Louis Leakey in the context of "Mary Leakey"

The Oldowan (or Mode I) was a widespread stone tool archaeological industry during the early Lower Paleolithic spanning the late Pliocene and the first half of the Early Pleistocene. These early tools were simple, usually made by chipping one, or a few, flakes off a stone using another stone. Oldowan tools were used during a period spanning from 2.9 million years ago up until at least 1.7 million years ago (Ma), by ancient hominins (early humans) across much of Africa. This technological industry was followed by the more sophisticated Acheulean industry (two sites associated with Homo erectus at Gona in the Afar Region of Ethiopia dating from 1.5 and 1.26 million years ago have both Oldowan and Acheulean tools).

The term Oldowan is taken from the site of Olduvai Gorge in Tanzania, where the first Oldowan stone tools were discovered by the archaeologist Louis Leakey in the 1930s. However, some contemporary archaeologists and palaeoanthropologists prefer to use the term Mode 1 tools to designate pebble tool industries (including Oldowan), with Mode 2 designating bifacially worked tools (including Acheulean handaxes), Mode 3 designating prepared-core tools, and so forth.

The Olduvai Gorge or Oldupai Gorge in Tanzania is one of the most important paleoanthropological localities in the world; the many sites exposed by the gorge have proven invaluable in furthering understanding of early human evolution. A steep-sided ravine in the Great Rift Valley that stretches across East Africa, it is about 48 km (30 mi) long, and is located in the eastern Serengeti Plains within the Ngorongoro Conservation Area in the Olbalbal ward located in Ngorongoro District of Arusha Region, about 45 kilometres (28 miles) from Laetoli, another important archaeological locality of early human occupation. The British/Kenyan paleoanthropologist-archeologist team of Mary and Louis Leakey established excavation and research programs at Olduvai Gorge that achieved great advances in human knowledge. The site is registered as one of the National Historic Sites of Tanzania.

The gorge takes its name from the Maasai word oldupai which means "the place of the wild sisal" as the East African wild sisal (Sansevieria ehrenbergii) grows abundantly throughout the gorge area. Twenty-five kilometers downstream of Lake Ndutu and Lake Masek, the gorge is the result of up to 90 m (300 ft) erosion cutting into the sediments of a Pleistocene lake bed. A side gorge, originating from Lemagrut Mountain, joins the main gorge 8 km (5.0 mi) from the mouth. This side gorge follows the shoreline of a prehistoric lake, rich in fossils and early hominin sites. Periodic flows of volcanic ash from Olmoti and Kerimasi helped to ensure preservation of the fossils in the gorge.

Dame Valerie Jane Morris Goodall (/ˈɡʊdˌɔːl/; née Morris-Goodall; 3 April 1934 – 1 October 2025) was an English primatologist and anthropologist. Regarded as a pioneer in primate ethology, and described by many publications as "the world's preeminent chimpanzee expert", she was best known for more than six decades of field research on the social and family life of wild chimpanzees in the Kasakela chimpanzee community at Gombe Stream National Park in Tanzania. Beginning in 1960, under the mentorship of the palaeontologist Louis Leakey, Goodall's research demonstrated that chimpanzees share many key traits with humans, such as using tools, having complex emotions, forming lasting social bonds, engaging in organised warfare, and passing on knowledge across generations, which redefined the traditional view that humans are uniquely different from other animals.

In 1965 Goodall was awarded a PhD in ethology from the University of Cambridge. In the 1960s Goodall published several accounts of her research in Tanzania, including a series of articles in National Geographic. Her first book-length study, In the Shadow of Man (1971), was later translated into 48 languages. She founded the Jane Goodall Institute in 1977 to promote wildlife conservation, followed by the Roots & Shoots youth programme in 1991, which grew into a global network. Goodall also established wildlife sanctuaries and reforestation projects in Africa and campaigned for the ethical treatment of animals in animal testing, animal husbandry and captivity. Goodall was appointed a United Nations Messenger of Peace in 2002, and advised organisations such as Save the Chimps and the Society for the Protection of Underground Networks.

Paranthropus boisei is a species of australopithecine from the Early Pleistocene of East Africa about 2.5 to 1.15 million years ago. The holotype specimen, OH 5, was discovered by palaeoanthropologist Mary Leakey in 1959 at Olduvai Gorge, Tanzania and described by her husband Louis a month later. It was originally placed into its own genus as "Zinjanthropus boisei", but is now relegated to Paranthropus along with other robust australopithecines. However, it is also argued that Paranthropus is an invalid grouping and synonymous with Australopithecus, so the species is also often classified as Australopithecus boisei.

Robust australopithecines are characterised by heavily built skulls capable of producing high stresses and bite forces, and some of the largest molars with the thickest enamel of any known ape. P. boisei is the most robust of this group. Brain size was about 450–550 cc (27–34 cu in), similar to other australopithecines. Some skulls are markedly smaller than others, which is taken as evidence of sexual dimorphism where females are much smaller than males, though body size is difficult to estimate given only one specimen, OH 80, definitely provides any bodily elements. The presumed male OH 80 may have been 156 cm (5 ft 1 in) tall and 61.7 kg (136 lb) in weight, and the presumed female KNM-ER 1500 124 cm (4 ft 1 in) tall (though its species designation is unclear). The arm and hand bones of OH 80 and KNM-ER 47000 suggest P. boisei was arboreal to a degree.