Expert: Ralph Salier - 5/9/2010

Question
QUESTION: I have 3 questions to ask. 1/ Name four important features of a skeleton, both cranial and post cranial, that indicate bipedal locomotion?
2/ Name on characteristic of modern humans that suggests that they interbred with Homo erecus?
3/ Although it is difficult to determine our exact lineage, name one characteristic (besides bipedal locomotion & a big brain) that musth ave been part of our basic behavioral survival strategies?

ANSWER: Hi Zohra,

1) The skull is carried on the top of the spinal column rather then extending from it.  This denotes a vertical attitude for the body.
    The positioning of the hip bone (pelvic bones) and acetabulum of the femur/hip joint also indicates vertical attitude and strongly suggests bipedalism and finally the arrangement of the foot bones at the end of the legs, especially the heal bone demonstrates bipedalism rather then "knuckel walking".  There are other indicators but these in my view are the best.  

2) I don't believe  that modern man interbred with Homo Erectus.  There have been some recent indicators that early "modern man" may have interbred with Homo Sapiens Neanderthalis based on some genetic studies being carried out.  But the work is still being done and they need to ensure that this was not a contaminated sample.  Had this occured, it would have taken place some 80,000 years ago.

3) language, not just grunting but real language.

---------- FOLLOW-UP ----------

QUESTION: Okay but for #2 it states there has to be atleast one characteristic of modern humans interbreding with Homo erectus, if you were to mention one characteristic. What would you say?

Answer
Hi Zohra,

Modern Humans and Homo Erectus did not interact.  There is a fair bit of time between the two species.  Below is a time line which shows that Modern man (Homo Sapiens Sapiens) is a rather recent evolution vs. erectus being old.  So, no interbreeding would have occurred.  Modern man does carry a fair amount of similarities to Erectus which is one reason we know that he is in our lineage.  Our teeth, hip bone, feet and hand bones are all very similar.  But there was no interbreeding between modern man and Erectus.  Now, of course, I can not read every article that comes out in the literature so it is possible that I may have missed something.  If you have read that they did, some where, I would be interested in reading the article and interpreting it for you, if you would send it to me, I would be glad  to do so.

Here is a time line:
http://www.wsu.edu:8001/vwsu/gened/learn-modules/top_longfor/timeline/timeline.h