Lecture 3- Evolution and its Mechanism-Buhmeida A. PDF

Evolution Abdelbaset Buhmeida CEGMR-KAU e-malil: [email protected]  Table of Content 1. Introduction to Evolution Definition, types and significance in biology 2. History of Evolutionary Theory Pre-Darwinian ideas (Lamarck, Cuvier,...

Evolution Abdelbaset Buhmeida CEGMR-KAU e-malil: [email protected]  Table of Content 1. Introduction to Evolution Definition, types and significance in biology 2. History of Evolutionary Theory Pre-Darwinian ideas (Lamarck, Cuvier, Malthus) Darwin’s Theory of Natural Selection Co-discovery by Alfred Russel Wallace 3. Post-Darwinian Evolution Mendelian Genetics and the Modern Synthesis Population genetics, mutation, genetic drift Molecular biology and DNA 4. Biogeography and Evolution Importance of biogeography in species distribution Evolution in different biogeographic regions 5. Island Biogeography Continental vs. oceanic islands Evolution on islands (adaptive radiation, island rule) Theories of island biogeography 6. Speciation and Evolutionary Mechanisms Types of speciation: allopatric, sympatric 7. Evidence for Evolution Fossils, anatomy, embryology, molecular biology 8. Conclusion Recap and current research in evolution  Definition and its significance in biology Evolution is defined as the process by which different species of organisms develop and diversify from earlier forms over successive generations. Significance of Evolution in Biology: 1. It is a central theme in biology that connects and explains the diversity of life on Earth. (Unifying Concept). 2. Helps explain how species adapt to their environments over time, which is crucial for survival and reproduction. (Understanding Adaptation) 3. Aids in understanding antibiotic resistance, the development of crops, and conservation of biodiversity. (Medical and Agricultural Applications) 4. Provides a framework to interpret the fossil record and molecular evidence, showing how life has changed over millions of years. (Fossil Record and Illustration that represents the impact of evolution in biology, incorporating Molecular Biology) the tree of life, DNA strands, and various species. These visuals highlight evolution as a unifying theme in biology.  Evolution The evolution works at two levels Key Concepts of Evolution: Works on population (evolution) rather than on 1. Natural Selection: Proposed by Charles Darwin, it's the individuals (development) process where organisms better adapted to their Works on genotype and not on phenotype environment tend to survive and reproduce more Process normally occurs slowly successfully. 2. Genetic Drift: Random changes in gene frequencies in a population, especially in small populations, can lead to evolutionary changes. 3. Mutation: Changes in DNA sequences that introduce new genetic variations into a population. 4. Gene Flow: Movement of genes between populations, which can introduce new genetic material. Natural selection Genetic drift Gene flow Genetic pool Types: Microevolution ITrefers to the small-scale evolutionary changes that occur within a species or population over a relatively short period of time. Key Processes in Microevolution: 1. Natural Selection: Traits that enhance survival and reproduction become more common. 2. Genetic Drift: Random changes in allele frequencies, particularly in small populations. 3. Mutations: Changes in the DNA sequence that introduce new genetic variants. 4. Gene Flow: The movement of genes between populations through migration or reproduction.  Macroevolution ITrefers to large-scale evolutionary changes that occur over long periods of time and lead to the formation of new species or other taxonomic groups Key Concepts: 1. Speciation: The process by which populations evolve to become distinct species. 2. Adaptive Radiation: The rapid diversification of a single ancestral species into many different forms adapted to specific environments, such as the evolution of Darwin's finches on the Galápagos Islands. 3. Mass Extinction Events: Large-scale extinction events can lead to opportunities for new species to evolve and fill ecological niches, driving macroevolutionary change. 4. Phylogenetic Trees: Macroevolution can be observed in the branching patterns of life over time, often represented by phylogenetic trees that show evolutionary relationships among species.  Microevolution in Humans Here is an illustration representing microevolution in humans, showcasing small genetic variations such as: Skin colour variation High variation Hair types Blue eyes Lactose tolerance Disease resistance. Cold adaptation High altitude adaptation Sickle cell trait & Malaria Resistance Thumb Flexibility (Hitchhiker’s Thumb) Take-home message: These minor genetic changes that have occurred over time in human populations are due to environmental (EXPOSOME) and genetic factors (GENOME). Recap Micro vs. Macro Microevolution: Involves small, observable changes within species. Can be studied empirically and is well-documented. It is testable and observable There is no dispute/debate about it Macroevolution: Refers to large-scale evolutionary changes that result in the emergence of new species. Requires millions of years to occur, making