Biology is a branch of science that seeks to understand the natural world specifically the part of the world that is living. It is the study of life. There are diverse disciplines within biology such as genetics, anatomy, botany, physiology, zoology, and ecology.
If biology is the study of life, we need to have a set of characteristics that classify something as biotic and differentiates it from something that is abiotic.
There are generally five characteristics that define something as biotic: hierarchical organization, response to stimuli, regulation, use and transformation of energy, and reproduction.
One fascinating aspect about biology is that while there are fundamental characteristics that unify and define living organisms, the variation within and among living organisms is great. All of this diversity from plants to bacteria to protists to animals is related. Therefore the concept of shared ancestry and change over time is key to understanding and classifying living organisms. Currently, scientists classify all living organisms into three domains of life: Archaea, Bacteria, and Eukarya. Within Domain Eukarya, organisms are classified by descending levels of inclusion as kingdom, phylum, class, order, family, genus and species. The bionomial name or scientific name of a species is represented by a genus and species name. For example, the sea otter is known as Enhydra lutris. The change in the traits of organisms, specifically populations, over time is called evolution.
Biology is all around us, all the time. In fact biology is in us all the time, as well. The scientific studies conducted in biology matter to our daily lives as humans. A pervasive theme in biology is connection and emergent properties; so although there are different branches of study in biology such as genetics, anatomy, botany, physiology, zoology, and ecology, each area is often tightly connected with other areas. The study of biology matters and yields significant information.
Biology is built on science. What is science actually? Science is a process to help us understand the natural world. It is a stepwise process that starts with an observation about the natural world which we then make into a hypothesis and set predictions.
The hypothesis and predictions are carefully tested in a systematic experimental design, which includes a control group(s), a test group(s) and experimental variables. Data is collected and results are analyzed leading to conclusions from the study. Scientific communication and publication are crucial parts of the process. Science is an iterative process so depending on the results of the study “the conclusion of one experiment often leads to another” (Mader & Windelspecht, 2015).
It is important to note scientific theories are hypotheses that have been repeatedly tested with the same or very similar results, unlike the colloquial use of the word theory that may suggest limited or no evidence. A scientific theory usually has substantial and significant data to back it up.
As we come to understand how science works, we can separate out scientific validity from psuedoscience, which is a crucial skill for making decisions about the issues of our modern world. Current issues in our modern world are diverse and complex and include human health, climate change, emerging diseases, and bioethics.
Evolution is the central unifying theme of biology. The development of evolutionary theory, or how the principle of evolution came about, is a useful illustration of how science works. The essential ideas and process that lead to Charles Darwin’s description of natural selection in 1859 included observations, hypotheses, predictions, results, and conclusions. Two key observations were that populations increase geometrically, and that observed patterns of organism variation suggest change through time from a common ancestor. Could the patterns of variations be explained by differences in ability to survive and reproduce? Individuals with characteristics that allow them to survive and reproduce increase in the population over time. Descent with modification is measured. With these observations, evolution by natural selection has severed as a testable hypothesis for over 150 years.
There are many examples of the usefulness of the principle of evolution in the world today and in our everyday lives.
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"Biological technicians James Walton and Jedediah Brodie collect plant cover data in the Toklat Basin ecoregion of Denali NP during the first season of fieldwork for this project in 2001. (8446139858)" by National Park Service, Alaska Region - Biological technicians James Walton and Jedediah Brodie collect plant cover data in the Toklat Basin ecoregion of Denali NP during the first season of fieldwork for this project in 2001.Uploaded by AlbertHerring. Licensed under CC BY 2.0 via Wikimedia Commons - https://commons.wikimedia.org/wiki/File:Biological_technicians_James_Walton_and_Jedediah_Brodie_collect_plant_cover_data_in_the_Toklat_Basin_ecoregion_of_Denali_NP_during_the_first_season_of_fieldwork_for_this_project_in_2001._(8446139858).jpg#/media/File:Biological_technicians_James_Walton_and_Jedediah_Brodie_collect_plant_cover_data_in_the_Toklat_Basin_ecoregion_of_Denali_NP_during_the_first_season_of_fieldwork_for_this_project_in_2001._(8446139858).jpg
"Malaria". Licensed under CC BY 2.5 via Commons - https://commons.wikimedia.org/wiki/File:Malaria.jpg#/media/File:Malaria.jpg
"Helicoverpa armigera larva" by Gyorgy Csoka, Hungary Forest Research Institute, Bugwood.org - This image is Image Number 5371126 at Insect Images, a source for entomological images operated by The Bugwood Network at the University of Georgia and the USDA Forest Service.. Licensed under CC BY 3.0 us via Commons - https://commons.wikimedia.org/wiki/File:Helicoverpa_armigera_larva.jpg#/media/File:Helicoverpa_armigera_larva.jpg
"Large ground finch (4229044630)" by Peter Wilton - Large ground finchUploaded by Magnus Manske. Licensed under CC BY 2.0 via Commons - https://commons.wikimedia.org/wiki/File:Large_ground_finch_(4229044630).jpg#/media/File:Large_ground_finch_(4229044630).jpg
"Certhidea olivacea". Licensed under CC BY-SA 2.0 via Commons - https://commons.wikimedia.org/wiki/File:Certhidea_olivacea.jpg#/media/File:Certhidea_olivacea.jpg