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- https://bio.libretexts.org/Courses/Citrus_College/Citrus_College_General_Biology_Textbook/13%3A_Evolution_and_Natural_Selection/13.02%3A_Discovering_How_Populations_ChangeEvolution by natural selection arises from three conditions: individuals within a species vary, some of those variations are heritable, and organisms have more offspring than resources can support. Th...Evolution by natural selection arises from three conditions: individuals within a species vary, some of those variations are heritable, and organisms have more offspring than resources can support. The consequence is that individuals with relatively advantageous variations will be more likely to survive and have higher reproductive rates than those individuals with different traits. The advantageous traits will be passed on to offspring in greater proportion.
- https://bio.libretexts.org/Courses/Gettysburg_College/01%3A_Ecology_for_All/06%3A_The_Evolution_of_Populations_and_Species/6.03%3A_The_Hardy-Weinberg_EquilibriumThe Hardy-Weinberg law argues that the gene frequencies and genotype ratios in a randomly-breeding population remain constant from generation to generation. Evolution involves changes in the gene poo...The Hardy-Weinberg law argues that the gene frequencies and genotype ratios in a randomly-breeding population remain constant from generation to generation. Evolution involves changes in the gene pool, while a population in Hardy-Weinberg equilibrium shows no change. Hence, populations are able to maintain a reservoir of variability so that if future conditions require it, the gene pool can change.
- https://bio.libretexts.org/Courses/Gettysburg_College/01%3A_Ecology_for_All/03%3A_Introduction_to_Evolution/3.05%3A_Adaptive_EvolutionFitness is often quantifiable and is measured by scientists in the field. However, it is not the absolute fitness of an individual that counts, but rather how it compares to the other organisms in the...Fitness is often quantifiable and is measured by scientists in the field. However, it is not the absolute fitness of an individual that counts, but rather how it compares to the other organisms in the population. This concept, called relative fitness, allows researchers to determine which individuals are contributing additional offspring to the next generation, and thus, how the population might evolve.
- https://bio.libretexts.org/Bookshelves/Introductory_and_General_Biology/Principles_of_Biology/03%3A_Chapter_3/22%3A_Evolution_in_Action/22.03%3A_Adaptive_EvolutionThat is, the big, strong orange males can fight off the blue males to mate with the blue’s pair-bonded females, the blue males are successful at guarding their mates against yellow sneaker males, and ...That is, the big, strong orange males can fight off the blue males to mate with the blue’s pair-bonded females, the blue males are successful at guarding their mates against yellow sneaker males, and the yellow males can sneak copulations from the potential mates of the large, polygynous orange males.
- https://bio.libretexts.org/Courses/Gettysburg_College/01%3A_Ecology_for_All/12%3A_Sex_Strategies/12.07%3A_Sexual_selectionThis chapter explores some of the multitude of hypotheses for why sexual reproduction exists, the variety of ways in which sexes are determined in plants and animals, and some of the variation in mati...This chapter explores some of the multitude of hypotheses for why sexual reproduction exists, the variety of ways in which sexes are determined in plants and animals, and some of the variation in mating systems of sexual organisms. This chapter also focuses on sexual selection, a form of natural selection that occurs when traits that improve mating success are favored by selection, even if they cause a decrease in survival.
- https://bio.libretexts.org/Workbench/General_Ecology_Ecology/Chapter_12%3A_Sex_Strategies/12.5%3A_Sexual_selectionThis chapter explores some of the multitude of hypotheses for why sexual reproduction exists, the variety of ways in which sexes are determined in plants and animals, and some of the variation in mati...This chapter explores some of the multitude of hypotheses for why sexual reproduction exists, the variety of ways in which sexes are determined in plants and animals, and some of the variation in mating systems of sexual organisms. This chapter also focuses on sexual selection, a form of natural selection that occurs when traits that improve mating success are favored by selection, even if they cause a decrease in survival.
- https://bio.libretexts.org/Courses/Evergreen_Valley_College/Introduction_to_Ecology_(Kappus)/04%3A_Natural_Selection_and_Evolution/4.02%3A_EvolutionEvolution describes the cumulative inherited change in a population of organisms through time leading to change in a lineage and/or the appearance of new forms or species. Small-scale changes (microev...Evolution describes the cumulative inherited change in a population of organisms through time leading to change in a lineage and/or the appearance of new forms or species. Small-scale changes (microevolution) drive huge events such as speciation (macroevolution). Microevolution is the change in allele frequencies that occurs over time within a population and may or may not be adaptive. This change is due to four different processes: natural selection, mutation, genetic drift, gene flow, and sexu
- https://bio.libretexts.org/Workbench/Bio_11A_-_Introduction_to_Biology_I/34%3A_Adaptive_Evolution/34.01%3A_Adaptive_EvolutionThat is, the big, strong orange males can fight off the blue males to mate with the blue’s pair-bonded females, the blue males are successful at guarding their mates against yellow sneaker males, and ...That is, the big, strong orange males can fight off the blue males to mate with the blue’s pair-bonded females, the blue males are successful at guarding their mates against yellow sneaker males, and the yellow males can sneak copulations from the potential mates of the large, polygynous orange males.
