Evolution PowerPoint Presentation PDF

EVOLUTION SANDEEP SHRESTHA PRESENTATION TITLE AGENDA EVOLUTION THEORIES ON EVOLUTION EVIDENCE OF EVOLUTION NATURAL SELECTION VARIATION AND MUTATION 2 PRESENTATION...

EVOLUTION SANDEEP SHRESTHA PRESENTATION TITLE AGENDA EVOLUTION THEORIES ON EVOLUTION EVIDENCE OF EVOLUTION NATURAL SELECTION VARIATION AND MUTATION 2 PRESENTATION TITLE INTRODUCTION Evolution is the process of change and development over time, whereby living organisms' characteristics and traits gradually undergo modifications from generation to generation. This process results in the diversification of life forms, leading to the emergence of new species and the extinction of others. Evolution occurs primarily through mechanisms such as natural selection, genetic drift, gene 3 flow, and mutation, which collectively shape the genetic makeup and adaptation of organisms to  IMPORTANCE OF UNDERSTANDING EVOLUTION Explanation of Biodiversity: Evolutionary theory provides an explanation for the incredible diversity of life on Earth. It helps us understand how different species have emerged and adapted to their environments over millions of years. Conservation: Knowledge of evolution is vital for conservation efforts. Understanding the genetic diversity and evolutionary relationships of species assists in creating effective conservation plans and preserving biodiversity. PRESENTATION TITLE EXPLAIN HOW IT INVOLVES CHANGES IN THE GENETIC MAKEUP OF A POPULATION OVER GENERATIONS? NATURAL SELECTION: THIS IS THE PROCESS WHERE CERTAIN TRAITS OR VARIATIONS IN A POPULATION BECOME MORE OR LESS COMMON OVER TIME BASED ON THEIR IMPACT ON AN INDIVIDUAL'S ABILITY TO SURVIVE AND REPRODUCE. INDIVIDUALS WITH ADVANTAGEOUS TRAITS HAVE A HIGHER CHANCE OF SURVIVING AND PASSING THOSE TRAITS TO THEIR OFFSPRING, WHILE THOSE WITH LESS BENEFICIAL TRAITS MAY NOT SURVIVE AS SUCCESSFULLY OR REPRODUCE AS MUCH. 5 AS A RESULT, BENEFICIAL TRAITS BECOME MORE PREVALENT IN THE POPULATION, PRESENTATION TITLE GENE FLOW GENE FLOW: GENE FLOW REFERS TO THE EXCHANGE OF GENETIC MATERIAL BETWEEN DIFFERENT POPULATIONS OF THE SAME SPECIES. WHEN INDIVIDUALS FROM ONE POPULATION MIGRATE AND INTERBREED WITH INDIVIDUALS FROM ANOTHER POPULATION, THEY INTRODUCE NEW GENETIC VARIATIONS INTO THE RECIPIENT POPULATION. THIS MIXING OF GENES CAN LEAD TO 6 CHANGES IN THE GENETIC MAKEUP OF BOTH POPULATIONS OVER TIME. PRESENTATION TITLE MUTATION MUTATIONS ARE RANDOM CHANGES IN THE DNA SEQUENCE OF AN ORGANISM'S GENES. THESE MUTATIONS CAN CREATE NEW GENETIC VARIATIONS, SOME OF WHICH MAY BE ADVANTAGEOUS, WHILE OTHERS MAY BE DETRIMENTAL. WHEN BENEFICIAL MUTATIONS ARISE, THEY CAN INCREASE IN FREQUENCY IN A POPULATION THROUGH NATURAL SELECTION, LEADING TO CHANGES IN 7 THE GENETIC MAKEUP OF SUBSEQUENT GENERATIONS. PRESENTATION TITLE THEORY OF SPECIAL CREATION According to the theory of special creation, life was created by supernatural power of God. He created all the plants and animals, which appeared on the earth in the form they exist today. This theory is based on faith. It has no scientific evidence; therefore, it is not widely accepted. 8 PRESENTATION TITLE THEORY OF SPONTANEOUS GENERATION According to this theory, life was originated from non-living things spontaneously. It was believed that the mud of the river Nile could give rise to living creatures like frogs, toads, snakes and crocodiles, when warmed in the sun. According to Van Helmont, human’s shirt wet in sweat and wheat bran is kept together for 21 days, it could form mice. However, Helmont’s claim was not found true 9 when checked by experiment.  