Physicist turned biologist in the search of aliens https://gillescolling.com/ Sat, 11 Apr 2026 07:29:44 +0000 The harpy eagle (Harpia harpyja) is one of the most iconic apex predators in the Neotropics, primarily inhabiting the Amazon basin and parts of Central America. It plays an important role in maintaining the balance of tropical forest ecosystems. In Costa Rica, however, populations have become highly fragmented, and the species is now considered locally extinct in the south. The last confirmed sighting in that region was more than 20 years ago. Osa Conservation is prepa... Sat, 11 Apr 2026 07:29:44 +0000 https://gillescolling.com/course-spattempdyn-project/ https://gillescolling.com/course-spattempdyn-project/ Education This lecture extended the concept of dispersal modeling by integrating population dynamics with spatially explicit dispersal kernels. The focus was on simulating how populations grow and spread across a raster landscape over multiple time steps. By combining population growth models with dispersal processes, the lecture demonstrated how species expand their range over time, influenced by both intrinsic demographic parameters and external dispersal constraints. Sat, 11 Apr 2026 07:29:44 +0000 https://gillescolling.com/course-spattempdyn-lecture8/ https://gillescolling.com/course-spattempdyn-lecture8/ Education Lecture 7 continued the discussion on random walks by integrating movement simulations with spatially explicit raster grids. Instead of modeling dispersal in continuous space, random-walk processes can be efficiently implemented on discrete raster environments. Working with rasters involves defining a spatially explicit grid characterized by: Sat, 11 Apr 2026 07:29:44 +0000 https://gillescolling.com/course-spattempdyn-lecture7/ https://gillescolling.com/course-spattempdyn-lecture7/ Education Lecture 6 introduced random walks as a fundamental model for dispersal, explaining how individuals move in space without a predefined direction. The lecture covered basic random walks, correlated random walks, and how to implement these models computationally. These concepts are widely used in animal movement ecology, invasive species spread, and diffusion models in ecology. Sat, 11 Apr 2026 07:29:44 +0000 https://gillescolling.com/course-spattempdyn-lecture6/ https://gillescolling.com/course-spattempdyn-lecture6/ Education Lecture 5 introduced class-structured population models, where individuals are categorized into different groups based on age, sex, developmental stage, or physiological condition. Unlike previous models that treated populations as homogeneous, class-structured models allow for more realistic representations of survival and reproduction patterns across different life stages. The lecture focused on age-structured models, particularly Leslie matrices, and included an application to whale popula... Sat, 11 Apr 2026 07:29:44 +0000 https://gillescolling.com/course-spattempdyn-lecture5/ https://gillescolling.com/course-spattempdyn-lecture5/ Education Lecture 4 introduced predator-prey models, focusing on the Lotka-Volterra equations and extensions like the Rosenzweig-MacArthur model. We also covered functional responses, which describe how predator feeding rates change with prey density. These models help us understand how populations cycle and how predators and prey influence each other’s abundance. Sat, 11 Apr 2026 07:29:44 +0000 https://gillescolling.com/course-spattempdyn-lecture4/ https://gillescolling.com/course-spattempdyn-lecture4/ Education Lecture 3 focused on density-dependent growth, introducing the logistic growth model as an extension of the exponential growth model covered in the previous lecture. The lecture examined how resource limitations affect population growth and how this leads to equilibrium population sizes. Additionally, concepts such as overcompensation, chaos, and bifurcation in discrete population models were introduced. Sat, 11 Apr 2026 07:29:44 +0000 https://gillescolling.com/course-spattempdyn-lecture3/ https://gillescolling.com/course-spattempdyn-lecture3/ Education In Lecture 2 we focused on single-species population models with an emphasis on exponential growth. The lecture began by revisiting the basic concepts of population dynamics in nature. A population is defined as a group of individuals of one species that live, reproduce, and interact within a particular area. Although real populations are affected by interactions with other species and environmental fluctuations, the simplest models assume that resources are unlimited and that the population ... Sat, 11 Apr 2026 07:29:44 +0000 https://gillescolling.com/course-spattempdyn-lecture2/ https://gillescolling.com/course-spattempdyn-lecture2/ Education The lecture started with a basic but crucial question: What is a model? In the context of ecology, a model is a simplified representation of reality, designed to capture the essential processes of an ecological system while ignoring unnecessary complexity. This abstraction is necessary because ecological systems are highly complex, with countless interactions between organisms, their environment, and external influences. Models allow us to test hypotheses, explore scenarios, and make predicti... Sat, 11 Apr 2026 07:29:44 +0000 https://gillescolling.com/course-spattempdyn-lecture1/ https://gillescolling.com/course-spattempdyn-lecture1/ Education This lecture series was based on the annotated reading by Ernst Mayr and Frank Sulloway, two major scholars in evolutionary biology and Darwin studies. Their commentary unpacks Darwin’s “one long argument.” During the intorductroy lecture we laid the groundwork for reading On the Origin of Species, not just as a historical document, but as a revolutionary scientific argument at the time. Understanding the structure of Darwin’s five theories, his strategy in presenting them, and the cultural e... Sat, 11 Apr 2026 07:29:44 +0000 https://gillescolling.com/course-foundevotheo-overview/ https://gillescolling.com/course-foundevotheo-overview/ Education Darwin begins Chapter 9 with a strategic pivot. After spending the first eight chapters laying out his theory of