- Jul 5, 2011
Acquired characteristics—characteristics gained after birth—cannot be inherited (a). For example, large muscles acquired by a man in a weight-lifting program cannot be inherited by his child. Nor did giraffes get long necks because their ancestors stretched to reach high leaves. While almost all evolutionists agree that acquired characteristics cannot be inherited, many unconsciously slip into this false belief. On occasion, Darwin did (b).
However, stressful environments for some animals and plants cause their offspring to express various defenses. New genetic traits are not created; instead, the environment can switch on genetic machinery already present. The marvel is that optimal (c) genetic machinery already exists to handle some contingencies, not that time, the environment, or “a need” can produce the machinery (d).
Also, rates of variation within a species (microevolution, not macroevolution) increase enormously when organisms are under stress, such as starvation (e). Stressful situations would have been widespread in the centuries after a global flood.
a. The false belief that acquired characteristics can be inherited, called Lamarckism, would mean that the environment can directly and beneficially change egg and sperm cells. Only a few biologists try to justify Lamarckism. The minor acquired characteristics they cite have no real significance for any present theory of organic evolution. For example, see “Lamarck, Dr. Steel and Plagiarism,” Nature, Vol. 337, 12 January 1989, pp. 101–102.
b. “This hypothesis [which Darwin called pangenesis] maintained the idea of inheritance of acquired characteristics.” A. M. Winchester, Genetics, 5th edition (Boston: Houghton Mifflin Co., 1977), p. 24.
c. In writing about this amazing capability, Queitsch admits:
“... it is a perplexing evolutionary question how a population might move to a different local optimum without an intervening period of reduced fitness (adaptive valley).” Christine Queitsch et al., “Hsp90 as a Capacitor of Phenotypic Variation,” Nature, Vol. 417, 6 June 2002, p. 623.
d. “... genes that were switched on in the parent to generate the defensive response are also switched on in the offspring.” Erkki Haukioja, “Bite the Mother, Fight the Daughter,” Nature, Vol. 401, 2 September 1999, p. 23.
“... non-lethal exposure of an animal to carnivores, and a plant to a herbivore, not only induces a defence, but causes the attacked organisms to produce offspring that are better defended than offspring from unthreatened parents.” Anurag A. Agrawal et al., “Transgenerational Induction of Defences in Animals and Plants,” Nature, Vol. 401, 2 September 1999, p. 60.
“... hidden genetic diversity exists within species and can erupt when [environmental] conditions change.” John Travis, “Evolutionary Shocker?: Stressful Conditions May Trigger Plants and Animals to Unleash New Forms Quickly,” Science News, Vol. 161, 22 June 2002, p. 394.
“Environmental stress can reveal genetic variants, presumably because it compromises buffering systems. If selected for, these uncovered phenotypes can lead to heritable changes in plants and animals (assimilation).” Queitsch et al., p. 618.
e. Marina Chicurel, “Can Organisms Speed Their Own Evolution?” Science, Vol. 292, 8 June 2001, pp. 1824–1827.
[From “In the Beginning” by Walt Brown]