Evolution: Expectations from Theory 
This may sound odd coming from a lecturer on the evolution of 
the human brain, but I'll say it anyway. One of the greatest imped- 
iments to a rational interpretation of the human fossil record has 
been the fact that, over the long haul, there has been an undeniable 
tendency among hominids toward increasing brain size. We’ll look 
later at the details; it’s sufficient for the present to note that this 
‘trend’? has distracted attention away from diversity in the hominid 
fossil record, and toward continuity—thereby reinforcing the notion, 
prevalent from paleoanthropology’s earliest days, that our evolu- 
tionary history has been one of a slow, singleminded progress from 
primitiveness to perfection. This transformational bias has proven 
very congenial to adaptationist paleoanthropologists concerned with 
projecting the origins of Homo sapiens as far back in time as pos- 
sible; but the terminology and the mindsets it has fostered are in 
my view totally inimical to the proper understanding of many im- 
portant facets of human evolution. And of none of the many aspects 
of the human story is this truer than it is of the origin of the human 
capacity. 
Strangely, perhaps, the first evolutionary biologist to hint at this 
last point was one of the fathers of the theory of evolution by natural 
selection, Alfred Russel Wallace. While his elder contemporary 
Charles Darwin had no doubts whatever that generation-by-gener- 
ation natural selection fully explained all aspects of human emer- 
gence, Wallace, ironically the staunchest advocate of natural selec- 
tion in all other contexts, simply could not see how this process 
could have brought into existence the extraordinary consciousness 
of human beings. “‘Darwinian theory,’’ he wrote, ‘““shows us how 
man’s body may have developed from that of a lower form under 
the law of natural selection; but it also teaches us that we possess 
intellectual and moral faculties which could not have been so de- 
veloped, but must have had another origin.’’ (Wallace, 1889). Wal- 
lace attempted to find this other origin by embracing Spiritualism, 
a movement that had initially developed in direct opposition to the 
‘“‘materialism”’ of which evolutionary thought was widely believed 
to be an excellent example, but which rapidly became rampant with 
