Species
[spè·cie]
DEFINITION“Classification category of organisms which includes individuals capable of mating with each other and generating fertile offspring; in the case of organisms with asexual reproduction it is defined by morphological or physiological criteria; several species related to each other make up a genus: the s. animals, plants; conservation of the s .; s. human, men as distinct from other animals “
You may not be familiar with the scientific names of ragweed beetles. These insects belong to the Coptoborus genus. But you are likely to recognize some iconic female science fiction characters among some of their species names. Let us consider C. katniss, C. scully and C. leia. The names of these and other beetles related are aimed at getting your attention.
“We’ve been wanting to do something fun like this for a while”says Sarah Smith. She is an insect biologist, or entomologist, at Michigan State University in East Lansing. The characteristics of the beetles inspired their science fiction names. C. leia, for example, is brown like Princess Leia’s sandwiches. The pointed shape of C. katniss’ body was reminiscent of Smith Katniss Everdeen and her bow and arrows.
Some names also fit the behavior of beetles, says Anthony Cognato, another Michigan State entomologist. He collaborated with Smith on a new study on beetles. Female ragweed beetles venture out of nests to create families at new sites. This behavior could explain how these beetles have spread in the tropics over the past 20 million years.
Their catchy names also draw attention to the taxonomy. This is the science of naming organisms. Taxonomy is a foundation of biology, he explains. A unique name allows scientists to know which individuals fall into a species. Only then can they continue to discuss and study what makes this species different from others. “This naming system provides the keys to unlock information”, adds Gustavo Hormiga. He is at George Washington University in Washington, DC He studies spiders and other arachnids.
Imagine you have a tick bite, says Hormiga. Some types of ticks carry Lyme disease, which causes skin rashes, fever, and headaches. The other mints do not. A doctor who decides the treatment may ask if the bite came from a deer tick. This Ixodes scapularis can be a carrier of Lyme disease.
The way modern scientists classify and name organisms was first developed more than 250 years ago. But that doesn’t mean the process hasn’t changed. Since then, scientists have adapted the naming system to reflect the evolution of species.
Some scientists, however, would like to start over with a new naming method. Many others are not ready for it. For most biologists, a name is not just a name. It is also a way not only to distinguish what separates species, but also to understand species.
Modern taxonomy dates back to Charles Linnaeus. This Swiss naturalist wrote the book on this foundation in 1753. His Species Plantarum, as it was called, listed all the plant species known at the time. It also marked the first time that a binomial nomenclature (two-part naming system) came into common use for plants. Five years later, Linnaeus’ Systema Naturae used the same system to name animals. That book contained some now familiar names, such as Homo sapiens and Boa constrictor.
Before the binomial nomenclature, animal names involved long descriptions. The honey bees, for example, were Apis pubescens, thorace subgriseo, abdomine fusco, pedibus posticus glabis, untrinque marginal ciliates. This mouthful of Latin words describes what insects look like. Short and soft hair, gray chest, brown belly and smooth hind legs bordered with hair on both sides. Linnaeus’ name for the species is much shorter: Apis mellifera, or “honey bee”.
The ordering of these two Latin words also has a special meaning. The first describes the gender and name of a related group. The second name specifies the particular species. The genus Canis, for example, includes several species. They include the domestic dog (Canis familiaris) and the gray wolf (Canis lupus).
Modern scientists still use this binomial system, as when they called those science fiction-inspired ambrosia beetles. The names also categorize organisms into groups, known as taxa. A group, or taxon (hence the name of the field: taxonomy), includes similar organisms. For example, the genus Canis constitutes a taxon. The genus Vulpes, which includes foxes, is another taxon. Taxa (the plural form of taxon) can also describe broader categories, such as the group of all mammals.
Linnaeus described five tiered rankings for animals. At the top were the kingdoms. After all, there were the species. Over time, scientists have added a few more degrees. The system now extends from kingdom to phylum, class, order, family, genus and species. One way to keep track of these labels is to remember “King Phillip Came Over For Great Spaghetti”. The first letter of each word corresponds to the first letter of a rank. Taxa can be defined at different levels.
