001 Evolution

As Homo sapi­ens we rep­re­sent the only hominin species able to sur­vive until now. All oth­er hominin species, includ­ing Homo erec­tus, the upright walk­ing man, Homo habilis, the tool-using man and Homo nean­derthalen­sis, the first artists of cave-paint­ing fame, though pos­sess­ing some com­bi­na­tion of fea­tures that char­ac­terise humans today, are all extinct.

Human evo­lu­tion coin­cid­ed with long peri­ods of severe envi­ron­men­tal changes, includ­ing mas­sive shifts in tem­per­a­ture. When trac­ing our ori­gins in a place like Maropeng, the offi­cial vis­i­tor cen­tre for the Cra­dle of Humankind Her­itage site, espe­cial­ly on a win­ter morn­ing with ice in the air, one has to won­der how humans with their rather piti­ful pelts did in fact man­age to sur­vive through so many cen­turies of cold.

It is now wide­ly accept­ed that the species Homo sapi­ens orig­i­nat­ed in Africa, a warm place com­pared to oth­er parts of the world where oth­er hominins lived and evolved. Some of these species may even have aid­ed the sur­vival of the human species by help­ing our ances­tors to deal with the cold.

Homo Neaderthalensis

Homo nead­erthalen­sis was a species of hominin able to deal with the cold weath­er of Europe and fur­ther north­ern regions

Homo nead­erthalen­sis was a species of hominin able to deal with the cold weath­er of Europe and fur­ther north­ern regions because of their unique anato­my,” says palaeo­bi­ol­o­gist Dr Chris­tine Steininger, Cooper’s Cave tour leader.

Nean­derthal pop­u­la­tions in Europe endured many envi­ron­men­tal changes, includ­ing large shifts in cli­mate between glacial and inter­glacial con­di­tions, she says.

They man­aged to live in habi­tats that were far cold­er than areas where most oth­er hominin species lived, and they were able to adjust their behav­iour to fit the circumstances.”

Dur­ing the cold glacial peri­ods, they would have focused on hunt­ing rein­deer – ani­mals that are also adapt­ed to the cold – and dur­ing the warmer inter­glacial peri­ods they would have turned to hunt­ing red deer. When the extreme cold peri­ods arrived, they prob­a­bly shift­ed their range south­wards toward warmer environments.

Around 46 000 years ago, Homo sapi­ens (humans) moved from Africa to Europe. They must have been quite unpre­pared for the cold and yet they sur­vived and set­tled across the globe, where­as the nean­derthals, who were adapt­ed to the cold, died out and became extinct.

This is where it starts to get inter­est­ing. Direct stud­ies of ancient DNA from nean­derthal bones sug­gest that humans and Nean­derthals inter­bred. Besides offer­ing some warm bod­ied shel­ter in the storm, this may also have con­tributed to a more robust genet­ic make­up for future human gen­er­a­tions. But still the ques­tion remains: why would one species who was, so to speak, built for the cold become extinct when anoth­er species, not real­ly built for the cold, survive?

Humans Vs Neanderthals 660X433 1

Direct stud­ies of ancient DNA from Nean­derthal bones sug­gest that humans and Nean­derthals interbred

Evi­dence sug­gests that adapt­abil­i­ty to vary­ing envi­ron­ments was one of the key dif­fer­ences between these two evo­lu­tion­ary paths,” says Steininger. Many species and organ­isms have habi­tat pref­er­ences, such as par­tic­u­lar types of veg­e­ta­tion (grass­land ver­sus forests). When there’s a change in the pre­ferred habi­tat they can either move and try to find it else­where, or they can adapt to the new habi­tat. Oth­er­wise, they become extinct.

Anoth­er pos­si­bil­i­ty is for the adapt­abil­i­ty of a pop­u­la­tion – in oth­er words, the poten­tial to adjust to new and chang­ing envi­ron­ments increas­es. A char­ac­ter­is­tic of humans is their abil­i­ty to adjust to a vari­ety of dif­fer­ent habi­tats and envi­ron­ments,” says Steininger.

Nean­derthals and mod­ern humans had dif­fer­ent ways of deal­ing with envi­ron­men­tal fluc­tu­a­tions and the sur­vival chal­lenges this posed. Homo sapi­ens had spe­cialised tools to extract a vari­ety of dietary resources. They also had broad social net­works – we see this from evi­dence point­ing to the exchange of goods over long dis­tances. They used sym­bols as a means of com­mu­ni­cat­ing and for stor­ing information.

This meant that despite many cli­mat­ic fluc­tu­a­tions, mod­ern humans were able to expand their range over Europe and Asia, and into new areas such as Aus­tralia and the Amer­i­c­as. The Nean­derthals, like many oth­er species, were not as adapt­able, and there­fore became extinct.”

As species, humans have suc­cess­ful­ly man­aged to weath­er many a storm and bliz­zard through the ages. The ques­tion we need to ask now is, how well will our resilience, as the lone species of hominins, con­tin­ue to suc­ceed in the future?