direct observation and experimental testing challenging. It is the core principle of Darwin's theory of evolution. It is disputable/debatable Public Acceptance of Evolution Theory  Pre-Darwinian Evolutionists: ▪ Anaximander (610-546 BCE): ▪ ‫( الجاحظ‬Al-Jahiz) (776-868 CE) ▪ Empedocles (495-430 BCE): ▪ Book: ‫كتاب الحيوان‬ ▪ Jean-Baptiste Lamarck (1744-1829): ▪ ‫( ابن خلدون‬Ibn Khaldun) (1332-1406 CE) ▪ Example: Lamarck suggested that giraffes developed ▪ Book: ‫المقدمة‬ long necks because their ancestors stretched to reach higher leaves, and this trait was passed on to ▪ ‫( إخوان الصفا‬Ikhwan al-Safa) (10th century CE) ▪ Book: ‫رسائل إخوان الصفا‬ subsequent generations. (use vs. disuse theory) ▪ ‫( ابن ميمون‬Maimonides) (1135–1204 CE) ▪ Erasmus Darwin (1731-1802): ▪ Book: ‫داللة الحائرين‬ ▪ Georges-Louis Leclerc, Comte de Buffon (1707–1788): ▪ ‫( ناصر الدين الطوسي‬Nasir al-Din al-Tusi) (1201-1274 CE) ▪ Book: ‫أخالق ناصري‬ ▪ James Hutton (1726-1797): ▪ ‫( ابن مسكويه‬Ibn Miskawayh) (932-1030 CE) ▪ Robert Chambers (1802-1871): ▪ Book: ‫تهذيب األخالق‬ ▪ Georges Cuvier (1769–1832): ▪ Thomas Malthus (1766-1834):  Charles Darwin (1809-1882) Charles Darwin was an English naturalist and biologist Best known for developing the theory of evolution by natural selection. This groundbreaking idea revolutionized biology and influenced various fields, including genetics, anthropology, and psychology. Darwin's theory suggests that all species of life have descended over time from common ancestors, and that the mechanism driving this process is natural selection. Organisms with traits better suited to their environments tend to survive and reproduce, passing those advantageous traits to future  How Darwin Was Inspired to Coin the Theory of Evolution? ▪ Influence of Earlier Thinkers: ▪ Lamarck: Believed species change over time, influencing Darwin. ▪ Malthus: Population growth and competition inspired natural selection. ▪ The Voyage of the HMS Beagle: ▪ Darwin's observations of species like Galápagos finches led him to conclude that species adapt and evolve. ▪ Geology: ▪ Lyell’s idea of gradual change over time influenced Darwin’s thinking on evolution. ▪ Artificial Selection: ▪ Darwin saw parallels between selective breeding and natural selection in the wild. 1.Influence of Earlier Thinkers: ▪ Jean-Baptiste Lamarck: Lamarck's theory of French naturalist who evolution proposed that organisms can pass on contributed early ideas characteristics acquired during their lifetime to to evolutionary theory, particularly the concept offspring , though this idea was later discredited. of the inheritance of However, his belief that species change over time acquired was a critical influence. characteristics ▪ Thomas Malthus: Darwin was significantly English scholar known influenced by Malthus's Essay on the Principle of for his theories on Population (1798). Malthus argued that population growth and populations grow faster than the resources they its limits. His work depend on, leading to competition and a representing the global struggle for survival. This concept of competition implications on informed Darwin’s thinking about natural population dynamics. selection. The Voyage of HMS Beagle in 1831-1836 5 years duration (‫)رحلة البيجل‬ 2. The Voyage of the HMS Beagle (1831–1836) ▪ Darwin's journey aboard the HMS Beagle (1831–1836) was the single most influential experience in his development of the theory of evolution. ▪ As the ship's naturalist, Darwin collected specimens of flora and fauna from various regions, including South America and the Galápagos Islands. ▪ His observations of unique species like the Galápagos finches, which had different beak shapes adapted to various food sources, were crucial in shaping his ideas on adaptation and natural selection. ▪ The diversity of species in different geographical locations suggested to Darwin that species might not be static, but instead, they change over time in response to their environments.  The Impact of the HMS Beagle Voyage on Darwin's Theory. The five-year voyage on the HMS Beagle (1831-1836) played a pivotal role in shaping Darwin's theory. Key impacts include: Diversity of Species: In South America, Darwin encountered a wide variety of animals and plants, which seemed to be related to, yet distinct from, species in Europe. Fossils and Extinction: Darwin collected fossils of extinct species, which provided evidence that life had changed over time. Galápagos Islands Observations: Darwin’s time in the Galápagos Islands was especially influential. He observed finches with different beak shapes on different islands, leading him to think about adaptation and how species change over time to survive in different environments. Geographical Distribution: Darwin noticed that species on the islands were similar to, but not the same as, species on the nearby mainland of South America, which further led him to theorize about common descent and geographical speciation.  3. Observations from Geology: Darwin was heavily influenced by the work of geologist Charles Lyell, who argued for uniformitarianism— the idea that Earth's geological features were shaped by slow, gradual processes over long periods, rather than sudden, catastrophic events. This concept of slow change over time resonated with Darwin's idea that species could similarly evolve over long periods.  