For example, Mammalia (the group of all mammals) is a taxon at the class rank. Likewise, an order can contain multiple families. And a class can contain multiple orders. The nested nature of these taxa provides scientists with useful information.
“If I told you that two species belong to the same family, you would immediately know that they are also in the same class and in the same phylum and in the same kingdom”, explains Diana Lipscomb. She is a retired evolutionary biologist at George Washington University.
However, there are no rules for deciding which rank a group of species or taxon falls into. One scientist may disagree with another on what defines a family, for example. Indeed, a third scientist might even think that the taxon should belong to a different rank, such as an order.
The International Code of Zoological Nomenclature, the rules for the naming of animals, states the official guidelines. But this code does not apply rules for defining the rank of a taxon. This includes determining families with respect to orders. For this reason, Hormiga notes, all grades may not really be comparable.
Species evolving with the times
In the 1970s, scientists argued fiercely about taxonomy. Those were turbulent years, says Hormiga. Eventually the field moved. Scientists have begun to classify species based on their evolution rather than their appearance. This evolutionary approach is known as phylogeny.
“Modern taxonomy must reflect phylogeny”, says Gonzalo Giribet. He is a zoologist at Harvard University in Cambridge, Massachusetts. Members within a taxon should be more related to each other than to species outside the group. Scientists draw these relationships like branched trees. Indeed, Charles Darwin described it in his tree of life. His included both living and extinct organisms.
I could tell you, says Hormiga, “there is a unique spider family in some parts of South America” and it has been classified on the basis of phylogenetic relationships. “So I’m saying this is a branch of the tree of life.”
Taxonomy and phylogeny are fundamental parts of a scientific field known as systematics. You may notice that the name is related to Linnaeus’ Systema Naturae. This field uses evolution to classify and name living things.
Systematists study the evolution of a species by looking at its genetic material: DNA and RNA. DNA is a molecule which stores genetic instructions in cells. To read these instructions, cells copy DNA into another molecule, RNA. Cells use that RNA to make proteins.
Scientists used these analyzes to divide life on Earth into three domains. Two describe much of single-celled life: bacteria and archaea. The third eukaryote includes everything else. Eukaryotes can be one or more cells. All have cellular parts with distinct roles, such as DNA-containing nuclei. Plants fall into this group. So do all animals. So also the unicellular amoebas.
You can forgive Linnaeus for not inventing this system. Lived long before scientists grasped the idea of evolution, much less than genetics. As a result, new findings may force systematists to reclassify taxa. For example, Smith and Cogn-in-law moved some species of ragweed beetles to the genus Coptoborus. This was after they discovered that Coptoborous and the Theoborus genus were actually the same.
For many systematists, these changes are fine. “Guess what this organism is, who it is related to and where it fits into that tree of life “, Lipscomb tells George Washington. Much science is interpreting new data to improve our understanding of our world and the cosmos.
Species
[spè·cie]
DEFINITION“Classification category of organisms which includes individuals capable of mating with each other and generating fertile offspring; in the case of organisms with asexual reproduction it is defined by morphological or physiological criteria; several species related to each other make up a genus: the s. animals, plants; conservation of the s .; s. human, men as distinct from other animals “
You may not be familiar with the scientific names of ragweed beetles. These insects belong to the Coptoborus genus. But you are likely to recognize some iconic female science fiction characters among some of their species names. Let us consider C. katniss, C. scully and C. leia. The names of these and other beetles related are aimed at getting your attention.
“We’ve been wanting to do something fun like this for a while”says Sarah Smith. She is an insect biologist, or entomologist, at Michigan State University in East Lansing. The characteristics of the beetles inspired their science fiction names. C. leia, for example, is brown like Princess Leia’s sandwiches. The pointed shape of C. katniss’ body was reminiscent of Smith Katniss Everdeen and her bow and arrows.
