The Brain Of Australopithecus Afarensis (Lucy & Selam)

Australopithecus afarensis was a hominin species that lived between 3.8 and 3.0 million years ago. In this video we will examine all research related to it's brain size, brain shape and brain function.
Arguably the most famous member of the Australopithecus afarensis species is Lucy, due to its almost complete skeleton and skull. Besides that, there is Selam, aka the Dikika child, which has an almost complete skull and the cranial volume is filled with sandstone, creating a natural endocast. This natural endocast has proven extremely valuable for research.
The brain size of Australopithecus afarensis is approximately 450 cc, which is about 20 percent larger than earlier species Ardipithecus, and Sahelanthropus tchadendis, as well as modern chimpanzees. There is however considerable variability between males and females, due to sexual dimorphism.
Research on the lunate sulcus of the dikika child shows that the occipital cortex of australopithecus afarensis is very similar to that of modern chimpanzees. This suggests that little had changed to the occipital cortex since the evolutionary split from chimpanzees.
In contrast, the frontal cortex may have increased in size. However, these findings are speculative and it is uncertain if it had an effect on intelligence. But besides that we also see prolonged childhoods in australopithecus afarensis suggest more time to learn, which may indicate increased intelligence.
Time stamps:
0:00 Who was Australopithecus afarensis?
0:32 Australopithecus afarensis fossils, skulls, endocasts
2:22 Australopithecus afarensis brain size
3:58 Australopithecus afarensis occipital cortex
5:33 Australopithecus afarensis frontal cortex
7:16 Australopithecus afarensis childhood development
9:13 Where Australopithecus afarensis fits in the evolutionary tree
References:
Brassey, C. A., O'Mahoney, T. G., Chamberlain, A. T., & Sellers, W. I. (2018). A volumetric technique for fossil body mass estimation applied to Australopithecus afarensis. Journal of human evolution, 115, 47-64. doi.org/10.1016/j.jhevol.2017...
Bruner E. (2019). Human paleoneurology: Shaping cortical evolution in fossil hominids. The Journal of comparative neurology, 527(10), 1753-1765. doi.org/10.1002/cne.24591
Cofran Z. (2019). Brain size growth in Australopithecus. Journal of human evolution, 130, 72-82. doi.org/10.1016/j.jhevol.2019...
Gunz, P., Neubauer, S., Falk, D., Tafforeau, P., Le Cabec, A., Smith, T. M., Kimbel, W. H., Spoor, F., & Alemseged, Z. (2020). Australopithecus afarensis endocasts suggest ape-like brain organization and prolonged brain growth. Science advances, 6(14), eaaz4729. doi.org/10.1126/sciadv.aaz4729
Haile-Selassie, Y., Melillo, S. M., Vazzana, A., Benazzi, S., & Ryan, T. M. (2019). A 3.8-million-year-old hominin cranium from Woranso-Mille, Ethiopia. Nature, 573(7773), 214-219. doi.org/10.1038/s41586-019-15...
Kimbel, W. H., & Rak, Y. (2010). The cranial base of Australopithecus afarensis: new insights from the female skull. Philosophical transactions of the Royal Society of London. Series B, Biological sciences, 365(1556), 3365-3376. doi.org/10.1098/rstb.2010.0070
Kimbel, W. H., & Delezene, L. K. (2009). "Lucy" redux: a review of research on Australopithecus afarensis. American journal of physical anthropology, 140 Suppl 49, 2-48. doi.org/10.1002/ajpa.21183
Narrated by: Miles Wischnewski
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[@Hominoids]

Interesting and well presented

[@real.psyched]

Thank you very much!! 😊

[@bananabreeding1362]

Your uncluttered exposition is really appreciated. I shall include your vids in my teaching material. Clear. Understandable and, I can imagine, leading to much student discussion.
Thank you!

[@real.psyched]

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[@cupatelj]

This vidro is gold.

[@real.psyched]

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