Mosaic evolution (or modular evolution) is one of the forms of evolution of organisms in which changes occur in some parts of the body or systems without simultaneously changing in other parts of the body or at an uneven pace [1] . Another definition is “Evolution characterized by different flow rates inside and between species” [2] . Mosaic evolution is a consequence of the relative independence of each other of individual functions and structures in the body; and one way or another is characteristic of the phylogenesis of all living things [3] . The place of mosaic evolution in evolutionary theory falls under long-term trends or macroevolution [2] .
Species that are examples of mosaic evolution are perceived and known as transitional forms .
Authorship
The principle of mosaic evolution was first formulated by the British scientist Gavin de Beers in 1954 , after analyzing the structure of the archeopteryx combining the signs of dinosaurs and birds . In the same year, the Soviet biologist A. L. Takhtadzhyan proposed the term “ heterobatmy ” to denote the different degrees of differentiation of different organs in the body [3] .
Examples
By its very nature, evidence for this concept comes mainly from paleontology . Science does not claim that this model is universal, but currently there is a wide range of examples from different taxa. Some examples:
- Seymuria . In 1919, David Watson established a mosaic in the anatomical structure of seymuria, bringing it closer to the ancestors of reptiles [3] .
- Archeopteryx . In the mid-19th century, Thomas Henry Huxley compared the archeopteryx to a small dinosaur, a compsognathus from the theropod suborder. These two fossils were found in the Zolnhofen limestone in Bavaria . The scientist showed that these two animals were very similar, with the exception of the forelimbs and feathers of the archeopteryx, the rest of the skeleton did not differ. Huxley's interest was mainly focused on the proximity of birds and reptiles, which he united in the Zavropsida class [4] .
- Evolution of hominids : the early appearance in Australopithecus of several characters that contributed to upright posture and pelvic modification took place long before any significant changes occurred in the skull, brain size, or in the hand, which retained many monkey features [3] [5] [ 6] .
Notes
- ↑ King RC Stansfield WD & Mulligan PK 2006. A dictionary of genetics . 7th ed, Oxford University Press. p286 ISBN 0-19-530761-5
- ↑ 1 2 (Eng.) Carroll RL 1997. Patterns and processes of vertebrate evolution . Cambridge University Press, p408. ISBN 0-521-47809-X
- ↑ 1 2 3 4 Mosaic evolution // “Biological Encyclopedic Dictionary.” Ch. ed. M.S. Gilyarov; Editorial: A. A. Babaev, G. G. Vinberg, G. A. Zavarzin et al. - 2nd ed. - M .: Owls. Encyclopedia, 1986.
- ↑ Foster, Michael and Lankester, E. Ray (eds) 1898-1903. The scientific memoirs of Thomas Henry Huxley . 4 vols and supplement, Macmillan, London ISBN 1-4326-4011-9
- ↑ Stanley SM 1979. Macroevolution: pattern and process . Freeman, San Francisco. p154 ISBN 0-7167-1092-7
- ↑ Jurmain, Robert. et al. 2008. Introduction to Physical Anthropology . Thompson Wadsworth. p479