Some names also fit the behavior of beetles, says Anthony Cognato, another Michigan State entomologist. He collaborated with Smith on a new study on beetles. Female ragweed beetles venture out of nests to create families at new sites. This behavior could explain how these beetles have spread in the tropics over the past 20 million years.
Their catchy names also draw attention to the taxonomy. This is the science of naming organisms. Taxonomy is a foundation of biology, he explains. A unique name allows scientists to know which individuals fall into a species. Only then can they continue to discuss and study what makes this species different from others. “This naming system provides the keys to unlock information”, adds Gustavo Hormiga. He is at George Washington University in Washington, DC He studies spiders and other arachnids.
Imagine you have a tick bite, says Hormiga. Some types of ticks carry Lyme disease, which causes skin rashes, fever, and headaches. The other mints do not. A doctor who decides the treatment may ask if the bite came from a deer tick. This Ixodes scapularis can be a carrier of Lyme disease.
The way modern scientists classify and name organisms was first developed more than 250 years ago. But that doesn’t mean the process hasn’t changed. Since then, scientists have adapted the naming system to reflect the evolution of species.
Some scientists, however, would like to start over with a new naming method. Many others are not ready for it. For most biologists, a name is not just a name. It is also a way not only to distinguish what separates species, but also to understand species.
Modern taxonomy dates back to Charles Linnaeus. This Swiss naturalist wrote the book on this foundation in 1753. His Species Plantarum, as it was called, listed all the plant species known at the time. It also marked the first time that a binomial nomenclature (two-part naming system) came into common use for plants. Five years later, Linnaeus’ Systema Naturae used the same system to name animals. That book contained some now familiar names, such as Homo sapiens and Boa constrictor.
Before the binomial nomenclature, animal names involved long descriptions. The honey bees, for example, were Apis pubescens, thorace subgriseo, abdomine fusco, pedibus posticus glabis, untrinque marginal ciliates. This mouthful of Latin words describes what insects look like. Short and soft hair, gray chest, brown belly and smooth hind legs bordered with hair on both sides. Linnaeus’ name for the species is much shorter: Apis mellifera, or “honey bee”.
The ordering of these two Latin words also has a special meaning. The first describes the gender and name of a related group. The second name specifies the particular species. The genus Canis, for example, includes several species. They include the domestic dog (Canis familiaris) and the gray wolf (Canis lupus).
Modern scientists still use this binomial system, as when they called those science fiction-inspired ambrosia beetles. The names also categorize organisms into groups, known as taxa. A group, or taxon (hence the name of the field: taxonomy), includes similar organisms. For example, the genus Canis constitutes a taxon. The genus Vulpes, which includes foxes, is another taxon. Taxa (the plural form of taxon) can also describe broader categories, such as the group of all mammals.
Linnaeus described five tiered rankings for animals. At the top were the kingdoms. After all, there were the species. Over time, scientists have added a few more degrees. The system now extends from kingdom to phylum, class, order, family, genus and species. One way to keep track of these labels is to remember “King Phillip Came Over For Great Spaghetti”. The first letter of each word corresponds to the first letter of a rank. Taxa can be defined at different levels.
For example, Mammalia (the group of all mammals) is a taxon at the class rank. Likewise, an order can contain multiple families. And a class can contain multiple orders. The nested nature of these taxa provides scientists with useful information.
“If I told you that two species belong to the same family, you would immediately know that they are also in the same class and in the same phylum and in the same kingdom”, explains Diana Lipscomb. She is a retired evolutionary biologist at George Washington University.
However, there are no rules for deciding which rank a group of species or taxon falls into. One scientist may disagree with another on what defines a family, for example. Indeed, a third scientist might even think that the taxon should belong to a different rank, such as an order.
The International Code of Zoological Nomenclature, the rules for the naming of animals, states the official guidelines. But this code does not apply rules for defining the rank of a taxon. This includes determining families with respect to orders. For this reason, Hormiga notes, all grades may not really be comparable.
