Concurrency in biology: examples and characteristics

There are three forms of evolution. Divergence based on the similarity of homologous organs, and convergence - similar bodies. The third form of evolution is parallelism.

In biology it is the process in which the development associated with the acquisition of similar characteristics and qualities, which develop independently and are based on homologous embryo.

Parallel evolution and speciation

Parallel speciation - a type of parallel evolution in which reproductive incompatibility between closely related populations is determined by the terms, developing independently due to adaptation in different environments. These reproductive groups of animals are incompatible, and only those populations that live in similar ecological conditions, are less likely to become reproductive isolated.

Evolution

Concurrency in biology describes how independent species acquire similar characteristics through their evolution in similar ecosystems, but not at the same time (e.g. dorsal fins of sharks, cetaceans and ichthyosaurs). The definition of a symptom is crucial when figuring out whether changing as divergent, convergent or parallel.

Based on this, the concurrency in biology is the development of similar traits in related, but separate species, having the same common ancestor.

Account of homology of morphological structures

To Consider is also the homology of morphological structures. For example, many insects have two pairs of flying wings. But in beetles the first pair of wings hardens into elytra, and the second is used in flight, while in flies the second pair of wings reduced to small neously used for balance.

If two pairs of wings are considered as interchangeable, homologous structures, it can be described as a parallel reduction in the number of wings, but otherwise the two changes occur with different variances one pair of wings.

Concurrency in biology: characteristics and examples

An Example of parallelism is the similarity of the axial skeleton of the ichthyosaur and Dolphin. For this form of evolutionary characteristic is the emergence in unrelated organisms with similar characteristics or adaptive mechanisms due to the nature of their environment.

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Or, in other words, the parallelism in biology is observed under similar conditions that result in the formation of such devices. The morphologies (or structural form) of two or more lines evolve in a similar manner in parallel evolution, not divergent (as with convergence) or not agree (as in divergence) to a specific point in time.

One example is the complex of models of feathers, which evolved independently in different species of birds. You can call other examples:

• In the plant Kingdom the most familiar examples of parallel evolution are similar to the shape of the leaves, which appear again and again in separate genera and families.
• Butterflies have a lot in common in models of coloring of the wings as within the same species, and among families.
• Ancient and modern porcupines share a common ancestor, both evolved strikingly similar body structure. It is also an example of convergent evolution as similar structures evolved from a hedgehog and echidna.
• Some extinct archosaurs developed a vertical posture and likely were warm-blooded. These two characteristics are also found in most mammals.
• Interestingly, modern crocodiles have a four-chambered heart and an additional so-called left artery, which was also the case transki mammals.
• Extinct pterosaurs and birds both developed wings, and a beak, but not from a common ancestor.
• Internal fertilization has evolved independently in sharks, some amphibians and amniotes.

There is, incidentally, a rather unusual examples of parallelism in biology. So, the octopus eye has the same complex structure as the human. This is quite unusual because the two species evolved in a time when animals evolved in vertebrates and invertebrates.

Concurrency in biology is the emergence in the evolution of living beings with similar characteristics and properties which are formed from the same rudiments on a single genetic basis, but this occurs independently from each other.

The Main difference from convergence

But this form should be distinguished from convergence when similar symptoms appear also independently, but the genetic basis for their occurrence is different. And there, and there are similarities in body structure, but species differ.

In Greek, parallelos means "the next coming". Concurrency in biology is an evolutionary development of genetically close groups on the basisfeatures that were inherited them from common ancestors. Some similarities and properties in concurrency point out the unity of origin of these living organisms, as well as the presence of similar conditions and habitats.