“ Lucy ” is one of the most well - live scientific discoveries in human story . The 1974Ethiopian fossilrevealed that our ascendent 3.2 million long time ago had already see to walk upright . Ever since , new Book of Revelation have come to Inner Light about her lifespan , include the fact that shedied falling out of a tree – hint that she was able to climb trees as well as take the air on the African aeroplane .
Now , a dramatic new survey in the journaleLifehas widened the history substantially . Her species – genus Australopithecus afarensis – include a lot of unknown , including the case of social structure they held , if any . This inquiry reveals that not only were males and female quite physically dissimilar , but that they were likely to be polygynous much in the manner many apes and scalawag are today .
Back in 1976 , British paleoanthropologist Mary Leakey came across a series of hominin footprints at Laetoli in Tanzania . keep involcanic ash tree , she square off they were 3.7 - million - class - previous marker of human ancestorswalking upright . Although it has long been unclear to which ascendent they belonged to , they were often assign toAu . afarensis .
research worker led by the University of Dar es Salaam have now dig up some steel new , immaculately preserved tracks within another ancient volcanic ashfall . The footprint were clearly made by both males and females based on the size difference . They were walking at the same speed and in the same direction .
In fact , the racetrack suggest that the male was 165 centimeter ( 5.41 feet ) grandiloquent , making him the marvelous at Laetoli . He was walking side - by - side with a female person , 145 centimeters ( 4.76 ft ) magniloquent , again making her the tallest discover at the land site . For comparison , Lucy was around 30 cm ( about 1 foot ) myopic .
Some of the freshly discovered footprint . Raffaello Pellizzon
Significantly , this shows that both male and females of Lucy ’s species were quite distinctly sexually dimorphic , meaning that there were pronounced forcible differences between the sexual urge .
“ This torso sizing remainder [ between the sex activity ] is comparable with that constitute in gorillas , ” study co - author Jacopo Moggi - Cecchi , a biologic anthropologist at the University of Florence , told IFLScience via a phone press group discussion . “ manlike silverback often weigh two or three times more than the females . ”
The authors of the study line that low level of dimorphism generally indicate a monogamous mating system , whereas the opposite word is true for polygyny , where one male person has multiple distaff partners . It ’s likely , then , that Lucy ’s lengthened folk were polygynous , based on modern equivalents .
Indeed , the tracks around the male person ’s shadow fossil footmark are tentatively thought to be all belonging to female . This particular chemical group included as many as three female person , along with two juvenile or smaller female .
“ Take gorilla , ” Cecchi added . “ You have a silverback male and a serial of unrelated female . ” Although nowhere nigh as sexually dimorphous , chimpanzeesalso have a likewise patriarchal social structure , but not quite as alpha male person - dominated as that set up in gorilla .
A standardized social social organisation is likely to be present inAu . afarensisbased on the uncommitted evidence . However , it ’s not totally clear that the male actually mates with all of them , or if there is one alpha male or several rule males .
Cecchi , however , did describe the specific situation at the site in Laetoli as being somewhat like a “ harem ” because it ’s the most likely scenario .
For plenty of primates today , polygyny is amating strategydesigned to go around manlike genes throughout the population as much as possible . It seems that Lucy ’s species was perhaps no different in that respect .
A male silverback Gorilla gorilla , the mod rendering of the solitary male at Laetoli ? bimserd / Shutterstock
