell Wallach and Colin Allen, Moral Machines: Teaching Robots Right from Wrong, 2009
  8. Ronald C. Arkin, Governing Lethal Behavior: Embedding Ethics in a Hybrid Deliberative/Reactive Robot Architecture. In: Artificial General Intelligence, Pei Wang et. al. (eds.), 2008