Uniformitarianism vs. Catastrophism Uniformitarianism/ Uniformism Catastrophism Aspect ‫ التنميطية‬- ‫النظرية االنتظامية‬ ‫النظرية الكوارثية‬ Change Process Slow, gradual, and consistent processes over long periods. Sudden, short-lived, dramatic events shape Earth's surface. Time Frame Geological changes occur over millions of years. Changes happen quickly over a short time frame. Key Forces Continuous processes like erosion, sedimentation, etc. Catastrophic events like floods, volcanic eruptions, and impacts. Proponents James Hutton, Charles Lyell Georges Cuvier Examples Erosion forming canyons, mountains uplifted over time Asteroid impacts, massive floods, or volcanic eruptions View of Extinction Gradual extinction and speciation over long periods. Species extinction due to major catastrophic events.  Intercontinental vs. Oceanic Islands Aspect Intercontinental Islands Oceanic Islands Never connected to a continent; formed by Geological Origin Once connected to a continent, later isolated volcanic or coral activity Species Origin Primarily from continental ancestors Primarily from long-distance dispersal Some isolation-driven evolution, but often less High isolation leads to greater divergence and Evolutionary Pressure extreme endemism Often highly distinct from any mainland Species Similarity Often closely related to mainland species species Examples of Animals Lemurs (Madagascar), Kiwi (New Zealand) Galápagos finches, Hawaiian honeycreepers Endemism Moderate (depends on time since isolation) High (due to long isolation) Arrived via air, ocean currents, or accidental Migration Mechanisms Some species remained after landmass split introduction Typically lack large predators, leading to Often contain predators and large herbivores (e.g., Predators and Competition unique adaptations like flightlessness or mammals) gigantism 4. Artificial Selection: selective breeding Darwin drew parallels between natural selection and artificial selection, a process in which humans breed plants or animals for specific traits. He observed that if humans could influence the traits of species through selective breeding, then nature could also "select" favorable traits in the wild, leading to the gradual development of new species.  Aspect Artificial Selection Industrial Selection Natural selection due to Artificial Definition Human-guided selection of organisms with desired traits environmental changes, often caused by industrial activities selection Humans select individuals to Traits that enhance survival in polluted Mechanism or industrial environments become vs. breed based on specific traits more common naturally Dark-colored peppered moths Industrial Examples Selective breeding of dogs, crops, or livestock becoming more common during the Industrial Revolution selection: Agent of Selection Humans Environmental factors (e.g., pollution, habitat changes due to industrialization) No intentional goal; survival of the To enhance or produce desired Goal fittest under changing environmental traits in organisms conditions Deliberate and controlled by Natural and driven by survival in Process humans altered environments Traits like size, productivity, or Evolution of traits like camouflage or Outcome disease resistance in plants and pollution tolerance (e.g., darker moths animals in soot-covered environments)  Aspect Natural Selection Industrial Selection A form of selection influenced by human activities, The process by which organisms better adapted to their particularly those related to industrialization, where certain Definition environment tend to survive and reproduce, passing on traits become favorable due to changes in the environment advantageous traits to their offspring. caused by industry. Natural environmental pressures (e.g., predators, climate, Human-induced environmental changes, often due to Driving Force food availability). pollution or industrial activities. Examples of Selective Pollution, habitat destruction, artificial changes in the Predators, competition for resources, changing climate. Pressure environment. Peppered Moths (Biston betularia): During the Industrial Darwin’s Finches: Different species of finches evolved Revolution, moths with darker wings had a survival advantage Key Example in Evolution beak shapes suited to available food sources on the due to the soot-covered trees, leading to an increase in the Galápagos Islands. dark-winged variety. Gradual adaptation over time to optimize survival in a Rapid changes in traits to cope with industrial pollution or Impact on Species natural environment. habitat changes. Typically operates over long periods, often millions of Can occur over relatively short periods (decades or centuries), Time Scale years. as seen during the Industrial Revolution. Individuals with favorable traits survive and reproduce Species with traits that help them survive industrial changes Mechanism more, while those with less favorable traits are less likely (e.g., pollution) thrive, while others decline or adapt to the new to pass on their genes. industrial environment. Can sometimes be reversible if industrial factors are reduced Often irreversible, leading to permanent species changes Reversibility (e.g., in the case of pollution control, the population of light- or speciation. colored peppered moths rebounded). No direct role—environmental changes occur naturally Direct or indirect role—changes are driven by human Role of Humans without human intervention. activities, such as industrialization or pollution. After pollution controls were implemented, the light-colored peppered Some species have evolved over time into entirely new species due Example of Reversibility moth populations increased again, demonstrating a reversal in selection to long-term environmental changes. pressure.  