A team of 102 scientists spent a year surveying a small area of the San Lorenzo rain forest in Panama to count the number of species of arthropods living there. After collecting 129,494 specimens—using nets, traps, shovels, tree-climbing harnesses, helium balloons, and other creative gear—it took the team eight years to sort and identify the arthropods. Which of the following nested groups best describes the taxonomic context for the San Lorenzo project?
a. Animalia > Bilateria > Arthropoda > Ecdysozoa
b. Protostomia > Lophotrochozoa > Ecdysozoa > Arthropoda
c. Arthropoda > Protostomia > Ecdysozoa > Bilateria
d. Bilateria > Protostomia > Ecdysozoa > Arthropoda

Verified step by step guidance

1. Step 1: Begin by understanding the taxonomic hierarchy. Taxonomy is the classification of organisms into nested groups based on shared characteristics. The major taxonomic ranks include Domain, Kingdom, Phylum, Class, Order, Family, Genus, and Species. In this problem, we are dealing with higher-level groupings such as Animalia, Bilateria, Protostomia, Ecdysozoa, and Arthropoda.
2. Step 2: Identify the organism group in question. Arthropods are invertebrates with segmented bodies, exoskeletons made of chitin, and jointed appendages. Examples include insects, spiders, and crustaceans. Arthropods belong to the Kingdom Animalia.
3. Step 3: Determine the nested groups leading to Arthropoda. Arthropods are part of the Bilateria, a group of animals with bilateral symmetry. Within Bilateria, they belong to Protostomia, which includes animals that develop the mouth before the anus during embryonic development. Protostomia is further divided into Lophotrochozoa and Ecdysozoa, with Arthropoda falling under Ecdysozoa (organisms that molt their exoskeleton).
4. Step 4: Analyze the options provided. The correct sequence should reflect the taxonomic hierarchy from broader to more specific groups: Kingdom Animalia > Bilateria > Protostomia > Ecdysozoa > Arthropoda.
5. Step 5: Match the correct sequence to the options. Based on the hierarchy, the correct nested group is: d. Bilateria > Protostomia > Ecdysozoa > Arthropoda.

Key Concepts

Taxonomy

Taxonomy is the science of classifying organisms into hierarchical categories based on shared characteristics. It involves grouping species into nested categories such as domain, kingdom, phylum, class, order, family, genus, and species. Understanding taxonomy is crucial for identifying the relationships between different organisms, which is essential for answering questions about biodiversity, such as the one posed in the San Lorenzo project.

Phylogenetic Relationships

Phylogenetic relationships refer to the evolutionary connections between different species or groups of organisms. These relationships are often depicted in phylogenetic trees, which illustrate how species have diverged from common ancestors over time. Recognizing these relationships helps in understanding the evolutionary history of the arthropods surveyed in the San Lorenzo rainforest and aids in selecting the correct nested group for classification.

Ecdysozoa

Ecdysozoa is a clade of animals characterized by their ability to molt, or shed their exoskeleton, as they grow. This group includes arthropods, nematodes, and several other phyla. Understanding the characteristics of Ecdysozoa is important for classifying the arthropods found in the San Lorenzo rainforest, as it helps to place them within the broader context of animal evolution and diversity.