death is one of those things that really does permit us to uh Bridge fairly deep breadths of distance between us and others at times and this was a a jump of empathy that I had that just made me more cognizant of her as an individual by thinking very pointedly about how she died Lucy's one of the earliest uh uh specimens of early human evolution so a Hamid she dates to about 3.2 million years ago and was found in the afar depression of Ethiopia in 1974 she's one of the most completely represented skeletons and as such she's been able to tell us a lot about early uh humans the reason Lucy came to UT was because we were the first industrial type CT scanner in a science department in the world in the Jackson School industrial CT is based on all the same principles as medical cat skinning where you lie in a bed and go through a big donut and x-rays are shining all around you and uh by gathering data from x-rays shining all around you in a circle and then reconstructing those with a computer you come up with a picture of what you look like along a slice and by building up a series of slices you can like rebuild the loaf of bread and come up with a complete representation of what the patient or the fossil is inside and out we had the idea that we could put together a complete story of how she lived now we didn't anticipate coming up with a complete story of how she died as well but that's something that happened well we've been working on the scans of you know plus and minus over the intervening years and it was in the course of uh examining uh some of the elements uh and first off the humoris that it struck me that the brakes on the end of the humorus at the shoulder so what we call the proximal end uh were unusual kinds of brakes they were compressive brakes uh rather than disloca break when you look at fossils for years and years all fossils are broken they're stepped on they're deformed just because of all the things that can happen between when something dies and when it gets fossilized and things and dug out and so you look at that for years and years until the idea suddenly hits well maybe there's a reason that bone is crushed in in that particular way looking at the configuration of the break that this is a unique signature so it's a compressive signature and one of the aspects of this with all of these tiny fragments is that if this had happened on dry bone somehow laying on the surface of the ground something impact in it which is really hard to figure out what that might have been but if that had happened on dry bone all of these fragments would have dispersed out on the surface and the fact that they're all still maintained in their relative positions to one another suggests very strongly that the covering of the bone called the periostium and also the joint capsule that holds that shoulder joint together were in pack at the time of the injury it was on that basis that we felt that we had identified a param morm fracture so a fracture that occurred in life and what's interesting with this kind of a fracture within humans today is that it occurs as a result of a fall so as a person Falls uh it can be either from standing height or from some elevation they reach out their arms you've probably done this too to try to break your fall and the force then when the hand hits the ground the force impacts the shoulder against the scap AA and that forces then the scapula down it works kind of as an anvil or a punch and it forces it down on top of the head and that Force then impacts the two elements together and causes that kind of a compressive break so not only is this a param morm fracture within Lucy but it's also a fracture that tells us that she was very probably conscious at the time that she fell lots of other fractures throughout the skeleton literally from Head to Toes we think that she probably landed feet first uh the fracture that we see at the knee suggests that her body Twisted to the right side her left humorous shoulder is also fractured not as severely as the right that tells us that when she hit conscious with her arms extended that there was more force on the right side than the left so we think she came down on the right side and in falling in that way she also fractured her hip so we have that fracture as well that shows that the force went from right to left and then there are fractures of of the ribs some of the vertebrae the mandible and some uh cranial elements so that leads us then to think about what kind of a height that would have required uh to suffer this sort of an injury the question with Lucy and with many of these early hominids is whether or not they were arboreal the debate for Lucy has been going on ever since she was discovered so more than 40 years uh with some camps arguing no she was absolutely terestrial no evidence for being in the trees and other groups saying yes she was AR Boral at times and she was also terrestrial so we see a combination of these things because she was so tiny she weighed a little bit less probably than 60 PBS it's likely that she went up into the trees just for safety at night to get away from predators the same reason that many chimpanzees nest in the trees now uh average chimpanzee Nest height in both Savannah and Forest settings comes out to nearly 14 M so if you imagine driving along at that speed and slamming into a brick wall that would be the kind of an impact that uh it would suffer It's a combination of both the fractures and internal organ injury that kills the person so it's not just the bones that are compressed by the fracture but all of the internal organs suffer decaration as well uh for some of these cases uh organs actually rip loose from their mour so uh it's likely we think based on uh the position of the legs and also the arms that she was conscious when she hit but because of the severity of the fractures it's very I think likely that she suffered s severe internal organ damage on probably every organ and that death followed very swiftly and so once I had all of these different pieces together I remember the the the point in time exactly that I had all of the fragments laying out on the skeleton and I could just picture for the very first time this assortment of Bones as an individual as a as a person not a human person but an early human person and uh the body literally being crumpled broken and uh Lucy dying laying at the foot of a tree that I could picture her as an individual for the very first time