Darwin's Key Books and Publications On the Origin of Species (1859): This is Darwin’s most famous work, in which he laid out the theory of evolution by natural selection. It is considered one of the most important scientific books ever written. The Descent of Man, and Selection in Relation to Sex (1871): In this book, Darwin applied his theory to human evolution, suggesting that humans and other animals share common ancestors. He also introduced the concept of sexual selection. The Expression of the Emotions in Man and Animals (1872): Darwin explored the biological basis for emotions and facial expressions, linking human emotional expressions to those of animals. The Structure and Distribution of Coral Reefs (1842): Based on observations from the Beagle voyage, this book presents Darwin’s theory on how coral reefs form, particularly the role of subsidence and the rise of coral structures. The Variation of Animals and Plants under Domestication (1868): In this work, Darwin explored the effects of artificial selection on plants and animals, drawing a parallel to natural selection. Insectivorous Plants (1875): This book delves into Darwin’s research on how certain plants, such as the Venus flytrap, can capture and digest insects. The Different Forms of Flowers on Plants of the Same Species (1877): This work explores how plants have evolved different forms of flowers to promote cross-pollination.  Year Edition Key Features Published On the Origin of Species First Original publication with 1,250 copies. (1859) Edition 1859 Introduced Darwin's theory of evolution by natural selection. Book chapters Second Minor corrections and additions based 1. Variation Under Domestication 1860 Edition on feedback from the first edition. 2. Variation Under Nature 3. Struggle for Existence Expanded with more references and 4. Natural Selection; or the Survival of the Fittest Third responses to critics. Includes 1861 5. Laws of Variation Edition historical sketch of earlier 6. Difficulties on Theory evolutionary ideas. 7. Instinct Further revisions, including more 8. Hybridism Fourth detailed responses to critics and 9. On the Imperfection of the Geological Record 1866 Edition additional evidence supporting 10. On the Geological Succession of Organic Beings evolution. 11. Geographical Distribution 12. Geographical Distribution—continued Fifth Introduced the phrase "survival of the 13. Mutual Affinities of Organic Beings: Morphology, 1869 Edition fittest" (coined by Herbert Spencer). Embryology, Rudimentary Organs 14. Recapitulation and Conclusion Final edition during Darwin’s lifetime, Sixth 1872 revised and condensed for a broader Edition readership.  The Darwinian Principle 1. Natural Selection: This is the process by which organisms better adapted to their environment tend to survive and reproduce, passing favorable traits to their offspring. Over time, this leads to the evolution of species as advantageous traits become more common. Example: In a population of animals, individuals with better camouflage are less likely to be eaten by predators and are more likely to survive and pass on this trait. 2. Survival of the Fittest: This phrase, often associated with Darwin, refers to the idea that organisms best suited to their environment have a higher chance of survival and reproduction, while those that are less adapted tend to die out. 3. Variation: Darwin observed that individuals in a population vary in many traits, such as size, color, or behavior. These variations can be inherited, and they form the raw material upon which natural selection acts. 4. Struggle for Existence: Darwin proposed that more individuals are born than can survive. Therefore, they compete for limited resources such as food, shelter, and mates. This struggle drives the process of natural selection. 5. Gradualism: Evolution is generally a slow and gradual process, occurring over long periods of time as small changes accumulate within a population. 6. Common Descent: All living organisms share a common ancestor. Over millions of years, species diverge and evolve into the diverse life forms seen today. These principles laid the foundation for modern evolutionary biology, shaping how we understand the diversity of life and the processes behind it.  