Almanac. Biology Blast from the Past. Classification

This is the first of a periodic series. Most of the content is extracted from a series of textbooks I wrote/edited for the Grossmont Union High School District. The four volumes are shown in the photo below. Each integrated concepts from Life, Earth, and Physical science around a theme. They were ahead of their time. They were readable. They were not boring.

We did sell some copies to LA Unified and school districts in Colorado, Idaho, and Texas. We never made the best-seller list . . . any best-seller list!

Each volume is a semester's worth of science content and activities. This post is from the "yellow" book: Making Connections - Integrating the Science of Energy.

I've got at least one copy of each volume, but only one Teacher's Edition. All my .doc files were erased from a shared folder I was using. What a serious bummer that was! I'm scanning sections of books as I need them. When it makes sense, a PDF version of the photos that follow.

I hope you enjoy these trips while we Make Connections.

Putting Things in Their Place

Vol. 1. Integrating the Science of Water

ISBN 1-889553-00-X

Pages 50-53

Used by permission of the Author/Editor

 Unless you are adopted, you most likely know who you are related to. Mother, father, sisters, brothers, aunts, uncles, and the rest of your extended family probably can be traced fairly easily. You also know that you are more closely related to your brother than to your aunt. And your aunt is more closely related to you than your nephew is.

But, as a human, are you more closely related to a dairy cow or to a sea cow? 

The science of determining what relationships exist and how organisms are classified is the science of taxonomy. Trying to determine what relationships exist between organisms is the job of scientists known as taxonomists. For example, a taxonomist could determine if you are more closely related to a dairy cow or to a sea cow.

Taxonomists of the past searched for their answer in the way things looked. Physical characteristics of organisms were very important in determining relationships between organisms. “If it looks like a duck, it is a duck,” was the standard line of reasoning. That thinking worked much of the time. However, certain organisms were hard to place.

The taxonomist of today relies on many different types of evidence before committing to the placement of an organism in the taxonomic scheme. The physical structure of an organism continues to be a part of the classification process, but genetics and biochemistry now play a much larger role than external appearance. As biochemical comparisons are made, organisms that have more chemical similarity are said to be more closely related than those with less chemical similarities. Looking at chromosomes and DNA sequences help taxonomists most accurately determine whom or what is related to who or what.

After relationships have been established, organisms are placed in a classification system. While there are many variations, the basic slots, taxa, in the system remain constant. The major taxa are the Kingdom, the Phylum, the Class, the Order, the Family, the Genus, and the Species.

Many scientists accept a classification system with five kingdoms.

Kingdom Monera consists of bacteria and blue-green algae (also known as photosynthetic bacteria).

Kingdom Protista includes algae and single-celled organisms (protozoa).

Kingdom Fungi includes only the fungi, including molds & mushrooms.

Kingdom Plantae consists of multicellular land and water plants.

Kingdom Animalia is made up of all of the animals, with and without vertebrae.   Every living thing is classified in one of these kingdoms.

The boxes above show the relationship between the different taxonomic taxa. The bigger the box, the greater diversity of organisms is found in it. The boxes are NOT to scale.

Once placed in a kingdom, organisms are further categorized into the taxa mentioned above. Each taxon, the singular form of taxa, from kingdom to species is more specific and includes fewer organisms than the one before it. By the time the genus and the species names are given, only that specific type of organism is included. A complete classification of humans would be:

 KINGDOM: Animalia - there are lots of different animals in the world. This just distinguishes us from plants, fungi, algae, and bacteria.

PHYLUM: Chordata - all animals with vertebrae are chordates. There are still a lot of different animals here, too. Fish, amphibians, reptiles, birds, and mammals are all chordates.

CLASS: Mammalia - all animals with hair or fur and a constant body temperature are mammals.  Dogs, cats, pigs, and lions are all mammals, too.

ORDER: Primates - monkeys and apes are our closest primate relatives. These animals have big brains and eyes on the front of their faces. Most of them have specialized thumbs or big toes, too.

FAMILY: Hominidae - the Hominids include only one living genus. Extinct members of this family have been found in fossils, but humans are the only living representatives.

GENUS: Homo - this name means “human.”  There is only one living species in this genus.

SPECIES: sapiens - this name means “smart.”  We are  “smart humans.”

You might have learned some jingle to remember the order of the major taxa. 

KP Cooks Often Fry Greasy Steaks 

or even 

Keeping Precious Creatures Organized For Grumpy Scientists 

are two examples. If you learned one other than those, the chances are that you just recited it.

