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

Quantitative characters - population density, Quantitative Characters - Pop...

Quantitative Characters - Population Density Density denotes the average number of individuals of a particular species in a unit area. In other words, it represents the numeri

What are the cytoplasmic inclusions, Q. What are the cytoplasmic inclusions...

Q. What are the cytoplasmic inclusions? Cytoplasmic inclusions are cytoplasmic molecular aggregates, such as organic polymers, pigments and crystals. They are not considered ce

Intermediary metabolism, High Energy Compounds Primary need of the animal b...

High Energy Compounds Primary need of the animal body from the nutrients is energy. Free energy is the term used to denote the energy available to do useful work. Anabolic or synth

What is the gas exchange unit of the mammalian lungs, Q. What is the gas ex...

Q. What is the gas exchange unit of the mammalian lungs? The gas exchange units of the mammalian lungs are the alveoli. Q. What is the physical process through which gas ex

Photosynthesis., what carbohydrates does a plant make from glucose

what carbohydrates does a plant make from glucose

Respiration, what are the organs of respiration in lower forms of animals?

what are the organs of respiration in lower forms of animals?

Explain about cmc information about drug substance, Question 1: Describ...

Question 1: Describe upon CMC information about drug substance to be submitted to IND for Phase 3 studies. Definition of CMC Explain about CMC information about drug subs

Define about the centrifuge, Define about the Centrifuge? Centrifuge is...

Define about the Centrifuge? Centrifuge is an apparatus consisting essentially of a compartment spun about a central axis to separate contained materials of different specific

List down the various mycotoxins associated with food, Q. List down the var...

Q. List down the various mycotoxins associated with food? Mycotoxins associated with foods are: • Aflatoxins (produced by Aspergillus flavus) • Ochratoxin (produced

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