BIOL 3200 Lecture Notes - Lecture 33: Louis Agassiz, Nominalism
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Darwin said differences between individuals provide the fuel for evolution. Problem: most variations were blends of characteristics inherited from both parents, so genetic material from parents was probably all mixed together. If traits were blended, then new characteristics that spontaneously arose would be passed on but slowly fade away as they would be blended with other traits. I(cid:374) that (cid:272)ase, (cid:374)atural sele(cid:272)tio(cid:374) (cid:449)ould(cid:374)"t ha(cid:448)e (cid:373)u(cid:272)h sta(cid:271)le (cid:272)hara(cid:272)teristi(cid:272)s to work on. In 18th and 19th (cid:272)e(cid:374)turies, (cid:449)ord (cid:862)spe(cid:272)ies(cid:863) i(cid:373)plied that it (cid:449)as u(cid:374)(cid:272)ha(cid:374)gea(cid:271)le. Georges buffon defined species as: 2 animals that are able to copulate, can successfully reproduce, and preserve the likeness of the species. Believed that diversity within species was limited, accumulations of individual differe(cid:374)(cid:272)es (cid:272)ould(cid:374)"t step outside spe(cid:272)ies type. Darwin believed natural selection acted on very small individual differences, and not fundamental characteristics that distinguished species. Species arose from accumulations of small differences.
