LESSON-4-Evolution-A-Historical-Perspective.pdf

EVOLUTION A Historical Perspective LESSON 4  OBJECTIVES discuss evolution, and the process of how the physical properties and characteristics of animals change through a long period of time. cite various observable phenomena and structures which serve as evidence...

EVOLUTION A Historical Perspective LESSON 4  OBJECTIVES discuss evolution, and the process of how the physical properties and characteristics of animals change through a long period of time. cite various observable phenomena and structures which serve as evidence of evolution. describe and explain the different theories of evolution. identify the: (1) dominant species; and (2) changes which occurred on both biotic and abiotic life through Geologic Time Scale  ESSENTIAL QUESTION What are the changes that occurred in the anatomical and physiological aspects of animal life upon the course of evolution? What are the different evidence and theories of evolution and how can you describe and explain each? What are the different time periods in the Geologic Time Scale and what events happened in each GTS time frame?  What is Evolution? The change in the characteristics of a species over several generations and relies on the process of natural selection.  What is Evolution? A process of continuous change from a lower, simpler, or worse to a higher, more complex, or better state. Theories of Evolution  Theory of Natural Selection Charles Darwin (1809 – 1882) An English naturalist who is recognized as the Father of Evolution, and whose discoveries became the foundation of modern evolutionary studies. Charles Darwin In 1835, Darwin's five-week stay in the Galapagos island (an archipelago located at Ecuador) and his discovery of its wildlife (especially the finches, a type of bird) would inspire him to develop his theory of evolution, as supported with compelling evidence on his book, ON THE ORIGIN OF SPECIES Charles Darwin By 1842, Darwin had developed the essence of his conclusions but delayed their publication because of uncertainty about how they would be received. His ideas were eventually presented before the Linnean Society in London in 1858, and On the Origin of Species by Means of Natural Selection was published in 1859 and revolutionized biology.  Theory of Natural Selection “the survival of the fittest” it is the process by which organisms change over time as a result of changes in heritable physical or behavioral traits (these changes allow an organism to better adapt to its environment will help it survive and have more offspring) because resources are limited in nature, organisms with heritable traits that favor survival and reproduction will tend to leave more offspring than their peers, causing the traits to increase in frequency over generations Theory of Natural Selection  Theory of Organic Evolution This theory of evolution was not invented by Charles Darwin. But he described it as “descent with modification”, stating that present complexities in animals and plants are as a result of evolution from simpler forms that existed earlier through eventual changes. Organic Evolution process by which changes in the genetic composition of populations of organisms occur in response to environmental changes.  References of Darwin Empedocles and Aristotle Both described different concepts of change in living organisms over time.  References of Darwin Empedocles (495 BC – 435 BC). Claimed that the Earth had given birth to living creatures, but that the first creatures had been disembodied organs. Organs finally joined into whole organisms, through the force of Love, but some of these organisms, being monstrous and unfit for life, had died out.  References of Darwin Aristotle (384 BC – 322 BC). Did not believe in the concept of evolution. Rather, species were fixed and unchanging. But he believed that living things have a natural tendency to develop and grow towards a final, perfect state, which he referred to as their "telos”. Telos was determined by the essence or "form" of the species, and was predetermined by the gods.  References of Darwin Aristotle (384 BC – 322 BC). His belief is that organisms are divided into hierarchy “chain of being” or “scale or nature”. Sequence of organisms where humans are at the top.  References of Darwin Georges-Louis Buffon (1707–1788) Studied Comparative Anatomy for several years. His observations of structural variations in particular organs of related animals convinced him that change must have occurred during the history of life on earth. Buffon attributed change in organisms to the action of the environment. He believed in a special creation of species and considered change as being degenerate—for example, he described apes as degenerate humans.  