MODERN CONCEPT OF PRESENTATION TITLE ORIGIN OF LIFE According to Oparin-Haldane theory, the first living cell arose from simple elements. Micro-molecules like carbon, hydrogen, oxygen, nitrogen,etc. united to macro-molecules like protein, carbohydrates, enzymes, nucleic acids, etc. They then interacted to produce the first living cell by a process called abiogenesis. Abiogenesis means development of a living thing from a non-living matter by the influence of external source of energy like UV radiation. It was 10 chemical evolution, followed by organic evolution. PRESENTATION TITLE ORGANIC EVOLUTION Organic evolution, also known as biological evolution, is the process through which living organisms change and diversify over time. It is the central concept of modern biology and is supported by substantial evidence from various scientific disciplines. Organic evolution occurs through the mechanisms of natural selection, genetic drift, and gene flow, leading to changes in the genetic makeup of populations over generations. The main driving force behind organic evolution is natural selection, proposed by Charles Darwin. It states that individuals with advantageous traits are more likely to survive and reproduce, passing those traits on to 11 their offspring, while less fit individuals are less likely to reproduce. Over time, this process leads to the accumulation of beneficial traits in a PRESENTATION TITLE EVIDENCES OF EVOLUTION Fossils record or palaeontological evidence Comparative morphology and anatomy Homologous and analogous organs Vestigial organs Embryo or embryo logical evidence Geographical distribution of organisms 12 Connecting or bridge animals  PALAEONTOLOGICAL EVIDENCE PRESENTATION TITLE Fossil evidence is one of the most significant pillars supporting the theory of evolution. Fossils provide a tangible record of past life on Earth, allowing scientists to study the changes in organisms over time. Here are some key aspects of fossil evidence for evolution: Transitional Fossils: Fossils that exhibit traits of both ancestral and descendant species are known as transitional fossils. These fossils demonstrate gradual changes and the evolutionary transition between different forms of life. For example, the fossilized remains of Archaeopteryx show a mix of reptilian and avian characteristics, supporting the idea of a link between dinosaurs and birds. Chronological Record: The fossil record provides a chronological sequence of life forms, revealing the progression of species over geological time. This record helps researchers understand the timing and order of evolutionary events and major shifts in biodiversity. 13 Extinction Events: Fossils also offer evidence of mass extinctions, which have occurred throughout Earth's history. These events have shaped the course of evolution by clearing the way for new species to emerge and diversify. PRESENTATION TITLE 14 ARCHAEOPTERYX IS AN EXTINCT ANIMAL WHICH LINKS BETWEEN REPTILES AND AVES. PRESENTATION TITLE EVIDENCES FROM COMPARATIVE MORPHOLOGY AND ANATOMY HOMOLOGOUS STRUCTURES: COMPARATIVE ANATOMY REVEALS HOMOLOGOUS STRUCTURES, WHICH ARE SIMILAR BODY PARTS FOUND IN DIFFERENT SPECIES DUE TO A SHARED COMMON ANCESTOR. THESE STRUCTURES MAY HAVE DIFFERENT FUNCTIONS BUT POSSESS UNDERLYING SIMILARITIES IN THEIR FORM AND DEVELOPMENT. AN EXAMPLE IS THE PENTADACTYL LIMB FOUND IN VARIOUS 15 VERTEBRATES, INCLUDING HUMANS, CATS, WHALES, AND