Bio second lesson

• Evolution is the process by which species of organisms undergo genetic change over successive generations, leading to the diversity of life observed on Earth
• Evolutionary theory underpins various fields of biology, including genetics, ecology, and paleontology, shaping our understanding of how life evolves and adapts to changing environments
• Evolutionary thought

  Emerged in the 19th century, notably with Charles Darwin's publication of "On the Origin of Species" in 1859, which proposed natural selection as the mechanism driving evolutionary change
• Pre-Darwinian ideas about the origin and diversity of life were diverse and often rooted in religious or mythological beliefs
• Lamarck's theory of evolution

  Proposed the inheritance of acquired characteristics, suggesting that organisms could pass on traits acquired during their lifetime to their offspring, leading to evolutionary change over time
• Charles Darwin


  • English naturalist whose groundbreaking work laid the foundation for modern evolutionary theory
  • Embarked on a five-year voyage aboard the HMS Beagle from 1831 to 1836, during which he collected numerous specimens and observed diverse ecosystems around the world, which greatly influenced his thinking on the origins of species
  • Published "On the Origin of Species" in 1859, which presented the theory of natural selection as the mechanism driving evolutionary change
• Natural selection


  The process by which organisms with traits better suited to their environment are more likely to survive and reproduce, passing on those advantageous traits to future generations
• Darwin's theory of natural selection revolutionized biology, providing a comprehensive explanation for the patterns of diversity and adaptation seen in the natural world
• Competing theories and controversies surrounding evolution were prevalent during this period, including Lamarckism and the concept of orthogenesis
• Discoveries in genetics and molecular biology have significantly advanced our understanding of evolution by providing insights into the mechanisms underlying genetic variation, inheritance, and evolutionary change
• Comparative genomics


  Analyzing and comparing the genomes of different organisms to shed light on evolutionary relationships and processes by identifying similarities and differences in DNA sequences
• One common misconception about evolution is the idea that it is solely driven by random chance, neglecting the significant role of natural selection in shaping adaptations
• Key figures in the development of evolutionary thought

  • Jean-Baptiste Lamarck
  • Charles Darwin
  • Alfred Russel Wallace
  • Gregor Mendel
  • Ronald Fisher, J.B.S. Haldane, and Sewall Wright
  • Georges-Louis Leclerc, Comte de Buffon
  • Erasmus Darwin
  • Georges Cuvier
• Evolutionary thought has evolved significantly over time, from early ideas rooted in religious beliefs to the groundbreaking theories of Jean-Baptiste Lamarck and Charles Darwin
• The Modern Synthesis integrated Mendelian genetics with Darwinian evolution, leading to a comprehensive understanding of evolutionary processes
• Recent advancements in genetics and molecular biology, particularly DNA sequencing and comparative genomics, have furthered our understanding of evolution
• Evolutionary theory remains a cornerstone of scientific inquiry, offering profound insights into the origins and diversity of life on Earth
• Lamarckism


  A theory of evolution proposed by Jean-Baptiste Lamarck that suggests an organism can change during its lifetime in response to its environment, and that these changes are then passed on to its offspring. This theory has been largely discredited by modern science.
• Darwinism


  A theory of evolution proposed by Charles Darwin that suggests evolution occurs through the process of natural selection, where organisms with traits that are advantageous for their environment are more likely to survive and reproduce, passing those traits onto their offspring. This theory is widely accepted as a fundamental principle of biology.
• Evolutionary biology


  The study of how living organisms have changed over time, involving natural selection, genetic drift, and mutation
• Molecular biology


  The study of biological systems at the molecular level, involving DNA, RNA, and proteins
• Variations


  Differences in traits among individuals within a population, arising from genetic differences caused by mutations, gene flow, or sexual reproduction. Provide the raw material for evolution to occur.
• Adaptations


  Specific features of an organism that increase its fitness in its environment, resulting from natural selection acting on existing variations. Not solely the result of random chance.
• Evolutionary biology


  The study of how living organisms have changed over time, involving natural selection, genetic drift, and mutation
• Natural selection


  The process by which organisms with traits that are advantageous for their environment are more likely to survive and reproduce, passing those traits on to their offspring
• Genetic drift


  Random changes in the frequency of traits in a population, more significant in small populations
• Mutation


  Changes in an organism's DNA that can lead to new traits
• Speciation


  The development of new species over time
• Fossil record


  The study of fossils to understand the history of life on Earth
• Orthogenesis, which suggested that

  evolution occurred in a predetermined direction, independent of natural selection.
• The Modern Synthesis, also known as the Neo-Darwinian Synthesis
• The Modern Synthesis, also known as the Neo-Darwinian Synthesis, is a scientific theory that combines Darwin’s ideas with Mendelian genetics and other discoveries from biology, chemistry, physics, mathematics, and philosophy.
• DNA sequencing has revolutionized the study of evolution by enabling researchers to compare the genetic makeup of different species, populations, and individuals with unprecedented accuracy.
• molecular biology techniques such as gene expression analysis and functional genomics have provided valuable insights into how genetic changes lead to phenotypic variation and adaptation.
• Orthogenesis

  • suggested that evolution occurred in a predetermined direction, independent of natural selection.
• Molecular biology

  • has provided important insights into evolutionary processes, while evolutionary biology has helped to contextualize molecular findings within a broader framework of biological diversity and history
• Significance of evolution in biology

  It is the central unifying principle that explains the interconnectedness of all living organisms, providing a framework to understand the origin, diversity, and adaptation of life forms
• Charles Lyell

  • Geologist whose work on uniformitarianism influenced Darwin, providing important insights into the gradual processes shaping Earth's geological features, which complemented Darwin's understanding of gradual evolutionary change 
• Charles Lyell a Geologist whose work on uniformitarianism influenced Darwin, providing important insights into the gradual processes shaping Earth's geological features, which complemented Darwin's understanding of gradual evolutionary change
• Population genetics, focusing on the study of genetic variation within populations and the mathematical modeling of how genetic traits change over time through processes such as natural selection, genetic drift, and gene flow