Evolution


Home
Biology Index


8 Different types of evolution

  1. Parallel evolution An evolutionary process by which two or more separate species in the same environment develop similar adaptation or characteristic for survival. Parallel evolution is similar to convergent evolution in a way that two unrelated species evolved similar traits. However, in parallel evolution, the two species evolved same traits while living in the same type of environment whereas in convergent evolution the two species evolved same traits in different types of environment. Examples
    1. North American cactus and the African euphorbia that developed similar adaptation, which is their thick stems and sharp quills to survive the hot, arid climates.
    2. Internal fertilization has evolved independently in sharks, some amphibians and amniotes.
    3. two groups of organisms living in similar habitats such as a marsupial mammals distinctive characteristic of these species are that most of the young are carried in a pouch in Australia and placental mammals on another continent.
    4. Colouration that serves as a warning to predators and for mating displays has evolved in many different species.
    5. The eye of the octopus has the same complicated structure as the human eye.
  2. Divergent evolution ( Homologous organs)
    Also called as Adaptive Radiation. The process by which an interbreeding population or species diverges into two or more descendant species, resulting in different speciesdeveloping new characteristics to enable them to survive to their new habitats. Homologous organs areexamples of divergent evolutionsimilar structures but dissimilar function is in the state of homology and such structures are referred to as homologous structures. Examples: The arm of a human, the wing of a bird. The leg of a dog and the flipper of a dolphin or whale are homologous structures.
  3. Advertise on gneet.com

  4. Convergent evolution ( Analogous organs)
    A kind of evolution wherein organisms evolve structures that have similar (analogous) structures or functions in spite of their evolutionary ancestors being very dissimilar or unrelated. convergent evolution is the process whereby organisms not closely related (not monophyletic), independently evolve similar traits as a result of having to adapt to similar environments or ecological niches example of convergent evolution is the similar nature of the flight/wings of insects, birds, pterosaurs, and bats. All four serve the same function and are similar in structure, but each evolved independently.
  5. Retrogressive evolution
    This is the process in which complex forms of organisms develop towards the simpler structural and physiological organizations. For eg - Monocot plants are considered as more advanced groups of plants with a simple structure and herbaceous habit. Several species of cave-dwelling animals, including fish, crabs, and salamanders, have evolved blindness and deteriorated eye structure.
  6. Progressive Evolution : This is the type of evolution in which simple forms of organisms develops towards the complex forms and physiological organizations. For eg - evolution of multicellular organisms from unicellular organisms.


Advertise on gneet.com
Back
Continue

download gneet.com's Evolution book

If you would rather download the free PDF of this notes.

found something wrong in this lesson?

Report mistake or Comment on This Lesson?
Your input is what keeps gneet improving with time!
Download solved 400+ MCQ's with detailed explanation
PDF
Advertise on gneet.com