Species evolving with the times
In the 1970s, scientists argued fiercely about taxonomy. Those were turbulent years, says Hormiga. Eventually the field moved. Scientists have begun to classify species based on their evolution rather than their appearance. This evolutionary approach is known as phylogeny.
“Modern taxonomy must reflect phylogeny”, says Gonzalo Giribet. He is a zoologist at Harvard University in Cambridge, Massachusetts. Members within a taxon should be more related to each other than to species outside the group. Scientists draw these relationships like branched trees. Indeed, Charles Darwin described it in his tree of life. His included both living and extinct organisms.
I could tell you, says Hormiga, “there is a unique spider family in some parts of South America” and it has been classified on the basis of phylogenetic relationships. “So I’m saying this is a branch of the tree of life.”
Taxonomy and phylogeny are fundamental parts of a scientific field known as systematics. You may notice that the name is related to Linnaeus’ Systema Naturae. This field uses evolution to classify and name living things.
Systematists study the evolution of a species by looking at its genetic material: DNA and RNA. DNA is a molecule which stores genetic instructions in cells. To read these instructions, cells copy DNA into another molecule, RNA. Cells use that RNA to make proteins.
Scientists used these analyzes to divide life on Earth into three domains. Two describe much of single-celled life: bacteria and archaea. The third eukaryote includes everything else. Eukaryotes can be one or more cells. All have cellular parts with distinct roles, such as DNA-containing nuclei. Plants fall into this group. So do all animals. So also the unicellular amoebas.
You can forgive Linnaeus for not inventing this system. Lived long before scientists grasped the idea of evolution, much less than genetics. As a result, new findings may force systematists to reclassify taxa. For example, Smith and Cogn-in-law moved some species of ragweed beetles to the genus Coptoborus. This was after they discovered that Coptoborous and the Theoborus genus were actually the same.
For many systematists, these changes are fine. “Guess what this organism is, who it is related to and where it fits into that tree of life “, Lipscomb tells George Washington. Much science is interpreting new data to improve our understanding of our world and the cosmos.
Species
[spè·cie]
DEFINITION“Classification category of organisms which includes individuals capable of mating with each other and generating fertile offspring; in the case of organisms with asexual reproduction it is defined by morphological or physiological criteria; several species related to each other make up a genus: the s. animals, plants; conservation of the s .; s. human, men as distinct from other animals “
You may not be familiar with the scientific names of ragweed beetles. These insects belong to the Coptoborus genus. But you are likely to recognize some iconic female science fiction characters among some of their species names. Let us consider C. katniss, C. scully and C. leia. The names of these and other beetles related are aimed at getting your attention.
“We’ve been wanting to do something fun like this for a while”says Sarah Smith. She is an insect biologist, or entomologist, at Michigan State University in East Lansing. The characteristics of the beetles inspired their science fiction names. C. leia, for example, is brown like Princess Leia’s sandwiches. The pointed shape of C. katniss’ body was reminiscent of Smith Katniss Everdeen and her bow and arrows.
Some names also fit the behavior of beetles, says Anthony Cognato, another Michigan State entomologist. He collaborated with Smith on a new study on beetles. Female ragweed beetles venture out of nests to create families at new sites. This behavior could explain how these beetles have spread in the tropics over the past 20 million years.
Their catchy names also draw attention to the taxonomy. This is the science of naming organisms. Taxonomy is a foundation of biology, he explains. A unique name allows scientists to know which individuals fall into a species. Only then can they continue to discuss and study what makes this species different from others. “This naming system provides the keys to unlock information”, adds Gustavo Hormiga. He is at George Washington University in Washington, DC He studies spiders and other arachnids.
Imagine you have a tick bite, says Hormiga. Some types of ticks carry Lyme disease, which causes skin rashes, fever, and headaches. The other mints do not. A doctor who decides the treatment may ask if the bite came from a deer tick. This Ixodes scapularis can be a carrier of Lyme disease.
The way modern scientists classify and name organisms was first developed more than 250 years ago. But that doesn’t mean the process hasn’t changed. Since then, scientists have adapted the naming system to reflect the evolution of species.
