Embryological evidences of evolution, Biology

Assignment Help:

EMBRYOLOGICAL EVIDENCES -

  • A comparative study of embryology of different groups of animals reveals certain features that provide evidences for organic evolution.
  • There are striking similarities among the different species of invertebrates that have a sequence of embryonic developments.
  • These similarities are as follows:

(i) Gill clefts and notochord appear on the embryonic development of all vertebrates from fishes to mammals. (ii) The notochord is replaced by the vertebral column in all adult vertebrates.

(iii) Lungs in adult amphibians, reptiles and mammals replace gills.

  • The embryonic evidences can be taken into consideration on the basis of the following facts -

(i) Similarly in early development: In all the multicellular animals the fertilized egg (zygote) under goes cleavage to produce morula (solid mass of cells), blastula (a single layered hollow structure) & gastrula.

(ii) Resemblance in vertebrate embryos: The embryos of all vertebrates resemble one another.

833_embryological evidences.png

(iii) Heart of a mammal or bird is initially two - chambered as in fished and finally becomes four-chambered. (iv) Tadpole of frog resembles to fish shows "ontogeny repeats phylogeny".

1437_tadpole of frog.png

Tadpole of frog


Related Discussions:- Embryological evidences of evolution

State the exocytosis in a skeletal muscle, Exocytosis in a skeletal muscle?...

Exocytosis in a skeletal muscle?   A.  During exocytosis in a skeletal muscle, there will be release of calcium ions from intracellular vesicles in the sarcoplasmic reticulum i

Pedigree charts, How do I complete a pedigree chart for genetics?

How do I complete a pedigree chart for genetics?

What is fixative, Question 1 What is fixative? Discuss the characteristics...

Question 1 What is fixative? Discuss the characteristics of a good fixative. What is the importance of using a good fixative for tissue processing? Question 2 What is embe

How to explain the high level of radiation resistance, Deinococcus radiodur...

Deinococcus radiodurans is a bacterium that was isolated from cooling ponds in and around nuclear power plants. It is highly resistant to ionizing radiation. Propose a hypothesis t

Procedures for diagnosis - epidemiological data , Procedures for diagnosis ...

Procedures for diagnosis Epidemiological data:   The epidemiological information with regard to the history, symptoms, morbidity, mortality, seasonality, age, sex, breed and spe

Homeostasis solution, In biology, Homeostasis is the ability of an open pro...

In biology, Homeostasis is the ability of an open program to manage its internal environment to sustain constant circumstances through several energetic stability improvements mana

Cobalt deficiency, Cobalt deficiency The deficiency of cobalt is more ...

Cobalt deficiency The deficiency of cobalt is more commonly seen in ruminants fed on diets deficient in this essential micronutrient. Cobalt is stored only in limited amounts

Fungi, what is the symmetry of fungi?

what is the symmetry of fungi?

Can serotonin used in consciousness, Q. Can Serotonin used in consciousness...

Q. Can Serotonin used in consciousness? Serotonin complements the action of noradrenalin and acetylcholine in promoting wakefulness and cortical responsiveness. Experiments pro

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd