General Biology 2 - Evolution PDF

Remedios National High School GENERAL BIOLOGY 2 Prepared by: Ms. Jennica Lyn N. Bagang Why there are so many similarities in different types of organisms? Theory: Maybe we came from a common ances...

Remedios National High School GENERAL BIOLOGY 2 Prepared by: Ms. Jennica Lyn N. Bagang Why there are so many similarities in different types of organisms? Theory: Maybe we came from a common ancestor who changed little bit by little bit to adjust to the environment Image source: https://thm-monocle-interactive.s3.amazonaws.com/xhxbyz8NvS%2FJaw+evolution.jpg  Change in heritable traits of biological populations over many generation Evolution stresses the relatedness of all life rather than its differences Image source: https://www.genome.gov/sites/default/files/media/images/tg/Evolution.jpg Based on scale: MACROEVOLUTION - which refers to large-scale changes that occur over extended time periods, such as the formation of new species and groups. MICROEVOLUTION - which refers to small-scale changes that affect just one or a few genes and happen in populations over shorter timescales. Organisms better suited for their environments are more likely to survive and produce offspring Image source: https://cdn.kastatic.org/ka-perseus-images/8f33aa4bd39c5c435af5e5dc4001d73721a25f85.png Organisms better suited for their environments are more likely to survive and produce offspring Image source: https://i0.wp.com/creationscience4kids.com/wp-content/uploads/2017/02/CS4K-Natural-Selection-Giraffes.png?resize=750%2C331 Image source: https://lh3.googleusercontent.com/proxy/HIG6lSirTkTPqChHChFI0BRTJR57iwkhFLhSZJv3xjGoOk0-rNdawXgyU-IDl8iDuEOFZJ  A change in the DNA sequence of an organism. 1. Harmful 2. Neutral 3. Beneficial Image source: https://bit.ly/3ISwMPF Individuals carry genes from one population to another and change the gene pool of the receiving population Image source: https://upload.wikimedia.org/wikipedia/commons/4/47/Gene_flow_final.png  Allele frequency leads to change due to chance Image source: https://upload.wikimedia.org/wikipedia/commons/thumb/0/0b/Random_sampling_genetic_drift.svg/550pxRandom_sampling_genetic_drift.svg.png  Bottleneck effect occurs with small population Image source: https://bit.ly/4cJJj5E Image source: https://bit.ly/49c7Mxo We can directly observe small-scale evolution in organisms with short lifecycles (e.g., antibiotic-resistant bacteria and pesticide-resistant insects). Image source: https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcTBSmNjyPHqtu_1OH90HV3xHHF35-M71VDrMduodMD  Physical features shared due to evolutionary history (a common ancestor) are said to be homologous. If two or more species share a unique physical feature, such as a complex bone structure or a body plan, they may all have inherited this feature from a common ancestor. Image source: https://cdn.kastatic.org/ka-perseus-images/d40a2f6d0904542471f597d0ff0c27517f8c30ab.png Structural similarities are usually result of common ancestry Example: forelimbs of whales, humans, birds, and dogs Image source: https://cdn.kastatic.org/ka-perseus-images/d40a2f6d0904542471f597d0ff0c27517f8c30ab.png Vertebrates embryos look very similar early in development Example: All vertebrate embryos (including humans) have gill slits and a tail during early development. Image source: https://eewevolution.weebly.com/uploads/5/3/4/6/53468969/6397984_orig.jpg  Features that are not useful to an organisms must be remnants of ancestral features Image source: https://eewevolution.weebly.com/uploads/5/3/4/6/53468969/6397984_orig.jpg Some physical similarities are analogous: they evolved independently in different organisms because the organisms lived in similar environments or experienced similar selective pressures. This process is called convergent evolution. (To converge means to come together, like two lines meeting at a point.) Example: two distantly related species that live in the Arctic, the arctic fox and the ptarmigan (a bird) Image source: https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/2840/2018/01/18182814/Figure_18_01_07ab.jpg Like structural homologies, similarities between biological molecules can reflect shared evolutionary ancestry. At the most basic level, all living organisms share: The same genetic material (DNA) The same, or highly similar, genetic codes The same basic process of gene expression (transcription and translation) The same molecular building blocks, such as amino acids Biologists often compare the sequences of related genes found in different species (often called homologous or orthologous genes) to figure out how those species are evolutionarily related to one another. Two species have the "same" gene because they inherited it from a common ancestor. For instance, humans, cows, chickens, and chimpanzees all have a gene that encodes the hormone insulin, because this gene was already present in their last common ancestor. For instance, human and chimpanzee insulin proteins are much more similar (about 98% identical) than human and chicken insulin proteins (about 64% identical) reflecting that humans and chimpanzees are more closely related than humans and chickens Image source: https://qph.cf2.quoracdn.net/main-qimg-995ce57f9e6f15f620b3664aec002f63-lq Biogeography - the study of the geographic distribution of plants, animals, and other forms of life. The geographic distribution of organisms on Earth follows patterns that are best explained by evolution, in combination with the movement of tectonic plates over geological time. For example, broad groupings of organisms that had already evolved before the breakup of the supercontinent Pangaea (about 200 million years ago) tend to be distributed worldwide. The evolution of unique species on islands is another example of how evolution and geography intersect. Marsupials Placental (carry young in a pouch) (nourish young through a placenta)  Paleontologist – scientists who study fossils Fossils document the existence of now-extinct past species that are related to present-day species. Fossils are remains of ancient organisms trapped in rocks, tar pits, frozen in ice or embedded in amber. Paleontologists use the fossils found in rocks to track the evolutionary history of many organisms.  Fossils are often contained in rocks that build up in layers called strata. Image source: https://www.nature.com/scitable/content/ne0000/ne0000/ne0000/ne0000/107975443/Fig.1_1_2.jpg Image source: https://lh6.googleusercontent.com/proxy/YwpJhreBjFAqRwzSGN3v-qyqHpsSi7KsonNBCd8TtwyIinLlvgMEe9hKPGI8lvdU- ddrBmBjZSceqrH3z8N4bDeh7eHRoZ_w476d6HZXqX6HARuVoR7iM-HAbBp_vnc0txn5Lu_3 In both biological evolution and human life experiences, those who can adjust to changing circumstances are more likely to thrive. Image source: https://hbr.org/resources/images/article_assets/2022/06/Jun22_17_107813677.jpg Humans have the capacity for learning and development throughout their lives. Image source: https://www.mdi-training.com/blog/wp-content/uploads/2020/11/Personalentwicklung_Learning_Development.jpg Image source: https://images.collegedunia.com/public/image/74beb7bb3c3d5673e3c8c5eb8ba806e9.png Dr. Sacha Dubois 15 January 2023 Get in touch! +123-456-7890 [email protected] www.reallygreatsite.com Borcelle Pharmacy @reallygreatsite