zwierzęta: Convergent evolution

Evidence: 100 • authority: 72

Convergent evolution is the independent evolution of similar features in species of different lineages. Convergent evolution creates analogous structures that have similar form or function but were not present in the last common ancestor of those groups. The cladistic term for the same phenomenon is homoplasy. The recurrent evolution of flight is a classic example, as flying insects, birds, pterosaurs, and bats have independently evolved the useful capacity of flight. Functionally similar features that have arisen through convergent evolution are analogous, whereas homologous structures or traits have a common origin but can have dissimilar functions. Bird, bat, and pterosaur wings are anal…

Evidence: 61 • authority: 88

Tandem Repeats Provide Evidence for Convergent Evolution to Similar Protein Structures. Abstract Homology is a key concept underpinning the comparison of sequences across organisms. Sequence-level homology is based on a statistical framework optimized over decades of work. Recently, computational protein structure prediction has enabled large-scale homology inference beyond the limits of accurate sequence alignment. In this regime, it is possible to observe nearly identical protein structures lacking detectable sequence similarity. In the absence of a robust statistical framework for structure comparison, it is largely assumed similar structures are homologous. However, it is conceivable th…

Evidence: 54 • authority: 92

Convergent Evolution of Cellular Weaponry.. Cellular weaponry includes a diverse array of ballistic structures, generally referred to as extrusomes, found across the tree of life. Extrusomes have evolved multiple times independently; are morphologically diverse, including structures such as coiled filaments, paracrystalline rods, and telescopic tubules; and facilitate prey capture, defense against predation, and host cell invasion. Their widespread distribution reflects extensive convergent evolution driven by similar ecological pressures. Conversely, homologous extrusomes in closely related taxa can diverge markedly in structure and function following lifestyle shifts, including transition…

Evidence: 54 • authority: 72

Convergent evolution—the repeated evolution of similar traits in multiple lineages which all ancestrally lack the trait—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 distinguishable by analysing their genetics. Distantly related organisms often develop analogous structures by adapting to similar environments.

Evidence: 42 • authority: 80

Local comparison of protein structures highlights cases of convergent evolution in analogous functional sites

Evidence: 42 • authority: 72

Divergent evolution or divergent selection is the accumulation of differences between closely related populations within a species, sometimes leading to speciation. It can occur when two populations become separated by some barrier (such as physical separation in allopatric or peripatric speciation) and become subject to differing selective pressures and potentially genetic drift. If sufficient evolutionary distance accumulates, the derived populations may become reproductively incompatible through various types of physiological or behavioral barriers. Charles Darwin discussed an early version of the concept at length, but the American naturalist J. T. Gulick (1832–1923) was the first to us…

Evidence: 42 • authority: 72

Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and lift, which help the fish swim. Apart from the tail or caudal fin, fish fins have no direct articulations with the axial skeleton and are attached to the core only via muscles and ligaments. Fish fins are highly distinctive anatomical features with varying internal structures among different clades: in ray-finned fish (Actinopterygii), fins are mainly composed of spreading bony spines or "rays" covered by a thin stretch of scaleless skin, resembling a folding fan; in lobe-finned fish (Sarcopterygii) such as coelacanths and lungfish, fins are short rays based around a muscular central…

Evidence: 36 • authority: 80

Analogous reserve distribution and tissue characteristics in quinoa and grass seeds suggest convergent evolution

Evidence: 36 • authority: 92

Perspective: the variable lymphocyte receptor B system in the gut of the sea lamprey.. The evolutionary origin of vertebrate adaptive immunity has been a longstanding problem in evolutionary biology. The diversified proteins that orchestrate this complex system are present throughout the jawed vertebrates but are absent in extant jawless vertebrates and invertebrates. From work initially carried out in the sea lamprey ( Petromyzon marinus ) and subsequently extended to other lampreys and hagfishes, we now know that, instead of immunoglobulin domain-based receptors, jawless vertebrates have leucine-rich repeat-based variable lymphocyte receptors (VLRs). Like immunoglobulins (Igs) and T cell…