Discuss the various evidences, which show that evolution has taken place.

K.C.S.E Biology Q & A - MODEL 1998PP1QN19

Discuss the various evidences, which show that evolution has taken place.

answers

​Comparative anatomy/taxonomy.

• Members of a phylum group show similarities; organisms have similar structures/similar organs performing similar functions e.g. digestive system/urinary system, nervous system. Any correct example i.e. vertebrate heart.
• The pentaductyle limbs/ any correct example; these are homologous organs/structures. Homologous – same origin structure different functions. Analogous structures – different structures performing the same function e.g. wings of insects, bats and birds. Analogous different origin structure, same function convergent.

Fossil records/palaeotology

• These are remains of organisms preserved in naturally occurring materials for many years show morphological changes of organisms over a long period of time.
  

Comparative embryology.

•  Any 2 names embryos> vertebrate embryos the morphologically similar; suggesting the organisms have a common origin/ancestry.

Geographical distribution.

• Present conditions are thought to have been a large land mass joined together, as a result of continental drift; isolation occurred bringing about different patterns of evolution i.e. The Ilamas in the Amazon resemble the Camel. Any other example e.g. Kangaroos in Australia, Jaguar in South America, Camel in Africa.

Comparative serology/physiology.

• Antigen/antibody reactions/Rh factor/blood group/haemoglobin structure; reveal some phytogenetic structure. Relationship among organism/common ancestry.