The genus and species name is an organism’s “official” scientific name. Genus and species names are the binomial nomenclature, two-word naming system, used in identifying organisms. The genus and the species are always italicized. For example, pigs are Sus scrofa. The bacteria that cause tetanus are Clostridium tetani. Your scientific name is Homo sapiens.

No organism but you has your scientific name. That’s a significant part of the beauty of the system.

In the “This just in” category, I found an article on where the science of classification was in 2015. It offers an up to date look at the science of taxonomy. I copied the Abstract, Table 1, and the Results and Discussion section. The title links to the entire article.

If you don’t want to know about or you don’t care about the current stuff, there’s more on classification after the table.

A Higher Level Classification of All Living Organisms

Abstract

We present a consensus classification of life to embrace the more than 1.6 million species already provided by more than 3,000 taxonomists’ expert opinions in a unified and coherent, hierarchically ranked system known as the Catalogue of Life (CoL). The intent of this collaborative effort is to provide a hierarchical classification serving not only the needs of the CoL’s database providers but also the diverse public-domain user community, most of whom are familiar with the Linnaean conceptual system of ordering taxon relationships. This classification is neither phylogenetic nor evolutionary but instead represents a consensus view that accommodates taxonomic choices and practical compromises among diverse expert opinions, public usages, and conflicting evidence about the boundaries between taxa and the ranks of major taxa, including kingdoms. Certain key issues, some not fully resolved, are addressed in particular. Beyond its immediate use as a management tool for the CoL and ITIS (Integrated Taxonomic Information System), it is immediately valuable as a reference for taxonomic and biodiversity research, as a tool for societal communication, and as a classificatory “backbone” for biodiversity databases, museum collections, libraries, and textbooks. Such a modern comprehensive hierarchy has not previously existed at this level of specificity.

 

Results and Discussion

We are proposing a two-superkingdom (Prokaryota and Eukaryota), seven-kingdom classification that is a practical extension of Cavalier-Smith’s six-kingdom schema [19]; the latter has been used, for example, in the compendious checklist of marine biota of Chinese seas [23] and in the first comprehensive national inventory of biodiversity for New Zealand [24–26]. For each of these kingdoms we had to exercise our taxonomic judgment and reach a practical compromise among diverse opinions and usages and conflicting evidence about certain phylogenetic questions important for defining the boundaries between and ranks of major taxa, including kingdoms. Our schema includes: the prokaryotic kingdoms Archaea (Archaebacteria) and Bacteria (Eubacteria), and the eukaryotic kingdoms Protozoa, Chromista, Fungi, Plantae, and Animalia. We have retained 14 ranks from superkingdom to order (Table 1). 

Table 1

If you can keep track of Karl, Please Come Over For Good Spaghetti, you’re going to be in good shape for the foreseeable future.

OTHER CLASSIFICATION SCHEMES

Not only living things are classified. You have been consciously or sub-consciously classifying things ever since you were an infant. Types of clothing, types of toys, different ways to travel-all these are examples of classification systems. Biomes are classifications of different geographic/environmental areas.

Scientists classify things that are not living too, For example, chemists classify elements. The elements are classified in a very orderly manner in what is known as The Periodic Table of the Elements or The Periodic Table.

THE PERIODIC TABLE

The Periodic Table, as we know it today, began with a Russian Chemist in the mid-1800's. Dmitri Mendeleev believed that the elements had properties which were based on their atomic weight. He also believed that the elements could be organized based on their "periodicity," the repeating of characteristics in a regular pattern. Mendeleev and a German chemist, Lothar Meyer, both published the idea of a periodic table with eight columns in 1871. There were blank spaces in Mendeleev's periodic table. He believed that there were elements, undiscovered in 1871, which would fill in those blank spaces. In fact, he predicted the properties of several of his "missing" elements. He was right in most of his predictions.

The table shown below is the modem periodic table. The arrangement of the elements is close to that of Mendeleev, but the modem organization of the periodic table is based on the number of protons in the nucleus of an atom of an element.

The periodic table is organized into rows—horizontally—and columns—vertically). Elements in the same column have many similar characteristics and similar chemical properties. As you read from left to right in any row, the atomic number of the elements in that row increases by one proton. Rows are also known as periods.

Observe the key in the upper left-hand corner. Each box in the chart contains three pieces of information for an element: the atomic symbol, the atomic number, and the atomic mass.

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