natural selection and defending it from a variety of objections, he now turns to a critical piece of missing evidence: the fossil record. This chapter addresses one of the most damaging arguments against his theory at the time, namely, that if all life evolved gradually from common ancestors, why doesn’t the fossil record show clear transitional forms linking all species together? Sat, 11 Apr 2026 07:29:44 +0000 https://gillescolling.com/course-foundevotheo-chapter9/ https://gillescolling.com/course-foundevotheo-chapter9/ Education In Chapter 8 of the Origin, Darwin turns to the question of hybridism: One of the most difficult and problematic issues for his theory. Unlike earlier chapters, where the gradual accumulation of evidence builds toward a coherent argument, this chapter presents a landscape of exceptions, contradictory data, and theoretical uncertainty. Darwin was working without a science of genetics, without knowledge of chromosomes, and without a clear understanding of how heredity operated at a cellular lev... Sat, 11 Apr 2026 07:29:44 +0000 https://gillescolling.com/course-foundevotheo-chapter8/ https://gillescolling.com/course-foundevotheo-chapter8/ Education In this chapter, Darwin tackles one of the most fascinating and controversial aspects of animal behavior: Instinct. His goal is not to explain the neurological basis of instinctive behavior, nor to speculate on the physiology of animal minds. Instead, he asks a more evolutionary question: how could natural selection have shaped complex, seemingly purposeful behaviors that occur without learning or reasoning? Darwin approaches instinct with the same framework he applies to morphology: as a pro... Sat, 11 Apr 2026 07:29:44 +0000 https://gillescolling.com/course-foundevotheo-chapter7/ https://gillescolling.com/course-foundevotheo-chapter7/ Education This chapter shows Darwin at his most rigorous and rhetorically masterful. Aware of the controversy surrounding his theory, Darwin opens by confronting its potential weaknesses directly. In his Autobiography, he described a golden rule he had followed for decades: to make immediate note of all serious objections and recalcitrant facts. In Chapter 6, this habit becomes a strength. Rather than dodging critique, Darwin anticipates the strongest objections his readers might raise and addresses th... Sat, 11 Apr 2026 07:29:44 +0000 https://gillescolling.com/course-foundevotheo-chapter6/ https://gillescolling.com/course-foundevotheo-chapter6/ Education In Chapter 5 of the Origin, Darwin turns to what he admits is the least understood and most mysterious part of his theory: the origin of variation. He opens with a candid confession. When he has previously referred to variations arising by chance, this was not to suggest randomness in the sense of uncaused events, but rather to acknowledge ignorance. The causes of variation were largely unknown in Darwin’s time, and this chapter makes no attempt to conceal that fact. Instead, it explores the ... Sat, 11 Apr 2026 07:29:44 +0000 https://gillescolling.com/course-foundevotheo-chapter5/ https://gillescolling.com/course-foundevotheo-chapter5/ Education Chapter 4 marks the centerpiece of Darwin’s argument in the Origin. It is the longest chapter of the book, and it has drawn more commentary than any other. Here, Darwin lays out the mechanism that underpins evolutionary change: natural selection. But this is not the only idea he weaves into this chapter. He also introduces the principles of divergence, sexual selection, common descent, and species multiplication, all of which are integral to how evolutionary change unfolds in the natural worl... Sat, 11 Apr 2026 07:29:44 +0000 https://gillescolling.com/course-foundevotheo-chapter4/ https://gillescolling.com/course-foundevotheo-chapter4/ Education In Chapter 3 of the Origin, Darwin introduces one of the most central concepts in his theory: the struggle for existence. It marks a turning point in the book, where Darwin transitions from establishing that variation exists to explaining how some variations persist and others are eliminated. This struggle, he argues, lies at the heart of natural selection and adaptation. Sat, 11 Apr 2026 07:29:44 +0000 https://gillescolling.com/course-foundevotheo-chapter3/ https://gillescolling.com/course-foundevotheo-chapter3/ Education In the second chapter of the Origin, Darwin shifts from domesticated animals to variation in wild populations. His goal is to show that the kind of variation we see under human influence also occurs in nature and that species, far from being rigidly defined categories, are fluid and variable. This move is key to Darwin’s argument: if species show variation in nature similar to what we observe in domestic animals, then the conditions for evolution are not confined to artificial selection but a... Sat, 11 Apr 2026 07:29:44 +0000 https://gillescolling.com/course-foundevotheo-chapter2/ https://gillescolling.com/course-foundevotheo-chapter2/ Education Darwin closes the Origin with a reflective and strategic chapter. One that summarizes, defends, and contextualizes the argument he has spent the entire book developing. He is cautious but confident, acknowledging the boldness of his claims and the controversy they provoked, while reiterating the logic and evidence that led him to them. This is not just a summary, but a final act of persuasion. After twenty years of study, experimentation, and writing, Darwin was convinced he was right, and he... Sat, 11 Apr 2026 07:29:44 +0000 https://gillescolling.com/course-foundevotheo-chapter14/ https://gillescolling.com/course-foundevotheo-chapter14/ Education In this penultimate chapter of the Origin, Darwin ties together three key areas: Morphology, embryology, and rudimentary organs. He wants to support the argument that all species descend from common ancestors. These subjects may seem disconnected at first, but for Darwin, they converge on a single principle: similarity, when properly understood, reflects shared ancestry. Sat, 11 Apr 2026 07:29:44 +0000 https://gillescolling.com/course-foundevotheo-chapter13/ https://gillescolling.com/course-foundevotheo-chapter13/ Education