{"id":376471,"date":"2026-04-05T15:31:10","date_gmt":"2026-04-05T15:31:10","guid":{"rendered":"https:\/\/www.newsbeep.com\/il\/376471\/"},"modified":"2026-04-05T15:31:10","modified_gmt":"2026-04-05T15:31:10","slug":"athol-mclachlan-obituary-zoology","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/il\/376471\/","title":{"rendered":"Athol McLachlan obituary | Zoology"},"content":{"rendered":"

All his working life, the zoologist Athol McLachlan, who has died aged 86, was fascinated by chironomid midges, tiny, non-biting flies that spend most of their lives as aquatic larvae before emerging briefly as adults. His work on these unassuming little insects, in habitats ranging from rock pools on the Zomba plateau in Malawi<\/a> to mating swarms beside British hedgerows, produced elegant insights into how natural selection adapts organisms to the most fleeting of environments.<\/p>\n

His interest in chironomid midges was sparked in the 1960s during his doctoral research on the insects of Lake Kariba in Zimbabwe, then Rhodesia. It was here that Athol first recognised that the tiny flies provided wonderful model systems to test classic ideas in ecology and evolution.<\/p>\n

Chironomids form vast swarms, billions strong, that rise like smoke over Africa\u2019s great lakes, but Athol was drawn instead to the smallest and most easily overlooked habitats: shallow rain pools that form in depressions in exposed rock. The pools fill after rain and persist for weeks or months before drying out, yet may recur in the same locations for thousands, perhaps even millions, of years. Athol realised they offered a natural experiment in adaptation to predictable but transient environments.<\/p>\n

Male chironomid midge on heathland, Sandy, Bedfordshire. Photograph: Nature Picture Library\/Alamy<\/p>\n

Over successive seasons of fieldwork on the Zomba plateau, he found that each of the neighbouring rain pools contained the larvae of only one of several midge species. Athol treated each pool as a tiny experimental arena and, by transplanting species between pools, showed that species presence is not due to chance but to a small set of factors that allow one species to exclude all others. Some were adapted to shallow, short-lived pools and could survive complete desiccation, others required deeper, more stable habitats. This rare experimental evidence of competing species struggling to coexist provided particularly clear confirmation of classic niche and competition theory.<\/p>\n

In the 80s, now based in the UK, Athol made a further breakthrough, while studying chironomid species closer to his Newcastle home. Midge swarms are a familiar sight on summer evenings in Britain, appearing beside trees and hedgerows. Females visit the swarms to mate, coupling in mid-air before falling to the ground. In a series of studies, Athol demonstrated that, while in most animals sexual selection favours large males in competition for females, within these mating swarms the smallest males achieved disproportionate success.<\/p>\n

This was because, his work showed, that for animals that mate on the wing, small size can confer an aerial advantage, allowing these males to respond more rapidly to intercept incoming females. More generally, Athol\u2019s work showed that where males compete in three-dimensional arenas such as air or water, agility can be favoured over size or strength, a finding that has now become incorporated into sexual selection theory.<\/p>\n

double quotation markFor insects that mate on the wing, agility can be favoured over size or strength <\/p>\n

This led Athol to ask why males did not simply evolve to be smaller. Working with his student Rachel Neems, he showed that, while small size conferred a mating advantage, it also carried costs. For most of their life, these flies live as tiny larvae (bloodworms) at the bottom of ponds and lakes, where small size was a disadvantage. Smaller worms got pushed out of safe refuges by big ones, exposing them to predation. Across the full lifespan, males of intermediate size proved most successful at passing on their genes, a particularly neat example of balancing selection.<\/p>\n

Born in Johannesburg to Elinor (nee Quine) and John McLachlan, a chemical engineer, Athol developed an early fascination with the plants and animals of southern Africa. During holidays from Longwood House boarding school in Meyerton, south of Johannesburg, he hunted insects, snakes and lizards, developing the sharp observational skills that would define his scientific life. As a teenager he and his younger brother, Ian, earned money by catching venomous snakes, extracting their venom, and selling it to a local medical school for antivenom production.<\/p>\n

After finishing his schooling at Damelin College in Johannesburg, Athol studied zoology and botany at the University of the Witwatersrand, graduating in 1962 before beginning doctoral research at Lake Kariba. He received his PhD from the University of London in 1968. Postdoctoral research at the University of Malawi was followed by an appointment in 1970 as lecturer in zoology at the University of Newcastle-upon-Tyne, which remained his academic home for the rest of his career. It was there, as an undergraduate student, that I first encountered Athol, and went on to work with him on the symmetry of midge wings in mating swarms.<\/p>\n

\"McLachlanMcLachlan on a field course in Great Cumbrae in the late 1990s<\/p>\n

In the 1980s Athol established a formal academic link between Newcastle and Malawi, funded by the British Council. He was awarded a DSc degree from the University of London in 1992, in recognition for his achievements in insect ecology and animal behaviour.<\/p>\n

At Newcastle Athol was an admired, slightly enigmatic lecturer who emphasised curiosity-driven research and the puzzles hidden in everyday nature. He had a dry, laconic wit that sometimes took a moment to register. He was most at home on field courses, where his skills as a naturalist were on full display. For many years he taught on Great Cumbrae in Scotland, turning over rocks in streams and fields, probing anthills, pointing out battles between dung flies on cow pats and other small dramas of the natural world.<\/p>\n

In the later stages of his career his early experience as a hunter in southern Africa found an unexpected outlet on the Isle of Mull, where he travelled each summer to assist the Glengorm Estate with deer management. There he met the ceramic artist Charlotte Mellis, whom he married in 1993. After retiring from Newcastle in 2004 they moved to Mull, where they restored a former schoolhouse and where he continued to publish research and maintain a science blog.<\/p>\n

He is survived by Charlotte.<\/p>\n

Athol John McLachlan, zoologist, born 22 September 1939; died 16 February 2026<\/p>\n","protected":false},"excerpt":{"rendered":"All his working life, the zoologist Athol McLachlan, who has died aged 86, was fascinated by chironomid midges,…\n","protected":false},"author":2,"featured_media":376472,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[85,46,141],"class_list":{"0":"post-376471","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-science","8":"tag-il","9":"tag-israel","10":"tag-science"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts\/376471","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/comments?post=376471"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts\/376471\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/media\/376472"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/media?parent=376471"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/categories?post=376471"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/tags?post=376471"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}