Answer to Question #147966 in Evolution for Abhijit

Question

Explain all evidences there are 6 evidences of evolution
1) MORPHOLOGICAL EVIDENCES 2) ANATOMICAL EVEDENCES 3) VESTIGIAL ORGAN
4) PALEONTOLOGICAL EVIDENCES 5)CONNECTING LINKS 6) EMBROLOGICAL EVIDENCES.....

Answer 1

1) MORPHOLOGICAL EVIDENCES

Comparative morphology provides support for the theory of evolution. By studying both living organisms and the fossils of their extinct ancestors scientists can draw conclusions about their origins. Some of the strongest evidence of evolution comes from comparative studies – comparing structural similarities of organisms to determine their evolutionary relationships. Organisms with similar anatomical features are assumed to be relatively closely related evolutionarily, and they are assumed to share a common ancestor. As a result of the study of evolutionary relationships, anatomical similarities and differences are important factors in determining and establishing classification of organisms.

2) ANATOMICAL EVIDENCES

Comparative anatomy has shown that the bones at the end of the forelimbs of many different vertebrates (including humans) are based on a common pattern or structure. The comparative anatomy data are used as evidence of evolution from a common ancestor in the distant past.

3) VESTIGIAL ORGAN

Vestigial structures are the inherited structures or characteristics that do not have an essential function. These structures may show the evolutionary relationship between animal species. An example of a vestigial structure is the pelvic or hip bones of dolphins, which were inherited from their ancestors when they walked on land millions of years ago. Over the years, their ancestors evolved and lost their hind limbs because these structures served no purpose anymore. The hip bones remained and they serve as vestigial structures.

4) PALEONTOLOGICAL EVIDENCES

Paleontology is the study of the history of life on Earth as based on fossils. As fossils were collected and analysed from various strata, it soon become apparent that the fossils in deeper sedimentary strata were less complex in body structure than fossils in higher strata. The fossils of the most primitive fish are found in much deeper and older layers than the earliest mammal fossils. The fossil evidence therefore supports the view that the earliest life forms were very simple and that they changed into more complex organisms over geological time.

5) CONNECTING LINKS

The living organisms having intermediate characters between two group are called as connecting link. Connecting links provide the evidence for the path of evolution and lie midway between the two groups that is they have features of both the groups of organisms. These confirm evolution of amphibians from fishes; mammals from reptiles; arthropods and molluscs from the annelids.

6) EMBRYOLOGICAL EVIDENCES

Vertebrate embryos in their early developmental stages from the fertilized egg show great similarity in structure. This suggests that the genes controlling this early development have been inherited from a common ancestor in the distant past. All the young vertebrate embryos show gill slits, even though fish are the only vertebrates to use gills in adult life. The comparative embryology data are used as evidence of evolution because they show that ancient characteristics have been passed on as organisms evolved.