LAB 2 
Carl Linnaeus (Carl von Linné) b. 1707
TAXONOMY/BINOMIAL NOMENCLATURE
A GARDEN
Carl Linnaeus loved plants from the time he was a small boy. Legend has it that when he was a baby, a flower blossom would instantly stop his crying. Carl’s father was also interested in plants and gave Carl his own plot of land for a garden when he was only five years old. As he grew, Carl remained more interested in plants than he was in school and often skipped studying to go on plant-collecting expeditions.
A NEW SYSTEM
Because of his interest in botany, the study of plants, Carl’s teachers suggested that he might enjoy medicine. He went to college to study medicine and botany, and while he was there he set up a new system for classifying plants. In 1732, when he was twenty-four years old, Carl went on a six-month expedition to Lapland to look for new plants and animals, and throughout his life he continued to go on these adventures.
THE PRINCE OF BOTANY
Carl Linnaeus became a medical doctor for several years to support his wife and children, but he continued to cultivate gardens and study new plants and animals. In 1753, he published a book called Species Plantarum, which organized and named all of the plants he’d encountered in his studies, and in 1758 he published Systema Naturae, which classified and named animals. These books were the official starting points for the way modern scientists name plants and animals.
TAXONOMY
Taxonomy is a system of classify things into groups. Linnaeus sorted living things using a naming system that moved from general categories to more specific ones. He divided organisms into either the plant or animal kingdom and then moved to progressively more specific levels, such as phylum, class, order, family, genus, and species. Since Carl’s time, scientists have discovered new kingdoms of life and made new discoveries about how species are related.
BINOMIAL NOMENCLATURE
For his naming system, Linnaeus used two-part names based on the Latin language, which became known as binomial (two-part) nomenclature (naming). This was probably his most important contribution to science. The first part of a name in binomial nomenclature is generic, or general, and the second part is more specific. Each species is given a two-part name—for example, Homo sapiens—where the first part of the name is the genus (Homo) and the second part is the species (sapiens).
AN HONOR
In 1757, the king of Sweden granted Carl Linnaeus nobility for his achievements and his name was changed to Carl von Linn.
IN TODAY’S WORLD
Scientists today still use Linnaeus’s binominal nomenclature to classify and name new species, using an expanded version with six kingdoms including fungi, eubacteria, and archaebacteria.
Carl Linnaeus was a wizard of sorting living things into groups based on their physical traits. Try your hand at sorting animals into groups such as phylum, class, order, and family, then use what you’ve learned to play Twenty Questions. If you’re not familiar with the difference between mammals, birds, reptiles, amphibians, insects, and arachnids, look up the definitions of the words and list a few traits that will help you tell them apart. For example, mammals are warm-blooded and have live young. Birds have feathers and lay eggs. 1 Lay out animals and sort them into categories using a dichotomous key. Fig. 1. Fig. 1. A dichotomous key allows you to identify organisms based on a series of choices. 2 To sort the animal kingdom into phylums, ask whether each animal is a vertebrate or invertebrate. Vertebrates are animals with their skeletons inside, such as humans and dogs. Invertebrates have skeletons on the outsides of their bodies. Insects and arthropods such as spiders and crabs, are invertebrates. 3 Continue sorting animals by class. Do they have fur or no fur? Feathers or no feathers? Dry skin or moist skin? Soon, you will have them sorted into basic groups, such as mammals, birds, fish, reptiles, and amphibians. Fig. 1, Fig. 2. Fig. 2. Sort animals into groups using a dichotomous key. 4 Further sort the animals by order. Do they eat meat? Plants? Both? Fig. 3. Fig. 3. Use a dichotomous key to sort the animals into smaller groups. 5 Sort them into families. Are they dog-like? Cat-like? Cow-like? Fig. 4. Fig. 4. Sort the animals into families. 6 To play Twenty Questions, have a friend or family member think of an animal they are familiar with. They shouldn’t tell you what it is. 7 Make guesses to find out what animal they have chosen. Each guess must have a yes or no answer. 8 Begin by asking very general questions and go from there, depending on the answers. For example, start with questions such as “does it have fur?” or “is it a mammal.” Depending on what you learn, your questions should get more specific, such as “is it a member of the cat family?” or “does it live in the salt water?” You will have twenty guesses to identify the mystery animal. Fig. 5. Danaus plexippus (monarch butterfly) Fig. 6. Tropaeolum majus (nasturtium) Fig. 7. Melanoplus differentialus (differential grasshopper) Fig. 8. Trifolium repens (white clover) CREATIVE ENRICHMENT Identify some plants and animals using binomial nomenclature, or make up and draw your own plant or animal! THE BIOLOGY BEHIND THE FUN Living things are separated into major ranks, moving from general descriptions to more specific ones: domain, kingdom, phylum, class, order, family, genus, and species. The game Twenty Questions sorts plants and animals into categories to identify a mystery species. Because the game gives you only two choices—yes or no—it mimics a scientific sorting tool called a dichotomous key. This game is played using common names, rather than scientific ones. Linnaeus initially sorted things into one of three categories: plants, animals, and minerals. He categorized animals by the way they moved, and sorted plants into categories by their appearance. Since his time, our understanding of how life on Earth is related has grown enormously. We still use Linnaeus’s binomial nomenclature (naming) system for genus and species, but today we have much more sophisticated techniques for identifying how living things are related. The dogs we keep as pets look different because they are bred to select certain traits for size, fur color, and so on. Domestic (pet) dogs belong to the family Canidae, with the genus and species name Canis familiaris. The genus name is always capitalized the species name starts with a lowercase (small) letter.TAXONOMY/BINOMIAL NOMENCLATURE
MATERIALS
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PROTOCOL
