How does embryology prove evolution?

Hint: Embryology is the branch of biology that involves the study of the development of embryos starting from gamete fusion.

Complete answer:
1)The process of evolution is supported by many processes and theories, like the presence of fossil records, morphological evidence, molecular evidence, embryological evidence, etc.

2)Embryological shreds of evidence show that the embryos of different organisms show similarity and are derived from common ancestors even though the adult organisms of that embryo are not similar, For example when the embryo of fish and embryo of human is observed, it can be seen that both the embryos have gill slits but they have vanished in humans before the birth of that human but in the case of fish those gill slits develop and form gills which form an essential part of the fish.

3)When embryos of reptiles, birds, fish, and mammals are observed it can be seen that they show many structural similarities. This shows that they all are derived from common ancestors and the reason why only the embryos show similarities is that adult organisms of different species show different patterns of evolution.

Note: Not all the structures present in the embryo stage of a particular organism need to be useful to the adult organism of that species, some structures may disappear or become vestigial in the process of evolution. Many embryos show the presence of tailbones but only some organisms will show the development of the tail.