References of Darwin Erasmus Darwin (1731–1802) A physician and the grandfather of Charles Darwin. He was intensely interested in questions of origin and change. He accepted the idea of a common ancestry of all organisms. He also discussed sexual selection which Charles Darwin later described as a combination of "female choosiness" and "direct competition between males"  References of Darwin Jean Baptiste de Lamarck (1744 – 1829) a French biologist and naturalist, he is an early proponent of the idea of biological evolution that acquired characteristics are inheritable, an idea referred to as Lamarckism, which is controverted by modern genetics and evolutionary theory Jean Baptiste de Lamarck Started his scientific career as a botanist, but later became one of the founding professors as an expert of invertebrates, and his research on the classification of worms, spiders, and mollusks was far ahead of his time. Hypothesized the theory of use and disuse  Theory of Use and Disuse Postulates that “frequent use of the organ gradually strengthens that organ, while permanent disuse of an organ weakens it” By Lamarck's account, animals, in responding to different environments, adopted new habits; their new habits caused them to use some organs more and some organs less, which resulted in the strengthening of the former and the weakening of the latter. Theory of Use and Disuse Theories of Evolution Theory of Use and Disuse Genetics  Revival of Lamarckism Within the last few years, a new evidence revived the Lamarckian ideas. A significant body of evidence is demonstrating that the environment can influence gene activity, and these altered activity states can be passed on to offspring. Altered activity states do not result from changes in DNA base sequences (unlike mutation), rather a result of DNA methylation and other gene control mechanisms.  Epigenetics The inheritance of environmentally induced change in a species. (Gr. epi, upon + gennan, to produce) Its overall contribution to evolutionary change is uncertain.  DARWIN’S EVIDENCES OF EVOLUTION  FOSSIL EVIDENCE Darwin found fossil remains of an extinct hippopotamus-like animal, now called Toxodon and fossils of a horselike animal, Thoatherium. These fossils were from animals that were clearly different from any other animal living in the region. Darwin also found fossils of giant armadillos and giant sloths. Except for their large size, these fossils were very similar to forms living in the region. Galápagos Islands Darwin noticed that the shapes of the tortoise shells from different parts of Albemarle Island differed. Tortoises from the drier regions had longer necks than tortoises from wetter habitats. In spite of their differences, the tortoises were quite similar to each other and to the tortoises on the mainland of South America. Darwin reasoned that the island forms were derived from a few ancestral animals that managed to travel from the mainland. Galápagos Islands The Galápagos Islands are volcanic and arose out of the seabed, no land connection with the mainland ever existed. So how did the tortoises travel? One modern hypothesis is that tortoises floated from the mainland on mats of vegetation that regularly break free from coastal riverbanks during storms. Without predators on the islands, tortoises gradually increased in number.  Galápagos Islands Darwin also noticed that the Galápagos finches bore similarities suggestive of common ancestry. Scientists now think that Galápagos finches also descended from an ancestral species that originally inhabited the mainland of South America. Ancestral finches, probably seed eaters, multiplied rapidly and filled the seed-bearing habitats most attractive to them. Each species is adapted to a specific habitat on the islands. The most obvious difference between these finches relates to dietary adaptations and is reflected in the size and shape of their bills. The finches of the Galápagos Islands provide an example of adaptive radiation—the formation of new forms from an ancestral species, usually in response to the opening of new habitats. Galápagos Islands  ARTIFICIAL SELECTION An evolutionary process in which humans consciously select for or against particular features in organisms.  NATURAL SELECTION  Natural Selection Charles Darwin had no knowledge of modern genetic concepts, and the genetic principles that are the basis of evolutionary theory as it exists today. The modern version of his theory can be summarized as follows: 1. All organisms have a far greater reproductive potential than is ever realized. 2. Inherited variations exist. They arise from a variety of sources, including mutation, genetic recombination, and random fertilization. 3. Because resources are limited, existence is a constant struggle. 4. Adaptive traits become more common in subsequent generations. EVOLUTION is brought by ADAPTATION as adaptations promote survival and make successful reproduction more likely. EVIDENCES OF EVOLUTION  Biogeography The study of the geographic distribution of plants and animals. One of the distribution patterns that biogeographers try to explain is how similar groups of organisms have dispersed to places separated by seemingly impenetrable barriers. For example, native cats are inhabitants of most continents of the earth, yet they cannot cross expanses of open oceans. Obvious similarities suggest a common ancestry, but similarly obvious differences result from millions of years of independent evolution  Paleontology The history of life on Earth as based on fossils. Provides some of the most direct evidence for evolution. The fossil record provides information regarding sequences in the appearance and disappearance of organisms  Analogy and Homology Similarity in the structure and functions of structures among organisms. Resemblance may occur when two unrelated organisms adapt to similar conditions. The evolution of superficially similar structures in unrelated organisms is called convergent evolution, and those structures having similar function are said to be analogous.  