Some scientists, however, would like to start over with a new naming method. Many others are not ready for it. For most biologists, a name is not just a name. It is also a way not only to distinguish what separates species, but also to understand species.
Modern taxonomy dates back to Charles Linnaeus. This Swiss naturalist wrote the book on this foundation in 1753. His Species Plantarum, as it was called, listed all the plant species known at the time. It also marked the first time that a binomial nomenclature (two-part naming system) came into common use for plants. Five years later, Linnaeus’ Systema Naturae used the same system to name animals. That book contained some now familiar names, such as Homo sapiens and Boa constrictor.
Before the binomial nomenclature, animal names involved long descriptions. The honey bees, for example, were Apis pubescens, thorace subgriseo, abdomine fusco, pedibus posticus glabis, untrinque marginal ciliates. This mouthful of Latin words describes what insects look like. Short and soft hair, gray chest, brown belly and smooth hind legs bordered with hair on both sides. Linnaeus’ name for the species is much shorter: Apis mellifera, or “honey bee”.
The ordering of these two Latin words also has a special meaning. The first describes the gender and name of a related group. The second name specifies the particular species. The genus Canis, for example, includes several species. They include the domestic dog (Canis familiaris) and the gray wolf (Canis lupus).
Modern scientists still use this binomial system, as when they called those science fiction-inspired ambrosia beetles. The names also categorize organisms into groups, known as taxa. A group, or taxon (hence the name of the field: taxonomy), includes similar organisms. For example, the genus Canis constitutes a taxon. The genus Vulpes, which includes foxes, is another taxon. Taxa (the plural form of taxon) can also describe broader categories, such as the group of all mammals.
Linnaeus described five tiered rankings for animals. At the top were the kingdoms. After all, there were the species. Over time, scientists have added a few more degrees. The system now extends from kingdom to phylum, class, order, family, genus and species. One way to keep track of these labels is to remember “King Phillip Came Over For Great Spaghetti”. The first letter of each word corresponds to the first letter of a rank. Taxa can be defined at different levels.
For example, Mammalia (the group of all mammals) is a taxon at the class rank. Likewise, an order can contain multiple families. And a class can contain multiple orders. The nested nature of these taxa provides scientists with useful information.
“If I told you that two species belong to the same family, you would immediately know that they are also in the same class and in the same phylum and in the same kingdom”, explains Diana Lipscomb. She is a retired evolutionary biologist at George Washington University.
However, there are no rules for deciding which rank a group of species or taxon falls into. One scientist may disagree with another on what defines a family, for example. Indeed, a third scientist might even think that the taxon should belong to a different rank, such as an order.
The International Code of Zoological Nomenclature, the rules for the naming of animals, states the official guidelines. But this code does not apply rules for defining the rank of a taxon. This includes determining families with respect to orders. For this reason, Hormiga notes, all grades may not really be comparable.
Species evolving with the times
In the 1970s, scientists argued fiercely about taxonomy. Those were turbulent years, says Hormiga. Eventually the field moved. Scientists have begun to classify species based on their evolution rather than their appearance. This evolutionary approach is known as phylogeny.
“Modern taxonomy must reflect phylogeny”, says Gonzalo Giribet. He is a zoologist at Harvard University in Cambridge, Massachusetts. Members within a taxon should be more related to each other than to species outside the group. Scientists draw these relationships like branched trees. Indeed, Charles Darwin described it in his tree of life. His included both living and extinct organisms.
I could tell you, says Hormiga, “there is a unique spider family in some parts of South America” and it has been classified on the basis of phylogenetic relationships. “So I’m saying this is a branch of the tree of life.”
Taxonomy and phylogeny are fundamental parts of a scientific field known as systematics. You may notice that the name is related to Linnaeus’ Systema Naturae. This field uses evolution to classify and name living things.
