He worked as an ethnologist, anthropologist and biologist who became famous as one of the earliest scientists to settle among and study indigenous people of New Guinea "who had never seen a European".

[2] Miklouho-Maclay spent the major part of his life travelling and conducted scientific research in the Middle East, Australia, New Guinea, Melanesia and Polynesia.

[5] While in Australia, he built the first biological research station in the Southern Hemisphere, was elected to the Linnean Society of New South Wales, was instrumental in establishing the Australasian Biological Association, stayed at the elite Australian Club, became the intimate of the leading amateur scientist and political figure Sir William Macleay, and married Margaret-Emma Robertson, the daughter of the Premier of New South Wales.

[4] One of the earliest followers of Charles Darwin, Miklouho-Maclay is also remembered today as a scholar who, on the basis of his comparative anatomical research, was one of the first anthropologists to refute the prevailing view that the different races of mankind belonged to different species.

[9] In fact, his Cossack lineage was extensive and also included the Otaman of Zaporizhian Host Okhrim Myklukha,[7] who later became the prototype of Nikolai Gogol's main character Taras Bulba.

After the annexation of the Ukraine, Stepan, one of the family, served as sotnik (a superior Cossack officer) under General Count Rumianzoff, and having distinguished himself at the storming of the Turkish fortress of Otshakoff, was by the order of Catherine II made a noble...Nicholai's father, Mykola Myklukha, graduated from the Nizhyn Lyceum (Nizhyn), after which he walked all the way to Saint Petersburg, where he enrolled in the Roadway Institute of Engineering Corps.

[7] Nicholai's mother, Ekaterina Semenovna, née Bekker, was of German and Polish descent (her three brothers took part in the January Uprising of 1863).

After 1873, the Miklouho-Maclay family purchased and lived in a country estate in Malyn, 100 kilometres (62 mi) northwest of Kiev in the Polesia region.

A third brother, Vladimir,[7] was a captain of the Russian coast defense ship Admiral Ushakov and participated in the Battle of Tsushima where he perished.

During his studies at the Second Saint Petersburg Gymnasium (1859–1863) along with his brother Sergei, he was arrested and kept for several days in the Peter and Paul Fortress for participating in student protests.

In 1863, without finishing the gymnasium, Nicholai enrolled as a free listener at the St. Petersburg University but only spent two months there before being expelled in February 1864 and debarred from tertiary education in Imperial Russia for "breaking the rules".

[5] Miklouho-Maclay's brilliant student records attracted the attention of Haeckel, who made him his assistant as part of a field expedition to the Canary Islands in 1866.

[3] He also became a close friend of the biologist Anton Dohrn, with whom he helped conceive the idea of research stations while staying with him at Messina, Italy.

[13] Miklouho-Maclay lived in northeastern New Guinea for a two-year period in between 1871 and 1880, from which he also visited the Philippines, Malay Peninsula and Australia on a number of occasions.

[15] Some scientists, such as Ernst Haeckel, a teacher of the young Miklouho-Maclay, relegated what they regarded as culturally "backward" people like Papuans, Bushmen and others to the role of 'intermediate links' between Europeans and their animal ancestors.

While adhering to Darwin's theory of evolution, Miklouho-Maclay diverged from these concepts, and it was this question that led him to gather scientific facts and to study the dark-skinned inhabitants of New Guinea.

On the basis of his comparative anatomical research, Miklouho-Maclay was one of the first anthropologists to refute polygenism, the view that the different races of mankind belonged to different species.

[17] In 1887 he left Australia, returned to St Petersburg to present his work to the Imperial Russian Geographical Society and took his young family with him.

[26] The Miklouho-Maclay Society succeeded in naming a park in his honour in Snails Bay (Birchgrove), not far from a house where he lived in Sydney for a time.