Friday 14 September 2018

Kurt Benirschke (1924 - 2018)

Kurt Benirschke (right) with Oliver Ryder
Sad to record the death of Kurt Benirschke at age 94. Among many achievements is his web site Comparative Placentation (previous post). This invaluable resource is particularly strong on primates and even-toed ungulates such as antelopes.

The placentas came mainly from San Diego Zoo where Kurt Benirschke also took the initiative to create a biobank of cryopreserved tissues (The Frozen Zoo) and laid the foundation for what became San Diego Global's Institute for Conservation Research. 

To many he is best known for his textbook Placental Pathology. The second  (1990) and subsequent editions were written with Peter Kaufmann. It is now in a sixth edition edited by Kurt Benirschke, Graham Burton and Rebecca Baergen.


The Annual Kurt Benirschke Lecture at UC San Diego 2018
Five years ago Kurt Benirschke suffered a stroke but he remained active and alert. According to today's obituary in San Diego Union Tribune, he and his wife visited San Diego Zoo as recently as last week. 

To learn about Kurt Benirschke's life in his own words see the short version here or his interview with Rebecca Baergen here.

Wednesday 5 September 2018

Why Luzia was important

Cast of the skull known as Luzia as displayed at
National Museum of Natural History Washington DC
Photo by Ryan Somma CC BY-SA 2.0
Luzia was excavated from Lapa Vermelha, Minas Gerais, Brazil and was the oldest human fossil from South America. She was found in strata dated to 11,000 years ago. Whilst casts of the skull exist elsewhere the original was lost (at best severely damaged) in the catastrophic fire that destroyed the National Museum in Rio de Janeiro. 

Luzia Woman belonged to an ancient population formerly known as Lagõa Santa Man or Paleoamerind. The first to excavate such skulls was the Danish Naturalist Peter Lund, who found them as far back as 1840. Based on the classical craniometric criteria used by anthropologists until well into the twentieth century, this population clearly diverged from all others in North and South America.

Lagõa Santa skull excavated 1840 by Peter Wilhelm Lund
There is an interesting correlate in modern genomic data. David Reich and colleagues postulate an ancient Population Y corresponding to a genetic signal borne by the Surui people of the Amazon region (discussed here - see previous post for Reich's book where this is further discussed). The interesting thing about this signal is that it is shared with the faraway Andaman Islanders and natives of New Guinea and Australia.

We already know of two branches to the population that crossed the Bering Strait and peopled North and South America - thanks to work by Eske Willerslev's group (here). Was there a third branch that gave rise to the Paleoamerinds or even a separate and earlier migration?

To piece this together it would have been useful to extract ancient DNA from the Luzia skull. That had not been done prior to the fire. There are other skulls around including those excavated by Peter Lund and now housed in Copenhagen. They may yet yield new pieces to complete the puzzle.