Driving nails into the 2014 Lawn Chair

It’s that time again, when we come to bury the year we’ve just defeated, only to celebrate the zombie birth of a new onslaught of days to clobber. In the spirit of auld lang syne, let’s recap the highlights of Lawn Chair in 2014.Georgia dinos 2014

Osteology was everywhere: although I am wont to see bones everywhere in everyday life, this year I only wrote about it four times. First there were the baby bones in cafe upholstery in my hometown of Kansas City, then the giant sheep bones in my new home of Astana. I discovered that animal bones littered the landscape of desert Mangystau, and then I spotted a vertebra hiding in a helmet at a conference in Italy. I also tweeted about a false femur head from a karaoke bar in Astana. You can’t escape. 2015 is sure to be more osseous.BONES!
eFfing Fossil Friday reboot: This old series focusing on fossils furtively restarted on a plane, when I uncovered the conspiracy that the Australopithecus africanus cranium Sts 71 was actually the Kryptonian codex. I later wrote about the Sima de los Huesos skulls, Neandertal poop, the origins of feathers on badass dinosaurs, the 45,000 year old Ust’-Ishim femur and its delicious DNA, and facial flanges in early mammals and nearly modern baboons. Fossils are the best, and 2015 is bound to be as fossiliferous as last year.Ancient DNA was boss: In addition to the earliest ‘modern’ human DNA from Ust’-Ishim, 2014 also witnessed a swath of studies early on attesting to the success of paleogenomics. We also got a first glimpse into epigenetics of ancient humans, and the potential importance this will have in uncovering how our DNA makes us human. Along these lines, for 2015, I’d be keen to see more work on miRNA and other aspects of gene regulation in ancient genomes.

Screen Shot 2014-10-24 at 11.26.31 AMR codes: I’ve posted R code for the analysis from my paper that came out this year, comparing mandibular growth in humans and Australopithecus robustus (I didn’t get to talk about that paper when it came out because I was in the middle of the Rising Star Workshop. Things to look forward to in 2015…). I’ll also be posting code for the analysis of brain growth in Homo erectus once that paper is published, and I have already posted code for creating the pretty pictures from the paper.

Brain size data (left) and the average annual rates from birth calculated from pairs of specimens (right). Black=humans, green=chimpanzees, red=gorillas, blue=Homo erectus.
Body size variation in Homo erectus: A response to a response to a paper led me to reexamine sexual dimorphism in body size in our early ancestor – seems it was higher than has lately been appreciated, and there are many potential reasons for this. I presented the initial results of this investigation on the blog and at a conference, and am now writing this up for publication. This investigation is based on resampling statistics, nothing as new and flashy as in the growth studies. I will post code for these analyses on the R Codes page in due time.

Dimorphism ratios copy

Resampled ratios of dimorphism, calculated by dividing the average of six randomly selected male body masses by a randomly selected female mass. The blue star in each plot is the empirical ratio of average male mass/average female mass. For all species the average resampled ratio is almost identical to this empirical value. The red line marks the ratio of the six largest (male?) Homo erectus mass estimates divided by the estimated mass of the Gona (female?) pelvis. The Homo erectus male/female difference is rarely observed in chimps and humans, but is common in gorillas. Gorillas display high levels of sexual dimorphism, suggesting this may have been the case for Homo erectus as well.

Classroom lab activities: This year I added a lab components to my courses here at NU, and I posted up two of the lab activities I did in my classes this semester. Last spring, I got the idea for an activity in which students measure toe joint angles on digital images, to test whether Ardipithecus kadabba and other hominin toes can be distinguished from apes’. This semester, students in my human evo-devo class did this study, and generally found hominin toes to be more angled than apes’. Hypothesis tested. My Intro to Bio Anthro class tested whether their limb proportions fit expectations based on Allen’s Rule, and mystery ensued. My classes next term aren’t as conducive to lab activities, but if I come up with any good assignments I’ll be sure to post them.class models both copy

Now that 2014 is laid to rest, here’s to a bright and successful zombied 2015! Жаңа Жылыңызбен!


One thought on “Driving nails into the 2014 Lawn Chair

  1. Pingback: Bone Broke Year in Review | Bone Broke

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