Personal History Born in in Bazentin-le-Petit, France Joined the French army at 17 when his father passed away While enlisted he studied plants in his free time After 7 years in the army he became injured and was forced to leave He then went on to study medicine and botany He was only 34 when he wrote a book on plants (Flore Francaise).
Organisms tend to increase in size and a) complexity with time Changes in environment made special b) demands on organisms. Formation of new organ in the body is the results of a specific need felt by the animal The extend of the development of organs c) and their efficiency is proportional to their use and disuse of the organs. The observable characteristic acquired d) by the parents during their lifetime can be transmitted through reproduction to the offspring..
Adaptation and Specialisation Lamarck noticed that organisms adapted to a particular place had well developed specialised organs • For example a carnivore will have long canine teeth to grip its prey.
The Law of Use and Disuse He proposed that if an organ is used a lot it will develop and strengthen • If it is not used it will degenerate • He called this the law of use and disuse.
Lamarck's most famous illustration was using the giraffe as an example The long neck of the giraffe has evolved as a) a result of generations of giraffes stretching their necks to feed on the leaves of tall trees due to food shortage Each generation has transmitted to its b) offspring a small increase in length caused by continual stretching The modern giraffe thus has a very long c) neck due to inheritance of the acquired characteristic.
specuesv A species is a group of organisms that can mate with one another to produce fertile offspring. A characteristic that helps an organism survive and reproduce in its environment is called an adaptation. Figure The red-eyed tree frog hides among a treets leaves during the day and coms out at night. Figure 2 The bright coloring of the strawberry poison arrow frog warns predators that the frog is poisonous. Figure 3 The smokey jungle frog blends into the forest floor..
00 OVER Scientists observe that species have changed over time. The process in which populations gradually change over time is called evolution..
'The remains or imprints of once-living organisms found in layers of rock called fossils. By studying fossils, scientists have made a timeline of life known as the fossil record. The fossil record organizes fossils by their estimated ages and physical similarities..
List four sources of Charles Darwin's ideas about evolution. Describe the four parts of Darwin's theory of evolution by natural that gradual processes had changed the Earth's surface over selection. Relate genetics to evolution..
• After Charles Darwin graduated from college, he served as naturalist on a ship called the HMS Beagle. During a voyage around the world, Darwin collected thousands of plant and animal sar--i.• APRICA SO TPA LIA.
Darwin noticed that the finches of the Galåpagos Islands were a little different from the finches in Ecuador. And the finches on each island differed from the finches on the other islands Some Finches of the Galäpagos Islands The large ground finch has a The cactus finch has a tough beak wide, strong beak that it uses to that it uses for eating cactus parts crack open big hard seeds. This beak works like a nutcracker. and insects. This beak works like a pair Of needle-nose pliers. The warbler finch has a small, narrow beak that it uses to catch small insects. This beak works like a pair Of tweezers..
OARVUkVS Ideas About Breeding The process in which humans select which plants or animals to reproduce based on certain desired traits is called selective breeding. Ideas About Population Only a limited number of individuals survive to reproduce. Thus, there is something special about the offspring of the survivors..
@ Thomas Malthus: wrote a book stating that humans have the potential to reproduce rapidly, eventually overrunning the food supply @ This led Darwin to realize that all species can reproduce rapidly, those who survive must pass on traits to their offspring to help them survive @ Charles Lyell: Earth is old, allowed evolution to be a slow gradual process.
What Is Natural Selection? Darwin proposed the theory that evolution happens through a process that he called natural selection. Individuals that are better adapted to their environment survive and reproduce more successfully than less well adapted individuals. Genetics and Evolution Today, scientists have found most of the evidence that Darwin lacked. They know that variation happens as a result of differences in genes..
O Overproduction A tarantula's qg sac may hold eggs. Some of the will survive and develop into adult spiders. Some will O Struggle to Survive Some tarantulas may be caught by such as this wasp. Chhet tarantulas rnay starve or get a disease. Only some of the tarantulas will survwe to adulthmd- O Inherited Variation Every individual has its own combination traits. Each tarantula is similar to, but not idertical to, parents. O Successful Reproduction t&antulas that are best adapted to their environnent ate fikely to have many offspring that suNive..
Lamarck vs. Darwin • Lamarck's theory required adaptation to create new variations • This was followed by the inheritance of these characteristics • Darwin's theory requires random hereditary variation first, followed by selection of the variations • The argument was over when Mendel's laws of genetics were rediscovered at the end of the 19th century • Variations are due to hereditary traits passing from one generation to the next in predictable frequencies.