The study also confirmed that chimpanzee social groups in the savannah are distributed over unusually large areas of around 100 km², while chimpanzees living in more forested areas have ranges between 3 and 30 km², approximately. 'Early hominins also had to deal with low water availability during part of the year,' Hernández adds. Another example the researcher highlights is the ways in which these chimpanzees try to hydrate themselves during the advanced dry season, such as digging for water when this resource is reduced to just a few spots in the landscape.

Some strategies are probably the same for chimpanzees and hominins, such as the use of caves or going into water pools to cool down,' notes the researcher. 'Understanding how they deal with heat can help us better understand what strategies human ancestors may have used to cope with high temperatures.

'Therefore -she continues-, understanding how our genetically closest living relatives adapt to a dry, hot, seasonal and open environment, very similar to those where early hominins lived, helps us to model how our ancestors might have adapted and how the features that define us as humans might have emerged.'Īmong the different characteristics of savannah chimpanzees described in the study, their strategies to deal with high temperatures stand out. 'We know that early hominins adapted to savannah environments similar to those occupied by chimpanzees today, and researchers think that savannah conditions caused adaptations in our ancestors, such as brain expansion or tolerance to high temperatures,' says Adriana Hernández, who is also the co-director of research at the Jane Goodall Institute Spain. For this reason, comparisons of behaviour, morphology and ecology with chimpanzees that live in more forested landscapes provide key information for hypothesising how early humans may have adapted millions of years ago while African forests were receding and gave place to savannahs. The chimpanzees that live in the savannah are taxonomically indistinguishable from other chimpanzees. Despite this proximity, they lack some of the biological and cultural traits that humans possess to adapt to extreme heat, such as numerous eccrine sweat glands, relative lack of hair, or the ability to create artefacts such as water containers and sun hats to mitigate dehydration and sunstroke. The genetically closest-to-humans evolutionary living relativeĬhimpanzees ( Pan troglodytes) are our closest living relatives, since they share 98.7% of their DNA with humans and have a common ancestor that lived between 4.5 and 6 million years ago. 'The study on savannah chimpanzees and what we call the landscape savannah effect have important implications for reconstructing the behaviour of the first hominis who lived in similar habitats and therefore, it helps us to better understand our own evolution,' notes Adriana Hernández, who co-led the study, published in the journal Evolutionary Anthropology, together with Stacy Lindshield, from the University of Purdue (United States).

Adriana Hernández, Serra Hunter professor at the Faculty of Psychology of the University of Barcelona, co-led the study conducted by an international team of primatologists who reviewed the existing research on the behaviour and ecology of savannah chimpanzees to understand how these apes adapt to extreme conditions.Īccording to the researchers, the environmental conditions of these places would lead to a specific type of behaviours and physiological responses in these chimpanzees -such as resting in caves or digging in order to get water- which are not observed in their counterparts that live in more forested areas, where they do not deal with these extreme environmental conditions.

These habituated chimpanzee meme