Question

explain all the evidences of evolution briefly

Answer 1

1.comparing fossils from older and younger rock layers

2.species evolve differently in different environments . different species evolve similarly in the same type of environment

3.2 variations; similar body structures that don't necessarily have similar functions

homologous- diff mature forms but develop from embryonic tissues

vestigial- similar structures with reduced size and lesser or no functions

4.early stages of many animals are very similar- suggesting that organisms share common ancestry.

Answer 2

Answer:

• Homologous Organs: The internal structure of forelimb of whale (swimmer), wing of bat (flyer), leg of cheetah (runner, claw of mole (digger) and hand of man (grasping), they show a common patterm in the arrangement of bones, even though their external form and functions are different. It indicates that all the vertebrates are evolved from a common ancestor and these organs are called Homologous organs (Divergent evolution)
• Analogous Organs: Birds and bats have wings. Wings of bats have skin folds (pathagium) stretched between elongated fingers but the wings of birds have a feathery covering all along the arm. The design of the two wings, their structure and components are different. They look similar because they have a common use for flying but their origin is not common. This gives the'analogous characteristics (traits). As the above mentioned organs which are structurally different but functionally similar are known as analogous organs (convergent evolution).
• Embryological Evidence: There are remarkable similarities in the embryos of different animals from fish to man. It indicates that life history of every individual exhibits the structural features of a common ancestor.
• Palaeontological Evidence : Fossils are evidences of ancient life forms which have been preserved by natural processes. Palaeontologists determine the age of fossils by using carbon dating method. Ex: Dinosaurs and Ketosaurs provide evidences of presence of extinct animals.