BATS. PRESENTATION TITLE ANALOGOUS ORGANS ON THE OTHER HAND, COMPARATIVE ANATOMY ALSO IDENTIFIES ANALOGOUS STRUCTURES, WHICH ARE BODY PARTS WITH SIMILAR FUNCTIONS IN DIFFERENT SPECIES BUT WITH DIFFERENT EVOLUTIONARY ORIGINS. THESE SIMILARITIES ARE DUE TO CONVERGENT EVOLUTION, WHERE UNRELATED ORGANISMS INDEPENDENTLY DEVELOP SIMILAR ADAPTATIONS TO SIMILAR ENVIRONMENTS. AN EXAMPLE IS THE WINGS OF BIRDS AND INSECTS, BOTH 16 ADAPTED FOR FLIGHT BUT WITH DIFFERENT UNDERLYING STRUCTURES. PRESENTATION TITLE VESTIGIAL ORGANS COMPARATIVE ANATOMY ALSO REVEALS VESTIGIAL STRUCTURES, WHICH ARE REMNANTS OF ONCE-FUNCTIONAL ORGANS OR BODY PARTS THAT HAVE LOST THEIR ORIGINAL PURPOSE THROUGH EVOLUTION. HUMAN EXAMPLES INCLUDE THE APPENDIX, WHICH IS THOUGHT TO BE A VESTIGE OF A LARGER CECUM FOUND IN OTHER MAMMALS, AND THE TAILBONE 17 (COCCYX), A REMNANT OF A TAIL THAT ANCESTRAL PRIMATES ONCE HAD. PRESENTATION TITLE EMBRYONIC EVIDENCE During early stages of development, embryos of different species often share similar structures, despite their adult forms being quite distinct. These homologous structures suggest common ancestry and shared evolutionary history. For example, the embryos of fish, reptiles, birds, and mammals initially exhibit gill slits and tails, indicating their shared aquatic ancestry. 18 According to Biogenetic law, ontogeny (embryo development) repeats phylogeny ( evolutionary PRESENTATION TITLE EVIDENCE FROM GEOGRAPHICAL DISTRIBUTION OF ORGANISMS Continental Drift: The distribution of organisms across continents supports the theory of continental drift, which states that the Earth's continents were once part of a supercontinent and have since drifted apart over millions of years. Biogeographical patterns reflect how species evolved in isolation and then spread to different 19 regions as the continents moved. PRESENTATION TITLE Dispersal and Migration: Geographical distribution also reflects the movement and migration of species. Some organisms have successfully dispersed across vast distances, leading to the colonization of new habitats and the establishment of new 20 populations. PRESENTATION TITLE EVIDENCE FROM BRIDGE ANIMALS OR CONNECTING LINKS The concept of "bridge animals" or "connecting links" refers to organisms that exhibit characteristics of both major groups, serving as transitional forms between different taxa. These creatures provide critical evidence for evolution by demonstrating gradual changes and evolutionary links between different species. Some well-known examples of bridge animals include: Archaeopteryx: Often referred to as a "missing link" between reptiles and birds, Archaeopteryx is an ancient bird-like dinosaur that lived during the Late Jurassic period. It possessed features 21 of both reptiles, such as teeth and a long bony tail, and birds, including feathers and wing-like structures. PRESENTATION TITLE Tiktaalik: Tiktaalik is an iconic example of a transitional fossil representing the transition from fish to tetrapods (four-limbed vertebrates). This creature, dating back to the Late Devonian period, had fish-like gills and fins but also limb-like structures with wrists, suggesting an intermediate stage between aquatic and terrestrial life. 22  SUMMARY PRESENTATION TITLE In summary, evolution is a scientifically well-supported theory that explains the rich tapestry of life's history, showcasing the dynamic nature of the natural world and the interconnectedness of all living beings. 23  THANK YOU SANDEEP SHRESTHA [email protected]