Analogy and Homology Similarity in the structure and functions of structures among organisms. Resemblance may also occur because two organisms share a common ancestry. Structures and processes in two kinds of organisms that are derived from common ancestry are said to be homologous. Homology can involve aspects of an organism’s structure, and these homologies are studied in the discipline called comparative anatomy  Developmental Patterns The developmental stages of related animals often retain common features because changes in the genes that control the development of animals are usually harmful and are eliminated by natural selection. For example, early embryonic stages of vertebrates are remarkably similar. Many organ systems of vertebrates also show similar developmental patterns. These similarities are compelling evidence of evolutionary relationships within animal groups  Molecular Biology Permitted the characterization of genetic diversity among individuals, populations, and species—the three cornerstones of evolution. Similarities between biological molecules can reflect shared evolutionary ancestry. Similarities and differences between the "same" gene in different organisms (that is, a pair of homologous genes) can help us determine how closely related the organisms are. Molecular Biology Molecular Biology Molecular Biology BREAK TIME  Geologic Time Scale  Geologic Time Scale It is the stratigraphic history of the Earth. Stratigraphy, also called chronostratigraphy is the ordering and analysis of the layers of the Earth (also called strata) based chronological dating techniques and the layers' positions relative to each other. Geologic time begins approximately 4.6 billion years ago, shortly after when the Earth began to form. Eons Eras Periods Epochs Hadean Eon Named after the Greek god and ruler of the underworld, Hades; inspired from the brutal, hell-like conditions of the earth and the constant barrage and bombardment of colossal meteorites and comets The oldest eon and dates from 4.5 to 4.0 billion years ago Characterized by an extremely hot temperate due to several mechanisms such as asteroid impacts, gravitational compression, and radioactive decay Hadean Eon Archean Eon Derived from the Greek word “archaios”, which means the beginning or origin Lasted from 4.0 to 2.5 billion years ago Formation of the first continents and the first oceans The first evidence of modern plate tectonics is found at the end of Archean eon, indicating the occurrence of at last some continental lithosphere Appearance of the first prokaryotic bacteria. Archean Eon Proterozoic Eon Meaning “earlier life”, eon of time after the archean eon and ranges from 2.5 billion years to 541 million years ago Oxygen accumulated in the atmosphere through photosynthesis performed by early-life form organisms First multicellular and eukaryotic organisms appeared Proterozoic Eon PRECAMBRIAN SUPER EON Phanerozoic Eon Referred to as “the eon of visible life” Extending about 541 million years ago to the present time Rapid expansion and evolution of biological forms as well as the formation of ecological niche Composed of three major eras: (a) Paleozoic era; (b) Mesozoic era; and (c) Cenozoic era Phanerozoic Eon Paleozoic Era The earliest of the three geologic eras of the phanerozoic eon and the longest of the three phanerozoic eras, lasting from 541 million years to approximately 252 million years ago Characterized by formation of the supercontinent and widespread of plants and early vertebrate life forms Paleozoic Era Cambrian Period The first geological period of the Paleozoic era, and of the phanerozoic eon, occurring at approximately 541 to 485 million years ago Produced the most intense burst of evolution through the phenomenon known as “the Cambrian Explosion”, which gave life to an incredible diversity including major animal groups alive today Trilobites are common Earliest forms of vertebrates appeared Trilobites  The second of six periods of the Paleozoic era which spanned from 485 to 443 million years ago During this period, majority of the area on the northern portion of the world is almost entirely ocean while Ordovician the most of the world’s land was collected into the southern Period supercontinent Gondwana Marine invertebrates flourished and the first jawless fish appeared On land, the first plants appeared  The third and acclaimed as the shortest period of the Paleozoic era, lasting from only 443 to 419 million years ago Stabilization of the earth’s general climate Melting of large glacial formation which gave Silurian way to a substantial rise in the levels of the major seas Period Rapid spread of jawless fish and highly significant appearances of both the first freshwater and jawed fishes Development of the first vascular plants May have marked the beginning of the first terrestrial animal life  The fourth period of the Paleozoic era which occurred from 419 to 358 million years ago Appearance of ferns, seed plants, and the first trees and first forests Devonian First terrestrial arthropods including wingless insects and earliest Period arachnids Sometimes referred to as “the age of fishes”, due to marine life diversity Appearance of the first amphibians  The fifth period of the Paleozoic era which lasted from 358 to 298 million years ago Carboniferous, which means “carbon- bearing”, amount of coal produced on the vast swamp forests during Carboniferous this period Occurrence of one of the greatest Period evolutionary innovations: the amniote egg, which provided the animals the ability to lay eggs Appearance of the first form of reptiles  The sixth and final period of the Paleozoic era which ranged from 298 to 251 million years ago Early formation of the