Meet the family

You, me and even Herald Sun readers all have at least one thing in common: we’re evolutionary winners.  We’re all part of the dominant species on the planet Homo Sapiens-sapiens.

Given this privileged, hard fought position we find ourselves in it begs the question: what is it that makes us special and separates us from other primate species?

Physiologically the we are very different from out primate family with the largest relative brain volume. This big melon comes at a high cost,  despite only making up 2% of body weight  approximately 20% of the energy  from the food we eat is spent keeping our neurons firing. We are also physically weak compared to our primate family.

It might not be genetic given that we share  about 99% of our DNA sequence with Chimps and Bonobos (which according to creationists is evidence of the a creator, how else could we be so different they claim).  But scientists are still probing the three genomes to see what effect that 1% difference plays.

Other scientists and economists have tackled this conundrum by studying how the behavior of chimps and other primates is similar to our own.

Termite terminators

One of the first people to study primate behavior was the amazing Jane Goodall. Goodall in 1960 observed chimpanzes using sticks to extract termites from the safety of their mounds. This simple act altered our perception of primates and of ourselves. Before this chance encounter it had been claimed that human exclusively used tools and this was one of the main reasons for our success. There have now been many other examples such in dolphins and octopus.

Chimpanzes also use rudimentary spears for hunting other monkeys. This is astonishing that chips have effectively formed a hunter gatherer society, ordered similarly to that of early human civilization. Thankfully  video footage of chimps use machetes  is only a well made promotional video  for Planet of the Apes

 

Image source @Doug88888 via Flickr [CC BY-NC-SA 2.0]
Just hanging around. Image source @Doug88888 via Flickr [CC BY-NC-SA 2.0]
Money, money money, it’s not funny; in a monkey’s world

Back in 2006 a behavioural economist and a psychologist teamed up to see if some monkeys make decisions in a similar way to people.  Are some of the influences of why we make the decisions uniquely human, such as past outcomes motivating future choices, or are they present in other species? The duo tested this by giving capuchins monkeys money. They trained the monkeys that money in the form of silver disks with a hole in the middle could be exchanged for various food items. Where it gets exciting is that the capuchins responded to changes in the priced of food by changing what they redeemed their silver disks for. The monkeys acted rationally!  This is more than can be said for some other more evolved simians . The monkeys also traded tokens amongst themselves for other services, namely…sex. Have a look at Chen and Lakshminarayanan’s freely available article here and look out for Leo’s next movie: the Capuchin on wall street.

You scratch my back , I’ll scratch yours, for a price

Another member of our extended family, Baboons live in groups as large as country towns and have a complex social hierarchy revolving around food, fights and favours. Troops of Baboons can be as large as 750, which are made up of several bands, in turn consisting of several males each with their own harem of females.  Within these groups baboons have a social hierarchy for males based on size and age. While for females their social rank is usually hereditary.

Female baboons groom each other as a way of maintaining and strengthening social bonds in addition to the practical reason of removing skin parasites. Who female baboons choose to be their ‘friends’  (by grooming) is strongly affected by social rank. Lower ranking females use grooming to gain favour from higher ranking female who have better access to food. Females will also adjust their strategy in response to the observed grooming strategy of other females.

So my fellow primates, it seems that we share many behaviours with our extended primate family. Take comfort though in the fact that if ever you are feeling down to be here reading this you’ve come from a long line of winners.

 

 

A Hamadryas Baboon surveying his troop. Image source Randolph via flickr [CC BY-NC-SA 2.0]
A Hamadryas Baboon surveying his troop. Image source Randolph via flickr [CC BY-NC-SA 2.0]