One place the two of you might enjoy discussing is her ideas on Lucy. She argues on her website that Lucy was fully human. This is outside mainstream, but not by much. Part of the problem is that we don’t really have a good definition of “human”, but setting that aside, there seems to be a lot of substance here to discuss.
This seems to be an old page, so @Alice_Linsley might be expected to update her argument with new facts here too if she likes.
A recent discovery of a complete fourth metatarsal of A. afarensis at Hadar shows the deep, flat base and tarsal facets that “imply that its midfoot had no ape-like midtarsal break. These features show that the A. afarensis foot was functionally like that of modern humans.” (Carol Ward, William H. Kimbel, Donald C. Johanson, Feb. 2011) Read the report here.
Additionally, A. afarensis apparently used polished bone tools, shared food (which apes don’t do) and used fire. Some of the earliest evidence of controlled use of fire by humans was found at Swartkrans in South Africa. Other sites that indicate fire use include Chesowanja near Lake Baringo, Koobi Fora and Olorgesailie in Kenya.
A. Afarensis also had human dentition which is quite easily distinguished from that of apes. In humans, the back teeth are larger than the front teeth (not so with apes), and the canines are not pointed. Humans also lack the characteristic diastema or tooth gap found in apes.
Mary Leakey’s 1979 discoveries in Tanzania added to the evidence that humans walked the earth about over 3 million years ago. At Laetoli, about 25 miles south of Olduvai Gorge in Tanzania, Leakey discovered footprints of a man, woman and child created about 3.6 million years ago and preserved under falling ash from the nearby Sadiman volcano. The raised arch and rounded heel of the footprints showed that whoever left these footprints walked as humans today.
Unfortunately, Donald C. Johanson had already announced to the world that the Australopithecus afarensis were apes, though Mary Leakey would have classified her Laetoli finds as Homo/human. She expressed her regret that “the Laetoli fellow is now doomed to be called Australopithecus afarensis.”
Johanson and Mary Leakey were scheduled to speak at a Nobel Symposium in Sweden in May 1978. The conference honored Mary Leakey, who received a medal from the King of Sweden for her scientific investigations. Mary Leakey received the Golden Linnaean Medal, but also was very embarrassed when Johanson announced the new name - Australopithecus afarensis - for his Afar Triangle finds and included Mary Leakey’s 4 million year old Laetoli specimen (jaw bone LH4) from Tanzania as an exhibit.
Johanson, who was scheduled to speak before Mary Leakey, scooped Mary’s speech. She was angry that Johanson had named her discoveries, using a designation that was totally at odds with what she believed to be the evidence. Johanson’s name stuck though he clearly has doubts based on more recent discoveries as to the accuracy of the ape designation.
The designation of the finds in Ethiopia as apes is contradicted by the evidence that these fossils had oppositional thumbs, short fingers, human dentition, and apparently built fires. Discoveries in Dikika, near Gona and Bouri, Ethiopia indicate that they shared their food, and used flints to scrap, saw and chop. Two fossilized bones have been found that appear to be marked by stone tools. On the basis of low-power microscopic and environmental scanning electron microscope observations, these bones show unambiguous stone-tool cut marks for flesh removal and to access bone marrow.
The evidence taken together indicates that Lucy and her community were human, though not modern humans. What do you think?