The model shows the process of evolution at work in a population of aphids with varying amounts of pesticide resistanceSelect ALL of the requirements for evolution to occur A) Sexual reproduction must occur. B) The final population is purely random Genetic variation must exist in the population D Those with the highest pesticide resistance reproduced . E) Only those with the highest pesticide resistance level survived exposure to the pesticide

the oldest known insects are believed to live around 400 millions ago as suggested by the fossil records.   some plants having woody stems also evolved during this time.

after the evolution of insects the first four legged species or the tetrapods evolved in shallow freshwater habitats from the intermediate species approximately 397 million years ago. the tetrapods went on conquering the land giving rise to amphibians, reptiles, mammals and birds.

the major split in tetrapods first occurred 340 million years ago branching off from amphibians.

363 million years ago when the carboniferous period began the insects started roaming on land and taking flights, following which the four limbed tetrapods adapted in the terrestrial habitat.

segmented body, an exoskeleton made from chitin, and joint appendages.