Describe various biochemical evidences or molecular evidences of evolution
 

- Among diverse organisms, the similarities in proteins and genes performing a common function indicates common ancestry.

- The metabolic process in different organism are also similar, thus also points in same shared ancestry.

Evidences from Embryology (How embryology helps in the study of evolution) : Organisms that show common descent show embryological patters on which they later build their adult patterns.

$\Rightarrow$ This was first observed by Von Baer.

- Later Ernest Haeckel reinterpreted Baer's law in forms of recapitulation theory in the light of evolution.

- The theory of recapitulation or biogenetic law states that ontogeny (development of embryo) recapitulates phylogeny (ancestral sequence).

This means that the life history of an animal reflects its evolutionary history.

For example during the life history, frog's tadpole larva resembles fishes the ancestors of Amphibia.

- The presence of gill clefts in all vertebrate embryos including human provides a strong evidence in support of organic evolution.

In the same line of argument, similarities in proteins and genes performing a giving function among diverse organisms give clues to common ancestry.

- These biochemical similarities point to the same shared ancestry as structural similarities among diverse organisms.

Man has bred selected plants and animals for agriculture, horticulture sports or security.

Man has domesticated many wild animals and crops.

- This intensive breeding programme has created breeds that differ from other breeds. (eg. dogs) but still are of the same group.

Another interesting observation supporting evolution by natural selection comes from England.

In collection of moths made in $1850 \mathrm{~s}$ in before industrialization set in it was observed that there were more white-winged moths on tree than dark winged or melanised moths.

However, in the collection carried out from the same area but after industrialization i.e. in $1920$ , there were more dark winged moths in the same area i.e. the proportion was reversed.

The explanation put forth for this observation was that 'predators will spot a moth against a contrasting background.'

During post industrialization period the tree trunks became dark due to industrial smoke and soots.

Under this condition the white winged moth did not survive to predators, dark winged or melanised moth survived.

Before industrialization set in thick growth of almost white-coloured lichens covered the trees in the background the white winged moth survived but the dark coloured moth were picked out by predators.

Lichens can be used as industrial pollution indicators.