Giraffes are browsers i.e. eat leaves, shoots, and twigs, unlike grazers who eat small plants and grass. The elongation of the giraffe’s neck is by its constant struggle to lengthen its neck to reach the leaves at the top. Sadly, that’s a myth! So the big question now is “How did Giraffes evolve to have a long neck?”
Can Lamarckian theory explain how did giraffes evolve?
The Lamarckian theory states that a change in an organism can pass to the offspring. The classic example that he used as Giraffes. He explained that a Giraffe with its constant strain over a lifetime to stretch its neck as long as they could developed an elongated neck. He discussed it as a “natural tendency towards perfection.” Lamarck concluded that animals evolve new traits that help them survive in the changing environment.
The second part of Lamarck’s evolution involved the inheritance of acquired traits. He believed that traits acquired over an individual’s lifetime can pass to the offspring. A Giraffe that lengthened its neck with its struggle passed it to its offspring rather than the original short neck. Authorities and the society did not accept Lamarck’s theory as acquired traits never pass to the next generation.
It was later explained by Darwin in “Origin of Species” which changed the world’s perception towards evolution. Darwin proposed that these traits developed by a random chance. Then the factor of natural selection came into light. Giraffes with longer necks could reach long heights and had better nutrition than the Giraffes with shorter ones. They live longer and reproduce more than others. Hence, they have a higher chance to pass their traits to the next generation. The consequence is a 2 meter long neck for a giraffe.
What are these random changes?
These changes can be the different evolutionary factors – Genetic drift, gene flow, and mutations.
- Genetic drift is the change in the frequency of an existing gene variant in a population due to random sampling of organisms.
- Gene flow is the transfer of genetic variation from one population to another.
- The mutation is a phenomenon in which the DNA is changed in such a way that the genetic message carried by that gene is altered.
These are the different reasons for our question “How did Giraffes evolve” Giraffes also have the same number of vertebrates as that of human i.e. seven. Each vertebrate is one foot long, unlike humans. Two forces that drove Giraffe to lengthen their neck is simple – the need to eat and the need to breed. Females choose males for breeding which have a long and strong neck. “Necking can determine the stronger neck. It’s a battle between Giraffes where they literally hit each other’s neck to identify the stronger one. This can sometimes lead to severe injuries or even death.
