By Adrian Woolfson
Perhaps the most remarkable feature of all species, living and extinct, is their extraordinary interconnectivity. Each species on Earth can trace its roots back to the same cluster of ancestral organisms and occupies a distinct position on a single, complex, prolifically branching, unfathomably extensive and largely invisible tree of life.
In his enjoyable and ambitious "The Tree of Life," Max Telford, an evolutionary biologist at University College London, takes us on an exhilarating cartographic journey in which he attempts to map out the various rivers and tributaries that make up the basic infrastructure of life's evolutionary history. Go back far enough and these pathways invariably converge, leading to life's ultimate source and origin -- the last universal common ancestor, or LUCA.
As the majority of this evolutionary terrain no longer exists, this charting of life's history, we learn, relies on our ability to create the rudiments of an engine that can facilitate travel back in evolutionary time. Remarkably, it turns out, the trunk, branches, twigs and leaves of the tree itself -- the species populating it -- furnish the mechanical components of such a device.
The branching evolutionary relationships between species were anticipated by Charles Darwin in his 1837 Notebook B sketch, in which he fashioned a minimalistic tree-like diagram that depicted the descent and diversification of species from common ancestors. He later referred to these branches in "On the Origin of Species" (1859), as forming "a great tree" of related beings. But it was Ernst Haeckel, the German biologist, in "Generelle Morphologie der Organismen" ("General Morphology of Organisms," 1866), who first represented the branching evolutionary relationships in the form of a tree rooted in common descent. Haeckel was himself inspired, Mr. Telford writes, by August Schleicher, a University of Jena colleague who believed that it was possible to "travel back in time, down the branches of his language tree" to construct the precursor of Indo-European languages.
The possibility of a genealogical tree of life is predicated on the existence of an underlying process of heredity. This enables the essential information defining an organism's core features -- represented in the nucleotide sequences of DNA -- to be passed down to its offspring. While in the past it was the often-misleading morphological features of organisms -- dentition, skeletal anatomy or the number of petals in the flowers of plants -- that were used to infer their presumed evolutionary relationships, the modern ability to read select parts of a species' genome sequence has allowed for the construction of a robust time machine that can calibrate both the temporal and genealogical relationships between species and enable an imperfect but meaningful form of navigation back to life's earliest incarnations.
Unlike the deliberate, premeditated approach of human engineers, the natural process for generating life has no preconceived plan. It is obliged, instead, to adopt what François Jacob, a French biologist, referred to in 1977 as a strategy of "tinkering." In contrast to a designer, a tinkerer must, Jacob argued, manage with odds and ends. In so doing, an old bicycle wheel may be fashioned into a roulette, or a broken chair transformed into the cabinet of a radio. Evolution has similarly purloined existing features and modified them, using great thrift, for example, to transmogrify a piece of jaw into an ear or to transform a leg into a wing.
If comprehensively deciphered, the relationships between the species populating the genealogical tree of life, Mr. Telford argues, offer the possibility of understanding the evolutionary history of every component of natural biology. As such, this enterprise could reveal the underlying rules-based nature of organismal construction and diversification. Mr. Telford and his colleagues have devised systematic and often painstaking methods of tree-building that rationalize confounding factors, such as convergence, wherein similar traits may evolve independently of one another, and the paradoxical loss of complexity seen in some species. Relying on the principle of parsimony -- which emphasizes simplicity and efficiency when configuring evolutionary pathways -- and a focus on specific morphological and biochemical characteristics, Mr. Telford rationalizes this complexity and teases out life's overarching themes and major evolutionary transitions.
With the emerging developments in AI and molecular genomics, humankind may soon progress from "received" life, generated by natural engineering, to designing and constructing synthetic life that is disconnected from history and heredity. In so doing, we may one day generate forests of trees whose ancestry does not intermingle with that of the species generated by the historic evolutionary process.
--Mr. Woolfson's "On the Future of Species" will be published in April.
(END) Dow Jones Newswires
December 26, 2025 09:23 ET (14:23 GMT)
Copyright (c) 2025 Dow Jones & Company, Inc.
Comments