DARWINS EVIDENCES AND WHAT HE NOTICED: he could found1-Darwin saw more types of species thaton his own country2-He was impresionated by the fact that casualy all theanimals and plantas were very well situated related to theclimate and the environment where they where and howthe organism survive and reproduce and make offsprings.3-He also found fossils some were like some animals thathe had seen but many of them were from species that haddisapeard and he had never seen, he started to makequestions about why they had disappeared and how torelated them with the species that were now alive.
The part of the journey that took more the attention of Darwin was THE GALAPAGO’S ISLAND. A group of islands that were in the coast of South America that were very close but each had a different climate and the species that inhabitate there were differents.(they variate)-That make darwin thinks a lot: he started to realise that if the animals of the defferent islands had beeb once many years ago had been of the same species.
LAMMARKS IDEAS The main points of Lammark theory were: 1-TENDENCY TOWARD PERFECTION: Organism continually change and acquire feautures that help them live more succesfully. Ex: Gueopards wanted to run faster to catch their food so their legs adapat to them in order to them to run faster.
2-2-USE AND DISUSE: .Body parts that were used developed,and those that were not went away. Ex) reptiles stop using their lengs they leftthem and turn into snakes.3-EVOLUTION OF ACQUIRED TRAITS .Organism that change a characteristic intheir lifetime ,would pass that change ontheir offspring.
DARWINS THEORY 1-INHERITED VARIATION-Members of each new species vary from one another in important ways. Ex: Some plants have biggest flowers, some cows give more milk.
2-SIURVIVAL OF THE FITTEST: Darwin called the hability of an organism to reproduce and survive fitness. He proposed that fitness is the result of the adpatations.Individuals with low level of fitness die and
DESCENDENT WITH MODIFICATIONDarwin proposed that each living species has descended, withchanges from other species over time, so each species had like ancestors that live years ago before they borned.
NATURAL SELECTION Darwin was sure that a process of natural selection occurs in the nature.-High birth rates and shortage for resources would force organisms to compite for resouces.- Natural selection results in changes in the inherited characteristics of a population(of any specie). These changes increase a species fitness in its environment
SUMMARY OF DARWINS THEORY1-Species (populations of interbreeding organisms) change over time andspace. The representatives of species living today differ from those that livedin the recent past, and populations in different geographic regions today differslightly in form or behavior.2-All organisms share common ancestors with other organisms. Over time,populations may divide into different species, which share a commonancestral population. Far enough back in time, any pair of organisms shares acommon ancestor. EXAMPLE: HUMANS AND CHIMPANZEES. 3-Evolutionary change is gradual and slow.It doesnt occurs suddenly they have to pass many years.
4-Natural selection with its four components: 1-Variation: Organisms (within populations) show individual variation in appearance and behavior. On the other hand, sometraits show little to no variation among individuals(number of eyes in the vertebrates).2-Inheritance: Some traits are consistently passed on from parent to offspring. Some traits are heritable,and others traits are strongly influenced by environmental conditions and show weak heritability. 3-High rate of population growth: Most populations have moreoffspring each year than local resources can support leading to a struggle for resources. Each generation experiences substantial mortality.(dead) 4-Differential survival and reproduction: Individuals possessingtraits well suited for the struggle for local resources will contribute more offspring to the next generation.
Voyage of the BeagleThe voyage of the beagle started on 27 December1831, he was 22 years old. The Galapagos island were the key he foundto propose his theory: they were closetogether they all had different climates anddifferences between the species.
On the Origin of SpeciesDarwin present the book presenting his theory of evolution in 1859 with the title of: ON THE ORIGION OF SPECIES
HOMOLOGOUS ANDANALOGOUS ORGANSHOMOLOGOUSSTRUCTURES: Structuresthat have different formsbut develop from thesame embryonic tissue
1-He recollected a lot of plants such us : - P. macrocarpa,kaulf(in james island) -Pleopeltis lepidota,Willd(Charles Island) -Hemmionitis pinaata, hook.fil(Charles islands)2-he also recollected lots of specimens such us birds in fact he recollected a number of314 slides of specimens,and also fossils that led him to propose that leving beingd had made an evolution.
A SIMILAR THEORY In 1858 Alfred Russel Wallace wrote toDarwin about a theory of evolution that was similar to his, so that means that he was thinking about a very similar theory to Darwins one at the same time.
CO-EVOLUTION:-The term co-evolution is used to describe cases where two (or more) species reciprocally affect each other’s evolution.EXAMPLE: an evolutionary change in the morphology of a plant, might affect the morphology of an herbivore that eats the plant, which in turn might affect the evolution of the plant, which might affect the evolution of the herbivore...and so on.
NEODARWINISMNeo-Darwinism is the modern synthesis of Darwinian evolution through natural selection with Mendelian genetics, the latter being a set of primary tenets specifying that evolution involves the transmission of characteristics from parent to child through the mechanism of genetic transfer, rather than the blending process of pre-Mendelian evolutionary science. Neo-Darwinism also separates Darwins ideas of natural selection from his hypothesis of Pangenesis as a Lamarckian source of variation involving blending inheritance