Abstract: G. G. Simpson, one of the chief architects of evolutionary biology’s modern synthesis, proposed that diversification occurs on a macroevolutionary adaptive landscape, but landscape models are seldom used to study adaptive divergence in large radiations. We show that for Caribbean Anolis lizards, diversification on similar Simpsonian landscapes leads to striking convergence of entire faunas on four islands. Parallel radiations unfolding at large temporal scales shed light on the process of adaptive diversification, indicating that the adaptive landscape may give rise to predictable evolutionary patterns in nature, that adaptive peaks may be stable over macroevolutionary time, and that available geographic area influences the ability of lineages to discover new adaptive peaks.

Phylogenetic trees and trait data for Greater Antillean Anolis lizards

This activity supports the film The Origin of Species: Lizards in an Evolutionary Tree. Students are guided to sort the lizard species by appearance, then generate a phylogenetic tree using the lizards’ DNA sequences to evaluate whether species that appear similar are closely related to each other.

A film produced In the Caribbean islands, adaptation to several common habitats has led to a large adaptive radiation with interesting examples of convergent evolution.

This activity supports the film The Origin of Species: Lizards in an Evolutionary Tree. Students are asked to formulate a hypothesis, and collect and analyze real research data to understand how quickly natural selection can act on specific traits in a population.  

In the 2013 Holiday Lectures on Science, leading medical researchers explain how advances in genomics are revolutionizing their work, leading to a better understanding of disease and to improved treatments.

Explore the phases, checkpoints, and protein regulators of the cell cycle in this highly interactive Click and Learn and find out how mutated versions of these proteins can lead to the development of cancer.

These two hands-on activities are based on a Howard Hughes Medical Institute 2013 Holiday Lectures on Science video featuring researcher Dr. Charles L. Sawyers.

Abstract: Over the past decade, comprehensive sequencing efforts have revealed the genomic landscapes of common forms of human cancer. For most cancer types, this landscape consists of a small number of “mountains” (genes altered in a high percentage of tumors) and a much larger number of “hills” (genes altered infrequently). To date, these studies have revealed ~140 genes that, when altered by intragenic mutations, can promote or “drive” tumorigenesis. A typical tumor contains two to eight of these “driver gene” mutations; the remaining mutations are passengers that confer no selective growth advantage. Driver genes can be classified into 12 signaling pathways that regulate three core cellular processes: cell fate, cell survival, and genome maintenance. A better understanding of these pathways is one of the most pressing needs in basic cancer research. Even now, however, our knowledge of cancer genomes is sufficient to guide the development of more effective approaches for reducing cancer morbidity and mortality.

Zoom into a coral reef and discover photosynthetic algae inside the coral’s cells. Reef-building corals rely on these symbionts for their survival.

Coral reefs, how they are threatened by climate change, and how to protect them.

To test whether corals can become more resistant to bleaching, Dr. Steve Palumbi and colleagues performed a series of experiments in the U.S. National Park of American Samoa off of Ofu Island. This BioInteractive activity includes a student worksheet and educator instructions.

All data files from Barshis et al. 2014

All data files from Tepolt and Palumbi 2015.

All data files from Seneca and Palumbi 2015.

Abstract: Reef corals are highly sensitive to heat, yet populations resistant to climate change have recently been identified. To determine the mechanisms of temperature tolerance, we reciprocally transplanted corals between reef sites experiencing distinct temperature regimes and tested subsequent physiological and gene expression profiles. Local acclimatization and fixed effects, such as adaptation, contributed about equally to heat tolerance and are reflected in patterns of gene expression. In less than 2 years, acclimatization achieves the same heat tolerance that we would expect from strong natural selection over many generations for these long-lived organisms. Our results show both short-term acclimatory and longer-term adaptive acquisition of climate resistance. Adding these adaptive abilities to ecosystem models is likely to slow predictions of demise for coral reef ecosystems.

Offers an evolutionary history of Darwin's finches since their origin almost 3 million years ago. By continuously tracking finch populations over a period of four decades, this title uncovers the causes and consequences of significant events leading to evolutionary changes in species.

All data files from Grant and Grant 2014.

Abstract: Introgressive hybridization, i.e. hybridization with backcrossing, can lead to the fusion of two species, but it can also lead to evolution of a new trajectory through an enhancement of genetic variation in a new or changed ecological environment. On Daphne Major Island in the Galápagos archipelago, ~1–2% of Geospiza fortis finches breed with the resident G. scandens and with the rare immigrant species G. fuliginosa in each breeding season. Previous research has demonstrated morphological convergence of G. fortis and G. scandens over a 30-year period as a result of bidirectional introgression. Here we examine the role of hybridization with G. fuliginosa in the evolutionary trajectory of G. fortis. Geospiza fuliginosa (~12 g) is smaller and has a more pointed beak than G. fortis (~17 g). Genetic variation of the G. fortis population was increased by receiving genes more frequently from G. fuliginosa than from G. scandens (~21 g). A severe drought in 2003–2005 resulted in heavy and selective mortality of G. fortis with large beaks, and they became almost indistinguishable morphologically from G. fuliginosa. This was followed by continuing hybridization, a further decrease in beak size and a potential morphological fusion of the two species under entirely natural conditions.

All data files from Grant and Grant 2015.

These two activities support the film The Origin of Species: The Beak of the Finch. They provide students with the opportunity to analyze data collected by Princeton University evolutionary biologists Peter and Rosemary Grant.

Four decades of research on finch species that live only on the Galápagos Islands illuminate how species form and multiply.