Andrew H. Knoll > Quotes

“Talk is cheap, exploration and discovery is hard”
― Andrew H. Knoll

“We will conserve what we love, love what we understand and understand what we are taught.”
― Andrew H Knoll

“Most new species arise not from the insensibly gradual transformation of large populations but rather by the rapid differentiation of small, isolated populations at the periphery of the main group.”
― Andrew H. Knoll, Life on a Young Planet: The First Three Billion Years of Evolution on Earth

“Earth writes its history with one hand and erases it with the other, and as we go further back in time, erasure gains the upper hand.”
― Andrew H. Knoll, A Brief History of Earth: Four Billion Years in Eight Chapters

“One clear theme of evolutionary history is the cumulative nature of biological diversity. Individual species (of nucleated organisms at least) may come and go in geological succession, their extinctions emphasizing the fragility of populations in a world of competition and environmental change. But the history of guilds—of fundamentally distinct morphological and physiological ways of making a biological living—is one of accrual. The long view of evolution is unmistakably one of accumulation through time, governed by rules of ecosystem function. The replacement series implied by the Generations of Abraham approach fails to capture this basic attribute of biological history.”
― Andrew H. Knoll, Life on a Young Planet: The First Three Billion Years of Evolution on Earth

“Neanderthals, often caricatured as brutes, but actually sophisticated hunter-gatherers, with diverse tools and brains larger than our own.”
― Andrew H. Knoll, A Brief History of Earth: Four Billion Years in Eight Chapters

“The face you see in the mirror may be decades old, but it is made of elements formed billions of years ago in ancient stars.”
― Andrew H. Knoll, A Brief History of Earth: Four Billion Years in Eight Chapters

“By way of contrast, on uninhabited Wrangell Island, an isolated scrap of land in the Chukchi Sea north of Siberia, mammoths survived until about 4,000 years ago.”
― Andrew H. Knoll, A Brief History of Earth: Four Billion Years in Eight Chapters

“Most people’s DNA includes a small admixture of Neanderthal genes; Melanesians, aboriginal Australians, and some other Asian populations also have genes derived from Denisovians.”
― Andrew H. Knoll, A Brief History of Earth: Four Billion Years in Eight Chapters

“call this interval “interglacial” rather than “post-glacial” because for the past million years, Earth has oscillated between glacial cold and interglacial warmth on a 100,000-year timescale dictated by metronomic variations in Earth’s orbit around the sun. There is no reason to believe that our current warmth is anything other than an interglacial interval destined to give way to renewed glacial advance in the future.”
― Andrew H. Knoll, A Brief History of Earth: Four Billion Years in Eight Chapters

“Population genetics certainly underpins the origin of species, but the persistence of species is commonly adjudicated by Earth’s environmental dynamism.”
― Andrew H. Knoll, A Brief History of Earth: Four Billion Years in Eight Chapters

“Once formed, a quartz crystal will not evolve into a diamond, but over billions of years, Earth's first simple organisms have given rise to a staggering diversity of species, including one with the audacity to ask how we got here.”
― Andrew H. Knoll, A Brief History of Earth: Four Billion Years in Eight Chapters

“La historia de la Tierra y de los organismos que la habitan es mucho más espectacular que cualquier película taquillera de Hollywood y nos sorprende con tantos giros de guion como cualquier buen best seller.”
― Andrew H. Knoll, A Brief History of Earth: Four Billion Years in Eight Chapters

“The cyanobacteria, a group of photosynthetic bacteria tinted blue-green by chlorophyll and other pigments, harvest sunlight and fix CO2 much like eukaryotic algae and land plants. However, when hydrogen sulfide (H2S, well known for its “rotten egg” smell) is present, many cyanobacteria use this gas rather than water to supply the electrons needed for photosynthesis. Sulfur and sulfate are formed as by-products, but oxygen is not.”
― Andrew H. Knoll, Life on a Young Planet: The First Three Billion Years of Evolution on Earth

“The Alvarez hypothesis did much to focus paleontological thinking on mass extinction, while further impetus came from another project that took shape about the same time. When I was a graduate student in the 1970s, my friend and fellow student Jack Sepkoski started to tabulate fossil diversity through time. Jack wasn’t the first to try this, but his perseverance and attention to detail enabled him to put together a remarkable database of the first and last appearances of every order, family and, eventually, genus of marine animals found in the fossil record. (Jack stayed away from tabulating species, correctly intuiting that the record at that level of detail would be prone to biases related to sediment abundance and the habits of collectors.) Jack’s data showed that the course of biological diversification never did run smooth.”
― Andrew H. Knoll, A Brief History of Earth: Four Billion Years in Eight Chapters

“can only conclude that the appearance of age and order in stratigraphic successions is an elaborate ruse, part of a great cosmic charade set up to trap the unfaithful. What sort of God would do that? One who can be petty and vengeful, who may love His creation but doesn’t trust it. A God, in other words, much like ourselves. In his zeal to know the mind of God, the creationist finds only a mirror.”
― Andrew H. Knoll, Life on a Young Planet: The First Three Billion Years of Evolution on Earth