Systematists study the evolution of a species by looking at its genetic material: DNA and RNA. DNA is a molecule which stores genetic instructions in cells. To read these instructions, cells copy DNA into another molecule, RNA. Cells use that RNA to make proteins.
Scientists used these analyzes to divide life on Earth into three domains. Two describe much of single-celled life: bacteria and archaea. The third eukaryote includes everything else. Eukaryotes can be one or more cells. All have cellular parts with distinct roles, such as DNA-containing nuclei. Plants fall into this group. So do all animals. So also the unicellular amoebas.
You can forgive Linnaeus for not inventing this system. Lived long before scientists grasped the idea of evolution, much less than genetics. As a result, new findings may force systematists to reclassify taxa. For example, Smith and Cogn-in-law moved some species of ragweed beetles to the genus Coptoborus. This was after they discovered that Coptoborous and the Theoborus genus were actually the same.
For many systematists, these changes are fine. “Guess what this organism is, who it is related to and where it fits into that tree of life “, Lipscomb tells George Washington. Much science is interpreting new data to improve our understanding of our world and the cosmos.
Species
[spè·cie]
DEFINITION“Classification category of organisms which includes individuals capable of mating with each other and generating fertile offspring; in the case of organisms with asexual reproduction it is defined by morphological or physiological criteria; several species related to each other make up a genus: the s. animals, plants; conservation of the s .; s. human, men as distinct from other animals “
You may not be familiar with the scientific names of ragweed beetles. These insects belong to the Coptoborus genus. But you are likely to recognize some iconic female science fiction characters among some of their species names. Let us consider C. katniss, C. scully and C. leia. The names of these and other beetles related are aimed at getting your attention.
“We’ve been wanting to do something fun like this for a while”says Sarah Smith. She is an insect biologist, or entomologist, at Michigan State University in East Lansing. The characteristics of the beetles inspired their science fiction names. C. leia, for example, is brown like Princess Leia’s sandwiches. The pointed shape of C. katniss’ body was reminiscent of Smith Katniss Everdeen and her bow and arrows.
Some names also fit the behavior of beetles, says Anthony Cognato, another Michigan State entomologist. He collaborated with Smith on a new study on beetles. Female ragweed beetles venture out of nests to create families at new sites. This behavior could explain how these beetles have spread in the tropics over the past 20 million years.
Their catchy names also draw attention to the taxonomy. This is the science of naming organisms. Taxonomy is a foundation of biology, he explains. A unique name allows scientists to know which individuals fall into a species. Only then can they continue to discuss and study what makes this species different from others. “This naming system provides the keys to unlock information”, adds Gustavo Hormiga. He is at George Washington University in Washington, DC He studies spiders and other arachnids.
Imagine you have a tick bite, says Hormiga. Some types of ticks carry Lyme disease, which causes skin rashes, fever, and headaches. The other mints do not. A doctor who decides the treatment may ask if the bite came from a deer tick. This Ixodes scapularis can be a carrier of Lyme disease.
The way modern scientists classify and name organisms was first developed more than 250 years ago. But that doesn’t mean the process hasn’t changed. Since then, scientists have adapted the naming system to reflect the evolution of species.
Some scientists, however, would like to start over with a new naming method. Many others are not ready for it. For most biologists, a name is not just a name. It is also a way not only to distinguish what separates species, but also to understand species.
Modern taxonomy dates back to Charles Linnaeus. This Swiss naturalist wrote the book on this foundation in 1753. His Species Plantarum, as it was called, listed all the plant species known at the time. It also marked the first time that a binomial nomenclature (two-part naming system) came into common use for plants. Five years later, Linnaeus’ Systema Naturae used the same system to name animals. That book contained some now familiar names, such as Homo sapiens and Boa constrictor.
Before the binomial nomenclature, animal names involved long descriptions. The honey bees, for example, were Apis pubescens, thorace subgriseo, abdomine fusco, pedibus posticus glabis, untrinque marginal ciliates. This mouthful of Latin words describes what insects look like. Short and soft hair, gray chest, brown belly and smooth hind legs bordered with hair on both sides. Linnaeus’ name for the species is much shorter: Apis mellifera, or “honey bee”.
