Page 180 - The Evolution Impasse 2

178 Recapitulation Theory

of Ramapithecus in his nat u ral hab i - Variation.) Thus ex cept in the case
tat, to geth er with his fam i ly. of iden ti cal twins, two off spring are
nev er iden ti cal to one an oth er, and
nei ther are their ge net ic con tents ex -
RECAPITULATION THEORY act ly the same as their par ents'.
— See Ontogeny Recapitulates Some ev o lu tion ists in ter pret var i -
Phylogeny Theory, The. a tion through re com bi na tion as an
ev o lu tion a ry fac tor. 199 However, this
is not sci en tif i cal ly val id. Variation is
RECOMBINATION a nat u ral proc ess aris ing from ge net -
ic mix ing dur ing re pro duc tion. Yet
Recombination means a new gen -
there is no ques tion of a new spe cies
o type (or he red i ta ry struc ture) be ing
emerg ing through re com bi na tion, or
pro duced by the ge net ic char ac ters
of new in for ma tion be ing add ed be -
of the two gen ders com bin ing.
yond that al ready re cord ed in the
However, re com bi na tions must not
genes.
be con fused with mu ta tions. In mu -
Studies on re com bi na tion oc cu py
ta tion, in or der for chan ges tak ing
a very im por tant place in the un der -
place in the in di vid u al's gen o type to
stand ing of ge net ic mech a nisms.
be ef fect ive, they must take place in
Recombination has guid ed sci en -
the re pro duc tion genes.
tists' pro duc tion of the chro mo some
Recombination, on the oth er
map, iden ti fi ca tion of ge net ic ab nor -
hand, is a con stant proc ess that gives
mal i ties, and in ge net ic trans plants
rise to new com bi na tions of genes in
of one chro mo some to an oth er.
ev ery off spring, as a re sult of nat u ral
sex u al re pro duc tion. Recombination
re sults from the re group ing of genes
RECONSTRUCTION
from the moth er and fa ther dur ing
(IMAGINARY PICTURES)
the for ma tion of their re pro duc tive
cells. Before cell di vi sion, the fer ti - Using var i ous prop a gan da tech -
lized egg al ways takes half its ge net - niques, ev o lu tion ists seek to cam ou -
ic ma te ri al from the moth er and half flage their lack of any ev i dence to
from the fa ther, but re com bi na tion sup port their the o ries. The most im -
plays a de fin i tive and in flu en tial role por tant of these tech niques is re con -
in the for ma tion of va ri e ty. (See struc tion, which in volves an "art ist's
con cep tion" of what a liv ing thing

The Evolution Impasse II