A fossil tooth could be a buffet of information for researchers at a dig. Teeth grow like trees in a sense. They add layer after layer of enamel and dentine tissues every day. And so they can help us reconstruct the biological events that individuals or even communities have undergone during their early years of life.

Among other things, teeth preserve “precise temporal changes and chemical records of key elements” involved in what and how we eat. Recently, Dr Renaud Joannes-Boyau and team used specialized laser sampling techniques to vaporize microscopic portions on the surface of teeth from Australopithecus africanus fossils. Their finding is the first direct evidence of maternal roles of one of our earliest ancestors.

Those
ancestral mothers, who lived from about two-to-three million years ago, breastfed their infants continuously — from birth to about one year of age. Nursing appears to follow in a cyclical pattern in the early years for infants. Mothers had to supplement solid food intake with breast milk when resources were scarce. This makes us rethink on the social organizations of our ancestors.

SNEAK PEEK

1. Stress in the hair

Arsenic in hair, death by poisoning. Crime fiction readers are familiar with this reasoning. A recent study established a connection between the levels of the stress hormone cortisol in the hair of adolescents and their susceptibility to depression. Who conducted the study?

1. Jodi Ford (Ohio State University)

2. Bugs are better

A new insect-sized robot can dart across the floor at nearly the speed of a cockroach. You can’t squash it under your foot easily. If an earthquake happens and machines and dogs fail in rescue missions, what we need exactly is this kind of robot. Who created this alternative?

2. UC Berkeley mechanical engineering student Yichuan Wu

3. Ignored symptom

Apathy (lack of interest or concern) is an under-researched and often ignored symptom of dementia because it isn’t disruptive. But it is extremely distressing for families and it is linked with more severe dementia and worse clinical symptoms. Who evinced this in a new study?

3. Dr Miguel de Silva Vasconcelos (University of Exeter)

4. Why people cheat?

Is cheating a product of the environment or a character trait? A closer look at it during periods of relative economic abundance and scarcity gives up hope. Who found evidence that cheating is more likely caused by an individual’s propensity to cheat than external factors?

4. Dr Marco Palma (Human Behavior Lab, Texas A&M)

5. Frog in the throat

Fear of public speaking can lead people to feel like there is “a frog in my throat”. Actually, stress-induced brain activations can cause a disorder from excessive or altered muscle tension in and around the voice box, changing the “feel” of one’s voice. Who found this?

5. Maria Dietrich (MU School of Health Professions)

6. Ket is great, but…

The ketogenic (keto) diet is one way to control weight gain or type 2 diabetes. Fine, but a sudden spike in glucose can damage a keto dieter’s’ blood vessel walls. Who warned that “a ketogenic diet is not something you do for six days a week and take Saturday off”?

6. Jonathan Little (University of British Columbia)

7. Pyrogenic carbon

Deforestation fires critically contribute to climate change, because they bring to pass a long-term loss of carbon to the atmosphere. Who, in an exploration, found that charcoal produced by wildfires could trap carbon for hundreds of years and help mitigate climate change?

7. Matthew Jones (University of East Anglia)

8. Brain’s junk food

“To the brain, information is its own reward, above and beyond whether it’s useful.” It can overvalue information that, like junk food, makes us feel good. This also explains why some people keep checking the phone when no message is expected. Who found it in an fMRI test?

8. UC Berkeley neuroeconomist Ming Hsu

9. Origin of moods

Seasons of birth have been connected with personality traits. Folklore and astrology have sought to explain it. A group of Hungarian researchers says that the season you are born has a biochemical influence on your risk of developing mood disorders. Who led the research?

9. Xenia Gonda (Semmelweis University)

QUIZ No. 915

1. Elephants save slow-growing trees having a strong ‘carbon backbone’. Who said it?

– Stephen Blake
– Sigurd Ferdinand Olson
– Stewart Lee Udall

1. Stephen Blake

2. Talking of microbes, who suggested that “too clean is not necessarily a good thing”?

– Selman A. Waksman
– Howard Walter Florey
– Zhongtang Yu

2. Zhongtang Yu

3. Who argued that men with large upper-bodies in politics share Stone Age intuitions?

– Cynthia Enloe
– Michael Bang Petersen
– Susan L. Woodward

3. Michael Bang Petersen

4. Which psychologist developed a preferential voting system that is named after him?

– Baruch Fischhoff
– Clyde Hamilton Coombs
– Robyn Mason Dawes

4. Clyde Hamilton Coombs

5. Which artist applied gold leaf to paintings during the height of his “Golden Period”?

– Gustav Klimt
– Elfriede Lohse-Wächtler
– Susan Rothenberg

5. Gustav Klimt