(GEN BIO)EVOLUTION, TAXONOMY AND ECOSYSTEM

EVOLUTION, CHARLES DARWIN

1. EVOLUTION, TAXONOMY AND ECOSYSTEM

2. EARTH’S AGE Earth is estimated to be 4.54 billion years old, plus or minus about 50 million years. Scientists have scoured the Earth searching for the oldest rocks to radiometrically date. Earth’s documented history is based on the life-forms that have existed on the planet.

3. GEOLOGIC TIME SCALE The “ calendar ” for events in Earth history It was developed after scientists observed changes in the fossils going from oldest to youngest sedimentary rocks . They used relative dating to divide Earth's past in several chunks of time when similar organisms were on Earth

4. PRE-CAMBRIAN S tarted at the beginning of the Earth . For billions of years, there was  no life on the planet. The earliest life consisted of cyanobacteria that were able to extract nutrition from chemicals in seawater.

5. EONS HADEAN 4.5 – 4.0 BYA T he planet was characterized by a partially molten surface, volcanism, and asteroid impacts. ARCHAEAN 4 – 2.5 BYA T he Earth's crust cooled enough that rocks and continental plates began to form. PROTEROZOIC 2.5 BYA – 541 M YA Great Oxygenation Event Cyanobacteria completely transformed the atmosphere by adding free oxygen gas (O2).

6. PHANEROZOIC EON PALEOZOIC ERA 542 – 250 MYA CAMBRIAN EXPLOSION It was when most of the major animal groups started to appear in the fossil record, a time of rapid expansion of different forms of life on Earth. MESOZOIC ERA 250 – 65 MYA “MIDDLE LIFE” T his is the time of the dinosaurs. This era includes the Triassic, Jurassic, and Cretaceous Periods . Mass Extinction of non-avian Dinosaurs. CENOZOIC ERA 65 MYA - PRESENT “RECENT LIFE” Ice Age covered most parts of the Earth. Mammals dominated the Earth, the age of mammals . All species of life—including humans—evolved into their present-day forms over the course of this era.

7. MASS EXTINCTIONS ORDOVICIAN-SILURIAN 444 MYA Glaciation and Heating Event The plant life removed CO2 from the air causing global cooling. Global warming made the creatures unable to adapt the temperature. 86% lost LATE DEVONIAN 365 MYA Algal Blooms and Glaciation The theory suggest algae consumed vast amounts of O2 in the ocean, suffocating the marine life. Other theory suggest that another global cooling leads to habitat loss of living organisms. 75% lost PERMIAN-TRIASSIC 252 MYA Volcanic activity released massive amount of CO2 , bacteria thrived. Bacteria released methane gas that warmed the planet. Ocean and water became acidic, Earth became toxic . 96% lost

8. MASS EXTINCTIONS TRIASSIC-JURASSIC 201.3 MYA Volcanic Activity and Asteroid Impact Volcanic eruptions spewed tons of CO2 into atmosphere, this acidified the ocean and warmed the Earth. An asteroid or comet impact triggered the extinction of dinosaurs. 80% lost CRETACEOUS-PALEOGENE 66 MYA Asteroid Impact A widely accepted theory tells that asteroid landed in the Y ucatain Peninsula in Mexico and wiped out the non-avian dinosaurs. This also caused global cooling, local fires, earthquakes, tsunamis, and acid rain. 60-76 % lost

9. EVOLUTIONARY IDEA

10. EVOLUTION Evolution is the change in the genetic composition of a population over time . T he change in the characteristics of a species over several generations. On a larger scale, evolution can be used to refer to the gradual appearance of all biological diversity.

11. CHARLES DARWIN Charles Darwin presented evidence that many modern organisms are descended from ancestral species that were different. Darwin presented a mechanism for evolution – natural selection. On the Origin of Species (1859)

12. NATURAL SELECTION

13. NATURAL SELECTION Natural selection occurs when organisms with particular heritable traits have more offspring that survive & reproduce. When an environment changes, or when individuals move to a new environment, natural selection may result in adaptation to the new conditions.

14. NATURAL SELECTION Individuals do not evolve; populations evolve. Natural selection can only work on heritable traits . Acquired traits are not heritable and are not subject to natural selection.

15. EVOLUTION

16. CATEGORIES OF EVOLUTION MICROEVOLUTION MACROEVOLUTION

17. MICROEVOLUTION Evolution at individual species scale. A change of allele frequencies in a population over a short time. The basis for all large-scale or macroevolution.

18. CAUSES OF MICROEVOLUTION GENETIC DRIFT The change in the gene pool of a small population due to chance. NATURAL SELECTION The species that can adapt and survive will pass their traits to the future generations. GENE FLOW Genetic exchange due to the migration of fertile individuals or gametes between populations.

19. CAUSES OF MICROEVOLUTION MUTATION Change in an organism’s DNA. Mutations can be inherited by offspring via gametes . NON-RANDOM MATING Mates are chosen on the basis of the best traits.

20. CATEGORIES OF EVOLUTION MICROEVOLUTION MACROEVOLUTION

21. MACROEVOLUTION A change that occurs at or above the species level. It is the occurrence of large-scale changes in the characteristics of life resulting to evolution of higher taxa. A change of one species into an entirely different species - SPECIATION

22. SPECIATION Formation of new species. Species – a group of organisms that can interbreed and produce a fertile offspring. Factors : Natural Selection, Continental Drift, Changes in Environment, Mutations, and Man.

23. FACTORS OF SPECIATION CONTINENTAL DRIFT When the continents separated, the animals were separated. NATURAL SELECTION The species that can adapt and survive will pass their traits to the future generations. CHANGES IN ENVIRONMENT Changes in the environment forces the species to change for survival .

