Thorne emphatically (and I believe sincerely) dismisses the idea that his theory is in any measure racist and accounts for the uniformity of human evolution by suggesting that there was a lot of movement back and forth between cultures and regions. "There's no reason to suppose that people only went in one direction," he says. "People were moving all over the place, and where they met they almost certainly shared genetic material through interbreeding. New arrivals didn't replace the indigenous populations, they joined them. They became them." He likens the situation to when explorers like Cook or Magellan encountered remote peoples for the first time. "They weren't meetings of different species, but of the same species with some physical differences."
卡尔顿·库恩坚决（这一点我确信无疑）否认他的理论有任何种族主义倾向。他认为，存在于不同的文化和地区之间的反反复复的交流，说明了人类进化的同源性。没有理由认定人类只沿着一个方向进化，” 他说，“人类在世界各地流动，几乎可以肯定，在交汇的地方，通过异种交配，分享了基因。新来的人并没有代替土著居民，而是融入到他们中间，最后变成一体。” 他打了一个比喻，当库克和麦哲伦这样的探险家第一次遇到偏远地区的居民时，“他们并没有遇到不同的种族，而只是遇到了某些身体特点有所不同的同类”。

What you actually see in the fossil record, Thorne insists, is a smooth, continuous transition. "There's a famous skull from Petralona in Greece, dating from about 300,000 years ago, that has been a matter of contention among traditionalists because it seems in some ways Homo erectus but in other ways Homo sapiens. Well, what we say is that this is just what you would expect to find in species that were evolving rather than being displaced."
桑恩坚持认为，在人类化石上你所能观察到的也是一个均衡而不断的变迁。有一副发现于希腊佩特拉朗纳的很著名的骸骨，大约生活于30万年前，就是一件在传统主义者中间一直富有争议的事，因为他似乎同时具有直立人和智人的某些特征。怎么说呢？我们要说的是，这正是你会期望在物种身上看到的：他们是在进化，不是在替代。”