Evolution and Lamarckism

 Jean Baptiste Lamarck, a French naturalist in 1801, proposed a theory that physical change in organisms during their lifetime would be transmitted to their offspring. An example of this would be a greater development of an organ once there is an increase use, and then would be passed down to offspring. Of course, this type of evolution has its flaws, but some of the concepts align slightly with the real theory of evolution that is known today. One of his ideas was how environmental factors play a big part in change in a species, in order for the species to be able to survive and breed. He got this aspect right because we can see from Darwin’s Galapagos Island finches, that relative beak size would change over time due to environmental factors. When a drought would run through the island, beak size began to increase with time when there were no nuts, seeds, and other food sources available. The finches with the larger beaks survived because they had other food sources they could attain, rather than the smaller beak size finches. Lamarck understood how environment brings change within plants and animals in several ways. According to Lamarck, new needs arise in animals as a result of a change in the environment. This leads to new types of behavior involving new uses of pre-existing organs (Britannica, 2017). Lamarck’s view of evolution differ from our current understanding is he believed that acquired characteristics were inheritable. Some examples would be that a giraffe could stretch its neck for higher leaves, and overtime would result in the gradual lengthening of all giraffes’ necks. This theory was rejected because we know that this is not possible, and characteristics do not bring change in an individual set of genes. This can also be disproven because we know that when a dog’s ears are cropped short, the offspring of that dog will have long ears. Just as the parent had before the ears were cropped. Darwin knew that traits were passed on, but now we know more about genetics and how they are passed down. From what we know about evolution, Lamarck was wrong because we know that the only thing affecting gene sets is by which individual lives and reproduces, and which ones die.  

Britannica, The Editors of Encyclopaedia. (2017). "Lamarckism". Encyclopedia Britannica, 11 Oct. 2017, https://www.britannica.com/science/Lamarckism.