New Darwinism (Neo-Darwinism): 1. Combination of Darwin’s Ideas and Genetics: o While Darwin introduced the concept of natural selection, he did not understand the mechanisms of inheritance (genes were unknown at the time). Neo-Darwinism merges Darwin’s theory with Mendelian genetics, explaining how traits are passed from one generation to the next through genes. o The modern synthesis of evolution, which developed in the early 20th century, combined insights from genetics, paleontology, and systematics to support and extend Darwin’s theory. 2. Key Concepts: o Natural Selection: Organisms with advantageous traits are more likely to survive and reproduce, passing these traits to their offspring. o Genetic Variation: Mutations, recombination, and other genetic processes create variation within a population, providing the raw material for evolution. o Population Genetics: Evolution is understood as a change in the frequency of alleles (gene variants) in a population over time. o Speciation: The process by which populations evolve to become distinct species, often driven by mechanisms like isolation.  Key Principles of the Modern Synthetic Theory of Evolution: 1.Genetic Variation: ▪ Variations arise from mutations, recombination, and gene flow. These differences, passed down through generations, fuel evolution. 2.Natural Selection: ▪ Traits beneficial for survival and reproduction are favored, increasing their frequency over time. Fitness measures reproductive success. 3.Gradualism: ▪ Evolution is slow, with small genetic changes accumulating over long periods, as seen in the fossil record. 4.Population as the Unit of Evolution: ▪ Evolution happens at the population level through changes in allele frequencies driven by selection, drift, mutation, and gene flow. 5.Gene Flow: ▪ Movement of genes between populations introduces new variations, preventing genetic isolation. 6.Genetic Drift: ▪ Random changes in allele frequencies, especially in small populations, can lead to genetic diversity loss (e.g., founder or bottleneck effects). 7.Speciation: ▪ Reproductive isolation and genetic divergence result in new species. 8.Mutation: ▪ Mutations provide new genetic material, essential for evolution. 9.Paleontological Evidence: ▪ Fossils show gradual evolutionary changes and transitions between species. 10.Neutral Evolution: ▪ Some changes are neutral and accumulate via genetic drift, not selection.  What is Speciation? ‫االنتواع‬ A species is the most basic unit of biological classification in taxonomy and refers to a group of organisms that can interbreed and produce fertile offspring under natural conditions. Species are typically similar in terms of appearance, behavior, and genetic makeup, but the ability to reproduce and create viable offspring is the key defining feature. Key Points: 1. Reproductive Isolation: A species is typically defined by reproductive isolation, meaning that members of the same species can breed with one another, but not with members of different species. 2. Morphological Similarity: Members of the same species generally share physical traits or characteristics, although there can be variations within a species (e.g., different breeds of dogs). 3. Genetic Similarity: Species are defined by similar genetic characteristics. Differences in DNA sequences can help differentiate species, even when physical traits overlap. Example: Humans (Homo sapiens) are an example of a species, as all humans can reproduce with each other and produce fertile offspring. Different species, like lions and tigers, though genetically similar, are generally considered distinct due to their geographic, behavioral, and reproductive isolation.  Genetic Drift vs. Natural Selection: Aspect Genetic Drift Natural Selection Adaptive traits that improve survival and Driving Force Random chance events reproduction Can operate in both large and small Population Size Has a stronger effect in small populations populations Non-random increase in frequency of Result Random changes in allele frequencies beneficial alleles Neutral, does not necessarily increase Increases fitness by favoring advantageous Impact on Fitness fitness traits Maintains or increases variation based on Effect on Variation Can lead to loss of genetic variation selective pressures  Types of Genetic Drift 1. Bottleneck Effect: o A population bottleneck o It occurs when a population is drastically reduced in size due to a catastrophic event (e.g., natural disaster, disease). o The small surviving population may not have the same genetic makeup as the original population, leading to a shift in allele frequencies. As the population recovers, it may have less genetic diversity than before the bottleneck. 2. Founder Effect: o The founder effect o It occurs when a small group of individuals from a population colonizes a new area. o The genetic makeup of the new population is determined by the alleles carried by the initial "founders." This can result in a population that is genetically distinct from the original population.  