Question

Which statement BEST explains Lamarck's theory of acquired characteristics as it relates to the neck length of giraffes?

Answer 1

Lamarck's theory of acquired characteristics suggests that useful traits, such as increased neck length in giraffes from stretching, could be passed to offspring. This contrasts with natural selection, which favors individuals with advantageous traits that are naturally present, not acquired.

Step-by-step explanation:

Lamarck's Theory of Acquired Characteristics

Jean-Baptiste Lamarck's theory of acquired characteristics suggests that traits developed during an organism's lifetime could be passed on to its offspring. In the context of giraffes, Lamarck hypothesized that their neck length increased because individuals stretched to reach leaves on taller trees, and these longer necks were then inherited by the next generation. His theory implies a purposeful evolution based on the use and disuse of characteristics, where traits that are beneficial for survival become more pronounced over generations, while those of less value diminish.

However, subsequent research and observations, such as those by Scientist B and Charles Darwin, have discredited Lamarck's ideas in favor of natural selection. Scientist B's experiments demonstrated that muscle stretching does not alter bone length or DNA in a way that would be heritable. Alternatively, Darwin's theory of evolution by natural selection posits that creatures with advantageous traits, like giraffes with naturally longer necks, are more likely to survive, reproduce, and pass on their advantageous traits without the need for the traits to be acquired during their lifetime.

Answer 2

LAMARCK's THEORY
Jean Baptiste Lamarck (1744-1829) proposed a theory which was published in "Philosophie Zoologique" (1809). This theory is simply known as Lamarckism. It has two main postulates:

1. Use and disuse of organs
2. Inheritance of acquired characters.

Example
He explained his theory by giving the examples:
1. Neck length of Girrafes
2. Webbed toes of water birds, and
3. Wings of penguins

Explanation
Lamarck explained that water birds use toe for swimming, with the passage of time webbed were developed in their toes. these features were then transferred to their offspring.

Drawback
Lamarck theory was based on natural observation. It did not explain the genetic basis of such characteristics.