Someone Cited My Thesis!

Some time last week, a little birdie sent me a link to what appears to be a page from American Museum of Natural History (AMNH). Said birdie also mentioned that the link has to do with my honors thesis. Along with the link was a thumbnail of a male hamadryas baboon that looked rather familiar. It took me a few seconds to realize that I am looking at Fadi, or Moja as what he is referred to by the zoo. (Follow this link for who's who at Prospect Park Zoo) Confused as to what my honors thesis, Moja and AMNH have in common, I opened the link. The link directed me to one of AMNH's Young Naturalist Awards winner, a young gentleman by the name of Henry.

Henry's winning entry is Hamadryas Baboons, Papio hamadryas: Captive vs. Wild. His research was on hamadryas baboon behaviors, where he compares the Prospect Park Zoo troops with the ones from Larissa Swedell's field work in Ethiopia. And guess what, he cited my thesis! I'm excited that someone dug up my baby and used it in their research. This is the first time (that I know of) someone actually cited my research. I'm so glad I uploaded my honor thesis on Scribd instead of just letting the bound copy collect dust in my college's library. Anyway ...

Henry's research is quite interesting. He found that there are behavioral differences between captive and wild hamadryas baboons. Also, grooming was not the highest in frequency compared to other behaviors (sitting was the highest in frequency). This could be explained by the hot weather or the fact that data for this research was only collected for about 9 hours. Nonetheless, this is heading in a good direction and a pretty good research topic for a 15 year-old. Hopefully he'll stick to his passion for primates (baboons) and go on to be the next primatologist.

Note that the male hamadryas photo "Simen, a 19-year-old Alpha Male" (above) is actually Moja, Simen's offspring. Simen can be identified with a mole underneath his left eye, which is absent in this photo. Click on the link to read my thesis, A Cross-Species Comparative Study: Grooming Patterns in Captive Populations of Hamadryas Baboons and Geladas.

20 million-year-old well preserved fossil skull: Ugandapithecus major

Map of Uganda showing the remote Karamoja region in the northeast of the country where a team of Ugandan and French paleontologists announced Tuesday they had found a 20-million-year-old ape skull, saying it could shed light on the region's evolutionary history. Illustration from PhysOrg.

A well preserved fossil skull of an ancient primate, Ugandapithecus major, has been excavated in the northeast region of Karamoja in Uganda (hence the genus name, Uganda monkey). The 20 million-year-old skull belongs to a male and probably died when it was about 10 years old, said researchers Pickford and Senut. The cranial size of Ugandapithecus major was about the same size as that of chimpanzees but its brain size is smaller. Ugandapithecus major is a tree-climbing catarrhine, an herbivore that lives around the Miocene. Although its genus name refers to it as a monkey, Ugandapithecus major is actually a hominoid (ape).

A well preserved skull of Ugandapithecus major. Photo from BBC News. 

The skull will be cleaned and prepared in France for about a year before returning it back to Uganda. Ugandapithecus major was described in 2000 by Senut et al. from a few dental and postcranial remains.

You can read Senut et al. (2000) A new genus of Early Miocene hominoid from East Africa: Ugandapithecus major (Le Gros Clark & Leakey, 1950) here (requires subscription).

AMNH Picturing Science Tweetup: In Living Colors

Atlantic Spotted Mackerel. Stained using red dye (bones) and blue dye (cartilage)

I was excited to be invited back to another tweetup at AMNH last night. This time, I was able to get Vance to come with me and I think he had a pretty good time. The tweetup was about "Picturing Science: Museum Scientists and Imaging Technologies", a vivid photo exhibition of specimens and phenomenon. And yet again, I have forgotten to bring my camera. You know, after I've got my Nexus S, I have barely used my camera. I just need to remember that sometimes my phone can't take pretty pictures. Anyway, we were treated to some behind-the-scene tour of some of the AMNH scientists at work using imaging technologies such as computed tomography (CT) scans, scanning electron microscope (SEM), infrared photography and even dyes to color bones and cartilage (staining technique). The latter was my favorite technique as I am quite fond of stained specimens.

We picked up a button when we arrived and on the brim of the button reveals the group that we will be part of. I subconsciously just chose the button of a upper mandible of a felid. Bones, bones, bones. So we were assigned to Group #2 for a behind-the-scene tour. But before the tour, we gathered at Akeley Hall of African Mammals to mingle. There was, of course, wine and cheese. Oh yea, it's classy like that.

