Human Evolution EVOLUTION is the slow and gradual process of change over a long period of time that has given rise to the diverse organisms around us today.

SKULL ORDER Modern Man Neanderthal (32, ,000) Cro magnon ( 100,000 ) Homo Erectus Pekinensis Broken Hill (200, million) Australopithicus Boisei ( million) Australopithicus Africanus (2.3 – 3 million)

UNIQUE FEATURES OF A HUMAN SKULL Top of the skull (ie cranium) is smooth. There is no anterior-posterior crest to hold huge jaw muscles No protruding brow No protruding jaw or teeth (ie the teeth are vertical) No protruding nose bone Teeth are arranged in a parabolic shape rather than a narrow u shape Small canines and small incisors Foramen magnum (hole for the spine) is positioned directly underneath the skull not in the back of the skull

Comparison of skulls CHIMPANZEE GORILLAHUMAN SKULL

Species a group of organisms capable of interbreeding and producing fertile offspring (except in the case of asexually reproducing species), and separated from other such groups with which interbreeding does not normally happen.

Variation and Adaptation This is best understood by looking at finches Darwin collected. Different beak types in the finches shows variation. Different beak types are required for different feeding habits. Variation are the changes within the population. Adaptation is the characteristic of the organism that has evolved due to natural selection. An origin of species on/darwin/origin/index.html on/darwin/origin/index.html

Evidence for explaining theory of evolution Natural Selection Fossil Evidence Comparative Anatomy Comparative Embryology Biogeography DNA Hybridisation

Natural Selection Example of Peppered Moths In country the industrial revolution has killed the lichen and you can see the light peppered moth is easier to see. Unpolluted woodlands where white lichen still around harder to see then dark coloured moth. Some controversy with this due to some fraud in Science but new evidence has determined still an example of natural selection

Fossil evidence Evidence that many of the species existed in the past can be see from the fossilised remains of plants and animals that were trapped during the process of rock formation. faculty.evansville.edugeography.berkeley.eduwww.albion-swords.com

Comparative anatomy Comparative anatomy is the study of similarities and differences in the anatomy of organisms. Homologous structures are similar in different species because the species have common descent Analogous structures are similar in different organisms because they evolved in a similar environment. E.g. the torpedo body shape of porpoises and sharks. Homologous structures Analologous structures

Comparative Embryology Closely related organisms go through similar stages in their embryonic development (Example see figure 7.31 of text book) nitro.biosci.arizona.edu/.../lect2.html

Biogeography Clues to past evolution can be found in the natural geographic distribution of related species. Major isolated land areas and island groups often evolved their own distinct plant and animal communi 200 million years ago all the continents were joined together in a giant land mass called Panagea. 20 million years ago Panagea broke up into 2 different land masses. Gondwana included Antartica, Australia, India, Africa and South America 45 million years ago Antartica and Australia seperated. 3NBo&feature=related 3NBo&feature=related weblogs.madrimasd.org/.../2007/01/04.aspx continental-drift-puzzle/

DNA hybridisation All plants and animals receive their specific characteristics from their parents by inheriting particular combinations of genes. Modern technology is able to use techniques such as sequencing and DNA of organism and hybridisationof DNA as tools in the investigation of the similarity DNA hybridization generally refers to a molecular biology technique that measures the degree of genetic similarity between pools of DNA sequences. It is usually used to determine thegenetic distance between two species. When several species are compared that way, the similarity values allow the species to be arranged in a phylogenic tree Relationship between humans and their close relatives using DNA hybridisation techniques