Finches on the Galapagos Islands have evolved to exploit almost every possible niche. This diagram shows the range of food sources available on the island and the different beak shapes adapted to exploit each of them.
Evolution has resulted in changes in the sizes and forms of organisms. Everything about the biology of an animal, including its physiology, anatomy, and ecology, is influenced by its body size. Frequently there seem to be limits on the sizes that different organisms can attain, even when larger size might be thought to be evolutionarily advantageous. Often an increase or decrease in size is correlated with a change in proportions. Understanding the significance of a particular morphology or interpreting the factors that underlie a particular evolutionary trend involve studying the relationships that exist among size, shape, and function. This lab introduces allometry, the study of size and its consequences, using celery and woodlice as subjects.
These images from the Smithsonian Institution depict Nancy Knowlton's work with snapping shrimp in Panama. Knowlton found that the closing of the isthmus -- dividing the Pacific Ocean from the Caribbean -- resulted in new species of shrimp.
First, students toss coins to determine what traits a set of mouse parents possess, such as fur color, body size, heat tolerance, and running speed. Next they use coin tossing to determine the traits a mouse pup born to these parents possesses. These physical features are then compared to features that would be most adaptive in several different environmental conditions. Finally, students consider what would happen to the mouse offspring if those environmental conditions were to change: which mice would be most likely to survive and produce the next generation?
This 12-minute video lesson addresses "Intelligent Design." [Biology playlist: Lesson 3 of 71].
This 18-minute video lesson provides an introduction to evolution, variation in a population, and Natural Selection. [Biology playlist: Lesson 1 of 71].
This 13-minute video discusses how the Owl Butterfly may have gotten the spot on its wings. [Biology playlist: Lesson 5 of 71].
This 20-minute video lesson discusses how variation can be introduced into a species. [Biology playlist: Lesson 7 of 71].
This graphic illustrates some of the marsupial mammals in Australia and placental mammals in North America. Even though they are not closely related, these mammals look alike because they have adapted to similar ecological roles. From The Human Evolution Coloring Book by by Adrienne Zihlman.
Learn how a cow eats and digests food in this video segment from Nature.
This Web site, created to complement the Museum's Darwin exhibit, examines the man and theory that changed the course of science and society.
This video from Nature offers a description of desirable traits in beef and dairy cattle.
In this video segment from Nature, learn about six different breeds of cattle.
" We will cover fundamentals of ecology, considering Earth as an integrated dynamic system. Topics include coevolution of the biosphere, geosphere, atmosphere and oceans; photosynthesis and respiration; the hydrologic, carbon and nitrogen cycles. We will examine the flow of energy and materials through ecosystems; regulation of the distribution and abundance of organisms; structure and function of ecosystems, including evolution and natural selection; metabolic diversity; productivity; trophic dynamics; models of population growth, competition, mutualism and predation. This course is designated as Communication-Intensive; instruction and practice in oral and written communication provided. Biology is a recommended prerequisite."
This in-depth, multi-part course takes you through evolutionary theory and mechanisms, from definitions to details, natural selection to genetic drift, mutations to punctuated equilibrium.
This 9-minute video lesson clarifies some points on evolution and intelligent design. [Biology playlist: Lesson 4 of 71].
This graphic from Ecology and Evolution of Darwin's Finches by Peter Grant presents data from the Galapagos Islands, showing that a severe drought put selective pressure on the population of Darwin's finches and resulted in a change in the average beak size in the next generation.
Basic subject in ecology: understanding the flow of energy and materials through ecosystems, and what regulates the distribution and abundance of organisms. Productivity and biogeochemical cycles in ecosystems; trophic dynamics; community structure and stability; competition and predation; evolution and natural selection; population growth; and physiological ecology. Emphasis on aquatic systems.
An integrated course stressing the principles of biology. Life processes are examined primarily at the organismal and population levels. Intended for students majoring in biology or for non-majors who wish to take advanced biology courses.
In this video profile adapted from NOVA scienceNOW, learn about geneticist and rock musician Pardis Sabeti, whose innovative insights into natural selection demonstrated how beneficial mutations spread quickly through a population.