Led by an ichthyologist and an entomologist graduate students, the first stop for this group was a classroom-like setting where we were treated to amber, flies, ants and stained fishes. Sweet. I got to hold a piece of Baltic amber that encases a pair of flies that are still in the heat of copulation. Pretty rad. There was also amber that encases a species of previously undescribed ant. That guy has a massive pair of mandibles. We also spent some time looking at stained fishes under the microscope, although the staining technique itself is sufficient to show the complexity of fish osteology. "Fish bones are jigsaw puzzle from hell". Yep, that pretty much sums it up along with articulating a snake. The staining technique uses red dye to color the bones and blue dye to color the cartilage. Here's a writeup on how to prepare a stained fish Hidden Blades, Glowing Scorpions and Bug Genitalia: Great Science Images From the American Museum of Natural History.

Using a microscope to looking inside an amber. This particular amber has an ant in it.

Vance loves ants. So he's particularly excited.

I hold in my hand a piece of amber that has encased a pair of copulating flies, hence the "IN LOVE" and an arrow pointing at the two amorous flies.

Next stop was the imaging technology area where we got to see some cool microscopes such as SEM and CT scan in action. The SEM was used to produce detailed close-up photos of goblin spider while the CT scan was used to take thousands of armadillo lizard x-rays. These x-rays are later incorporated into a 3D program to produce a comprehensive 3D image of an armadillo lizard. Pretty neat stuff. There was also a microscope that they dubbed "microscope on steroid" and is used to scan comet dust. They mean business there. LOL!

Scanning electron microscope (SEM) on the left. Image of the carapace of a goblin spider on the right.

Using a CT scan to look inside an armadillo lizard.

"Microscope on steroid". Scanning comet dust.

As the behind-the-scene tour ends, we were ushered back into the Akeley Hall of African Mammals and got to spend more time mingling and taking in the new photo exhibition. There was a photo exhibit of Chilecebus (Chilean Monkey), an extinct primate and the only specimen of its kind ever found. Using a CT scan, the researchers were able to look inside the skull of Chilecebus to reveal its brain size and the shape of its head's semicircular canal. 

Chilecebus photo exhibit. Using a CT scan to look inside the skull of the one and only specimen found.

Chilecebus skull (left). CT scan reveals the shape of its head's semicircular canal. 

Brownie points to Denton Ebel, the Curator-In-Charge of Department of Earth and Planetary Sciences for walking us through the exhibition and explaining to us in depth the "Warhol" meteorite photo exhibit. And also thanks for all the jokes "It's perfectly round, just like tears of astronauts in space ... because they missed home". Oh yes, I forgot about the swag. This time we were ushered away with some postcards from the photo exhibition and also a scorpion sucker! Hmm ... I dunno, I don't think I am gonna eat THAT. But thanks for another great tweetup, American Museum of Natural History! Looking forward to the next one.

Buttons for the group tour (left). Scorpion suckers as parting gift (right). I dunno, but I doubt it'll taste like chicken.

You can follow American Museum of Natural History on Twitter at @AMNH for more info on the museum, upcoming events and also future tweetups. The photo exhibition, Picturing Science: Museum Scientists and Imaging Technologies, opened June 25, 2011 and ends June 24, 2012. It is free with museum admission and opens daily.

Maternal Infanticide and Cannibalism in Moustached Tamarin

Infanticide and cannibalism are two extreme behaviors seen in primates. Though extreme, the persistence of these behaviors in primates suggest that they are adapted for and had evolved to serve different purposes. Infanticide and cannibalism can be considered as both reproductive and survival strategies. Infanticide has always been associated with males killing off the progeny of former dominant males to make females more sexually receptive and to shorten the birth interval. Cannibalism, on the other hand, is not as sinister as it has always portrayed to be but just a coping mechanism. Ingestion of body parts, usually own offspring, is a response to cope with food scarcity. Lack of food resources would inevitably result in the death of the offspring thus cannibalization returns the caloric investment back into the mother. A new paper by Culot et al. (2011) has documented a case of infanticide and cannibalism in a wild female moustached tamarin (Saguinus mystax).

Moustached Tamarin (S. mystax) from The Bronx Zoo, New York City. Photo from Wikipedia.