24. FACTORS OF SPECIATION MUTATION Change in an organism’s DNA. Mutations can be inherited by offspring via gametes . ARTIFICIAL SELECTION Selective breeding as practiced by humans on domesticated plants and animals.

25. FACTORS OF SPECIATION

26. EVIDENCES OF EVOLUTION

27. EVIDENCES OF EVOLUTION F – FOSSIL evidences (remains of the ancient organisms) A – ANATOMICAL STRUCTURE or comparative anatomy (body parts) M – MOLECULAR EVIDENCE (DNA/RNA/ATP ) E – EMBRYOLOGY (embryos look similar from one species to the next)

28. EVIDENCES OF EVOLUTION FOSSILS Fossils are remnants of past life preserved in the Earth. Complete remains, petrifies skeletal parts, traces of organisms. ANATOMICAL STRUCTURES The comparative study of the body structures of different species of animals in order to understand the adaptive changes they have undergone in the course of evolution from common ancestors.

29. EVIDENCES OF EVOLUTION MOLECULAR BIOLOGY similarities between biological molecules can reflect shared evolutionary ancestry. Similarities in DNA, RNA, Proteins, and Amino Acids. EMBRYOLOGY All vertebrate embryos exhibit pharyngeal pouches at a certain stage of their development. These features, which develop into neck and face parts, suggest relatedness.

30. TAXONOMY

31. TAXONOMY Taxonomy is the science of naming, describing and classifying organisms and includes all plants, animals and microorganisms of the world. A taxon is a group of organisms in a classification system. Father of Taxonomy: Carl Linnaeus developed the scientific naming system.

32. BINOMIAL NOMENCLATURE Binomial nomenclature is a two-part scientific naming system. It uses LATIN words Scientific names always written in italics Composed of two parts : genus name and species descriptor.

33. BINOMIAL NOMENCLATURE: GENUS A genus includes one or more physically similar species. Species in the same genus are thought to be closely related. Genus name is always capitalized . e .g Homo sapiens – Humans Canis lupus familiaris - Dogs

34. BINOMIAL NOMENCLATURE: SPECIES A species descriptor is the second part of a scientific name. Species name is always written in lowercase . Species name always follows genus name ; never written alone. e.g Carlito syrichta - Philippine Tarsier

35. SCIENTIFIC NAMES Scientific names help scientists to clearly communicate about species. Some species have very similar common names. Some species have many common names. Scientific name : Hibiscus rosa sinensis Common names : Gumamela , Hibiscus, Tapurang ( Bis .) Shoe flower (Engl.)

36. LINNAEAN CLASSIFICATION SYSTEM Linnaeus’ classification system has seven levels. Limitations : It doesn’t account for molecular evidence such as DNA sequencing. Linnaean system based only on physical similarities .

37. MODERN CLASSIFICATION SYSTEM Cladistics – classification based on common ancestry. Phylogeny – evolutionary history for a group of species. Based from evidences from living species, fossil records, and molecular data. Phylogenetic tree - a diagram that depicts the lines of evolutionary descent of different species, organisms, or genes from a common ancestor.

38. MODERN CLASSIFICATION SYSTEM

39. ECOSYSTEM

40. ECOSYSTEM A biological community of interacting organisms and their physical environment . It has two major components: Abiotic and Biotic components.

41. COMPONENTS OF ECOSYSTEM BIOTIC COMPONENTS Living components of an ecosystem. producers, consumers, and decomposers ABIOTIC COMPONENTS The physical and/or the chemical factors that act on the living organisms at any part of their life. Light, air, soil, and nutrients.

42. SYMBIOTIC RELATIONSHIPS MUTUALISM when two species of organisms benefit from living in close association with each other. COMMENSALISM a symbiotic relationship in which one species benefit and the other species is not significantly affected . PARASITISM relationship between the two living species in which one organism is benefitted at the expense of the other.

43. ECOLOGICAL RELATIONSHIP PREDATION one population is the resource of the other. COMPETITION individuals seek to obtain the same environmental resource.

44. FOOD CHAINS AND FOOD WEBS A food chain is a series of steps in which organisms transfer energy by eating and being eaten. Food chains can vary in length. Composed of: Producers Primary Consumers Secondary Consumers Tertiary Consumers Apex Predator Decomposers

45. TROPHIC LEVELS TROPHIC LEVEL WHERE IT GETS FOOD EXAMPLES 1st Trophic Level: Producer Makes its own food Plants make food 2nd Trophic Level: Primary Consumer Consumes producers Mice eat plant seeds 3rd Trophic Level: Secondary Consumer Consumes primary consumers Snakes eat mice 4th Trophic Level: Tertiary Consumer Consumes secondary consumers Hawks eat snakes

46. FOOD CHAINS AND FOOD WEBS Food Web - feeding relationships are much more complicated than the relationships described in a single, simple chain because many animals eat more than one kind of food. Each path through a food web is a food chain. A food web, like the one shown, links all of the food chains in an ecosystem together.

47. ENERGY FLOW IN ECOSYSTEMS Ecological Pyramids show the relative amount pf energy or matter contained within each trophic level in a given food chain or food web. Types : Pyramid of energy Pyramid of biomass Pyramid of numbers

48. ENERGY FLOW IN ECOSYSTEMS Ecological Pyramids show the relative amount pf energy or matter contained within each trophic level in a given food chain or food web. Types : Pyramid of energy Pyramid of biomass Pyramid of numbers

49. PYRAMID OF ENERGY Pyramids of energy show the relative amount of energy available at each trophic level. Organisms expend much of the energy they acquire on life processes, such as respiration, movement, growth, and reproduction. Most of the remaining energy is released into the environment as heat — a byproduct of these activities.

50. PYRAMID OF ENERGY On average, about 10 percent of the energy available within one trophic level is transferred to the next trophic level.

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