Use it or lose it: In the absence of light, vision is not beneficial, and the energy expenditure for eye development and maintenance is selected against. Similarly, pigmentation is not advantageous in a dark environment.

Bottleneck effect: A random event reduced the cave population, and the surviving organisms happened to lack eyes and pigmentation. These traits then became fixed in the population.

Founder effect: The original cave-dwelling organisms lacked eyes and pigmentation, and these traits persisted in subsequent generations.

Sexual selection: In the dark cave environment, mates are selected based on traits other than vision and pigmentation.

Convergent evolution

Divergent evolution

Coevolution

Parallel evolution

Lamarck

Darwin

Hugo de Vries

Malthus

Modified forlimbs

Modified hindlimbs

Modified gill

Modified fins

Palaeontological evidence

Physiological evidence

Embryological evidence

Anatomical evidence

Ctenophora and Platyhelminthes

Mollusca and Echinodermata

Annelida and Arthropoda

Coelenterata and Porifera

Eye of octopus, bat and man

Forelimbs of man, bat and cheetah

Brain of bat, man and cheetah

Heart of bat, man and cheetah

Mimosa pudica

Triticum aestivum

Biston betularia

Rock python

Completely disprove the evolutionary connection between species based on embryology.

Refine the understanding of embryological development and its relation to evolutionary history.

Emphasize that differences in later embryonic development are more significant than early similarities.

Demonstrate the profound impact of environmental factors on embryonic development.

Vermiform appendix, body hair and patella

Wisdom teeth, body hair and atlas vertebre

Ear muscles, cochlea and coccyx

Vermiform appendix, ear muscles and coccyx

Bats wings and insect wings are analogous

Seal flippers and bats paw are homologous

Insect wings and bird wings are homologous

Thorns of Bougainvillea and tendrils of pea are analogous