S. mystax belong to the Callitrichid family, and like all Callitrichids has an interesting reproductive strategy unlike those of other primate families. Callitrichids form multimale-multifemale group and has a polyandrous (one female, multiple male) mating system. Callitrichids are the only primate family that consistently give birth to twins. The gestation period for S. mystax is 6 months. Usually, only one dominant female is reproductively active and shares offspring rearing responsibilities with multiple males in the group. However, an unstable dominance hierarchy among females might lead to multiple births within the group and will compromise the survivability of both the group and the offspring from stress, less parental investment and lack of food resources.

The researchers were studying how help from male moustached tamarins in the same group and the absence of female competition ensure the survival of offspring when they observed a female cannibalizing an infant. Necropsy and genetic analyses were used to rule out diseases and to determine paternity. They found that the infant has no diseases and did not die from trauma (falling from tree). Instead, it was a healthy infant and was being cannibalized by its own mother.

The mother was seen biting and then eating the head of its own infant during a period when another female was pregnant and gave birth just 1 month later. Before that, the perpetrator had given birth to twins three times successfully when four to five adult and subadult males were present in the group. Although we do not know for certain that the infant was alive when the mother started biting it, our field observations preceding the event suggest it probably was. The possible infanticide case and the two cases of births and early death of the infants occurred while only two to three adult males were present in the group. This could be the second case of maternal infanticide reported in the genus Saguinus and the similar circumstances suggest a common pattern. Culot et al. (2011).

Five common hypotheses proposed by Hrdy (1979) were used by the authors to try to explain maternal infanticide and cannibalism in this scenario. These hypotheses are resource competition, sexual selection, social pathology, exploitation, and parental manipulation.


The resource competition and sexual selection hypotheses were rejected because it was maternal infanticide, and not infanticide from another female. The social pathology hypothesis was rejected because it predicts infanticide restricted in areas that are disturbed by humans. The study group was habituated and had many successful births, therefore social pathology was ruled out. The exploitation hypothesis was also reject because the mother did not kill her infant to exploit its meat. Observation shows that the mother only consumed the brain and parts of the infant's neck. 


The parental manipulation hypothesis was accepted because the authors think that it best explains the scenario. The offspring was not pathological nor did it fell from the tree. Instead, it was a healthy infant that was killed by its own mother. According to Hrdy (1979), victim of parental manipulation does not necessarily have to be defective but also born "at the wrong place in the wrong time".

The authors concluded that parental manipulation is the best explanation for this possible maternal infanticide scenario. Parental manipulation strategy can happen in a group with poor capacity to raise the offspring from multiple breeding females, birth intervals that are shorter than 3 months, and low infant survival probability due to physical injuries or weakness.

References:

Culot, L. Lledo-Ferrer, Y. Hoelscher, O. Lazo, FJJM. Huynen, C. Heymann EW. 2011. Reproductive failure, possible maternal infanticide, and cannibalism in wild moustached tamarins, Saguinus mystax. Primates 52(2): 179-186.

Hrdy, SB. 1979. Infanticide among animals: A review, classification, and examination of the implications for the reproductive strategies of females. Ethology and Sociobiology 1(1): 13-40.

New adapiform species discovered in West Texas

Do you know that fossil primates once roam North America? I didn't know either so this discovery was a shock and a "d'oh" moment at the same time.

Lingual view (side that touches the tongue) of Mescalerolemur horneri partial mandible.

Scale bar equals 2 mm. Photo from Kirk & Williams (2011).

Anywho ... A fossil primate from the Eocene Epoch was discovered in Devil's Graveyard badlands of West Texas by Anthropologists Christopher Kirk and Blythe Williams. Named Mescalerolemur horneri, this new fossil primate lived about 43 million years ago is a member of the extinct group, adapiforms, that are found all over the Northern Hemisphere. Mescalerolemur looked like a modern-day greater dwarf lemur and weighs about 370 grams.

Interestingly enough, Mescalerolemur are more closely related to Eurasian and African adapiforms than those from North America. Darwinius masillae, famously known as Aunt Ida, was a Eurasian adapiform. Another interesting fact to point out is that Mescalerolemur had unfused mandibular symphysis, similar to those of Strepsirrhines (lemurs, lorises and galagos). The authors posit that this is definitive evidence that adapiforms are more similar to Strepsirrhines than Haplorrhines (humans are Haplorrhines). Kirk &Williams (2011) published their findings on Journal of Evolution: New adapiform primate of Old World affinities from the Devil’s Graveyard Formation of Texas.(PDF)

You can also read more about the discovery at EurekAlert: Anthropologist discovers new fossil primate species in West Texas.