supercontinent Pangaea Permian Proliferation of early form of reptiles and other gymnosperms Period Phenomenon known as “the great dying”, which is acknowledged as the largest mass extinction in the history of life on earth Mesozoic Era The second of the three geologic eras of the phanerozoic eon, lasting from 251 million years to 65 million years ago Mesozoic means “middle animals”, this is due to the drastic change in the world fauna compared to what have been seen on the Paleozoic era A time of great change in the terrestrial vegetation Mesozoic Era Triassic Period The first and recognized as the shortest period of the Mesozoic era, spanning only from 251 to 201 million years ago The supercontinent Pangaea finished forming, altering the global climate and water circulation Reptiles increased in diversity and in number Appearance of the first dinosaur First mammals emerged; tiny, fur-bearing, mouse-like animals derived from reptiles Jurassic Period The second period of the Mesozoic era which occurred from 201 to 145 million years ago Dubbed as “the age of reptiles” Propagation and domination of dinosaurs on the land fauna Oceans exhibit a wide diversity of marine animals Characterized by vertebrates taking to the air and the appearance of the first bird Cretaceous Period The third, last, and longest period of the Mesozoic era which ranged from 145 to 66 million years ago Continuation of the drifting apart of the supercontinent Pangaea, which led to regional differences in the floras and faunas between the northern and southern continents Appearance of the first flowering plants or angiosperms Many modern groups of insects diversified Marked with the phenomenon known as “The Cretaceous- Tertiary Extinction” Cenozoic Era The recent and third of the three geologic eras of the phanerozoic eon, lasting from 66 million years ago to the present day Cenozoic which means “new life” and is sometimes referred to as “the age of mammals”, due to the dominant terrestrial fauna Interval of time during which the continents have assumed their current configuration TERTIARY PERIOD The first period of the Cenozoic era which occurred from 66 to 23 million years ago; known as the earliest division Paleogene of the tertiary period Period A Greek word which means “ancient-born”  PALEOGENE PERIOD: Epoch continents drift towards their current Paleocene positions; fern spikes and development of Epoch modern plant species Eocene development of modern orders of Epoch mammals; open savannah-like vegetation PALEOCENE PALEOCENE EOCENE  PALEOGENE PERIOD: Epoch Oligocene temperate and subtropical climatic conditions; terrestrial and vertebrate Epoch faunas become diverse and abundant TERTIARY PERIOD The second period of the Cenozoic era which lasted from 23 to 2.6 million years ago Neogene A Greek word which means “new Period born”, designed to give emphasis that the marine and terrestrial fossils found in the strata of this time are closely related  NEOGENE PERIOD: Epoch ancestors of modern, land-dwelling animals Miocene such as giraffes, elephants, antelopes, and dears; horse evolution occurred in North America, first Epoch dogs and bears appeared colder and drier climate; mastodons (elephant- Pliocene like animals) had a great evolutionary Epoch diversification; appearance of the first primates and australopithecines, the first creatures that can be termed human MIOCENE PLIOCENE PLIOCENE  The current and most recent of the three periods under Cenozoic era, spanning from 2.8 million years ago to the current time Characterized by several periods of Quaternary glaciations, commonly referred to as “ice age” which resulted in rapid Period changes in climate and sea level Rapid changes in life forms, both flora and fauna and known for the rise of modern humans  QUATERNARY PERIOD: Epoch Informally referred to as “the great ice age”, this is the time period during which a succession of glacial and interglacial climate cycles occurred; characterized by Pleistocene the presence of distinctively large mammals Epoch and birds; and saw the evolution and expansion of our own species, homo sapiens  QUATERNARY PERIOD: Epoch Recognized as “the age of man”, since it has witnessed all of humanity’s recorded Holocene history and the rise and fall of its civilizations, and characterized by the Epoch great advancement and development of human knowledge and technology  Anthropocene Epoch The “Age of Humans” Start of naming geologic-time terms needs to define what exactly the boundary is, where it appears in the rock strata. Proposed epoch  ❖Human global nuclear annihilation ❖Biological warfare Anthropogenic ❖Dysgenics ❖Overpopulation Extinction ❖Ecological collapse ❖Climate Change  ESSENTIAL QUESTION What are the changes that occurred in the anatomical and physiological aspects of animal life upon the course of evolution? What are the different evidence and theories of evolution and how can you describe and explain each? What are the different time periods in the Geologic Time Scale and what events happened in each GTS time frame?  OBJECTIVES discuss evolution, and the process of how the physical properties and characteristics of animals change through a long period of time. cite various observable phenomena and structures which serve as evidence of evolution. describe and explain the different theories of evolution. identify the: (1) dominant species; and (2) changes which occurred on both biotic and abiotic life through Geologic Time Scale EVOLUTION A Historical Perspective LESSON 4