 The 19th century was a turbulent time. The turn of the century was marked by the Napoleonic Wars, which for more than a decade had tested the very balance of power maintained in Europe. Latin America, after decades of struggling under foreign rule, successfully vied for its independence. And by the middle of the century, much of Europe was being rocked in the wake of the democratic upheavals of the monarchies of Europe. The instability created from the events of the day was hardly the climate to foster great discoveries. But between the chaos and confusion, a handful of scientists attempted to peer back the veil of confusion and better understand the complex world that lay before them. Our story begins with a single man and a ship. In 1854, he set out on an expedition to study the natural history of the world and collect specimens for study and sail. Far from the conveniences of the modern era, expeditions in this time were dangerous. Just two years before, his ship burns in the Atlantic Ocean on its return voyage from South America, losing many of his specimens to the sea and leaving him adrift for 10 days before his rescue by a British-bound vessel. Although much of his four years of work had gone down with the ship, that wouldn't stop his desire to try again. On this voyage, while exploring an archipelago, he began to refine his thoughts on evolution and what would come to be his famous insight on natural selection. That archipelago, not the Galapagos, but the Mele archipelago, and the man's name, not Charles Darwin, but Alfred Russell Wallace, the man whose findings would start a race to claim the discovery of evolution. Wallace was a British naturalist, explorer, geographer, anthropologist, and biologist. He had previously led expeditions in the Amazon, but his discoveries here on these collections of islands would come to define his legacy and the legacy of the man who he was forever in the shadow of. Over a period of eight years, he accumulated more than an astonishing 125,000 specimens, including more than 5,000 species new to western science. In his studies, Wallace noticed a striking pattern in the distribution of animals around the archipelago. He proposed an imaginary line that would come to be determined Wallace's line, dividing the region into two parts that marked the boundary between the animal life of the Australian region and that of Asia. One day in 1858, while feverish and confined to his hut on the island of Ternate, now in Indonesia, Wallace had a realization. He came to understand how species evolved. They changed because the fittest individuals survived and reproduced, passing their advantageous characteristics on to their offspring. Wallace began to wonder, why would there be such a distinct line dividing the islands and what led to the differences in species across them? Wallace immediately wrote to someone he knew was interested in the subject, Charles Darwin, unaware that he had been wrestling with similar notions for more than a decade prior. To understand why he did this, we'll have to take a step back. Charles Darwin was born in the winter of 1809, the son of a wealthy doctor and financier. In his studies at university, Darwin was fascinated by natural history and evidence for divine design and nature. After his studies and time spent mapping the strata, the orderly layers of sediment left over millions of years in Wales, he was invited aboard the HMS Beagle on an expedition to chart the coastline of South America. Despite his father's objections, who would prefer he follow in his footsteps into medicine, Charles Darwin set sail on December 27, 1831. The planned two-year voyage stretched on to five, while the HMS Beagle surveyed and charted coasts, Darwin spent most of that time on land investigating the geology of the continent and making additions to his natural history collection. Despite some previous work collecting beetles and marine invertebrates, at the time, Darwin was largely a novice in the nature of most specimens he collected, periodically sending them back to Cambridge for expert appraisal. After stops in Cape Verde in Brazil, the expedition moved southward towards Patagonia. It was here, in the cliffs of Punta Alta, that Darwin would make his first major discovery. The fossils of a huge extinct mammal beside modern-day seashells indicating a recent extinction with no signs of a catastrophe or drastic change in the climate, since many believed species largely didn't change and were perfectly suited towards their environment. For them to die out, their environment would have to change drastically to the point where they could no longer survive. So Darwin began to wonder, what had made these species go extinct? As he continued southward, more things began to stand out to him. He discovered seashells high in the Andes Mountains, where the ground had seemingly risen out of the ocean. But like Wallace, who would take an archipelago to reveal the truth to him? In September of 1835, the HMS Beagle landed on San Cristobal, the easternmost of the Galapagos Islands. On the islands, he noticed mockingbirds similar to those he had seen in Chile, but differing slightly from island to island. He had heard from locals that slight variations in tortoise shells could be used to tell from which island they originated, although Darwin failed to collect any of these shells. Despite having a liking for the taste of the tortoises held within. In fact, not even Darwin would realize the magnitude of his discoveries here until long after he left the Galapagos. So little did he think of his discoveries of slight differences between finch populations from island to island that he failed to make note from which island his specimens originated, later having to backtrack where they came from from the journals of his fellow sailors aboard the ship. Analyzing his specimens on the way home, Darwin had the first inklings of what would become his theory of natural selection. In his notes, Darwin wrote that if his growing suspicions about the mockingbirds and the tortoises were correct, such facts undermined the stability of species. Then cautiously added wood before undermined. The orthologist John Goode soon announced that the Galapagos birds that Darwin had thought were a mixture of several different birds were in fact all finches. Furthermore, Goode told Darwin that Galapagos mockingbirds from different islands were separate species, not just varieties of one. After conferring with the journals of his fellow sailors and allocating each species to islands, he first realized how their distribution changed going southwards. By mid-March of 1837, barely six months after his return to England, Darwin was speculating in his notes on the possibility that one species does change into another, in the geographical distribution of living species of numerous birds throughout South America. He further detailed his thoughts on sexual reproduction around variation and offspring to adapt and alter the race to a changing world, explaining his observations in the Galapagos. Darwin's findings remained unpublished as he worked on them for more than a decade. Today, there is debate over whether this delay was caused by Darwin's fear of being ostracized by society for going against the commonly held belief that species were fixed or whether frequent illness and work on other projects slowed his efforts. When Darwin's close friend and confidant Charles Lyell read a paper by Alfred Wallace on the law which has regulated the introduction of new species, he saw similarities with Darwin's thoughts and urged him to publish to establish precedents. Though Darwin saw no threat, on May 14th, 1856, he began writing a short paper which expanded into a full book. For years he continued his research, obtaining information and specimens from naturalists worldwide, including Wallace, who was working in Borneo. Racing to finish his book before it was too late, the next year, on the origin of species was published and proved unexpectedly popular. In the book, Darwin set out a long argument of detailed observations, inferences, and consideration of anticipated objections. Darwin's theory is simply stated in the introduction. As many more individuals of each species are born than can possibly survive and as consequently there is a frequently reoccurring struggle for existence, it follows that any being, if it vary however slightly in any manner profitable to itself, under the complex and sometimes varying conditions of life will have a better chance of surviving and thus be naturally selected. From the strong principle of inheritance, any selected variety will tend to propagate its new and modified form. At the end of the book, he concluded that there is grandeur in this view of life with its several powers having been originally breathed into a few forms or into one and that whilst this planet has gone cycling on according to the fixed law of gravity from so simple a beginning, endless forms most beautiful and most wonderful have been and are being evolved. The last word was the only time any variant of evolved appeared in the first five editions of the book. While Alfred Wallace has largely been consigned to the footnote of history, he continued to push the needle of human knowledge for decades and was elected to the Royal Society in 1893 for his contributions to the theory of natural selection. Darwin and Wallace continued to exchange communications and were even good friends sharing their discoveries until Darwin's death in 1882. Well, that's it for today on Everything Science. If you like this content, be sure to subscribe so you don't miss out on any future uploads. 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