Army Races in Evolution ‫سباق التسلح التطوري‬ Cheetah and Gazelle. It showcases the Bird and Insect: This image illustrates Snake and Predator: This image co-evolutionary struggle where the an evolutionary arms race between a represents the dynamic evolutionary predator (like a cheetah) evolves sharper bird and an insect. The bird evolves arms race between a venomous snake claws and greater speed, while the prey sharper beaks and better hunting and a predator like a mongoose. The (such as a gazelle) develops enhanced skills, while the insect evolves better snake evolves increasingly potent venom, camouflage and faster running abilities camouflage and quicker speed to while the mongoose evolves resistance to escape. escape predation. to it, reflecting a continuous cycle of adaptations.  Triumph : we are a product of success story Here is an illustration depicting the triumph in Here is another illustration representing the Here is another illustration representing the triumph evolution, showcasing a successful species triumph in evolution, highlighting various of evolution across various species, including the that has adapted over time. This image species that have adapted successfully over development of mammals from early reptiles, highlights birds, which evolved from time. The image showcases evolutionary humans evolving advanced brains and bipedalism, dinosaurs, illustrating the development of milestones such as the emergence of modern and the rise of birds with the ability to fly. These key features like feathers, flight, and specialized humans, mammals evolving from reptiles, and adaptations highlight evolutionary success in beaks—key adaptations that represent birds developing specialized traits like flight different life forms. evolutionary success. and feathers, all symbolizing evolutionary success. Evolution in the Context of Modern Science With advances in molecular biology, Darwin's theory has been further supported by genetics. The discovery of DNA as the material of inheritance allowed scientists to identify the mechanisms of variation and heritability, showing how genetic mutations provide the raw material for natural selection. Studies in population genetics, genomics, and comparative genomics have deepened our understanding of evolutionary processes at the molecular level. The Modern Synthesis: This 20th-century update to Darwin's theory integrates natural selection with Mendelian genetics, explaining how evolution works at the level of genes and populations. Genomics: The sequencing of genomes across species has provided evidence for common ancestry and has allowed scientists to track the evolutionary history of species in unprecedented detail.  The Future of Evolutionary Theory: Genomics vs. Exposomics In recent years, the concept of the exposome—the cumulative environmental exposures throughout an organism's life—has become increasingly important in understanding human health and disease. The exposome includes factors such as diet, pollution, and lifestyle, and how these interact with our genome. Genome: The total genetic material of an organism, providing the hereditary basis for traits and disease susceptibility. Exposome: All the environmental exposures (including chemical, biological, and social factors) that an individual experiences over their lifetime, which can influence gene expression (epigenetics), health outcomes, and evolutionary processes. As we move into the future, the integration of genomics and exposomics is crucial for a more comprehensive understanding of human evolution and adaptation. While Darwin focused on natural selection as a driver of evolution, modern science shows that both genetic inheritance and environmental exposures shape organisms in complex ways.  The Future of Evolutionary Theory: Genomics vs. Exposomics In recent years, the concept of the exposome—the cumulative environmental exposures throughout an organism's life—has become increasingly important in understanding human health and disease. The exposome includes factors such as diet, pollution, and lifestyle, and how these interact with our genome. Genome: The total genetic material of an organism, providing the hereditary basis for traits and disease susceptibility. Exposome: All the environmental exposures (including chemical, biological, and social factors) that an individual experiences over their lifetime, which can influence gene expression (epigenetics), health outcomes, and evolutionary processes. As we move into the future, the integration of genomics and exposomics is crucial for a more comprehensive understanding of human evolution and adaptation. While Darwin focused on natural selection as a driver of evolution, modern science shows that both genetic inheritance and environmental exposures shape organisms in complex ways.  Conclusion: Current Research in Evolution: ▪ Genomics: Advances in DNA sequencing and epigenetics reveal evolutionary relationships and gene regulation. ▪ Evo-Devo biology: Studies how developmental genes drive morphological changes across species. ▪ Speciation & Hybridization: Focus on how new species form and the role of hybridization in evolution. ▪ Behavioural Evolution: Investigates the evolution of social behaviours, including altruism and cooperation. ▪ Human Evolution: New fossil evidence and ancient DNA studies refine our understanding of human ancestry. ▪ Evolutionary Medicine: Evolutionary theory helps explain disease patterns and pathogen resistance. ▪ Climate Change: Research on how species adapt or fail to adapt to rapidly changing environments. Than Q