The ordering of these two Latin words also has a special meaning. The first describes the gender and name of a related group. The second name specifies the particular species. The genus Canis, for example, includes several species. They include the domestic dog (Canis familiaris) and the gray wolf (Canis lupus).
Modern scientists still use this binomial system, as when they called those science fiction-inspired ambrosia beetles. The names also categorize organisms into groups, known as taxa. A group, or taxon (hence the name of the field: taxonomy), includes similar organisms. For example, the genus Canis constitutes a taxon. The genus Vulpes, which includes foxes, is another taxon. Taxa (the plural form of taxon) can also describe broader categories, such as the group of all mammals.
Linnaeus described five tiered rankings for animals. At the top were the kingdoms. After all, there were the species. Over time, scientists have added a few more degrees. The system now extends from kingdom to phylum, class, order, family, genus and species. One way to keep track of these labels is to remember “King Phillip Came Over For Great Spaghetti”. The first letter of each word corresponds to the first letter of a rank. Taxa can be defined at different levels.
For example, Mammalia (the group of all mammals) is a taxon at the class rank. Likewise, an order can contain multiple families. And a class can contain multiple orders. The nested nature of these taxa provides scientists with useful information.
“If I told you that two species belong to the same family, you would immediately know that they are also in the same class and in the same phylum and in the same kingdom”, explains Diana Lipscomb. She is a retired evolutionary biologist at George Washington University.
However, there are no rules for deciding which rank a group of species or taxon falls into. One scientist may disagree with another on what defines a family, for example. Indeed, a third scientist might even think that the taxon should belong to a different rank, such as an order.
The International Code of Zoological Nomenclature, the rules for the naming of animals, states the official guidelines. But this code does not apply rules for defining the rank of a taxon. This includes determining families with respect to orders. For this reason, Hormiga notes, all grades may not really be comparable.
Species evolving with the times
In the 1970s, scientists argued fiercely about taxonomy. Those were turbulent years, says Hormiga. Eventually the field moved. Scientists have begun to classify species based on their evolution rather than their appearance. This evolutionary approach is known as phylogeny.
“Modern taxonomy must reflect phylogeny”, says Gonzalo Giribet. He is a zoologist at Harvard University in Cambridge, Massachusetts. Members within a taxon should be more related to each other than to species outside the group. Scientists draw these relationships like branched trees. Indeed, Charles Darwin described it in his tree of life. His included both living and extinct organisms.
I could tell you, says Hormiga, “there is a unique spider family in some parts of South America” and it has been classified on the basis of phylogenetic relationships. “So I’m saying this is a branch of the tree of life.”
Taxonomy and phylogeny are fundamental parts of a scientific field known as systematics. You may notice that the name is related to Linnaeus’ Systema Naturae. This field uses evolution to classify and name living things.
Systematists study the evolution of a species by looking at its genetic material: DNA and RNA. DNA is a molecule which stores genetic instructions in cells. To read these instructions, cells copy DNA into another molecule, RNA. Cells use that RNA to make proteins.
Scientists used these analyzes to divide life on Earth into three domains. Two describe much of single-celled life: bacteria and archaea. The third eukaryote includes everything else. Eukaryotes can be one or more cells. All have cellular parts with distinct roles, such as DNA-containing nuclei. Plants fall into this group. So do all animals. So also the unicellular amoebas.
You can forgive Linnaeus for not inventing this system. Lived long before scientists grasped the idea of evolution, much less than genetics. As a result, new findings may force systematists to reclassify taxa. For example, Smith and Cogn-in-law moved some species of ragweed beetles to the genus Coptoborus. This was after they discovered that Coptoborous and the Theoborus genus were actually the same.
For many systematists, these changes are fine. “Guess what this organism is, who it is related to and where it fits into that tree of life “, Lipscomb tells George Washington. Much science is interpreting new data to improve our understanding of our world and the cosmos.